[clang] [compiler-rt] [llvm] [PGO][AMDGPU] Add offload profiling with uniformity-aware optimization (PR #177665)

Yaxun Liu via llvm-commits llvm-commits at lists.llvm.org
Wed Jan 28 05:12:17 PST 2026


https://github.com/yxsamliu updated https://github.com/llvm/llvm-project/pull/177665

>From 9435c08ef53fcb51d41860c4726553de6dabfcc7 Mon Sep 17 00:00:00 2001
From: "Yaxun (Sam) Liu" <yaxun.liu at amd.com>
Date: Tue, 27 Jan 2026 17:26:37 -0500
Subject: [PATCH] [PGO][AMDGPU] Add offload profiling infrastructure for HIP

Add device-side profile-guided optimization support for HIP/AMDGPU targets.
This enables PGO instrumentation and profile collection on GPU kernels.

Key components:

1. Profile Format (Version 14):
   - Add NumOffloadProfilingThreads field for per-thread counter slots
   - Add UniformityBits for tracking wave-uniform vs divergent blocks

2. Device Instrumentation (InstrProfiling.cpp):
   - Per-TU contiguous counter/data allocation with CUID-suffixed symbols
   - Uniform counter instrumentation for divergence detection
   - Section symbol registration for HIP memcpy compatibility

3. Runtime Collection (InstrProfilingPlatformROCm.c):
   - Device-to-host profile data transfer using HIP APIs
   - Per-TU indexed profile file output
   - Dynamic module support for hipModuleLoad workflows

4. Profile Merge (llvm-profdata):
   - Reduce per-thread counter slots during merge
   - Compute and store uniformity bits from counter patterns

5. PGO-Use Metadata:
   - Attach per-block uniformity metadata during profile application
   - Enable downstream codegen passes to query block divergence

The uniformity-aware optimization prevents PGO from moving spills to
"cold" divergent paths that still execute with partial wave occupancy
on SIMT architectures, avoiding potential 3x+ performance regressions.

RFC: https://discourse.llvm.org/t/rfc-offload-pgo-for-hip-amdgpu-device-side-profile-guided-optimization/89577
---
 clang/lib/Driver/ToolChains/HIPAMD.cpp        |   15 +
 compiler-rt/include/profile/InstrProfData.inc |    8 +-
 compiler-rt/lib/profile/CMakeLists.txt        |    1 +
 compiler-rt/lib/profile/InstrProfiling.h      |   20 +
 compiler-rt/lib/profile/InstrProfilingFile.c  |    2 +
 .../lib/profile/InstrProfilingInternal.h      |    7 +
 .../lib/profile/InstrProfilingPlatformROCm.c  |  567 ++++++++
 llvm/include/llvm/ProfileData/InstrProf.h     |   48 +-
 .../llvm/ProfileData/InstrProfData.inc        |   15 +-
 .../llvm/ProfileData/InstrProfWriter.h        |   10 +
 .../llvm/Transforms/Instrumentation/CFGMST.h  |   26 +-
 llvm/lib/Passes/StandardInstrumentations.cpp  |   10 +-
 llvm/lib/ProfileData/InstrProf.cpp            |  139 +-
 llvm/lib/ProfileData/InstrProfCorrelator.cpp  |    2 +
 llvm/lib/ProfileData/InstrProfReader.cpp      |  107 +-
 llvm/lib/ProfileData/InstrProfWriter.cpp      |   72 +-
 .../Instrumentation/InstrProfiling.cpp        | 1217 ++++++++++++++++-
 .../Instrumentation/PGOInstrumentation.cpp    |   80 +-
 .../amdgpu-contiguous-counters.ll             |   41 +
 .../InstrProfiling/amdgpu-uniform-counters.ll |   31 +
 .../InstrProfiling/coverage.ll                |    8 +-
 .../InstrProfiling/inline-data-var-create.ll  |   23 +-
 .../InstrProfiling/platform.ll                |   20 +-
 .../Transforms/PGOProfile/comdat_internal.ll  |    4 +-
 .../instrprof_burst_sampling_fast.ll          |    2 +-
 .../tools/llvm-profdata/profile-version.test  |    2 +-
 llvm/tools/llvm-profdata/llvm-profdata.cpp    |  125 +-
 27 files changed, 2485 insertions(+), 117 deletions(-)
 create mode 100644 compiler-rt/lib/profile/InstrProfilingPlatformROCm.c
 create mode 100644 llvm/test/Instrumentation/InstrProfiling/amdgpu-contiguous-counters.ll
 create mode 100644 llvm/test/Instrumentation/InstrProfiling/amdgpu-uniform-counters.ll

diff --git a/clang/lib/Driver/ToolChains/HIPAMD.cpp b/clang/lib/Driver/ToolChains/HIPAMD.cpp
index 617809285c165..56bf753d62948 100644
--- a/clang/lib/Driver/ToolChains/HIPAMD.cpp
+++ b/clang/lib/Driver/ToolChains/HIPAMD.cpp
@@ -303,6 +303,21 @@ HIPAMDToolChain::TranslateArgs(const llvm::opt::DerivedArgList &Args,
   const OptTable &Opts = getDriver().getOpts();
 
   for (Arg *A : Args) {
+    // Handle device-side profile data file for PGO
+    if (A->getOption().matches(options::OPT_fprofile_use_EQ)) {
+      StringRef ProfileFile = A->getValue();
+      auto [Base, Ext] = ProfileFile.rsplit('.');
+      std::string DeviceProfileFile;
+      if (!Ext.empty()) {
+        DeviceProfileFile = (Base + "." + getTriple().str() + "." + Ext).str();
+      } else {
+        DeviceProfileFile = (ProfileFile + "." + getTriple().str()).str();
+      }
+      DAL->AddJoinedArg(A, Opts.getOption(options::OPT_fprofile_instr_use_EQ),
+                        DeviceProfileFile);
+      A->claim();
+      continue;
+    }
     // Filter unsupported sanitizers passed from the HostTC.
     if (!handleSanitizeOption(*this, *DAL, Args, BoundArch, A))
       DAL->append(A);
diff --git a/compiler-rt/include/profile/InstrProfData.inc b/compiler-rt/include/profile/InstrProfData.inc
index 46d6bb5bd8896..fffe5a26b1cb9 100644
--- a/compiler-rt/include/profile/InstrProfData.inc
+++ b/compiler-rt/include/profile/InstrProfData.inc
@@ -90,8 +90,12 @@ INSTR_PROF_DATA(IntPtrT, llvm::PointerType::getUnqual(Ctx), Values, \
 INSTR_PROF_DATA(const uint32_t, llvm::Type::getInt32Ty(Ctx), NumCounters, \
                 ConstantInt::get(llvm::Type::getInt32Ty(Ctx), NumCounters))
 INSTR_PROF_DATA(const uint16_t, Int16ArrayTy, NumValueSites[IPVK_Last+1], \
-                ConstantArray::get(Int16ArrayTy, Int16ArrayVals)) \
-INSTR_PROF_DATA(const uint32_t, llvm::Type::getInt32Ty(Ctx), NumBitmapBytes, \
+                ConstantArray::get(Int16ArrayTy, Int16ArrayVals))
+INSTR_PROF_DATA(const uint16_t, llvm::Type::getInt16Ty(Ctx),
+                NumOffloadProfilingThreads,
+                ConstantInt::get(llvm::Type::getInt16Ty(Ctx),
+                                 NumOffloadProfilingThreadsVal))
+INSTR_PROF_DATA(const uint32_t, llvm::Type::getInt32Ty(Ctx), NumBitmapBytes,
                 ConstantInt::get(llvm::Type::getInt32Ty(Ctx), NumBitmapBytes))
 #undef INSTR_PROF_DATA
 /* INSTR_PROF_DATA end. */
diff --git a/compiler-rt/lib/profile/CMakeLists.txt b/compiler-rt/lib/profile/CMakeLists.txt
index 7c8473cc5f200..d4f64dcb2c6c7 100644
--- a/compiler-rt/lib/profile/CMakeLists.txt
+++ b/compiler-rt/lib/profile/CMakeLists.txt
@@ -73,6 +73,7 @@ set(PROFILE_SOURCES
   InstrProfilingPlatformFuchsia.c
   InstrProfilingPlatformLinux.c
   InstrProfilingPlatformOther.c
+  InstrProfilingPlatformROCm.c
   InstrProfilingPlatformWindows.c
   )
 
diff --git a/compiler-rt/lib/profile/InstrProfiling.h b/compiler-rt/lib/profile/InstrProfiling.h
index 187ef55ef3784..6ebeb4c2dc6c7 100644
--- a/compiler-rt/lib/profile/InstrProfiling.h
+++ b/compiler-rt/lib/profile/InstrProfiling.h
@@ -349,4 +349,24 @@ extern char INSTR_PROF_PROFILE_NAME_VAR[1]; /* __llvm_profile_filename. */
 
 const __llvm_gcov_init_func_struct *__llvm_profile_begin_covinit();
 const __llvm_gcov_init_func_struct *__llvm_profile_end_covinit();
+
+/* A struct to hold the device pointers and sizes for the profile sections. */
+typedef struct OffloadProfileSectionInfo {
+  void *CountersBegin;
+  size_t CountersSize;
+  void *DataBegin;
+  size_t DataSize;
+  void *NamesBegin;
+  size_t NamesSize;
+} OffloadProfileSectionInfo;
+
+/*!
+ * \brief Register an offload module's device-side profile data sections.
+ *
+ * This function is called by the host-side instrumentation code to provide
+ * the runtime with the necessary information to collect profile data from
+ * the device.
+ */
+void __llvm_profile_offload_register_module(OffloadProfileSectionInfo *Info);
+
 #endif /* PROFILE_INSTRPROFILING_H_ */
diff --git a/compiler-rt/lib/profile/InstrProfilingFile.c b/compiler-rt/lib/profile/InstrProfilingFile.c
index 71127b05aafb8..aa9d567a1d17f 100644
--- a/compiler-rt/lib/profile/InstrProfilingFile.c
+++ b/compiler-rt/lib/profile/InstrProfilingFile.c
@@ -1198,6 +1198,8 @@ int __llvm_profile_write_file(void) {
   if (rc)
     PROF_ERR("Failed to write file \"%s\": %s\n", Filename, strerror(errno));
 
+  __llvm_profile_hip_collect_device_data();
+
   // Restore SIGKILL.
   if (PDeathSig == 1)
     lprofRestoreSigKill();
diff --git a/compiler-rt/lib/profile/InstrProfilingInternal.h b/compiler-rt/lib/profile/InstrProfilingInternal.h
index 5647782527eb7..be6d2627dd100 100644
--- a/compiler-rt/lib/profile/InstrProfilingInternal.h
+++ b/compiler-rt/lib/profile/InstrProfilingInternal.h
@@ -212,5 +212,12 @@ int __llvm_write_binary_ids(ProfDataWriter *Writer);
 int lprofWriteOneBinaryId(ProfDataWriter *Writer, uint64_t BinaryIdLen,
                           const uint8_t *BinaryIdData,
                           uint64_t BinaryIdPadding);
+#ifdef __cplusplus
+extern "C" {
+#endif
+COMPILER_RT_VISIBILITY int __llvm_profile_hip_collect_device_data(void);
+#ifdef __cplusplus
+}
+#endif
 
 #endif
diff --git a/compiler-rt/lib/profile/InstrProfilingPlatformROCm.c b/compiler-rt/lib/profile/InstrProfilingPlatformROCm.c
new file mode 100644
index 0000000000000..679e64977a55f
--- /dev/null
+++ b/compiler-rt/lib/profile/InstrProfilingPlatformROCm.c
@@ -0,0 +1,567 @@
+//===- InstrProfilingPlatformROCm.c - Profile data ROCm platform ---------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "InstrProfiling.h"
+#include "InstrProfilingInternal.h"
+#include "InstrProfilingPort.h"
+#include <dlfcn.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int ProcessDeviceOffloadPrf(void *DeviceOffloadPrf, int TUIndex);
+
+static int IsVerboseMode() {
+  static int IsVerbose = -1;
+  if (IsVerbose == -1)
+    IsVerbose = getenv("LLVM_PROFILE_VERBOSE") != NULL;
+  return IsVerbose;
+}
+
+/* -------------------------------------------------------------------------- */
+/*  Dynamic loading of HIP runtime symbols                                   */
+/* -------------------------------------------------------------------------- */
+
+typedef int (*hipMemcpyFromSymbolTy)(void *, const void *, size_t, size_t, int);
+typedef int (*hipGetSymbolAddressTy)(void **, const void *);
+typedef int (*hipMemcpyTy)(void *, void *, size_t, int);
+typedef int (*hipModuleGetGlobalTy)(void **, size_t *, void *, const char *);
+
+static hipMemcpyFromSymbolTy pHipMemcpyFromSymbol = NULL;
+static hipGetSymbolAddressTy pHipGetSymbolAddress = NULL;
+static hipMemcpyTy pHipMemcpy = NULL;
+static hipModuleGetGlobalTy pHipModuleGetGlobal = NULL;
+
+/* -------------------------------------------------------------------------- */
+/*  Device-to-host copies                                                     */
+/*  Keep HIP-only to avoid an HSA dependency.                                 */
+/* -------------------------------------------------------------------------- */
+
+static void EnsureHipLoaded(void) {
+  static int Initialized = 0;
+  if (Initialized)
+    return;
+  Initialized = 1;
+
+  void *Handle = dlopen("libamdhip64.so", RTLD_LAZY | RTLD_LOCAL);
+  if (!Handle) {
+    fprintf(stderr, "compiler-rt: failed to open libamdhip64.so: %s\n",
+            dlerror());
+    return;
+  }
+
+  pHipMemcpyFromSymbol =
+      (hipMemcpyFromSymbolTy)dlsym(Handle, "hipMemcpyFromSymbol");
+  pHipGetSymbolAddress =
+      (hipGetSymbolAddressTy)dlsym(Handle, "hipGetSymbolAddress");
+  pHipMemcpy = (hipMemcpyTy)dlsym(Handle, "hipMemcpy");
+  pHipModuleGetGlobal =
+      (hipModuleGetGlobalTy)dlsym(Handle, "hipModuleGetGlobal");
+}
+
+/* -------------------------------------------------------------------------- */
+/*  Public wrappers that forward to the loaded HIP symbols                   */
+/* -------------------------------------------------------------------------- */
+
+static int hipMemcpyFromSymbol(void *dst, const void *symbol, size_t sizeBytes,
+                               size_t offset, int kind) {
+  EnsureHipLoaded();
+  return pHipMemcpyFromSymbol
+             ? pHipMemcpyFromSymbol(dst, symbol, sizeBytes, offset, kind)
+             : -1;
+}
+
+static int hipGetSymbolAddress(void **devPtr, const void *symbol) {
+  EnsureHipLoaded();
+  return pHipGetSymbolAddress ? pHipGetSymbolAddress(devPtr, symbol) : -1;
+}
+
+static int hipMemcpy(void *dest, void *src, size_t len, int kind /*2=DToH*/) {
+  EnsureHipLoaded();
+  return pHipMemcpy ? pHipMemcpy(dest, src, len, kind) : -1;
+}
+
+/* Copy from device to host using HIP.
+ * This requires that the device section symbols are registered with CLR,
+ * otherwise hipMemcpy may attempt a CPU path and crash. */
+static int memcpyDeviceToHost(void *Dst, void *Src, size_t Size) {
+  return hipMemcpy(Dst, Src, Size, 2 /* DToH */);
+}
+
+static int hipModuleGetGlobal(void **DevPtr, size_t *Bytes, void *Module,
+                              const char *Name) {
+  EnsureHipLoaded();
+  return pHipModuleGetGlobal ? pHipModuleGetGlobal(DevPtr, Bytes, Module, Name)
+                             : -1;
+}
+
+/* -------------------------------------------------------------------------- */
+/*  Dynamic module tracking                                                   */
+/* -------------------------------------------------------------------------- */
+
+#define MAX_DYNAMIC_MODULES 256
+
+typedef struct {
+  void *ModulePtr; /* hipModule_t returned by hipModuleLoad            */
+  void *DeviceVar; /* address of __llvm_offload_prf in this module     */
+  int Processed;   /* 0 = not yet collected, 1 = data already copied   */
+} OffloadDynamicModuleInfo;
+
+static OffloadDynamicModuleInfo DynamicModules[MAX_DYNAMIC_MODULES];
+static int NumDynamicModules = 0;
+
+/* -------------------------------------------------------------------------- */
+/*  Registration / un-registration helpers                                   */
+/* -------------------------------------------------------------------------- */
+
+void __llvm_profile_offload_register_dynamic_module(int ModuleLoadRc,
+                                                     void **Ptr) {
+  if (IsVerboseMode())
+    PROF_NOTE("Registering loaded module %d: rc=%d, module=%p\n",
+              NumDynamicModules, ModuleLoadRc, *Ptr);
+
+  if (ModuleLoadRc)
+    return;
+
+  if (NumDynamicModules >= MAX_DYNAMIC_MODULES) {
+    PROF_ERR("Too many dynamic modules registered. Maximum is %d.\n",
+             MAX_DYNAMIC_MODULES);
+    return;
+  }
+
+  OffloadDynamicModuleInfo *Info = &DynamicModules[NumDynamicModules++];
+  Info->ModulePtr = *Ptr;
+  Info->DeviceVar = NULL;
+  Info->Processed = 0;
+
+  size_t Bytes = 0;
+  if (hipModuleGetGlobal(&Info->DeviceVar, &Bytes, *Ptr,
+                         "__llvm_offload_prf") != 0) {
+    PROF_WARN("Failed to get symbol __llvm_offload_prf for module %p\n", *Ptr);
+    /* Leave DeviceVar NULL so later code can recognise the failure */
+    return;
+  }
+
+  if (IsVerboseMode())
+    PROF_NOTE("Module %p: Device profile var %p\n", *Ptr, Info->DeviceVar);
+}
+
+void __llvm_profile_offload_unregister_dynamic_module(void *Ptr) {
+  for (int i = 0; i < NumDynamicModules; ++i) {
+    OffloadDynamicModuleInfo *Info = &DynamicModules[i];
+
+    if (Info->ModulePtr == Ptr) {
+      if (IsVerboseMode())
+        PROF_NOTE("Unregistering module %p (DeviceVar=%p, Processed=%d)\n",
+                  Info->ModulePtr, Info->DeviceVar, Info->Processed);
+
+      if (Info->Processed) {
+        PROF_WARN("Module %p has already been unregistered or processed\n",
+                  Ptr);
+        return;
+      }
+
+      if (Info->DeviceVar) {
+        // Use module index as TU index for dynamic modules
+        // to ensure each module gets a unique profile file
+        if (ProcessDeviceOffloadPrf(Info->DeviceVar, i) == 0)
+          Info->Processed = 1;
+        else
+          PROF_WARN(
+              "Failed to process profile data for module %p on unregister\n",
+              Ptr);
+      } else {
+        PROF_WARN("Module %p has no device profile variable to process\n", Ptr);
+      }
+      return;
+    }
+  }
+
+  if (IsVerboseMode())
+    PROF_WARN("Unregister called for unknown module %p\n", Ptr);
+}
+
+#define MAX_SHADOW_VARIABLES 256
+static void *OffloadShadowVariables[MAX_SHADOW_VARIABLES];
+static int NumShadowVariables = 0;
+
+void __llvm_profile_offload_register_shadow_variable(void *ptr) {
+  if (NumShadowVariables >= MAX_SHADOW_VARIABLES) {
+    PROF_ERR("Too many shadow variables registered. Maximum is %d.\n",
+             MAX_SHADOW_VARIABLES);
+    return;
+  }
+  if (IsVerboseMode())
+    PROF_NOTE("Registering shadow variable %d: %p\n", NumShadowVariables, ptr);
+  OffloadShadowVariables[NumShadowVariables++] = ptr;
+}
+
+#define MAX_SECTION_SHADOW_VARIABLES 1024
+static void *OffloadSectionShadowVariables[MAX_SECTION_SHADOW_VARIABLES];
+static int NumSectionShadowVariables = 0;
+
+void __llvm_profile_offload_register_section_shadow_variable(void *ptr) {
+  if (NumSectionShadowVariables >= MAX_SECTION_SHADOW_VARIABLES) {
+    PROF_ERR("Too many section shadow variables registered. Maximum is %d.\n",
+             MAX_SECTION_SHADOW_VARIABLES);
+    return;
+  }
+  if (IsVerboseMode())
+    PROF_NOTE("Registering section shadow variable %d: %p\n",
+              NumSectionShadowVariables, ptr);
+  OffloadSectionShadowVariables[NumSectionShadowVariables++] = ptr;
+}
+
+static int ProcessDeviceOffloadPrf(void *DeviceOffloadPrf, int TUIndex) {
+  void *HostOffloadPrf[8];
+
+  if (IsVerboseMode())
+    PROF_NOTE("HostOffloadPrf buffer size: %zu bytes\n",
+              sizeof(HostOffloadPrf));
+
+  if (hipMemcpy(HostOffloadPrf, DeviceOffloadPrf, sizeof(HostOffloadPrf),
+                2 /*DToH*/) != 0) {
+    PROF_ERR("%s\n", "Failed to copy offload prf structure from device");
+    return -1;
+  }
+
+  void *DevCntsBegin = HostOffloadPrf[0];
+  void *DevDataBegin = HostOffloadPrf[1];
+  void *DevNamesBegin = HostOffloadPrf[2];
+  void *DevUniformCntsBegin = HostOffloadPrf[3];
+  void *DevCntsEnd = HostOffloadPrf[4];
+  void *DevDataEnd = HostOffloadPrf[5];
+  void *DevNamesEnd = HostOffloadPrf[6];
+  void *DevUniformCntsEnd = HostOffloadPrf[7];
+
+  if (IsVerboseMode()) {
+    PROF_NOTE("%s", "Device Profile Pointers:\n");
+    PROF_NOTE("  Counters:        %p - %p\n", DevCntsBegin, DevCntsEnd);
+    PROF_NOTE("  Data:            %p - %p\n", DevDataBegin, DevDataEnd);
+    PROF_NOTE("  Names:           %p - %p\n", DevNamesBegin, DevNamesEnd);
+    PROF_NOTE("  UniformCounters: %p - %p\n", DevUniformCntsBegin,
+              DevUniformCntsEnd);
+  }
+
+  size_t CountersSize = (char *)DevCntsEnd - (char *)DevCntsBegin;
+  size_t DataSize = (char *)DevDataEnd - (char *)DevDataBegin;
+  size_t NamesSize = (char *)DevNamesEnd - (char *)DevNamesBegin;
+  size_t UniformCountersSize =
+      (char *)DevUniformCntsEnd - (char *)DevUniformCntsBegin;
+
+  if (IsVerboseMode()) {
+    PROF_NOTE("Section sizes: Counters=%zu, Data=%zu, Names=%zu, "
+              "UniformCounters=%zu\n",
+              CountersSize, DataSize, NamesSize, UniformCountersSize);
+  }
+
+  if (CountersSize == 0 || DataSize == 0) {
+    if (IsVerboseMode())
+      PROF_NOTE("%s\n", "Counters or Data section has zero size. No profile "
+                        "data to collect.");
+    return 0;
+  }
+
+  // Pre-register device section symbols with CLR memory tracking.
+  // This makes the section base pointers (and sub-pointers) safe for hipMemcpy.
+  if (IsVerboseMode())
+    PROF_NOTE("Pre-registering %d section symbols\n",
+              NumSectionShadowVariables);
+  for (int i = 0; i < NumSectionShadowVariables; ++i) {
+    void *DevPtr = NULL;
+    (void)hipGetSymbolAddress(&DevPtr, OffloadSectionShadowVariables[i]);
+  }
+
+  char *DeviceFilename = NULL;
+  FILE *File = NULL;
+  int ret = -1;
+
+  // Allocate host memory for the device sections
+  char *HostCountersBegin = (char *)malloc(CountersSize);
+  char *HostDataBegin = (char *)malloc(DataSize);
+  char *HostNamesBegin = (char *)malloc(NamesSize);
+  char *HostUniformCountersBegin =
+      (UniformCountersSize > 0) ? (char *)malloc(UniformCountersSize) : NULL;
+
+  if (!HostCountersBegin || !HostDataBegin ||
+      (NamesSize > 0 && !HostNamesBegin) ||
+      (UniformCountersSize > 0 && !HostUniformCountersBegin)) {
+    PROF_ERR("%s\n", "Failed to allocate host memory for device sections");
+    goto cleanup;
+  }
+
+  // Copy data from device to host using HIP.
+  if (memcpyDeviceToHost(HostCountersBegin, DevCntsBegin, CountersSize) != 0 ||
+      memcpyDeviceToHost(HostDataBegin, DevDataBegin, DataSize) != 0 ||
+      (NamesSize > 0 &&
+       memcpyDeviceToHost(HostNamesBegin, DevNamesBegin, NamesSize) != 0) ||
+      (UniformCountersSize > 0 &&
+       memcpyDeviceToHost(HostUniformCountersBegin, DevUniformCntsBegin,
+                          UniformCountersSize) != 0)) {
+    PROF_ERR("%s\n", "Failed to copy profile sections from device");
+    goto cleanup;
+  }
+
+  if (IsVerboseMode())
+    PROF_NOTE("Copied device sections: Counters=%zu, Data=%zu, Names=%zu, "
+              "UniformCounters=%zu\n",
+              CountersSize, DataSize, NamesSize, UniformCountersSize);
+
+  if (IsVerboseMode() && UniformCountersSize > 0) {
+    PROF_NOTE("Successfully copied %zu bytes of uniform counters from device\n",
+              UniformCountersSize);
+  }
+
+  // Construct the device-specific filename
+  // Format: <base>.<target>[.<TUIndex>].<ext>
+  // TUIndex is included when >= 0 to support multi-TU programs
+  char *BaseFilename = (char *)__llvm_profile_get_filename();
+  if (!BaseFilename) {
+    PROF_ERR("%s\n", "Failed to get base profile filename");
+    goto cleanup;
+  }
+  if (IsVerboseMode())
+    PROF_NOTE("Base profile filename: %s\n", BaseFilename);
+
+  const char *TargetInfix = "amdgcn-amd-amdhsa";
+  const char *Extension = strrchr(BaseFilename, '.');
+  char TUIndexStr[16] = "";
+  if (TUIndex >= 0) {
+    snprintf(TUIndexStr, sizeof(TUIndexStr), ".%d", TUIndex);
+  }
+
+  if (Extension) {
+    size_t BaseLen = Extension - BaseFilename;
+    size_t InfixLen = strlen(TargetInfix);
+    size_t TUIndexLen = strlen(TUIndexStr);
+    size_t ExtLen = strlen(Extension);
+    DeviceFilename =
+        (char *)malloc(BaseLen + 1 + InfixLen + TUIndexLen + ExtLen + 1);
+    strncpy(DeviceFilename, BaseFilename, BaseLen);
+    DeviceFilename[BaseLen] = '\0';
+    strcat(DeviceFilename, ".");
+    strcat(DeviceFilename, TargetInfix);
+    strcat(DeviceFilename, TUIndexStr);
+    strcat(DeviceFilename, Extension);
+  } else {
+    DeviceFilename =
+        (char *)malloc(strlen(BaseFilename) + 1 + strlen(TargetInfix) +
+                       strlen(TUIndexStr) + 1);
+    strcpy(DeviceFilename, BaseFilename);
+    strcat(DeviceFilename, ".");
+    strcat(DeviceFilename, TargetInfix);
+    strcat(DeviceFilename, TUIndexStr);
+  }
+  free(BaseFilename);
+
+  if (IsVerboseMode())
+    PROF_NOTE("Device profile filename: %s\n", DeviceFilename);
+
+  // Manually write the profile data with a proper header
+  File = fopen(DeviceFilename, "w");
+  if (!File) {
+    PROF_ERR("Failed to open %s for writing\n", DeviceFilename);
+    goto cleanup;
+  }
+
+  __llvm_profile_header Header;
+  const uint64_t NumData = DataSize / sizeof(__llvm_profile_data);
+  const uint64_t NumCounters = CountersSize / sizeof(uint64_t);
+  const uint64_t NumBitmapBytes = 0;
+  const uint64_t VTableSectionSize = 0;
+  const uint64_t VNamesSize = 0;
+  uint64_t PaddingBytesBeforeCounters, PaddingBytesAfterCounters,
+      PaddingBytesAfterBitmapBytes, PaddingBytesAfterNames,
+      PaddingBytesAfterVTable, PaddingBytesAfterVNames;
+
+  if (__llvm_profile_get_padding_sizes_for_counters(
+          DataSize, CountersSize, NumBitmapBytes, NamesSize, VTableSectionSize,
+          VNamesSize, &PaddingBytesBeforeCounters, &PaddingBytesAfterCounters,
+          &PaddingBytesAfterBitmapBytes, &PaddingBytesAfterNames,
+          &PaddingBytesAfterVTable, &PaddingBytesAfterVNames) != 0) {
+    PROF_ERR("%s\n", "Failed to get padding sizes");
+    goto cleanup;
+  }
+
+  // Relocate pointers
+  __llvm_profile_data *RelocatedData = (__llvm_profile_data *)HostDataBegin;
+  for (uint64_t i = 0; i < NumData; ++i) {
+    if (RelocatedData[i].CounterPtr) {
+      ptrdiff_t DeviceCounterPtrOffset = (ptrdiff_t)RelocatedData[i].CounterPtr;
+      void *DeviceDataStructAddr =
+          (char *)DevDataBegin + (i * sizeof(__llvm_profile_data));
+      void *DeviceCountersAddr =
+          (char *)DeviceDataStructAddr + DeviceCounterPtrOffset;
+      ptrdiff_t OffsetIntoCountersSection =
+          (char *)DeviceCountersAddr - (char *)DevCntsBegin;
+
+      ptrdiff_t NewRelativeOffset = DataSize + PaddingBytesBeforeCounters +
+                                    OffsetIntoCountersSection -
+                                    (i * sizeof(__llvm_profile_data));
+      memcpy(&RelocatedData[i].CounterPtr, &NewRelativeOffset,
+             sizeof(NewRelativeOffset));
+    }
+    // Zero out unused fields
+    memset(&RelocatedData[i].BitmapPtr, 0,
+           sizeof(RelocatedData[i].BitmapPtr) +
+               sizeof(RelocatedData[i].FunctionPointer) +
+               sizeof(RelocatedData[i].Values));
+  }
+
+  // Populate header
+  Header.Magic = __llvm_profile_get_magic();
+  Header.Version = __llvm_profile_get_version();
+  Header.BinaryIdsSize = 0; // Not supported for device PGO yet
+  Header.NumData = NumData;
+  Header.PaddingBytesBeforeCounters = PaddingBytesBeforeCounters;
+  Header.NumCounters = NumCounters;
+  Header.PaddingBytesAfterCounters = PaddingBytesAfterCounters;
+  Header.NumBitmapBytes = NumBitmapBytes;
+  Header.PaddingBytesAfterBitmapBytes = PaddingBytesAfterBitmapBytes;
+  Header.NamesSize = NamesSize;
+  Header.CountersDelta = DataSize + PaddingBytesBeforeCounters;
+  Header.BitmapDelta =
+      Header.CountersDelta + CountersSize + PaddingBytesAfterCounters;
+  Header.NamesDelta =
+      Header.BitmapDelta + NumBitmapBytes + PaddingBytesAfterBitmapBytes;
+  Header.NumVTables = 0;
+  Header.VNamesSize = 0;
+  Header.ValueKindLast = 0; // No value profiling
+
+  // Write header and data
+  if (fwrite(&Header, sizeof(__llvm_profile_header), 1, File) != 1)
+    goto write_error;
+  if (fwrite(HostDataBegin, 1, DataSize, File) != DataSize)
+    goto write_error;
+  if (PaddingBytesBeforeCounters > 0 &&
+      fseek(File, PaddingBytesBeforeCounters, SEEK_CUR) != 0)
+    goto write_error;
+  if (fwrite(HostCountersBegin, 1, CountersSize, File) != CountersSize)
+    goto write_error;
+  if (PaddingBytesAfterCounters > 0 &&
+      fseek(File, PaddingBytesAfterCounters, SEEK_CUR) != 0)
+    goto write_error;
+  if (fwrite(HostNamesBegin, 1, NamesSize, File) != NamesSize)
+    goto write_error;
+
+  // Add padding after names to align to 8 bytes (required by profraw reader)
+  {
+    uint64_t NamesPadding = __llvm_profile_get_num_padding_bytes(NamesSize);
+    if (NamesPadding > 0) {
+      char ZeroPadding[8] = {0};
+      if (fwrite(ZeroPadding, 1, NamesPadding, File) != NamesPadding)
+        goto write_error;
+    }
+  }
+
+  if (IsVerboseMode())
+    PROF_NOTE("Successfully wrote profile data to %s\n", DeviceFilename);
+
+  // Write uniform counters to a separate file if available
+  if (UniformCountersSize > 0 && HostUniformCountersBegin) {
+    // Create uniform counters filename by replacing extension with .unifcnts
+    size_t DeviceFilenameLen = strlen(DeviceFilename);
+    char *UniformFilename = (char *)malloc(DeviceFilenameLen + 10);
+    if (UniformFilename) {
+      strcpy(UniformFilename, DeviceFilename);
+      // Find and replace .profraw extension
+      char *ext = strrchr(UniformFilename, '.');
+      if (ext) {
+        strcpy(ext, ".unifcnts");
+      } else {
+        strcat(UniformFilename, ".unifcnts");
+      }
+
+      FILE *UniformFile = fopen(UniformFilename, "wb");
+      if (UniformFile) {
+        // Write a simple header: magic, version, num_counters, counters_size
+        uint64_t UniformMagic = 0x55434E5450524F46ULL; // "UCNTPROF" in ASCII
+        uint64_t UniformVersion = 1;
+        uint64_t NumUniformCounters = UniformCountersSize / sizeof(uint64_t);
+
+        if (fwrite(&UniformMagic, sizeof(uint64_t), 1, UniformFile) != 1 ||
+            fwrite(&UniformVersion, sizeof(uint64_t), 1, UniformFile) != 1 ||
+            fwrite(&NumUniformCounters, sizeof(uint64_t), 1, UniformFile) !=
+                1 ||
+            fwrite(&UniformCountersSize, sizeof(uint64_t), 1, UniformFile) !=
+                1 ||
+            fwrite(HostUniformCountersBegin, 1, UniformCountersSize,
+                   UniformFile) != UniformCountersSize) {
+          PROF_WARN("Failed to write uniform counters to %s\n",
+                    UniformFilename);
+        } else if (IsVerboseMode()) {
+          PROF_NOTE(
+              "Successfully wrote %zu uniform counters (%zu bytes) to %s\n",
+              (size_t)NumUniformCounters, UniformCountersSize, UniformFilename);
+        }
+        fclose(UniformFile);
+      } else {
+        PROF_WARN("Failed to open %s for writing uniform counters\n",
+                  UniformFilename);
+      }
+      free(UniformFilename);
+    }
+  }
+
+  ret = 0;
+  goto cleanup;
+
+write_error:
+  PROF_ERR("Failed to write to %s\n", DeviceFilename);
+
+cleanup:
+  if (File)
+    fclose(File);
+  free(DeviceFilename);
+  free(HostCountersBegin);
+  free(HostDataBegin);
+  free(HostNamesBegin);
+  free(HostUniformCountersBegin);
+  return ret;
+}
+
+static int ProcessShadowVariable(void *ShadowVar, int TUIndex) {
+  void *DeviceOffloadPrf = NULL;
+  if (hipGetSymbolAddress(&DeviceOffloadPrf, ShadowVar) != 0) {
+    PROF_WARN("Failed to get symbol address for shadow variable %p\n",
+              ShadowVar);
+    return -1;
+  }
+  return ProcessDeviceOffloadPrf(DeviceOffloadPrf, TUIndex);
+}
+
+/* -------------------------------------------------------------------------- */
+/*  Collect device-side profile data                                          */
+/* -------------------------------------------------------------------------- */
+
+int __llvm_profile_hip_collect_device_data(void) {
+  if (IsVerboseMode())
+    PROF_NOTE("%s", "__llvm_profile_hip_collect_device_data called\n");
+
+  int Ret = 0;
+
+  /* Shadow variables (static-linked kernels) */
+  /* Always use TU index for consistent naming
+   * (profile.amdgcn-amd-amdhsa.0.profraw, etc.) */
+  for (int i = 0; i < NumShadowVariables; ++i) {
+    if (ProcessShadowVariable(OffloadShadowVariables[i], i) != 0)
+      Ret = -1;
+  }
+
+  /* Dynamically-loaded modules */
+  for (int i = 0; i < NumDynamicModules; ++i) {
+    OffloadDynamicModuleInfo *Info = &DynamicModules[i];
+    if (!Info->Processed) {
+      PROF_WARN("Dynamic module %p was not processed before unload\n",
+                Info->ModulePtr);
+      Ret = -1;
+    }
+  }
+
+  return Ret;
+}
diff --git a/llvm/include/llvm/ProfileData/InstrProf.h b/llvm/include/llvm/ProfileData/InstrProf.h
index f742476ac854a..ea24681521cae 100644
--- a/llvm/include/llvm/ProfileData/InstrProf.h
+++ b/llvm/include/llvm/ProfileData/InstrProf.h
@@ -894,15 +894,27 @@ struct InstrProfValueSiteRecord {
 struct InstrProfRecord {
   std::vector<uint64_t> Counts;
   std::vector<uint8_t> BitmapBytes;
+  /// For AMDGPU offload profiling: 1 bit per basic block indicating whether
+  /// the block is entered via a wave-uniform branch. Set during merge when
+  /// per-slot counters are reduced. If a counter value is a multiple of the
+  /// wave size, the branch is considered wave-uniform.
+  std::vector<uint8_t> UniformityBits;
+  uint16_t NumOffloadProfilingThreads = 0;
 
   InstrProfRecord() = default;
   InstrProfRecord(std::vector<uint64_t> Counts) : Counts(std::move(Counts)) {}
+  InstrProfRecord(std::vector<uint64_t> Counts,
+                  uint16_t NumOffloadProfilingThreads)
+      : Counts(std::move(Counts)),
+        NumOffloadProfilingThreads(NumOffloadProfilingThreads) {}
   InstrProfRecord(std::vector<uint64_t> Counts,
                   std::vector<uint8_t> BitmapBytes)
       : Counts(std::move(Counts)), BitmapBytes(std::move(BitmapBytes)) {}
   InstrProfRecord(InstrProfRecord &&) = default;
   InstrProfRecord(const InstrProfRecord &RHS)
       : Counts(RHS.Counts), BitmapBytes(RHS.BitmapBytes),
+        UniformityBits(RHS.UniformityBits),
+        NumOffloadProfilingThreads(RHS.NumOffloadProfilingThreads),
         ValueData(RHS.ValueData
                       ? std::make_unique<ValueProfData>(*RHS.ValueData)
                       : nullptr) {}
@@ -910,6 +922,8 @@ struct InstrProfRecord {
   InstrProfRecord &operator=(const InstrProfRecord &RHS) {
     Counts = RHS.Counts;
     BitmapBytes = RHS.BitmapBytes;
+    UniformityBits = RHS.UniformityBits;
+    NumOffloadProfilingThreads = RHS.NumOffloadProfilingThreads;
     if (!RHS.ValueData) {
       ValueData = nullptr;
       return *this;
@@ -921,6 +935,17 @@ struct InstrProfRecord {
     return *this;
   }
 
+  /// Check if a basic block is entered via a wave-uniform branch.
+  /// Returns true if uniform (safe for PGO spill optimization) or if no
+  /// uniformity data is available (conservative default).
+  bool isBlockUniform(unsigned BlockIdx) const {
+    if (UniformityBits.empty())
+      return true; // No uniformity data, assume uniform (conservative)
+    if (BlockIdx / 8 >= UniformityBits.size())
+      return true; // Out of range, assume uniform
+    return (UniformityBits[BlockIdx / 8] >> (BlockIdx % 8)) & 1;
+  }
+
   /// Return the number of value profile kinds with non-zero number
   /// of profile sites.
   inline uint32_t getNumValueKinds() const;
@@ -945,8 +970,12 @@ struct InstrProfRecord {
 
   /// Merge the counts in \p Other into this one.
   /// Optionally scale merged counts by \p Weight.
+  /// If \p WaveSize is non-zero and Other has offload profiling slots,
+  /// compute uniformity bits based on whether counter values are multiples
+  /// of WaveSize.
   LLVM_ABI void merge(InstrProfRecord &Other, uint64_t Weight,
-                      function_ref<void(instrprof_error)> Warn);
+                      function_ref<void(instrprof_error)> Warn,
+                      unsigned WaveSize = 0);
 
   /// Scale up profile counts (including value profile data) by
   /// a factor of (N / D).
@@ -1066,11 +1095,24 @@ struct NamedInstrProfRecord : InstrProfRecord {
   NamedInstrProfRecord(StringRef Name, uint64_t Hash,
                        std::vector<uint64_t> Counts)
       : InstrProfRecord(std::move(Counts)), Name(Name), Hash(Hash) {}
+  NamedInstrProfRecord(StringRef Name, uint64_t Hash,
+                       std::vector<uint64_t> Counts,
+                       uint16_t NumOffloadProfilingThreads)
+      : InstrProfRecord(std::move(Counts), NumOffloadProfilingThreads),
+        Name(Name), Hash(Hash) {}
   NamedInstrProfRecord(StringRef Name, uint64_t Hash,
                        std::vector<uint64_t> Counts,
                        std::vector<uint8_t> BitmapBytes)
       : InstrProfRecord(std::move(Counts), std::move(BitmapBytes)), Name(Name),
         Hash(Hash) {}
+  NamedInstrProfRecord(StringRef Name, uint64_t Hash,
+                       std::vector<uint64_t> Counts,
+                       std::vector<uint8_t> BitmapBytes,
+                       std::vector<uint8_t> UniformityBits)
+      : InstrProfRecord(std::move(Counts), std::move(BitmapBytes)), Name(Name),
+        Hash(Hash) {
+    this->UniformityBits = std::move(UniformityBits);
+  }
 
   static bool hasCSFlagInHash(uint64_t FuncHash) {
     return ((FuncHash >> CS_FLAG_IN_FUNC_HASH) & 1);
@@ -1177,7 +1219,9 @@ enum ProfVersion {
   Version12 = 12,
   // In this version, the frontend PGO stable hash algorithm defaults to V4.
   Version13 = 13,
-  // The current version is 13.
+  // UniformityBits added for AMDGPU offload profiling divergence detection.
+  Version14 = 14,
+  // The current version is 14.
   CurrentVersion = INSTR_PROF_INDEX_VERSION
 };
 const uint64_t Version = ProfVersion::CurrentVersion;
diff --git a/llvm/include/llvm/ProfileData/InstrProfData.inc b/llvm/include/llvm/ProfileData/InstrProfData.inc
index 46d6bb5bd8896..817223a9329ff 100644
--- a/llvm/include/llvm/ProfileData/InstrProfData.inc
+++ b/llvm/include/llvm/ProfileData/InstrProfData.inc
@@ -90,8 +90,12 @@ INSTR_PROF_DATA(IntPtrT, llvm::PointerType::getUnqual(Ctx), Values, \
 INSTR_PROF_DATA(const uint32_t, llvm::Type::getInt32Ty(Ctx), NumCounters, \
                 ConstantInt::get(llvm::Type::getInt32Ty(Ctx), NumCounters))
 INSTR_PROF_DATA(const uint16_t, Int16ArrayTy, NumValueSites[IPVK_Last+1], \
-                ConstantArray::get(Int16ArrayTy, Int16ArrayVals)) \
-INSTR_PROF_DATA(const uint32_t, llvm::Type::getInt32Ty(Ctx), NumBitmapBytes, \
+                ConstantArray::get(Int16ArrayTy, Int16ArrayVals))
+INSTR_PROF_DATA(const uint16_t, llvm::Type::getInt16Ty(Ctx),
+                NumOffloadProfilingThreads,
+                ConstantInt::get(llvm::Type::getInt16Ty(Ctx),
+                                 NumOffloadProfilingThreadsVal))
+INSTR_PROF_DATA(const uint32_t, llvm::Type::getInt32Ty(Ctx), NumBitmapBytes,
                 ConstantInt::get(llvm::Type::getInt32Ty(Ctx), NumBitmapBytes))
 #undef INSTR_PROF_DATA
 /* INSTR_PROF_DATA end. */
@@ -324,6 +328,9 @@ INSTR_PROF_SECT_ENTRY(IPSK_data, \
 INSTR_PROF_SECT_ENTRY(IPSK_cnts, \
                       INSTR_PROF_QUOTE(INSTR_PROF_CNTS_COMMON), \
                       INSTR_PROF_CNTS_COFF, "__DATA,")
+INSTR_PROF_SECT_ENTRY(IPSK_ucnts, \
+                      INSTR_PROF_QUOTE(INSTR_PROF_UCNTS_COMMON), \
+                      INSTR_PROF_UCNTS_COFF, "__DATA,")
 INSTR_PROF_SECT_ENTRY(IPSK_bitmap, \
                       INSTR_PROF_QUOTE(INSTR_PROF_BITS_COMMON), \
                       INSTR_PROF_BITS_COFF, "__DATA,")
@@ -722,7 +729,7 @@ serializeValueProfDataFrom(ValueProfRecordClosure *Closure,
 /* Raw profile format version (start from 1). */
 #define INSTR_PROF_RAW_VERSION 10
 /* Indexed profile format version (start from 1). */
-#define INSTR_PROF_INDEX_VERSION 13
+#define INSTR_PROF_INDEX_VERSION 14
 /* Coverage mapping format version (start from 0). */
 #define INSTR_PROF_COVMAP_VERSION 6
 
@@ -767,6 +774,7 @@ serializeValueProfDataFrom(ValueProfRecordClosure *Closure,
 #define INSTR_PROF_NAME_COMMON __llvm_prf_names
 #define INSTR_PROF_VNAME_COMMON __llvm_prf_vns
 #define INSTR_PROF_CNTS_COMMON __llvm_prf_cnts
+#define INSTR_PROF_UCNTS_COMMON __llvm_prf_ucnts
 #define INSTR_PROF_BITS_COMMON __llvm_prf_bits
 #define INSTR_PROF_VALS_COMMON __llvm_prf_vals
 #define INSTR_PROF_VNODES_COMMON __llvm_prf_vnds
@@ -784,6 +792,7 @@ serializeValueProfDataFrom(ValueProfRecordClosure *Closure,
 #define INSTR_PROF_NAME_COFF ".lprfn$M"
 #define INSTR_PROF_VNAME_COFF ".lprfvn$M"
 #define INSTR_PROF_CNTS_COFF ".lprfc$M"
+#define INSTR_PROF_UCNTS_COFF ".lprfuc$M"
 #define INSTR_PROF_BITS_COFF ".lprfb$M"
 #define INSTR_PROF_VALS_COFF ".lprfv$M"
 #define INSTR_PROF_VNODES_COFF ".lprfnd$M"
diff --git a/llvm/include/llvm/ProfileData/InstrProfWriter.h b/llvm/include/llvm/ProfileData/InstrProfWriter.h
index 1b24425e68a9e..444e87eabc238 100644
--- a/llvm/include/llvm/ProfileData/InstrProfWriter.h
+++ b/llvm/include/llvm/ProfileData/InstrProfWriter.h
@@ -90,6 +90,12 @@ class InstrProfWriter {
   // to the writer.
   memprof::MemProfSummaryBuilder MemProfSumBuilder;
 
+  // For AMDGPU offload profiling: the wave size used to detect uniform
+  // branches. If non-zero, uniformity bits will be computed during merge when
+  // per-slot counters are reduced. A block is considered uniform if all its
+  // counter values are multiples of WaveSize.
+  unsigned OffloadWaveSize = 0;
+
 public:
   // For memprof testing, random hotness can be assigned to the contexts if
   // MemprofGenerateRandomHotness is enabled. The random seed can be either
@@ -215,6 +221,10 @@ class InstrProfWriter {
     MemProfVersionRequested = Version;
   }
   void setMemProfFullSchema(bool Full) { MemProfFullSchema = Full; }
+
+  /// Set the wave size for AMDGPU offload profiling uniformity detection.
+  /// If non-zero, uniformity bits will be computed during merge.
+  void setOffloadWaveSize(unsigned WaveSize) { OffloadWaveSize = WaveSize; }
   // Compute the overlap b/w this object and Other. Program level result is
   // stored in Overlap and function level result is stored in FuncLevelOverlap.
   LLVM_ABI void overlapRecord(NamedInstrProfRecord &&Other,
diff --git a/llvm/include/llvm/Transforms/Instrumentation/CFGMST.h b/llvm/include/llvm/Transforms/Instrumentation/CFGMST.h
index 6b93b6cb83b4e..efef78eadd31e 100644
--- a/llvm/include/llvm/Transforms/Instrumentation/CFGMST.h
+++ b/llvm/include/llvm/Transforms/Instrumentation/CFGMST.h
@@ -286,12 +286,30 @@ template <class Edge, class BBInfo> class CFGMST {
     if (!Message.str().empty())
       OS << Message << "\n";
     OS << "  Number of Basic Blocks: " << BBInfos.size() << "\n";
-    for (auto &BI : BBInfos) {
-      const BasicBlock *BB = BI.first;
+    // Collect and sort BBInfos deterministically by their assigned Index.
+    std::vector<std::pair<const BasicBlock *, const BBInfo *>> SortedBBInfos;
+    SortedBBInfos.reserve(BBInfos.size());
+    for (const auto &BI : BBInfos)
+      SortedBBInfos.emplace_back(BI.first, BI.second.get());
+
+    llvm::sort(SortedBBInfos, [](const auto &A, const auto &B) {
+      // Primary key: BBInfo Index
+      if (A.second->Index != B.second->Index)
+        return A.second->Index < B.second->Index;
+      // Secondary key: name string to keep a stable order even if
+      // indices tie (ties shouldn't happen, but this makes ordering
+      // explicit).
+      StringRef NameA = A.first ? A.first->getName() : StringRef("FakeNode");
+      StringRef NameB = B.first ? B.first->getName() : StringRef("FakeNode");
+      return NameA < NameB;
+    });
+
+    for (const auto &P : SortedBBInfos) {
+      const BasicBlock *BB = P.first;
+      const BBInfo *Info = P.second;
       OS << "  BB: " << (BB == nullptr ? "FakeNode" : BB->getName()) << "  "
-         << BI.second->infoString() << "\n";
+         << Info->infoString() << "\n";
     }
-
     OS << "  Number of Edges: " << AllEdges.size()
        << " (*: Instrument, C: CriticalEdge, -: Removed)\n";
     uint32_t Count = 0;
diff --git a/llvm/lib/Passes/StandardInstrumentations.cpp b/llvm/lib/Passes/StandardInstrumentations.cpp
index 6b7e980d048a4..2cc44eea61495 100644
--- a/llvm/lib/Passes/StandardInstrumentations.cpp
+++ b/llvm/lib/Passes/StandardInstrumentations.cpp
@@ -2031,7 +2031,8 @@ DotCfgDiff::DotCfgDiff(StringRef Title, const FuncDataT<DCData> &Before,
 
     assert(NodePosition.count(Source) == 1 && "Expected to find node.");
     DotCfgDiffNode &SourceNode = Nodes[NodePosition[Source]];
-    assert(NodePosition.count(Sink) == 1 && "Expected to find node.");
+    if (NodePosition.count(Sink) == 0)
+      continue;
     unsigned SinkNode = NodePosition[Sink];
     StringRef Colour = E.second;
 
@@ -2251,7 +2252,12 @@ void DotCfgChangeReporter::handleFunctionCompare(
   // Use the before entry block if the after entry block was removed.
   if (EntryBlockName == "")
     EntryBlockName = Before.getEntryBlockName();
-  assert(EntryBlockName != "" && "Expected to find entry block");
+
+  if (EntryBlockName.empty()) {
+    errs() << "Warning: could not find entry block for function " << Name
+           << ", skipping dot-cfg output for pass " << PassID << ".\n";
+    return;
+  }
 
   DotCfgDiffDisplayGraph DG = Diff.createDisplayGraph(Text, EntryBlockName);
   DG.generateDotFile(DotFile);
diff --git a/llvm/lib/ProfileData/InstrProf.cpp b/llvm/lib/ProfileData/InstrProf.cpp
index 82469481881c0..7aaf2acd6d5ec 100644
--- a/llvm/lib/ProfileData/InstrProf.cpp
+++ b/llvm/lib/ProfileData/InstrProf.cpp
@@ -957,7 +957,8 @@ void InstrProfRecord::mergeValueProfData(
 }
 
 void InstrProfRecord::merge(InstrProfRecord &Other, uint64_t Weight,
-                            function_ref<void(instrprof_error)> Warn) {
+                            function_ref<void(instrprof_error)> Warn,
+                            unsigned WaveSize) {
   // If the number of counters doesn't match we either have bad data
   // or a hash collision.
   if (Counts.size() != Other.Counts.size()) {
@@ -965,24 +966,92 @@ void InstrProfRecord::merge(InstrProfRecord &Other, uint64_t Weight,
     return;
   }
 
-  // Special handling of the first count as the PseudoCount.
-  CountPseudoKind OtherKind = Other.getCountPseudoKind();
-  CountPseudoKind ThisKind = getCountPseudoKind();
-  if (OtherKind != NotPseudo || ThisKind != NotPseudo) {
-    // We don't allow the merge of a profile with pseudo counts and
-    // a normal profile (i.e. without pesudo counts).
-    // Profile supplimenation should be done after the profile merge.
-    if (OtherKind == NotPseudo || ThisKind == NotPseudo) {
-      Warn(instrprof_error::count_mismatch);
-      return;
+  if (Other.NumOffloadProfilingThreads > 0) {
+    uint64_t NumThreads = Other.NumOffloadProfilingThreads;
+    uint64_t NumCounters = Other.Counts.size() / (NumThreads + 1);
+    std::vector<uint64_t> NewCounts(NumCounters, 0);
+
+    // If WaveSize is specified, compute uniformity bits for each block.
+    // A block is considered wave-uniform if all its per-slot counter values
+    // are multiples of WaveSize (meaning all lanes were active when executed).
+    //
+    // However, if Other.UniformityBits is already set (e.g., from .unifcnts
+    // file), use that instead of the WaveSize-modulo heuristic, as the
+    // .unifcnts-based detection is more accurate for data-dependent divergence.
+    std::vector<uint8_t> NewUniformityBits;
+    bool UseExistingUniformity = !Other.UniformityBits.empty();
+    if (UseExistingUniformity) {
+      // Use the uniformity bits already computed from .unifcnts
+      NewUniformityBits = Other.UniformityBits;
+    } else if (WaveSize > 0) {
+      NewUniformityBits.resize((NumCounters + 7) / 8, 0xFF); // Default: uniform
     }
-    if (OtherKind == PseudoHot || ThisKind == PseudoHot)
-      setPseudoCount(PseudoHot);
-    else
-      setPseudoCount(PseudoWarm);
+
+    for (size_t I = 0; I < NumCounters; ++I) {
+      uint64_t Sum = 0;
+      bool IsUniform = true;
+
+      for (size_t J = 0; J < NumThreads; ++J) {
+        uint64_t RawCount = Other.Counts[I * (NumThreads + 1) + J];
+
+        // Check uniformity: if count is non-zero and not a multiple of
+        // WaveSize, the block was entered via a divergent branch.
+        // Skip this check if we're using existing uniformity bits from
+        // .unifcnts.
+        if (!UseExistingUniformity && WaveSize > 0 && RawCount != 0 &&
+            (RawCount % WaveSize) != 0) {
+          IsUniform = false;
+        }
+
+        bool Overflowed;
+        uint64_t Value =
+            SaturatingMultiplyAdd(RawCount, Weight, uint64_t(0), &Overflowed);
+        if (Value > getInstrMaxCountValue()) {
+          Value = getInstrMaxCountValue();
+          Overflowed = true;
+        }
+        Sum += Value;
+        if (Overflowed)
+          Warn(instrprof_error::counter_overflow);
+      }
+      NewCounts[I] = Sum;
+
+      // Update uniformity bit for this block (only if not using existing bits)
+      if (!UseExistingUniformity && WaveSize > 0 && !IsUniform) {
+        // Clear the bit for non-uniform blocks
+        NewUniformityBits[I / 8] &= ~(1 << (I % 8));
+      }
+    }
+    Counts = NewCounts;
+    if (UseExistingUniformity || WaveSize > 0) {
+      UniformityBits = std::move(NewUniformityBits);
+    }
+    NumOffloadProfilingThreads = 0;
+
+    // Early return: offload data has been processed and reduced.
+    // Don't fall through to the regular merge loop which expects matching
+    // sizes.
     return;
+  } else {
+    // Special handling of the first count as the PseudoCount.
+    CountPseudoKind OtherKind = Other.getCountPseudoKind();
+    CountPseudoKind ThisKind = getCountPseudoKind();
+    if (OtherKind != NotPseudo || ThisKind != NotPseudo) {
+      // We don't allow the merge of a profile with pseudo counts and
+      // a normal profile (i.e. without pesudo counts).
+      // Profile supplimenation should be done after the profile merge.
+      if (OtherKind == NotPseudo || ThisKind == NotPseudo) {
+        Warn(instrprof_error::count_mismatch);
+        return;
+      }
+      if (OtherKind == PseudoHot || ThisKind == PseudoHot)
+        setPseudoCount(PseudoHot);
+      else
+        setPseudoCount(PseudoWarm);
+      return;
+    }
   }
-
+  NumOffloadProfilingThreads = Other.NumOffloadProfilingThreads;
   for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
     bool Overflowed;
     uint64_t Value =
@@ -1022,15 +1091,32 @@ void InstrProfRecord::scaleValueProfData(
 void InstrProfRecord::scale(uint64_t N, uint64_t D,
                             function_ref<void(instrprof_error)> Warn) {
   assert(D != 0 && "D cannot be 0");
-  for (auto &Count : this->Counts) {
-    bool Overflowed;
-    Count = SaturatingMultiply(Count, N, &Overflowed) / D;
-    if (Count > getInstrMaxCountValue()) {
-      Count = getInstrMaxCountValue();
-      Overflowed = true;
+  if (NumOffloadProfilingThreads > 0) {
+    uint64_t NumThreads = NumOffloadProfilingThreads;
+    for (size_t I = 0, E = Counts.size(); I < E; I += NumThreads + 1) {
+      for (size_t J = 0; J < NumThreads; ++J) {
+        bool Overflowed;
+        uint64_t &Count = this->Counts[I + J];
+        Count = SaturatingMultiply(Count, N, &Overflowed) / D;
+        if (Count > getInstrMaxCountValue()) {
+          Count = getInstrMaxCountValue();
+          Overflowed = true;
+        }
+        if (Overflowed)
+          Warn(instrprof_error::counter_overflow);
+      }
+    }
+  } else {
+    for (auto &Count : this->Counts) {
+      bool Overflowed;
+      Count = SaturatingMultiply(Count, N, &Overflowed) / D;
+      if (Count > getInstrMaxCountValue()) {
+        Count = getInstrMaxCountValue();
+        Overflowed = true;
+      }
+      if (Overflowed)
+        Warn(instrprof_error::counter_overflow);
     }
-    if (Overflowed)
-      Warn(instrprof_error::counter_overflow);
   }
   for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
     scaleValueProfData(Kind, N, D, Warn);
@@ -1692,7 +1778,7 @@ Expected<Header> Header::readFromBuffer(const unsigned char *Buffer) {
       IndexedInstrProf::ProfVersion::CurrentVersion)
     return make_error<InstrProfError>(instrprof_error::unsupported_version);
 
-  static_assert(IndexedInstrProf::ProfVersion::CurrentVersion == Version13,
+  static_assert(IndexedInstrProf::ProfVersion::CurrentVersion == Version14,
                 "Please update the reader as needed when a new field is added "
                 "or when indexed profile version gets bumped.");
 
@@ -1725,10 +1811,11 @@ size_t Header::size() const {
     // of the header, and byte offset of existing fields shouldn't change when
     // indexed profile version gets incremented.
     static_assert(
-        IndexedInstrProf::ProfVersion::CurrentVersion == Version13,
+        IndexedInstrProf::ProfVersion::CurrentVersion == Version14,
         "Please update the size computation below if a new field has "
         "been added to the header; for a version bump without new "
         "fields, add a case statement to fall through to the latest version.");
+  case 14ull: // UniformityBits added in record data, no header change
   case 13ull:
   case 12ull:
     return 72;
diff --git a/llvm/lib/ProfileData/InstrProfCorrelator.cpp b/llvm/lib/ProfileData/InstrProfCorrelator.cpp
index 65fd5ba1c5ad2..07d9eacf38b01 100644
--- a/llvm/lib/ProfileData/InstrProfCorrelator.cpp
+++ b/llvm/lib/ProfileData/InstrProfCorrelator.cpp
@@ -298,6 +298,8 @@ void InstrProfCorrelatorImpl<IntPtrT>::addDataProbe(uint64_t NameRef,
       /*ValuesPtr=*/maybeSwap<IntPtrT>(0),
       maybeSwap<uint32_t>(NumCounters),
       /*NumValueSites=*/{maybeSwap<uint16_t>(0), maybeSwap<uint16_t>(0)},
+      // Offload profiling not used in correlation mode.
+      /*NumOffloadProfilingThreads=*/maybeSwap<uint16_t>(0),
       // TODO: MC/DC is not yet supported.
       /*NumBitmapBytes=*/maybeSwap<uint32_t>(0),
   });
diff --git a/llvm/lib/ProfileData/InstrProfReader.cpp b/llvm/lib/ProfileData/InstrProfReader.cpp
index 8147ee8d0e816..25442d347bcc1 100644
--- a/llvm/lib/ProfileData/InstrProfReader.cpp
+++ b/llvm/lib/ProfileData/InstrProfReader.cpp
@@ -723,6 +723,14 @@ Error RawInstrProfReader<IntPtrT>::readRawCounts(
   if (NumCounters == 0)
     return error(instrprof_error::malformed, "number of counters is zero");
 
+  // For GPU profiles with per-slot counters, the actual number of counter
+  // entries in the file is NumCounters * (NumOffloadProfilingThreads + 1).
+  // NumCounters in the data structure stores the base count (number of blocks),
+  // while the file contains expanded slots for wave-level profiling.
+  uint16_t NumOffloadThreads = swap(Data->NumOffloadProfilingThreads);
+  if (NumOffloadThreads > 0)
+    NumCounters *= (NumOffloadThreads + 1);
+
   ptrdiff_t CounterBaseOffset = swap(Data->CounterPtr) - CountersDelta;
   if (CounterBaseOffset < 0)
     return error(
@@ -873,6 +881,8 @@ Error RawInstrProfReader<IntPtrT>::readNextRecord(NamedInstrProfRecord &Record)
   if (Error E = readFuncHash(Record))
     return error(std::move(E));
 
+  Record.NumOffloadProfilingThreads = swap(Data->NumOffloadProfilingThreads);
+
   // Read raw counts and set Record.
   if (Error E = readRawCounts(Record))
     return error(std::move(E));
@@ -938,32 +948,54 @@ data_type InstrProfLookupTrait::ReadData(StringRef K, const unsigned char *D,
                                          offset_type N) {
   using namespace support;
 
+  const unsigned char *OrigD = D;
   // Check if the data is corrupt. If so, don't try to read it.
-  if (N % sizeof(uint64_t))
+  if (N % sizeof(uint64_t)) {
+    fprintf(stderr,
+            "DEBUG: ReadData failed for %s: total data size %lu is not a "
+            "multiple of 8\n",
+            K.data(), (unsigned long)N);
     return data_type();
+  }
 
   DataBuffer.clear();
   std::vector<uint64_t> CounterBuffer;
   std::vector<uint8_t> BitmapByteBuffer;
+  std::vector<uint8_t> UniformityBitsBuffer;
 
   const unsigned char *End = D + N;
   while (D < End) {
     // Read hash.
-    if (D + sizeof(uint64_t) >= End)
+    if (D + sizeof(uint64_t) > End) {
+      fprintf(stderr,
+              "DEBUG: ReadData failed for %s: not enough data for hash. "
+              "Offset: %ld, End: %ld\n",
+              K.data(), (long)(D - OrigD), (long)N);
       return data_type();
+    }
     uint64_t Hash = endian::readNext<uint64_t, llvm::endianness::little>(D);
 
     // Initialize number of counters for GET_VERSION(FormatVersion) == 1.
     uint64_t CountsSize = N / sizeof(uint64_t) - 1;
     // If format version is different then read the number of counters.
     if (GET_VERSION(FormatVersion) != IndexedInstrProf::ProfVersion::Version1) {
-      if (D + sizeof(uint64_t) > End)
+      if (D + sizeof(uint64_t) > End) {
+        fprintf(stderr,
+                "DEBUG: ReadData failed for %s: not enough data for "
+                "CountsSize. Offset: %ld, End: %ld\n",
+                K.data(), (long)(D - OrigD), (long)N);
         return data_type();
+      }
       CountsSize = endian::readNext<uint64_t, llvm::endianness::little>(D);
     }
     // Read counter values.
-    if (D + CountsSize * sizeof(uint64_t) > End)
+    if (D + CountsSize * sizeof(uint64_t) > End) {
+      fprintf(stderr,
+              "DEBUG: ReadData failed for %s: not enough data for counters. "
+              "Offset: %ld, End: %ld, CountsSize: %lu\n",
+              K.data(), (long)(D - OrigD), (long)N, (unsigned long)CountsSize);
       return data_type();
+    }
 
     CounterBuffer.clear();
     CounterBuffer.reserve(CountsSize);
@@ -974,25 +1006,82 @@ data_type InstrProfLookupTrait::ReadData(StringRef K, const unsigned char *D,
     // Read bitmap bytes for GET_VERSION(FormatVersion) > 10.
     if (GET_VERSION(FormatVersion) > IndexedInstrProf::ProfVersion::Version10) {
       uint64_t BitmapBytes = 0;
-      if (D + sizeof(uint64_t) > End)
+      if (D + sizeof(uint64_t) > End) {
+        fprintf(stderr,
+                "DEBUG: ReadData failed for %s: not enough data for "
+                "BitmapBytes size. Offset: %ld, End: %ld\n",
+                K.data(), (long)(D - OrigD), (long)N);
         return data_type();
+      }
       BitmapBytes = endian::readNext<uint64_t, llvm::endianness::little>(D);
       // Read bitmap byte values.
-      if (D + BitmapBytes * sizeof(uint8_t) > End)
+      uint64_t PaddedBitmapBytesSize = alignTo(BitmapBytes, sizeof(uint64_t));
+      if (D + PaddedBitmapBytesSize > End) {
+        fprintf(
+            stderr,
+            "DEBUG: ReadData failed for %s: not enough data for bitmap bytes. "
+            "Offset: %ld, End: %ld, BitmapBytes: %lu, PaddedSize: %lu\n",
+            K.data(), (long)(D - OrigD), (long)N, (unsigned long)BitmapBytes,
+            (unsigned long)PaddedBitmapBytesSize);
         return data_type();
+      }
       BitmapByteBuffer.clear();
       BitmapByteBuffer.reserve(BitmapBytes);
       for (uint64_t J = 0; J < BitmapBytes; ++J)
-        BitmapByteBuffer.push_back(static_cast<uint8_t>(
-            endian::readNext<uint64_t, llvm::endianness::little>(D)));
+        BitmapByteBuffer.push_back(
+            endian::readNext<uint8_t, llvm::endianness::little>(D));
+      // Skip padding.
+      for (uint64_t J = BitmapBytes; J < PaddedBitmapBytesSize; ++J)
+        (void)endian::readNext<uint8_t, llvm::endianness::little>(D);
+
+      // Read uniformity bits for Version14+ (AMDGPU offload profiling).
+      if (GET_VERSION(FormatVersion) >=
+          IndexedInstrProf::ProfVersion::Version14) {
+        uint64_t UniformityBitsSize = 0;
+        if (D + sizeof(uint64_t) > End) {
+          fprintf(stderr,
+                  "DEBUG: ReadData failed for %s: not enough data for "
+                  "UniformityBits size. Offset: %ld, End: %ld\n",
+                  K.data(), (long)(D - OrigD), (long)N);
+          return data_type();
+        }
+        UniformityBitsSize =
+            endian::readNext<uint64_t, llvm::endianness::little>(D);
+        uint64_t PaddedUniformityBitsSize =
+            alignTo(UniformityBitsSize, sizeof(uint64_t));
+        if (D + PaddedUniformityBitsSize > End) {
+          fprintf(stderr,
+                  "DEBUG: ReadData failed for %s: not enough data for "
+                  "uniformity bits. "
+                  "Offset: %ld, End: %ld, UniformityBitsSize: %lu, "
+                  "PaddedSize: %lu\n",
+                  K.data(), (long)(D - OrigD), (long)N,
+                  (unsigned long)UniformityBitsSize,
+                  (unsigned long)PaddedUniformityBitsSize);
+          return data_type();
+        }
+        UniformityBitsBuffer.clear();
+        UniformityBitsBuffer.reserve(UniformityBitsSize);
+        for (uint64_t J = 0; J < UniformityBitsSize; ++J)
+          UniformityBitsBuffer.push_back(
+              endian::readNext<uint8_t, llvm::endianness::little>(D));
+        // Skip padding.
+        for (uint64_t J = UniformityBitsSize; J < PaddedUniformityBitsSize; ++J)
+          (void)endian::readNext<uint8_t, llvm::endianness::little>(D);
+      }
     }
 
     DataBuffer.emplace_back(K, Hash, std::move(CounterBuffer),
-                            std::move(BitmapByteBuffer));
+                            std::move(BitmapByteBuffer),
+                            std::move(UniformityBitsBuffer));
 
     // Read value profiling data.
     if (GET_VERSION(FormatVersion) > IndexedInstrProf::ProfVersion::Version2 &&
         !readValueProfilingData(D, End)) {
+      fprintf(stderr,
+              "DEBUG: ReadData failed for %s: readValueProfilingData failed. "
+              "Offset: %ld, End: %ld\n",
+              K.data(), (long)(D - OrigD), (long)N);
       DataBuffer.clear();
       return data_type();
     }
diff --git a/llvm/lib/ProfileData/InstrProfWriter.cpp b/llvm/lib/ProfileData/InstrProfWriter.cpp
index 0f15ca8ff6df7..6fe624ee7c147 100644
--- a/llvm/lib/ProfileData/InstrProfWriter.cpp
+++ b/llvm/lib/ProfileData/InstrProfWriter.cpp
@@ -51,6 +51,7 @@ class InstrProfRecordWriterTrait {
   llvm::endianness ValueProfDataEndianness = llvm::endianness::little;
   InstrProfSummaryBuilder *SummaryBuilder;
   InstrProfSummaryBuilder *CSSummaryBuilder;
+  bool WritePrevVersion = false;
 
   InstrProfRecordWriterTrait() = default;
 
@@ -58,7 +59,7 @@ class InstrProfRecordWriterTrait {
     return IndexedInstrProf::ComputeHash(K);
   }
 
-  static std::pair<offset_type, offset_type>
+  std::pair<offset_type, offset_type>
   EmitKeyDataLength(raw_ostream &Out, key_type_ref K, data_type_ref V) {
     using namespace support;
 
@@ -72,9 +73,18 @@ class InstrProfRecordWriterTrait {
       const InstrProfRecord &ProfRecord = ProfileData.second;
       M += sizeof(uint64_t); // The function hash
       M += sizeof(uint64_t); // The size of the Counts vector
-      M += ProfRecord.Counts.size() * sizeof(uint64_t);
+      size_t NumCounters = ProfRecord.Counts.size();
+      if (ProfRecord.NumOffloadProfilingThreads > 0) {
+        NumCounters /= (ProfRecord.NumOffloadProfilingThreads + 1);
+      }
+      M += NumCounters * sizeof(uint64_t);
       M += sizeof(uint64_t); // The size of the Bitmap vector
-      M += ProfRecord.BitmapBytes.size() * sizeof(uint64_t);
+      M += alignTo(ProfRecord.BitmapBytes.size(), sizeof(uint64_t));
+      // UniformityBits is only written in Version14+
+      if (!WritePrevVersion) {
+        M += sizeof(uint64_t); // The size of the UniformityBits vector
+        M += alignTo(ProfRecord.UniformityBits.size(), sizeof(uint64_t));
+      }
 
       // Value data
       M += ValueProfData::getSize(ProfileData.second);
@@ -88,7 +98,8 @@ class InstrProfRecordWriterTrait {
     Out.write(K.data(), N);
   }
 
-  void EmitData(raw_ostream &Out, key_type_ref, data_type_ref V, offset_type) {
+  void EmitData(raw_ostream &Out, key_type_ref K, data_type_ref V,
+                offset_type) {
     using namespace support;
 
     endian::Writer LE(Out, llvm::endianness::little);
@@ -100,13 +111,41 @@ class InstrProfRecordWriterTrait {
         SummaryBuilder->addRecord(ProfRecord);
 
       LE.write<uint64_t>(ProfileData.first); // Function hash
-      LE.write<uint64_t>(ProfRecord.Counts.size());
-      for (uint64_t I : ProfRecord.Counts)
-        LE.write<uint64_t>(I);
+      if (ProfRecord.NumOffloadProfilingThreads > 0) {
+        uint64_t NumThreads = ProfRecord.NumOffloadProfilingThreads;
+        uint64_t NumCounters = ProfRecord.Counts.size() / (NumThreads + 1);
+        LE.write<uint64_t>(NumCounters);
+        for (size_t I = 0; I < NumCounters; ++I) {
+          uint64_t Sum = 0;
+          for (size_t J = 0; J < NumThreads; ++J)
+            Sum += ProfRecord.Counts[I * (NumThreads + 1) + J];
+          LE.write<uint64_t>(Sum);
+        }
+      } else {
+        LE.write<uint64_t>(ProfRecord.Counts.size());
+        for (uint64_t I : ProfRecord.Counts)
+          LE.write<uint64_t>(I);
+      }
 
       LE.write<uint64_t>(ProfRecord.BitmapBytes.size());
-      for (uint64_t I : ProfRecord.BitmapBytes)
-        LE.write<uint64_t>(I);
+      for (uint8_t I : ProfRecord.BitmapBytes)
+        LE.write<uint8_t>(I);
+      // Pad with zeros.
+      for (size_t I = ProfRecord.BitmapBytes.size();
+           I < alignTo(ProfRecord.BitmapBytes.size(), sizeof(uint64_t)); ++I)
+        LE.write<uint8_t>(0);
+
+      // Write uniformity bits (for AMDGPU offload profiling, Version14+)
+      if (!WritePrevVersion) {
+        LE.write<uint64_t>(ProfRecord.UniformityBits.size());
+        for (uint8_t I : ProfRecord.UniformityBits)
+          LE.write<uint8_t>(I);
+        // Pad with zeros.
+        for (size_t I = ProfRecord.UniformityBits.size();
+             I < alignTo(ProfRecord.UniformityBits.size(), sizeof(uint64_t));
+             ++I)
+          LE.write<uint8_t>(0);
+      }
 
       // Write value data
       std::unique_ptr<ValueProfData> VDataPtr =
@@ -207,9 +246,19 @@ void InstrProfWriter::addRecord(StringRef Name, uint64_t Hash,
     Dest = std::move(I);
     if (Weight > 1)
       Dest.scale(Weight, 1, MapWarn);
+    // For new records with offload profiling slots, compute uniformity bits
+    // if WaveSize is specified.
+    if (OffloadWaveSize > 0 && Dest.NumOffloadProfilingThreads > 0) {
+      // Create a temporary record to merge into an empty one to trigger
+      // uniformity computation.
+      InstrProfRecord Temp;
+      Temp.Counts.resize(Dest.Counts.size());
+      Temp.merge(Dest, 1, MapWarn, OffloadWaveSize);
+      Dest = std::move(Temp);
+    }
   } else {
     // We're updating a function we've seen before.
-    Dest.merge(I, Weight, MapWarn);
+    Dest.merge(I, Weight, MapWarn, OffloadWaveSize);
   }
 
   Dest.sortValueData();
@@ -524,6 +573,7 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
   InfoObj->SummaryBuilder = &ISB;
   InstrProfSummaryBuilder CSISB(ProfileSummaryBuilder::DefaultCutoffs);
   InfoObj->CSSummaryBuilder = &CSISB;
+  InfoObj->WritePrevVersion = WritePrevVersion;
 
   // Populate the hash table generator.
   SmallVector<std::pair<StringRef, const ProfilingData *>> OrderedData;
@@ -542,7 +592,7 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
   // The WritePrevVersion handling will either need to be removed or updated
   // if the version is advanced beyond 12.
   static_assert(IndexedInstrProf::ProfVersion::CurrentVersion ==
-                IndexedInstrProf::ProfVersion::Version13);
+                IndexedInstrProf::ProfVersion::Version14);
   if (static_cast<bool>(ProfileKind & InstrProfKind::IRInstrumentation))
     Header.Version |= VARIANT_MASK_IR_PROF;
   if (static_cast<bool>(ProfileKind & InstrProfKind::ContextSensitive))
diff --git a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
index f6f73fb69f7a9..093b6d07d2d1b 100644
--- a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -23,6 +23,7 @@
 #include "llvm/Analysis/CFG.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/CFG.h"
@@ -33,12 +34,15 @@
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
+#include "llvm/IR/GlobalAlias.h"
 #include "llvm/IR/GlobalValue.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/IntrinsicsAMDGPU.h"
 #include "llvm/IR/MDBuilder.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
@@ -160,6 +164,28 @@ cl::opt<bool> SpeculativeCounterPromotionToLoop(
              " update can be further/iteratively promoted into an acyclic "
              " region."));
 
+static cl::opt<unsigned> OffloadProfilingThreadBitWidth(
+    "offload-profiling-thread-bitwidth",
+    cl::desc("Bit width that encodes the number of profiling threads on the "
+             "offload device.  The actual thread count used is "
+             "(1 << bitwidth) - 1.  Supported for AMDGPU only."),
+    cl::init(8));
+
+enum class OffloadPGOSamplingMode {
+  PatternOverflow, // sampling by pattern, overflow slot, non-atomic store
+  AtomicWarpLeader // no sampling; warp leader uses atomicrmw add 1
+};
+
+static llvm::cl::opt<OffloadPGOSamplingMode> OffloadPGOSampling(
+    "offload-pgo-sampling-mode", llvm::cl::desc("Offload PGO sampling mode"),
+    llvm::cl::values(
+        clEnumValN(OffloadPGOSamplingMode::PatternOverflow, "pattern-overflow",
+                   "Use sampling pattern and overflow slot (default)"),
+        clEnumValN(
+            OffloadPGOSamplingMode::AtomicWarpLeader, "atomic-warp-leader",
+            "Leader lane only; atomic increment per slot; no overflow slot")),
+    llvm::cl::init(OffloadPGOSamplingMode::AtomicWarpLeader));
+
 cl::opt<bool> IterativeCounterPromotion(
     "iterative-counter-promotion", cl::init(true),
     cl::desc("Allow counter promotion across the whole loop nest."));
@@ -242,6 +268,20 @@ static bool profDataReferencedByCode(const Module &M) {
   return enablesValueProfiling(M);
 }
 
+// Extract CUID (Compilation Unit ID) from the module.
+// HIP/CUDA modules have a global variable __hip_cuid_<hash> that uniquely
+// identifies each translation unit. Returns empty string if not found.
+static std::string getCUIDFromModule(const Module &M) {
+  for (const GlobalVariable &GV : M.globals()) {
+    StringRef Name = GV.getName();
+    if (Name.starts_with("__hip_cuid_")) {
+      // Extract the hash suffix after "__hip_cuid_"
+      return Name.drop_front(strlen("__hip_cuid_")).str();
+    }
+  }
+  return "";
+}
+
 class InstrLowerer final {
 public:
   InstrLowerer(Module &M, const InstrProfOptions &Options,
@@ -266,7 +306,8 @@ class InstrLowerer final {
   struct PerFunctionProfileData {
     uint32_t NumValueSites[IPVK_Last + 1] = {};
     GlobalVariable *RegionCounters = nullptr;
-    GlobalVariable *DataVar = nullptr;
+    GlobalVariable *UniformCounters = nullptr; // For AMDGPU divergence tracking
+    GlobalValue *DataVar = nullptr;
     GlobalVariable *RegionBitmaps = nullptr;
     uint32_t NumBitmapBytes = 0;
 
@@ -288,6 +329,24 @@ class InstrLowerer final {
   GlobalVariable *NamesVar = nullptr;
   size_t NamesSize = 0;
 
+  // For GPU targets: per-TU contiguous allocation of profile data.
+  // Instead of separate per-function counters (which linker can reorder),
+  // we allocate one contiguous array for all counters in the TU.
+  GlobalVariable *ContiguousCnts = nullptr; // All counters in one array
+  GlobalVariable *ContiguousData =
+      nullptr; // All __llvm_profile_data in one array
+  GlobalVariable *ContiguousUCnts =
+      nullptr; // All uniform counters in one array
+  StructType *ProfileDataTy = nullptr;
+  SmallVector<Constant *, 16> ContiguousDataInits;
+  std::string CachedCUID; // CUID cached for consistent section naming
+
+  // Map from function name GlobalVariable to offset in contiguous arrays
+  DenseMap<GlobalVariable *, uint64_t> FunctionCounterOffsets;
+  DenseMap<GlobalVariable *, uint64_t> FunctionDataOffsets;
+  uint64_t TotalCounterSlots = 0; // Total slots across all functions
+  uint64_t TotalDataEntries = 0;  // Total __llvm_profile_data entries
+
   // vector of counter load/store pairs to be register promoted.
   std::vector<LoadStorePair> PromotionCandidates;
 
@@ -325,6 +384,9 @@ class InstrLowerer final {
   /// Replace instrprof.increment with an increment of the appropriate value.
   void lowerIncrement(InstrProfIncrementInst *Inc);
 
+  /// AMDGPU specific implementation of lowerIncrement.
+  void lowerIncrementAMDGPU(InstrProfIncrementInst *Inc);
+
   /// Force emitting of name vars for unused functions.
   void lowerCoverageData(GlobalVariable *CoverageNamesVar);
 
@@ -349,6 +411,10 @@ class InstrLowerer final {
   /// referring to them will also be created.
   GlobalVariable *getOrCreateRegionCounters(InstrProfCntrInstBase *Inc);
 
+  /// Get the uniform entry counters for AMDGPU divergence tracking.
+  /// These counters track how often blocks are entered with all lanes active.
+  GlobalVariable *getOrCreateUniformCounters(InstrProfCntrInstBase *Inc);
+
   /// Create the region counters.
   GlobalVariable *createRegionCounters(InstrProfCntrInstBase *Inc,
                                        StringRef Name,
@@ -408,6 +474,30 @@ class InstrLowerer final {
   /// Create a static initializer for our data, on platforms that need it,
   /// and for any profile output file that was specified.
   void emitInitialization();
+
+  /// For GPU targets: Collect all profiling intrinsics and allocate
+  /// contiguous arrays for counters, data, and uniform counters.
+  /// This avoids linker reordering issues with section boundaries.
+  void allocateContiguousProfileArrays();
+
+  /// Return the __llvm_profile_data struct type.
+  StructType *getProfileDataTy();
+
+  /// Finalize initializer for contiguous __llvm_profile_data array.
+  void finalizeContiguousProfileData();
+
+  /// Create __llvm_offload_prf structure for GPU targets.
+  /// Must be called AFTER contiguous arrays are allocated.
+  void createProfileSectionSymbols();
+
+  /// Create HIP device variable registration for profile symbols
+  void createHIPDeviceVariableRegistration();
+
+  /// Create HIP dynamic module registration call
+  void createHIPDynamicModuleRegistration();
+
+  /// Create HIP dynamic module unregistration call
+  void createHIPDynamicModuleUnregistration();
 };
 
 ///
@@ -939,6 +1029,10 @@ bool InstrLowerer::lower() {
   if (!ContainsProfiling && !CoverageNamesVar)
     return MadeChange;
 
+  // For GPU targets: allocate contiguous arrays for all profile data.
+  // This avoids linker reordering issues with per-function arrays.
+  allocateContiguousProfileArrays();
+
   // We did not know how many value sites there would be inside
   // the instrumented function. This is counting the number of instrumented
   // target value sites to enter it as field in the profile data variable.
@@ -983,10 +1077,22 @@ bool InstrLowerer::lower() {
   if (!MadeChange)
     return false;
 
+  finalizeContiguousProfileData();
+
   emitVNodes();
   emitNameData();
   emitVTableNames();
 
+  // Create start/stop symbols for device code profile sections
+  createProfileSectionSymbols();
+
+  // Create host shadow variables and registration calls for HIP device profile
+  // symbols
+  createHIPDeviceVariableRegistration();
+
+  createHIPDynamicModuleRegistration();
+  createHIPDynamicModuleUnregistration();
+
   // Emit runtime hook for the cases where the target does not unconditionally
   // require pulling in profile runtime, and coverage is enabled on code that is
   // not eliminated by the front-end, e.g. unused functions with internal
@@ -1046,7 +1152,7 @@ void InstrLowerer::lowerValueProfileInst(InstrProfValueProfileInst *Ind) {
   assert(It != ProfileDataMap.end() && It->second.DataVar &&
          "value profiling detected in function with no counter increment");
 
-  GlobalVariable *DataVar = It->second.DataVar;
+  GlobalValue *DataVar = It->second.DataVar;
   uint64_t ValueKind = Ind->getValueKind()->getZExtValue();
   uint64_t Index = Ind->getIndex()->getZExtValue();
   for (uint32_t Kind = IPVK_First; Kind < ValueKind; ++Kind)
@@ -1058,7 +1164,7 @@ void InstrLowerer::lowerValueProfileInst(InstrProfValueProfileInst *Ind) {
   CallInst *Call = nullptr;
   auto *TLI = &GetTLI(*Ind->getFunction());
   auto *NormalizedDataVarPtr = ConstantExpr::getPointerBitCastOrAddrSpaceCast(
-      DataVar, PointerType::get(M.getContext(), 0));
+      cast<Constant>(DataVar), PointerType::get(M.getContext(), 0));
 
   // To support value profiling calls within Windows exception handlers, funclet
   // information contained within operand bundles needs to be copied over to
@@ -1108,6 +1214,9 @@ GlobalVariable *InstrLowerer::getOrCreateBiasVar(StringRef VarName) {
 }
 
 Value *InstrLowerer::getCounterAddress(InstrProfCntrInstBase *I) {
+  // Note: For AMDGPU targets, lowerIncrementAMDGPU handles counter addressing
+  // directly using ContiguousCnts. This function is called for non-AMDGPU
+  // targets.
   auto *Counters = getOrCreateRegionCounters(I);
   IRBuilder<> Builder(I);
 
@@ -1190,6 +1299,10 @@ void InstrLowerer::lowerTimestamp(
 }
 
 void InstrLowerer::lowerIncrement(InstrProfIncrementInst *Inc) {
+  if (TT.isAMDGPU()) {
+    lowerIncrementAMDGPU(Inc);
+    return;
+  }
   auto *Addr = getCounterAddress(Inc);
 
   IRBuilder<> Builder(Inc);
@@ -1208,6 +1321,349 @@ void InstrLowerer::lowerIncrement(InstrProfIncrementInst *Inc) {
   Inc->eraseFromParent();
 }
 
+// Lowers an InstrProfIncrementInst for AMDGPU to per-wave aggregated counter
+// updates. It computes a "slot" index based on block and warp-local indices,
+// elects a leader lane, and increments a counter by (Inc->getStep() *
+// number_of_active_lanes) to reflect that only one lane performs the update on
+// behalf of the whole wave.
+//
+// Assumptions:
+// - AMDGPU Wave32 (32 lanes): uses ballot.i32, mbcnt.lo with a full mask, and
+// lane = mbcnt & 31.
+// - OffloadProfilingThreadBitWidth (KSlotBits) >= 5; kWarpBits is 5 for Wave32.
+// - Two modes:
+//   - PatternOverflow: performs a non-atomic RMW, routes to an overflow slot
+//   based on sampling.
+//   - AtomicWarpLeader: only the elected leader performs an atomic add.
+// - Inc->getStep() is an LLVM integer-typed Value (often a constant 1), and may
+// not equal 1.
+// - The increment amount in both modes is Inc->getStep() *
+// popcount(activeMask).
+void InstrLowerer::lowerIncrementAMDGPU(InstrProfIncrementInst *Inc) {
+  IRBuilder<> Builder(Inc);
+  LLVMContext &Context = M.getContext();
+  auto *Int1Ty = Type::getInt1Ty(Context);
+  auto *Int8Ty = Type::getInt8Ty(Context);
+  auto *Int16Ty = Type::getInt16Ty(Context);
+  auto *Int32Ty = Type::getInt32Ty(Context);
+  auto *Int64Ty = Type::getInt64Ty(Context);
+
+  // Constants/configuration
+  const unsigned KSlotBits =
+      OffloadProfilingThreadBitWidth; // must be >= 5 (Wave32)
+  const unsigned KSlots = 1u << KSlotBits;
+  const unsigned KOverflow = KSlots - 1u; // only used in PatternOverflow mode
+  const unsigned KPattern14 = 0x2A3Fu;    // only used in PatternOverflow mode
+  const unsigned kWarpBits = 5u;          // Wave32 lane width
+
+  if (KSlotBits < kWarpBits)
+    report_fatal_error(
+        "OffloadProfilingThreadBitWidth must be >= 5 for wave32");
+
+  // --- Get thread and block identifiers ---
+  FunctionCallee BlockIdxFn =
+      M.getOrInsertFunction("llvm.amdgcn.workgroup.id.x", Int32Ty);
+  Value *BlockIdx = Builder.CreateCall(BlockIdxFn, {}, "BlockIdxX");
+
+  FunctionCallee ThreadIdxFn =
+      M.getOrInsertFunction("llvm.amdgcn.workitem.id.x", Int32Ty);
+  Value *ThreadIdx = Builder.CreateCall(ThreadIdxFn, {}, "ThreadIdxX");
+
+  // --- Get launch-time data from implicit arguments ---
+  FunctionCallee ImplicitArgFn = M.getOrInsertFunction(
+      "llvm.amdgcn.implicitarg.ptr", PointerType::get(Context, 4));
+  Value *ImplicitArgPtr = Builder.CreateCall(ImplicitArgFn, {});
+
+  // gridDim.x (i32) at base
+  Value *GridDimX = Builder.CreateLoad(Int32Ty, ImplicitArgPtr, "GridDimX");
+
+  // blockDim.x (i16) at offset 12
+  Value *BlockDimXAddr = Builder.CreateInBoundsGEP(
+      Int8Ty, ImplicitArgPtr, ConstantInt::get(Int64Ty, 12), "BlockDimXAddr");
+  Value *BlockDimX = Builder.CreateLoad(Int16Ty, BlockDimXAddr, "BlockDimX");
+
+  // --- Optional: 64-bit gid (not used by slot calc, but useful to keep) ---
+  Value *BlockIdx64 = Builder.CreateZExt(BlockIdx, Int64Ty, "BlockIdxX.zext");
+  Value *ThreadIdx64 =
+      Builder.CreateZExt(ThreadIdx, Int64Ty, "ThreadIdxX.zext");
+  Value *BlockDimX64 = Builder.CreateZExt(BlockDimX, Int64Ty, "BlockDimX.zext");
+  Value *Gid = Builder.CreateAdd(Builder.CreateMul(BlockIdx64, BlockDimX64),
+                                 ThreadIdx64, "Gid");
+  (void)Gid;
+
+  // ----------------------------
+  // Common slot computation (Wave32)
+  // ----------------------------
+
+  // lane id via amdgcn.mbcnt.lo (count active lanes below me); lane = & 31
+  auto *MbcntLoTy = FunctionType::get(Int32Ty, {Int32Ty, Int32Ty}, false);
+  FunctionCallee MbcntLoFnByName =
+      M.getOrInsertFunction("llvm.amdgcn.mbcnt.lo", MbcntLoTy);
+  Value *MbcntLo = Builder.CreateCall(
+      MbcntLoFnByName,
+      {ConstantInt::getSigned(Int32Ty, -1), ConstantInt::get(Int32Ty, 0)},
+      "mbcnt.lo");
+  Value *Lane = Builder.CreateAnd(MbcntLo, 31, "lane");
+
+  // warpLocal = threadIdx.x >> 5
+  Value *WarpLocal = Builder.CreateLShr(ThreadIdx, kWarpBits, "warpLocal");
+
+  // blockBits = (gridDim.x > 1) ? (32 - ctlz(gridDim.x - 1)) : 1
+  Value *GridGt1 = Builder.CreateICmpUGT(GridDimX, ConstantInt::get(Int32Ty, 1),
+                                         "grid_gt_1");
+  Value *GridDimXMinus1 = Builder.CreateSub(
+      GridDimX, ConstantInt::get(Int32Ty, 1), "gridDimX_minus_1");
+  FunctionCallee CtlzI32Fn =
+      Intrinsic::getOrInsertDeclaration(&M, Intrinsic::ctlz, {Int32Ty});
+  Value *CtlzVal = Builder.CreateCall(
+      CtlzI32Fn, {GridDimXMinus1, Builder.getFalse()}, "ctlz_gridDimX_minus_1");
+  Value *BlockBitsCandidate = Builder.CreateSub(ConstantInt::get(Int32Ty, 32),
+                                                CtlzVal, "blockBits_cand");
+  Value *BlockBits = Builder.CreateSelect(
+      GridGt1, BlockBitsCandidate, ConstantInt::get(Int32Ty, 1), "blockBits");
+
+  // usedForHi = min(blockBits, KSlotBits - kWarpBits)
+  Value *SlotHiBits = ConstantInt::get(Int32Ty, (int)(KSlotBits - kWarpBits));
+  Value *BlockLtSlotHi = Builder.CreateICmpULT(BlockBits, SlotHiBits);
+  Value *UsedForHi =
+      Builder.CreateSelect(BlockLtSlotHi, BlockBits, SlotHiBits, "usedForHi");
+
+  // sampBits = blockBits - usedForHi
+  Value *SampBits = Builder.CreateSub(BlockBits, UsedForHi, "sampBits");
+  Value *SampBitsIsZero = Builder.CreateIsNull(SampBits, "sampBits_is_zero");
+
+  // blockHi = (sampBits == 0) ? blockIdx.x : (blockIdx.x >> sampBits)
+  Value *BlockHiShifted =
+      Builder.CreateLShr(BlockIdx, SampBits, "blockHi_shifted");
+  Value *BlockHi =
+      Builder.CreateSelect(SampBitsIsZero, BlockIdx, BlockHiShifted, "blockHi");
+
+  // slotRaw = (blockHi << 5) | warpLocal
+  Value *SlotRawUpper = Builder.CreateShl(BlockHi, kWarpBits, "slotRaw_upper");
+  Value *SlotRaw = Builder.CreateOr(SlotRawUpper, WarpLocal, "slotRaw");
+
+  // Find warp leader using ballot.i32 + cttz
+  auto *BallotTy = FunctionType::get(Int32Ty, {Int1Ty}, false);
+  FunctionCallee BallotI32ByName =
+      M.getOrInsertFunction("llvm.amdgcn.ballot.i32", BallotTy);
+  Value *ActiveMask = Builder.CreateCall(
+      BallotI32ByName, {ConstantInt::getTrue(Context)}, "activeMask");
+
+  FunctionCallee CttzI32Fn =
+      Intrinsic::getOrInsertDeclaration(&M, Intrinsic::cttz, {Int32Ty});
+  Value *ActiveMaskNonZero =
+      Builder.CreateICmpNE(ActiveMask, ConstantInt::get(Int32Ty, 0), "mask_nz");
+  Value *LeaderLane = Builder.CreateCall(
+      CttzI32Fn, {ActiveMask, ConstantInt::getTrue(Context)}, "leaderLane");
+  Value *IsLeader = Builder.CreateICmpEQ(Lane, LeaderLane, "isLeader");
+  Value *IsLeaderGuarded =
+      Builder.CreateSelect(ActiveMaskNonZero, IsLeader,
+                           ConstantInt::getFalse(Context), "isLeader_guarded");
+
+  // Compute number of active lanes and step * active lanes
+  FunctionCallee CtpopI32Fn =
+      Intrinsic::getOrInsertDeclaration(&M, Intrinsic::ctpop, {Int32Ty});
+  Value *NumActive = Builder.CreateCall(CtpopI32Fn, {ActiveMask}, "numActive");
+
+  Value *IncStep = Inc->getStep(); // integer-typed Value (often i64)
+  Value *NumActiveCast = Builder.CreateZExtOrTrunc(
+      NumActive, IncStep->getType(), "numActive.cast");
+  Value *StepTimesActive =
+      Builder.CreateMul(IncStep, NumActiveCast, "step_times_active");
+
+  // Check if all lanes are active (uniform execution for wave32)
+  // A full wave has ActiveMask == 0xFFFFFFFF. Partial waves (last wave of
+  // workgroup) will be conservatively marked as divergent.
+  Value *FullWaveMask =
+      ConstantInt::getSigned(Int32Ty, -1); // 0xFFFFFFFF for wave32
+  Value *IsUniform =
+      Builder.CreateICmpEQ(ActiveMask, FullWaveMask, "isUniform");
+
+  // ----------------------------
+  // Mode-dependent writer logic
+  // ----------------------------
+
+  Value *Slot = nullptr;
+  Value *IsWriter = nullptr;
+
+  if (OffloadPGOSampling == OffloadPGOSamplingMode::PatternOverflow) {
+    // Sampling mask/pattern over low sampBits of blockIdx.x
+    Value *One32 = ConstantInt::get(Int32Ty, 1);
+    Value *SampMaskShift =
+        Builder.CreateShl(One32, SampBits, "sampMask_shift"); // 1<<sampBits
+    Value *SampMaskMinus1 =
+        Builder.CreateSub(SampMaskShift, One32, "sampMask_minus1");
+    Value *SampMask =
+        Builder.CreateSelect(SampBitsIsZero, ConstantInt::get(Int32Ty, 0),
+                             SampMaskMinus1, "sampMask");
+
+    // sampPat = KPattern14 & sampMask
+    Value *SampPat = Builder.CreateAnd(ConstantInt::get(Int32Ty, KPattern14),
+                                       SampMask, "sampPat");
+
+    // matched = (sampBits == 0) ? true : ((blockIdx.x & sampMask) == sampPat)
+    Value *BlockMasked = Builder.CreateAnd(BlockIdx, SampMask, "blockMasked");
+    Value *CmpMaskPat =
+        Builder.CreateICmpEQ(BlockMasked, SampPat, "cmp_mask_pat");
+    Value *Matched = Builder.CreateSelect(
+        SampBitsIsZero, ConstantInt::getTrue(Context), CmpMaskPat, "matched");
+
+    // Only leader writes when matched
+    IsWriter = Builder.CreateAnd(IsLeaderGuarded, Matched, "isWriter");
+
+    // Route to overflow if not writer or slotRaw == KOverflow
+    Value *SlotRawIsOverflow = Builder.CreateICmpEQ(
+        SlotRaw, ConstantInt::get(Int32Ty, KOverflow), "slot_is_overflow");
+    Value *GoodWriter = Builder.CreateAnd(
+        IsWriter, Builder.CreateNot(SlotRawIsOverflow), "goodWriter");
+    Slot = Builder.CreateSelect(GoodWriter, SlotRaw,
+                                ConstantInt::get(Int32Ty, KOverflow), "Slot");
+  } else {
+    // AtomicWarpLeader: no sampling, no overflow. Only the leader writes
+    // atomically.
+    IsWriter = IsLeaderGuarded;
+    Slot = SlotRaw;
+  }
+
+  // --- Calculate final counter index ---
+  auto *OldCounterIdx = Inc->getIndex();
+  auto *NumSlots = Builder.getInt32(KSlots);
+  auto *CounterIdxBase = Builder.CreateMul(OldCounterIdx, NumSlots);
+  auto *CounterIdx = Builder.CreateAdd(CounterIdxBase, Slot, "CounterIdx");
+
+  // --- Counter address ---
+  // For contiguous allocation, use the contiguous array with function offset
+  GlobalVariable *Counters = nullptr;
+  GlobalVariable *UniformCounters = nullptr;
+  Value *Addr = nullptr;
+  Value *UniformAddr = nullptr;
+
+  if (ContiguousCnts) {
+    // Contiguous allocation mode: use offset into shared array
+    GlobalVariable *NamePtr = Inc->getName();
+    uint64_t FuncOffset = FunctionCounterOffsets.lookup(NamePtr);
+
+    // Add function offset to counter index
+    Value *OffsetCounterIdx = Builder.CreateAdd(
+        CounterIdx, Builder.getInt32(FuncOffset), "OffsetCounterIdx");
+
+    Counters = ContiguousCnts;
+    Value *Indices[] = {Builder.getInt32(0), OffsetCounterIdx};
+    Addr = Builder.CreateInBoundsGEP(Counters->getValueType(), Counters,
+                                     Indices, "ctr.addr");
+
+    // Uniform counters also use contiguous array
+    if (ContiguousUCnts) {
+      UniformCounters = ContiguousUCnts;
+      Value *UniformIndices[] = {Builder.getInt32(0), OffsetCounterIdx};
+      UniformAddr = Builder.CreateInBoundsGEP(UniformCounters->getValueType(),
+                                              UniformCounters, UniformIndices,
+                                              "unifctr.addr");
+    }
+  } else {
+    // Per-function allocation mode (non-GPU or fallback)
+    Counters = getOrCreateRegionCounters(Inc);
+    Value *Indices[] = {Builder.getInt32(0), CounterIdx};
+    Addr = Builder.CreateInBoundsGEP(Counters->getValueType(), Counters,
+                                     Indices, "ctr.addr");
+
+    // Uniform counter address (for divergence tracking)
+    UniformCounters = getOrCreateUniformCounters(Inc);
+    if (UniformCounters) {
+      Value *UniformIndices[] = {Builder.getInt32(0), CounterIdx};
+      UniformAddr = Builder.CreateInBoundsGEP(UniformCounters->getValueType(),
+                                              UniformCounters, UniformIndices,
+                                              "unifctr.addr");
+    }
+  }
+
+  // --- Increment ---
+  if (OffloadPGOSampling == OffloadPGOSamplingMode::PatternOverflow) {
+    // Non-atomic increment by (Inc->getStep() * numActive) (legacy mode)
+    Type *CounterTy =
+        cast<ArrayType>(Counters->getValueType())->getElementType();
+    Value *Load = Builder.CreateLoad(CounterTy, Addr, "pgocount");
+    Value *ProdToCounterTy = Builder.CreateZExtOrTrunc(
+        StepTimesActive, CounterTy, "step_times_active.cast");
+    auto *Count = Builder.CreateAdd(Load, ProdToCounterTy, "pgocount.next");
+    Builder.CreateStore(Count, Addr);
+
+    // Also update uniform counter if uniform
+    if (UniformAddr) {
+      Value *UniformLoad =
+          Builder.CreateLoad(CounterTy, UniformAddr, "unifcount");
+      // Only add to uniform counter if IsUniform is true
+      Value *UniformIncr =
+          Builder.CreateSelect(IsUniform, ProdToCounterTy,
+                               ConstantInt::get(CounterTy, 0), "unifincr");
+      auto *UniformCount =
+          Builder.CreateAdd(UniformLoad, UniformIncr, "unifcount.next");
+      Builder.CreateStore(UniformCount, UniformAddr);
+    }
+  } else {
+    // AtomicWarpLeader: only the leader performs atomicrmw add (step *
+    // numActive) Correct control-flow: split block at Inc, create ThenBB, and
+    // conditional branch.
+
+    // 1) Split the current block before Inc. The split inserts an unconditional
+    //    branch from CurBB to ContBB; we'll replace it with a conditional
+    //    branch.
+    BasicBlock *CurBB = Builder.GetInsertBlock();
+    Function *F = CurBB->getParent();
+    BasicBlock *ContBB =
+        CurBB->splitBasicBlock(BasicBlock::iterator(Inc), "atomic_cont");
+
+    // After split, CurBB ends with "br label %atomic_cont".
+    // 2) Create the ThenBB (atomic path).
+    BasicBlock *ThenBB = BasicBlock::Create(Context, "atomic_then", F);
+
+    // 3) Replace the terminator in CurBB with a conditional branch to ThenBB or
+    // ContBB.
+    Instruction *OldTerm =
+        CurBB->getTerminator(); // unconditional branch inserted by split
+    OldTerm->eraseFromParent();
+    IRBuilder<> HeadBuilder(CurBB);
+    HeadBuilder.CreateCondBr(IsWriter, ThenBB, ContBB);
+
+    // 4) Emit the atomicrmw in ThenBB, then branch to ContBB.
+    IRBuilder<> ThenBuilder(ThenBB);
+    Type *CounterTy =
+        cast<ArrayType>(Counters->getValueType())->getElementType();
+    Value *ProdToCounterTy = ThenBuilder.CreateZExtOrTrunc(
+        StepTimesActive, CounterTy, "step_times_active.cast");
+    ThenBuilder.CreateAtomicRMW(AtomicRMWInst::Add, Addr, ProdToCounterTy,
+                                MaybeAlign(Align(8)),
+                                AtomicOrdering::Monotonic);
+
+    // Also update uniform counter if uniform (inside the ThenBB, so leader does
+    // it)
+    if (UniformAddr) {
+      // Create a nested conditional: only update uniform counter if IsUniform
+      BasicBlock *UniformBB = BasicBlock::Create(Context, "uniform_then", F);
+      BasicBlock *AfterUniformBB =
+          BasicBlock::Create(Context, "uniform_cont", F);
+
+      ThenBuilder.CreateCondBr(IsUniform, UniformBB, AfterUniformBB);
+
+      IRBuilder<> UniformBuilder(UniformBB);
+      UniformBuilder.CreateAtomicRMW(AtomicRMWInst::Add, UniformAddr,
+                                     ProdToCounterTy, MaybeAlign(Align(8)),
+                                     AtomicOrdering::Monotonic);
+      UniformBuilder.CreateBr(AfterUniformBB);
+
+      IRBuilder<> AfterUniformBuilder(AfterUniformBB);
+      AfterUniformBuilder.CreateBr(ContBB);
+    } else {
+      ThenBuilder.CreateBr(ContBB);
+    }
+
+    // 5) Continue in the continuation block and erase the original Inc.
+    Builder.SetInsertPoint(ContBB, ContBB->begin());
+  }
+
+  Inc->eraseFromParent();
+}
+
 void InstrLowerer::lowerCoverageData(GlobalVariable *CoverageNamesVar) {
   ConstantArray *Names =
       cast<ConstantArray>(CoverageNamesVar->getInitializer());
@@ -1611,7 +2067,15 @@ GlobalVariable *InstrLowerer::setupProfileSection(InstrProfInstBase *Inc,
   Ptr->setVisibility(Visibility);
   // Put the counters and bitmaps in their own sections so linkers can
   // remove unneeded sections.
-  Ptr->setSection(getInstrProfSectionName(IPSK, TT.getObjectFormat()));
+  // For GPU targets, use per-TU sections with CUID suffix for proper
+  // memory tracking via anchor variable registration.
+  std::string SectionName = getInstrProfSectionName(IPSK, TT.getObjectFormat());
+  if (isGPUProfTarget(M)) {
+    std::string CUID = getCUIDFromModule(M);
+    if (!CUID.empty())
+      SectionName = SectionName + "_" + CUID;
+  }
+  Ptr->setSection(SectionName);
   Ptr->setLinkage(Linkage);
   maybeSetComdat(Ptr, Fn, VarName);
   return Ptr;
@@ -1647,7 +2111,12 @@ InstrLowerer::getOrCreateRegionBitmaps(InstrProfMCDCBitmapInstBase *Inc) {
 GlobalVariable *
 InstrLowerer::createRegionCounters(InstrProfCntrInstBase *Inc, StringRef Name,
                                    GlobalValue::LinkageTypes Linkage) {
+  const unsigned OffloadNumProfilingThreads =
+      (1u << OffloadProfilingThreadBitWidth) - 1;
+
   uint64_t NumCounters = Inc->getNumCounters()->getZExtValue();
+  if (TT.isAMDGPU())
+    NumCounters *= (OffloadNumProfilingThreads + 1);
   auto &Ctx = M.getContext();
   GlobalVariable *GV;
   if (isa<InstrProfCoverInst>(Inc)) {
@@ -1676,6 +2145,18 @@ InstrLowerer::getOrCreateRegionCounters(InstrProfCntrInstBase *Inc) {
   if (PD.RegionCounters)
     return PD.RegionCounters;
 
+  // For GPU targets with contiguous allocation, use the contiguous array
+  // instead of creating a per-function array
+  if (ContiguousCnts) {
+    // Store the contiguous array as RegionCounters for this function
+    // The actual offset is handled in lowerIncrementAMDGPU
+    PD.RegionCounters = ContiguousCnts;
+
+    // Still create the data variable (it will point to the right offset)
+    createDataVariable(Inc);
+    return PD.RegionCounters;
+  }
+
   // If RegionCounters doesn't already exist, create it by first setting up
   // the corresponding profile section.
   auto *CounterPtr = setupProfileSection(Inc, IPSK_cnts);
@@ -1723,6 +2204,59 @@ InstrLowerer::getOrCreateRegionCounters(InstrProfCntrInstBase *Inc) {
   return PD.RegionCounters;
 }
 
+GlobalVariable *
+InstrLowerer::getOrCreateUniformCounters(InstrProfCntrInstBase *Inc) {
+  // Only create uniform counters for AMDGPU targets
+  if (!TT.isAMDGPU())
+    return nullptr;
+
+  GlobalVariable *NamePtr = Inc->getName();
+  auto &PD = ProfileDataMap[NamePtr];
+  if (PD.UniformCounters)
+    return PD.UniformCounters;
+
+  // For contiguous allocation, use the contiguous uniform counter array
+  if (ContiguousUCnts) {
+    PD.UniformCounters = ContiguousUCnts;
+    return PD.UniformCounters;
+  }
+
+  // Ensure RegionCounters exists first (we need the same size)
+  getOrCreateRegionCounters(Inc);
+
+  // Create uniform counters with the same size as region counters
+  const unsigned OffloadNumProfilingThreads =
+      (1u << OffloadProfilingThreadBitWidth) - 1;
+
+  uint64_t NumCounters = Inc->getNumCounters()->getZExtValue();
+  NumCounters *= (OffloadNumProfilingThreads + 1);
+
+  auto &Ctx = M.getContext();
+  auto *CounterTy = ArrayType::get(Type::getInt64Ty(Ctx), NumCounters);
+
+  // Use a different prefix for uniform counters
+  bool Renamed;
+  std::string VarName = getVarName(Inc, "__llvm_prf_unifcnt_", Renamed);
+
+  auto *GV = new GlobalVariable(M, CounterTy, false, NamePtr->getLinkage(),
+                                Constant::getNullValue(CounterTy), VarName);
+  GV->setAlignment(Align(8));
+  GV->setVisibility(NamePtr->getVisibility());
+
+  // For GPU targets, use per-TU sections with CUID suffix
+  std::string SectionName =
+      getInstrProfSectionName(IPSK_ucnts, TT.getObjectFormat());
+  std::string CUID = getCUIDFromModule(M);
+  if (!CUID.empty())
+    SectionName = SectionName + "_" + CUID;
+  GV->setSection(SectionName);
+
+  PD.UniformCounters = GV;
+  CompilerUsedVars.push_back(GV);
+
+  return PD.UniformCounters;
+}
+
 void InstrLowerer::createDataVariable(InstrProfCntrInstBase *Inc) {
   // When debug information is correlated to profile data, a data variable
   // is not needed.
@@ -1784,8 +2318,25 @@ void InstrLowerer::createDataVariable(InstrProfCntrInstBase *Inc) {
         ValuesVar, PointerType::get(Fn->getContext(), 0));
   }
 
+  // NumCounters in __llvm_profile_data is the ORIGINAL counter count,
+  // not the expanded count with slots. The expansion factor is stored
+  // separately in NumOffloadProfilingThreads.
   uint64_t NumCounters = Inc->getNumCounters()->getZExtValue();
-  auto *CounterPtr = PD.RegionCounters;
+
+  // For contiguous allocation, CounterPtr should point to this function's
+  // offset within the contiguous array
+  Constant *CounterPtr;
+  if (ContiguousCnts && PD.RegionCounters == ContiguousCnts) {
+    uint64_t FuncOffset = FunctionCounterOffsets.lookup(NamePtr);
+    // Create a GEP to the function's counter offset
+    CounterPtr = ConstantExpr::getInBoundsGetElementPtr(
+        ContiguousCnts->getValueType(), ContiguousCnts,
+        ArrayRef<Constant *>{
+            ConstantInt::get(Type::getInt64Ty(Ctx), 0),
+            ConstantInt::get(Type::getInt64Ty(Ctx), FuncOffset)});
+  } else {
+    CounterPtr = PD.RegionCounters;
+  }
 
   uint64_t NumBitmapBytes = PD.NumBitmapBytes;
 
@@ -1793,11 +2344,7 @@ void InstrLowerer::createDataVariable(InstrProfCntrInstBase *Inc) {
   auto *IntPtrTy = M.getDataLayout().getIntPtrType(M.getContext());
   auto *Int16Ty = Type::getInt16Ty(Ctx);
   auto *Int16ArrayTy = ArrayType::get(Int16Ty, IPVK_Last + 1);
-  Type *DataTypes[] = {
-#define INSTR_PROF_DATA(Type, LLVMType, Name, Init) LLVMType,
-#include "llvm/ProfileData/InstrProfData.inc"
-  };
-  auto *DataTy = StructType::get(Ctx, ArrayRef(DataTypes));
+  auto *DataTy = getProfileDataTy();
 
   Constant *FunctionAddr = getFuncAddrForProfData(Fn);
 
@@ -1805,6 +2352,10 @@ void InstrLowerer::createDataVariable(InstrProfCntrInstBase *Inc) {
   for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
     Int16ArrayVals[Kind] = ConstantInt::get(Int16Ty, PD.NumValueSites[Kind]);
 
+  uint16_t NumOffloadProfilingThreadsVal = 0;
+  if (TT.isAMDGPU())
+    NumOffloadProfilingThreadsVal = (1u << OffloadProfilingThreadBitWidth) - 1;
+
   if (isGPUProfTarget(M)) {
     Linkage = GlobalValue::ExternalLinkage;
     Visibility = GlobalValue::ProtectedVisibility;
@@ -1826,8 +2377,25 @@ void InstrLowerer::createDataVariable(InstrProfCntrInstBase *Inc) {
     Linkage = GlobalValue::PrivateLinkage;
     Visibility = GlobalValue::DefaultVisibility;
   }
-  auto *Data =
-      new GlobalVariable(M, DataTy, false, Linkage, nullptr, DataVarName);
+  GlobalValue *DataVar = nullptr;
+  Constant *DataAddr = nullptr;
+  uint64_t DataIndex = 0;
+  if (ContiguousData) {
+    DataIndex = FunctionDataOffsets.lookup(NamePtr);
+    assert(DataIndex < ContiguousDataInits.size() &&
+           "missing contiguous data slot");
+    DataAddr = ConstantExpr::getInBoundsGetElementPtr(
+        ContiguousData->getValueType(), ContiguousData,
+        ArrayRef<Constant *>{
+            ConstantInt::get(Type::getInt64Ty(Ctx), 0),
+            ConstantInt::get(Type::getInt64Ty(Ctx), DataIndex)});
+  } else {
+    auto *Data =
+        new GlobalVariable(M, DataTy, false, Linkage, nullptr, DataVarName);
+    DataVar = Data;
+    DataAddr = Data;
+  }
+
   Constant *RelativeCounterPtr;
   GlobalVariable *BitmapPtr = PD.RegionBitmaps;
   Constant *RelativeBitmapPtr = ConstantInt::get(IntPtrTy, 0);
@@ -1845,29 +2413,48 @@ void InstrLowerer::createDataVariable(InstrProfCntrInstBase *Inc) {
     DataSectionKind = IPSK_data;
     RelativeCounterPtr =
         ConstantExpr::getSub(ConstantExpr::getPtrToInt(CounterPtr, IntPtrTy),
-                             ConstantExpr::getPtrToInt(Data, IntPtrTy));
+                             ConstantExpr::getPtrToInt(DataAddr, IntPtrTy));
     if (BitmapPtr != nullptr)
       RelativeBitmapPtr =
           ConstantExpr::getSub(ConstantExpr::getPtrToInt(BitmapPtr, IntPtrTy),
-                               ConstantExpr::getPtrToInt(Data, IntPtrTy));
+                               ConstantExpr::getPtrToInt(DataAddr, IntPtrTy));
   }
 
   Constant *DataVals[] = {
 #define INSTR_PROF_DATA(Type, LLVMType, Name, Init) Init,
 #include "llvm/ProfileData/InstrProfData.inc"
   };
-  Data->setInitializer(ConstantStruct::get(DataTy, DataVals));
-
-  Data->setVisibility(Visibility);
-  Data->setSection(
-      getInstrProfSectionName(DataSectionKind, TT.getObjectFormat()));
-  Data->setAlignment(Align(INSTR_PROF_DATA_ALIGNMENT));
-  maybeSetComdat(Data, Fn, CntsVarName);
+  auto *DataInit = ConstantStruct::get(DataTy, DataVals);
+
+  if (ContiguousData) {
+    ContiguousDataInits[DataIndex] = DataInit;
+    auto *Alias = GlobalAlias::create(
+        DataTy, DataAddr->getType()->getPointerAddressSpace(), Linkage,
+        DataVarName, DataAddr, &M);
+    Alias->setVisibility(Visibility);
+    DataVar = Alias;
+  } else {
+    auto *DataGV = cast<GlobalVariable>(DataVar);
+    DataGV->setInitializer(DataInit);
+
+    DataGV->setVisibility(Visibility);
+    // For GPU targets, use per-TU sections with CUID suffix
+    std::string DataSectionName =
+        getInstrProfSectionName(DataSectionKind, TT.getObjectFormat());
+    if (isGPUProfTarget(M)) {
+      std::string CUID = getCUIDFromModule(M);
+      if (!CUID.empty())
+        DataSectionName = DataSectionName + "_" + CUID;
+    }
+    DataGV->setSection(DataSectionName);
+    DataGV->setAlignment(Align(INSTR_PROF_DATA_ALIGNMENT));
+    maybeSetComdat(DataGV, Fn, CntsVarName);
+  }
 
-  PD.DataVar = Data;
+  PD.DataVar = DataVar;
 
   // Mark the data variable as used so that it isn't stripped out.
-  CompilerUsedVars.push_back(Data);
+  CompilerUsedVars.push_back(DataVar);
   // Now that the linkage set by the FE has been passed to the data and counter
   // variables, reset Name variable's linkage and visibility to private so that
   // it can be removed later by the compiler.
@@ -1927,6 +2514,104 @@ void InstrLowerer::emitVNodes() {
   UsedVars.push_back(VNodesVar);
 }
 
+void InstrLowerer::createHIPDynamicModuleRegistration() {
+  if (isGPUProfTarget(M))
+    return;
+  LLVM_DEBUG(llvm::dbgs() << "Entering createHIPDynamicModuleRegistration\n");
+  StringRef FuncNames[] = {"hipModuleLoad", "hipModuleLoadData",
+                           "hipModuleLoadDataEx"};
+  for (StringRef FuncName : FuncNames) {
+    Function *F = M.getFunction(FuncName);
+    if (!F)
+      continue;
+
+    for (User *U : F->users()) {
+      if (auto *CB = dyn_cast<CallBase>(U)) {
+        Instruction *InsertPt = nullptr;
+        // If the call is an invoke instruction, we should insert the
+        // registration call in the normal destination block.
+        if (auto *Invoke = dyn_cast<InvokeInst>(CB)) {
+          InsertPt = &*Invoke->getNormalDest()->getFirstInsertionPt();
+        } else if (CB->isTerminator()) {
+          // If it's another kind of terminator (e.g., callbr), we don't
+          // know the semantics of the successors, so we conservatively
+          // skip it. The hipModuleLoad* functions are not expected to be
+          // used in other terminator instructions.
+          continue;
+        } else {
+          // This is a normal call instruction, so we can insert after it.
+          InsertPt = CB->getNextNode();
+        }
+
+        // If there's no valid insertion point (e.g., a malformed block),
+        // skip.
+        if (!InsertPt)
+          continue;
+
+        IRBuilder<> Builder(InsertPt);
+        auto *VoidTy = Type::getVoidTy(M.getContext());
+        // The second argument to the registration function is the module
+        // handle, which is an out-parameter (hipModule_t*), so its type in the
+        // call is hipModule_t**.
+        auto *ModuleHandlePtrTy = PointerType::get(M.getContext(), 0);
+        auto *Int32Ty = Type::getInt32Ty(M.getContext());
+        auto *RegisterDynamicModuleTy =
+            FunctionType::get(VoidTy, {Int32Ty, ModuleHandlePtrTy}, false);
+        FunctionCallee RegisterFunc =
+            M.getOrInsertFunction("__llvm_profile_offload_register_dynamic_module",
+                                  RegisterDynamicModuleTy);
+
+        // The first argument to the registration function is the return value
+        // of the hipModuleLoad* call (hipError_t, which is i32).
+        Value *ReturnValue = CB;
+        // The second argument is the module handle itself, which is the first
+        // argument to the hipModuleLoad* call.
+        Value *ModuleHandle = CB->getArgOperand(0);
+
+        auto *Call =
+            Builder.CreateCall(RegisterFunc, {ReturnValue, ModuleHandle});
+        LLVM_DEBUG(llvm::dbgs() << "Register HIP module loaded by "; CB->dump();
+                   llvm::dbgs() << "BB:\n"; Call->getParent()->dump(););
+      }
+    }
+  }
+}
+
+void InstrLowerer::createHIPDynamicModuleUnregistration() {
+  LLVM_DEBUG(llvm::dbgs() << "Entering createHIPDynamicModuleUnregistration\n");
+  Function *F = M.getFunction("hipModuleUnload");
+  if (!F)
+    return;
+
+  for (User *U : F->users()) {
+    if (auto *CB = dyn_cast_or_null<CallBase>(U)) {
+      // The insertion point is right before the call to hipModuleUnload.
+      Instruction *InsertPt = CB;
+
+      IRBuilder<> Builder(InsertPt);
+      auto *VoidTy = Type::getVoidTy(M.getContext());
+      auto *VoidPtrTy = PointerType::getUnqual(M.getContext());
+
+      auto *UnregisterDynamicModuleTy =
+          FunctionType::get(VoidTy, {VoidPtrTy}, false);
+      FunctionCallee UnregisterFunc =
+          M.getOrInsertFunction("__llvm_profile_hip_unregister_dynamic_module",
+                                UnregisterDynamicModuleTy);
+
+      // The argument is the module handle, which is the first
+      // argument to the hipModuleUnload call.
+      Value *ModuleHandle = CB->getArgOperand(0);
+      Value *CastedModuleHandle =
+          Builder.CreatePointerCast(ModuleHandle, VoidPtrTy);
+
+      auto *Call = Builder.CreateCall(UnregisterFunc, {CastedModuleHandle});
+      LLVM_DEBUG(llvm::dbgs() << "Unregister HIP module unloaded by ";
+                 CB->dump(); llvm::dbgs() << "BB:\n";
+                 Call->getParent()->dump(););
+    }
+  }
+}
+
 void InstrLowerer::emitNameData() {
   if (ReferencedNames.empty())
     return;
@@ -1940,9 +2625,15 @@ void InstrLowerer::emitNameData() {
   auto &Ctx = M.getContext();
   auto *NamesVal =
       ConstantDataArray::getString(Ctx, StringRef(CompressedNameStr), false);
-  NamesVar = new GlobalVariable(M, NamesVal->getType(), true,
-                                GlobalValue::PrivateLinkage, NamesVal,
-                                getInstrProfNamesVarName());
+  std::string NamesVarName = std::string(getInstrProfNamesVarName());
+  if (isGPUProfTarget(M)) {
+    std::string CUID = CachedCUID.empty() ? getCUIDFromModule(M) : CachedCUID;
+    if (!CUID.empty())
+      NamesVarName = NamesVarName + "_" + CUID;
+  }
+  NamesVar =
+      new GlobalVariable(M, NamesVal->getType(), true,
+                         GlobalValue::PrivateLinkage, NamesVal, NamesVarName);
   if (isGPUProfTarget(M)) {
     NamesVar->setLinkage(GlobalValue::ExternalLinkage);
     NamesVar->setVisibility(GlobalValue::ProtectedVisibility);
@@ -1950,10 +2641,17 @@ void InstrLowerer::emitNameData() {
 
   NamesSize = CompressedNameStr.size();
   setGlobalVariableLargeSection(TT, *NamesVar);
-  NamesVar->setSection(
+  // For GPU targets, use per-TU sections with CUID suffix
+  std::string NamesSectionName =
       ProfileCorrelate == InstrProfCorrelator::BINARY
           ? getInstrProfSectionName(IPSK_covname, TT.getObjectFormat())
-          : getInstrProfSectionName(IPSK_name, TT.getObjectFormat()));
+          : getInstrProfSectionName(IPSK_name, TT.getObjectFormat());
+  if (isGPUProfTarget(M)) {
+    std::string CUID = getCUIDFromModule(M);
+    if (!CUID.empty())
+      NamesSectionName = NamesSectionName + "_" + CUID;
+  }
+  NamesVar->setSection(NamesSectionName);
   // On COFF, it's important to reduce the alignment down to 1 to prevent the
   // linker from inserting padding before the start of the names section or
   // between names entries.
@@ -2160,3 +2858,466 @@ void createProfileSamplingVar(Module &M) {
   appendToCompilerUsed(M, SamplingVar);
 }
 } // namespace llvm
+
+namespace {
+
+// For GPU targets: Allocate contiguous arrays for all profile data.
+// This solves the linker reordering problem by using ONE symbol per section
+// type, so there's nothing for the linker to reorder.
+StructType *InstrLowerer::getProfileDataTy() {
+  if (ProfileDataTy)
+    return ProfileDataTy;
+
+  auto &Ctx = M.getContext();
+  auto *IntPtrTy = M.getDataLayout().getIntPtrType(M.getContext());
+  auto *Int16Ty = Type::getInt16Ty(Ctx);
+  auto *Int16ArrayTy = ArrayType::get(Int16Ty, IPVK_Last + 1);
+  Type *DataTypes[] = {
+#define INSTR_PROF_DATA(Type, LLVMType, Name, Init) LLVMType,
+#include "llvm/ProfileData/InstrProfData.inc"
+  };
+  ProfileDataTy = StructType::get(Ctx, ArrayRef(DataTypes));
+  return ProfileDataTy;
+}
+
+void InstrLowerer::finalizeContiguousProfileData() {
+  if (!ContiguousData || ContiguousDataInits.empty())
+    return;
+
+  auto *DataTy = getProfileDataTy();
+  for (auto &Entry : ContiguousDataInits)
+    if (!Entry)
+      Entry = Constant::getNullValue(DataTy);
+
+  auto *DataArrayTy = cast<ArrayType>(ContiguousData->getValueType());
+  ContiguousData->setInitializer(
+      ConstantArray::get(DataArrayTy, ContiguousDataInits));
+}
+
+void InstrLowerer::allocateContiguousProfileArrays() {
+  LLVM_DEBUG(llvm::dbgs() << "allocateContiguousProfileArrays() called\n");
+
+  // Only for GPU device targets
+  if (!isGPUProfTarget(M)) {
+    LLVM_DEBUG(llvm::dbgs()
+               << "Not a GPU target, skipping contiguous allocation\n");
+    return;
+  }
+
+  // Get and cache the CUID for consistent section naming
+  CachedCUID = getCUIDFromModule(M);
+  if (CachedCUID.empty()) {
+    LLVM_DEBUG(llvm::dbgs() << "No CUID found in module, using fallback\n");
+    CachedCUID = std::to_string(std::hash<std::string>{}(M.getName().str()));
+  }
+
+  LLVM_DEBUG(llvm::dbgs() << "Allocating contiguous arrays for CUID="
+                          << CachedCUID << "\n");
+
+  // First pass: collect all instrprof intrinsics and count total counters
+  const unsigned KSlots = 1u << OffloadProfilingThreadBitWidth;
+  TotalCounterSlots = 0;
+  TotalDataEntries = 0;
+
+  // We need to iterate through all functions and collect the first profiling
+  // intrinsic from each, which determines the counter size for that function.
+  SmallVector<std::pair<GlobalVariable *, uint64_t>, 16> FunctionCounters;
+
+  for (Function &F : M) {
+    for (BasicBlock &BB : F) {
+      for (Instruction &I : BB) {
+        if (auto *Inc = dyn_cast<InstrProfIncrementInst>(&I)) {
+          GlobalVariable *NamePtr = Inc->getName();
+          // Only count each function once
+          if (FunctionCounterOffsets.count(NamePtr) == 0) {
+            uint64_t NumCounters = Inc->getNumCounters()->getZExtValue();
+            uint64_t NumSlots = NumCounters * KSlots;
+
+            FunctionCounterOffsets[NamePtr] = TotalCounterSlots;
+            FunctionDataOffsets[NamePtr] = TotalDataEntries;
+            FunctionCounters.push_back({NamePtr, NumSlots});
+
+            TotalCounterSlots += NumSlots;
+            TotalDataEntries++;
+
+            LLVM_DEBUG(llvm::dbgs()
+                       << "  Function " << getPGOFuncNameVarInitializer(NamePtr)
+                       << ": " << NumCounters << " counters, " << NumSlots
+                       << " slots, offset=" << (TotalCounterSlots - NumSlots)
+                       << "\n");
+          }
+          break; // Only need first intrinsic per function
+        }
+        if (auto *Cover = dyn_cast<InstrProfCoverInst>(&I)) {
+          GlobalVariable *NamePtr = Cover->getName();
+          if (FunctionCounterOffsets.count(NamePtr) == 0) {
+            uint64_t NumCounters = Cover->getNumCounters()->getZExtValue();
+            // Coverage uses i8 counters, but for simplicity we still allocate
+            // as if slots
+            FunctionCounterOffsets[NamePtr] = TotalCounterSlots;
+            FunctionDataOffsets[NamePtr] = TotalDataEntries;
+            FunctionCounters.push_back({NamePtr, NumCounters});
+
+            TotalCounterSlots += NumCounters;
+            TotalDataEntries++;
+          }
+          break;
+        }
+      }
+    }
+  }
+
+  LLVM_DEBUG(llvm::dbgs() << "Total: " << TotalCounterSlots
+                          << " counter slots, " << TotalDataEntries
+                          << " data entries\n");
+
+  if (TotalCounterSlots == 0) {
+    LLVM_DEBUG(llvm::dbgs()
+               << "No counters found, skipping contiguous array creation\n");
+    return;
+  }
+
+  auto &Ctx = M.getContext();
+  auto *Int64Ty = Type::getInt64Ty(Ctx);
+
+  // Create contiguous counter array
+  auto *CntsArrayTy = ArrayType::get(Int64Ty, TotalCounterSlots);
+  std::string CntsSectionName = "__llvm_prf_cnts_" + CachedCUID;
+  ContiguousCnts = new GlobalVariable(
+      M, CntsArrayTy, /*isConstant=*/false, GlobalValue::ExternalLinkage,
+      Constant::getNullValue(CntsArrayTy), "__profc_all_" + CachedCUID);
+  ContiguousCnts->setSection(CntsSectionName);
+  ContiguousCnts->setAlignment(Align(8));
+  ContiguousCnts->setVisibility(GlobalValue::ProtectedVisibility);
+  CompilerUsedVars.push_back(ContiguousCnts);
+
+  // Create contiguous uniform counter array (for AMDGPU divergence tracking)
+  std::string UCntsSectionName = "__llvm_prf_ucnts_" + CachedCUID;
+  ContiguousUCnts = new GlobalVariable(
+      M, CntsArrayTy, /*isConstant=*/false, GlobalValue::ExternalLinkage,
+      Constant::getNullValue(CntsArrayTy), "__profu_all_" + CachedCUID);
+  ContiguousUCnts->setSection(UCntsSectionName);
+  ContiguousUCnts->setAlignment(Align(8));
+  ContiguousUCnts->setVisibility(GlobalValue::ProtectedVisibility);
+  CompilerUsedVars.push_back(ContiguousUCnts);
+
+  LLVM_DEBUG(llvm::dbgs() << "Created contiguous arrays: "
+                          << ContiguousCnts->getName() << " ("
+                          << TotalCounterSlots << " slots), "
+                          << ContiguousUCnts->getName() << "\n");
+
+  if (TotalDataEntries > 0) {
+    auto *DataTy = getProfileDataTy();
+    auto *DataArrayTy = ArrayType::get(DataTy, TotalDataEntries);
+    std::string DataSectionName = getInstrProfSectionName(
+        ProfileCorrelate == InstrProfCorrelator::BINARY ? IPSK_covdata
+                                                        : IPSK_data,
+        TT.getObjectFormat());
+    DataSectionName = DataSectionName + "_" + CachedCUID;
+
+    ContiguousData = new GlobalVariable(M, DataArrayTy, /*isConstant=*/false,
+                                        GlobalValue::ExternalLinkage, nullptr,
+                                        "__profd_all_" + CachedCUID);
+    ContiguousData->setSection(DataSectionName);
+    ContiguousData->setAlignment(Align(INSTR_PROF_DATA_ALIGNMENT));
+    ContiguousData->setVisibility(GlobalValue::ProtectedVisibility);
+    CompilerUsedVars.push_back(ContiguousData);
+
+    ContiguousDataInits.assign(TotalDataEntries,
+                               Constant::getNullValue(DataTy));
+  }
+}
+
+// Create __llvm_offload_prf structure for GPU targets.
+// Uses the contiguous arrays allocated by allocateContiguousProfileArrays().
+void InstrLowerer::createProfileSectionSymbols() {
+  LLVM_DEBUG(llvm::dbgs() << "createProfileSectionSymbols() called\n");
+
+  // Only create symbols for device targets (GPU)
+  if (!isGPUProfTarget(M)) {
+    LLVM_DEBUG(llvm::dbgs() << "Not a GPU target, skipping symbol creation\n");
+    return;
+  }
+
+  // No contiguous arrays = no profiling in this TU
+  if (!ContiguousCnts) {
+    LLVM_DEBUG(llvm::dbgs()
+               << "No contiguous counters, skipping symbol creation\n");
+    return;
+  }
+
+  LLVM_DEBUG(llvm::dbgs() << "Creating profile symbols for CUID=" << CachedCUID
+                          << "\n");
+
+  auto &Ctx = M.getContext();
+  auto *Int8Ty = Type::getInt8Ty(Ctx);
+  auto *Int64Ty = Type::getInt64Ty(Ctx);
+
+  // Get address space from the contiguous counters
+  unsigned AS = ContiguousCnts->getType()->getPointerAddressSpace();
+  auto *Int8PtrTy = PointerType::get(Ctx, AS);
+
+  // Calculate sizes
+  uint64_t CntsSize =
+      M.getDataLayout().getTypeAllocSize(ContiguousCnts->getValueType());
+  uint64_t UCntsSize =
+      M.getDataLayout().getTypeAllocSize(ContiguousUCnts->getValueType());
+
+  // Data section boundaries.
+  GlobalValue *DataStart = nullptr;
+  GlobalValue *DataEndBase = nullptr;
+  uint64_t DataSize = 0;
+  if (ContiguousData) {
+    DataStart = ContiguousData;
+    DataEndBase = ContiguousData;
+    DataSize =
+        M.getDataLayout().getTypeAllocSize(ContiguousData->getValueType());
+  } else {
+    // Legacy per-function data variables: best-effort by scanning.
+    GlobalVariable *FirstData = nullptr;
+    GlobalVariable *LastData = nullptr;
+    for (auto &PD : ProfileDataMap) {
+      if (auto *GV = dyn_cast_or_null<GlobalVariable>(PD.second.DataVar)) {
+        if (!FirstData)
+          FirstData = GV;
+        LastData = GV;
+      }
+    }
+    DataStart = FirstData;
+    DataEndBase = LastData;
+    if (LastData)
+      DataSize = M.getDataLayout().getTypeAllocSize(LastData->getValueType());
+  }
+
+  LLVM_DEBUG({
+    llvm::dbgs() << "Section sizes: Cnts=" << CntsSize << " UCnts=" << UCntsSize
+                 << " Data=" << DataSize << " Names=" << NamesSize << "\n";
+  });
+
+  // Helper to get start pointer
+  auto getStartPtr = [&](GlobalValue *GV) -> Constant * {
+    if (!GV)
+      return Constant::getNullValue(Int8PtrTy);
+    return ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, Int8PtrTy);
+  };
+
+  // Helper to get end pointer (base + size)
+  auto getEndPtr = [&](GlobalValue *GV, uint64_t Size) -> Constant * {
+    if (!GV)
+      return Constant::getNullValue(Int8PtrTy);
+    auto *BasePtr =
+        ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, Int8PtrTy);
+    return ConstantExpr::getGetElementPtr(Int8Ty, BasePtr,
+                                          ConstantInt::get(Int64Ty, Size));
+  };
+
+  // Build the __llvm_offload_prf structure
+  // Order: cnts_start, data_start, names_start, ucnts_start, cnts_end,
+  // data_end, names_end, ucnts_end
+  std::vector<Type *> StructFields(8, Int8PtrTy);
+  std::vector<Constant *> StructValues = {
+      getStartPtr(ContiguousCnts),          // cnts_start
+      getStartPtr(DataStart),               // data_start
+      getStartPtr(NamesVar),                // names_start
+      getStartPtr(ContiguousUCnts),         // ucnts_start
+      getEndPtr(ContiguousCnts, CntsSize),  // cnts_end
+      getEndPtr(DataEndBase, DataSize),     // data_end
+      getEndPtr(NamesVar, NamesSize),       // names_end
+      getEndPtr(ContiguousUCnts, UCntsSize) // ucnts_end
+  };
+
+  auto *UnifiedStructTy = StructType::get(Ctx, StructFields);
+  auto *UnifiedStructInit = ConstantStruct::get(UnifiedStructTy, StructValues);
+
+  // Use CUID-suffixed name to avoid symbol collision in multi-TU programs.
+  // For static modules, the host side registers each TU's shadow variable.
+  // For dynamic modules (hipModuleLoad), the runtime would need to enumerate
+  // symbols matching __llvm_offload_prf_* pattern (future enhancement).
+  std::string OffloadPrfName = "__llvm_offload_prf_" + CachedCUID;
+  auto *UnifiedStruct = new GlobalVariable(
+      M, UnifiedStructTy, /*isConstant=*/true, GlobalValue::ExternalLinkage,
+      UnifiedStructInit, OffloadPrfName);
+  UnifiedStruct->setVisibility(GlobalValue::DefaultVisibility);
+  CompilerUsedVars.push_back(UnifiedStruct);
+
+  LLVM_DEBUG(llvm::dbgs() << "Created " << OffloadPrfName
+                          << " with contiguous arrays\n");
+}
+
+// Create HIP device variable registration for profile symbols
+void InstrLowerer::createHIPDeviceVariableRegistration() {
+  LLVM_DEBUG(llvm::dbgs() << "createHIPDeviceVariableRegistration called\n");
+  if (isGPUProfTarget(M)) {
+    LLVM_DEBUG(llvm::dbgs() << "GPU target, skipping registration\n");
+    return;
+  }
+
+  // Get the CUID from the module (same as device side)
+  std::string CUID = getCUIDFromModule(M);
+  if (CUID.empty()) {
+    LLVM_DEBUG(llvm::dbgs() << "No CUID found, skipping registration\n");
+    return;
+  }
+
+  // Find the existing __hip_module_ctor function
+  Function *Ctor = M.getFunction("__hip_module_ctor");
+  if (!Ctor) {
+    LLVM_DEBUG(llvm::dbgs() << "No __hip_module_ctor function found\n");
+    // M.dump();
+    //  No HIP compilation context, skip registration
+    return;
+  }
+
+  // Locate the HIP fat-binary registration call and capture its return value
+  Value *Handle = nullptr;
+  for (BasicBlock &BB : *Ctor)
+    for (Instruction &I : BB)
+      if (auto *CB = dyn_cast<CallBase>(&I))
+        if (Function *Callee = CB->getCalledFunction())
+          if (Callee->getName() == "__hipRegisterFatBinary") {
+            Handle = &I; // call result
+            break;
+          }
+  if (!Handle) {
+    LLVM_DEBUG(llvm::dbgs() << "__hipRegisterFatBinary call not found\n");
+    return;
+  }
+  GlobalVariable *FatbinHandleGV = nullptr;
+  if (auto *HandleInst = dyn_cast<Instruction>(Handle))
+    for (Instruction *Cur = HandleInst->getNextNode(); Cur;
+         Cur = Cur->getNextNode()) {
+      auto *SI = dyn_cast<StoreInst>(Cur);
+      if (!SI || SI->getValueOperand() != Handle)
+        continue;
+      if (auto *GV = dyn_cast<GlobalVariable>(
+              SI->getPointerOperand()->stripPointerCasts())) {
+        FatbinHandleGV = GV;
+        break;
+      }
+    }
+
+  if (!FatbinHandleGV) {
+    LLVM_DEBUG(llvm::dbgs()
+               << "store of __hipRegisterFatBinary call not found\n");
+  }
+
+  // Insert the new registration just before the ctor’s return
+  ReturnInst *RetInst = nullptr;
+  for (auto &BB : llvm::reverse(*Ctor))
+    if ((RetInst = dyn_cast<ReturnInst>(BB.getTerminator())))
+      break;
+  if (!RetInst) {
+    LLVM_DEBUG(llvm::dbgs() << "No return instruction found in ctor\n");
+    return;
+  }
+  IRBuilder<> Builder(RetInst);
+
+  LLVM_DEBUG(
+      llvm::dbgs() << "Found __hip_module_ctor, registering anchors for CUID="
+                   << CUID << "\n");
+
+  // Get or create the __hipRegisterVar declaration
+  auto *VoidTy = Type::getVoidTy(M.getContext());
+  auto *VoidPtrTy = PointerType::getUnqual(M.getContext());
+  auto *Int32Ty = Type::getInt32Ty(M.getContext());
+  auto *Int64Ty = Type::getInt64Ty(M.getContext());
+
+  auto *RegisterVarTy =
+      FunctionType::get(VoidTy,
+                        {VoidPtrTy, VoidPtrTy, VoidPtrTy, VoidPtrTy, Int32Ty,
+                         Int64Ty, Int32Ty, Int32Ty},
+                        false);
+  FunctionCallee RegisterVarFunc =
+      M.getOrInsertFunction("__hipRegisterVar", RegisterVarTy);
+
+  Value *HipHandle =
+      FatbinHandleGV ? Builder.CreateLoad(VoidPtrTy, FatbinHandleGV) : Handle;
+
+  // Create __llvm_offload_prf_<CUID> shadow structure on host
+  // This will be populated with section boundary addresses from the device
+  // Use CUID-suffixed name to match device symbol and avoid multi-TU collision
+  std::string OffloadPrfName = "__llvm_offload_prf_" + CUID;
+  auto *Int8PtrTy = PointerType::get(M.getContext(), 0);
+  std::vector<Type *> StructFields(8, Int8PtrTy);
+  auto *StructTy = StructType::get(M.getContext(), StructFields);
+
+  auto *OffloadPrfShadow = new GlobalVariable(
+      M, StructTy, /*isConstant=*/false, GlobalValue::ExternalLinkage,
+      ConstantAggregateZero::get(StructTy), OffloadPrfName);
+  CompilerUsedVars.push_back(OffloadPrfShadow);
+
+  // Register the unified structure with HIP runtime
+  auto *UnifiedNameStr =
+      ConstantDataArray::getString(M.getContext(), OffloadPrfName, true);
+  auto *UnifiedNameGlobal = new GlobalVariable(
+      M, UnifiedNameStr->getType(), /*isConstant=*/true,
+      GlobalValue::PrivateLinkage, UnifiedNameStr, OffloadPrfName + ".name");
+
+  Builder.CreateCall(RegisterVarFunc,
+                     {HipHandle,
+                      Builder.CreatePointerCast(OffloadPrfShadow, VoidPtrTy),
+                      Builder.CreatePointerCast(UnifiedNameGlobal, VoidPtrTy),
+                      Builder.CreatePointerCast(UnifiedNameGlobal, VoidPtrTy),
+                      Builder.getInt32(0),   // extern = 0
+                      Builder.getInt64(64),  // size = 64 (8 pointers * 8 bytes)
+                      Builder.getInt32(0),   // constant = 0
+                      Builder.getInt32(0)}); // global = 0
+
+  // Register with the profile runtime so it knows to collect data from this TU
+  auto *RegisterShadowVarTy = FunctionType::get(VoidTy, {VoidPtrTy}, false);
+  FunctionCallee RegisterShadowVarFunc = M.getOrInsertFunction(
+      "__llvm_profile_offload_register_shadow_variable", RegisterShadowVarTy);
+  Builder.CreateCall(RegisterShadowVarFunc,
+                     {Builder.CreatePointerCast(OffloadPrfShadow, VoidPtrTy)});
+
+  // Register per-section device symbols so compiler-rt can pre-register them
+  // with CLR before doing hipMemcpy (avoids HSA dependency).
+  FunctionCallee RegisterSectionShadowVarFunc = M.getOrInsertFunction(
+      "__llvm_profile_offload_register_section_shadow_variable",
+      RegisterShadowVarTy);
+
+  auto registerSectionSymbol = [&](StringRef SymName) {
+    // Create a 1-byte shadow global. The type/size are only used as a handle.
+    auto *I8Ty = Type::getInt8Ty(M.getContext());
+    GlobalVariable *Shadow = M.getGlobalVariable(SymName);
+    if (!Shadow) {
+      Shadow = new GlobalVariable(M, I8Ty, /*isConstant=*/false,
+                                  GlobalValue::ExternalLinkage,
+                                  ConstantInt::get(I8Ty, 0), SymName);
+      CompilerUsedVars.push_back(Shadow);
+    }
+
+    auto *NameStr = ConstantDataArray::getString(M.getContext(), SymName, true);
+    auto *NameGlobal = new GlobalVariable(
+        M, NameStr->getType(), /*isConstant=*/true, GlobalValue::PrivateLinkage,
+        NameStr, (SymName + ".name").str());
+
+    Builder.CreateCall(RegisterVarFunc,
+                       {HipHandle, Builder.CreatePointerCast(Shadow, VoidPtrTy),
+                        Builder.CreatePointerCast(NameGlobal, VoidPtrTy),
+                        Builder.CreatePointerCast(NameGlobal, VoidPtrTy),
+                        Builder.getInt32(0), // extern = 0
+                        Builder.getInt64(1), // size = 1 byte (handle only)
+                        Builder.getInt32(0), // constant = 0
+                        Builder.getInt32(0)} // global = 0
+    );
+
+    Builder.CreateCall(RegisterSectionShadowVarFunc,
+                       {Builder.CreatePointerCast(Shadow, VoidPtrTy)});
+  };
+
+  // Per-TU contiguous symbols (device side).
+  std::string CntsSym = std::string("__profc_all_") + CUID;
+  std::string DataSym = std::string("__profd_all_") + CUID;
+  std::string UCntsSym = std::string("__profu_all_") + CUID;
+  std::string NamesSym = std::string(getInstrProfNamesVarName()) + "_" + CUID;
+  registerSectionSymbol(CntsSym);
+  registerSectionSymbol(DataSym);
+  registerSectionSymbol(UCntsSym);
+  registerSectionSymbol(NamesSym);
+
+  LLVM_DEBUG(llvm::dbgs() << "Registered " << OffloadPrfName
+                          << " for CUID=" << CUID << "\n");
+}
+
+} // namespace
diff --git a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
index 02f06bebb8f0d..a24b8718d0ce9 100644
--- a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
+++ b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
@@ -118,6 +118,7 @@
 #include <algorithm>
 #include <cassert>
 #include <cstdint>
+#include <cstdlib>
 #include <memory>
 #include <numeric>
 #include <optional>
@@ -1201,6 +1202,9 @@ class PGOUseFunc {
   // Annotate the irreducible loop header weights.
   void annotateIrrLoopHeaderWeights();
 
+  // Annotate per-block uniformity info for offload profiling.
+  void setBlockUniformityAttribute();
+
   // The hotness of the function from the profile count.
   enum FuncFreqAttr { FFA_Normal, FFA_Cold, FFA_Hot };
 
@@ -1307,11 +1311,34 @@ bool PGOUseFunc::setInstrumentedCounts(
 
   setupBBInfoEdges(FuncInfo);
 
-  unsigned NumCounters =
-      InstrumentBBs.size() + FuncInfo.SIVisitor.getNumOfSelectInsts();
+  unsigned NumInstrumentedBBs = InstrumentBBs.size();
+  unsigned NumSelects = FuncInfo.SIVisitor.getNumOfSelectInsts();
+  unsigned NumCounters = NumInstrumentedBBs + NumSelects;
   // The number of counters here should match the number of counters
   // in profile. Return if they mismatch.
   if (NumCounters != CountFromProfile.size()) {
+    LLVM_DEBUG({
+      dbgs() << "PGO COUNTER MISMATCH for function " << F.getName() << ":\n";
+      dbgs() << "  Expected counters: " << NumCounters << "\n";
+      dbgs() << "    - From instrumented edges: " << NumInstrumentedBBs << "\n";
+      for (size_t i = 0; i < InstrumentBBs.size(); ++i) {
+        dbgs() << "      " << i << ": " << InstrumentBBs[i]->getName() << "\n";
+      }
+      dbgs() << "    - From select instructions: " << NumSelects << "\n";
+      dbgs() << "  Actual counters from profile: " << CountFromProfile.size()
+             << "\n";
+
+      // Dump module
+      std::error_code EC;
+      std::string Filename = "pgo_mismatch_" + F.getName().str() + ".ll";
+      raw_fd_ostream OS(Filename, EC);
+      if (!EC) {
+        dbgs() << "Dumping module to " << Filename << "\n";
+        M->print(OS, nullptr);
+      } else {
+        dbgs() << "Error opening file " << Filename << " for writing\n";
+      }
+    });
     return false;
   }
   auto *FuncEntry = &*F.begin();
@@ -1319,6 +1346,7 @@ bool PGOUseFunc::setInstrumentedCounts(
   // Set the profile count to the Instrumented BBs.
   uint32_t I = 0;
   for (BasicBlock *InstrBB : InstrumentBBs) {
+
     uint64_t CountValue = CountFromProfile[I++];
     PGOUseBBInfo &Info = getBBInfo(InstrBB);
     // If we reach here, we know that we have some nonzero count
@@ -1764,6 +1792,47 @@ void PGOUseFunc::annotateIrrLoopHeaderWeights() {
   }
 }
 
+void PGOUseFunc::setBlockUniformityAttribute() {
+  if (ProfileRecord.UniformityBits.empty())
+    return;
+
+  // Annotate uniformity on each instrumented IR basic block so later codegen
+  // passes (MachineFunction) can consume it without relying on fragile block
+  // numbering heuristics.
+  //
+  // Metadata name: "offload-block-uniformity"
+  // Payload: i1 (true = uniform, false = divergent)
+  static constexpr const char *OffloadBlockUniformityMD =
+      "offload-block-uniformity";
+
+  std::vector<BasicBlock *> InstrumentBBs;
+  FuncInfo.getInstrumentBBs(InstrumentBBs);
+
+  LLVMContext &Ctx = F.getContext();
+  Type *Int1Ty = Type::getInt1Ty(Ctx);
+
+  for (size_t I = 0, E = InstrumentBBs.size(); I < E; ++I) {
+    BasicBlock *BB = InstrumentBBs[I];
+    if (!BB || !BB->getTerminator())
+      continue;
+    bool IsUniform = ProfileRecord.isBlockUniform(I);
+    auto *MD = MDNode::get(
+        Ctx, ConstantAsMetadata::get(ConstantInt::get(Int1Ty, IsUniform)));
+    BB->getTerminator()->setMetadata(OffloadBlockUniformityMD, MD);
+  }
+
+  // Keep a function attribute for debugging / IR inspection.
+  // Format: "U" for uniform, "D" for divergent, one per instrumented block.
+  std::string UniformityStr;
+  UniformityStr.reserve(InstrumentBBs.size());
+  for (size_t I = 0, E = InstrumentBBs.size(); I < E; ++I)
+    UniformityStr += ProfileRecord.isBlockUniform(I) ? 'U' : 'D';
+  F.addFnAttr("offload-block-uniformity", UniformityStr);
+
+  LLVM_DEBUG(dbgs() << "PGO: Set offload block uniformity for " << F.getName()
+                    << ": " << UniformityStr << "\n");
+}
+
 void SelectInstVisitor::instrumentOneSelectInst(SelectInst &SI) {
   Module *M = F.getParent();
   IRBuilder<> Builder(&SI);
@@ -2275,6 +2344,7 @@ static bool annotateAllFunctions(
     Func.setBranchWeights();
     Func.annotateValueSites();
     Func.annotateIrrLoopHeaderWeights();
+    Func.setBlockUniformityAttribute();
     PGOUseFunc::FuncFreqAttr FreqAttr = Func.getFuncFreqAttr();
     if (FreqAttr == PGOUseFunc::FFA_Cold)
       ColdFunctions.push_back(&F);
@@ -2409,14 +2479,14 @@ void llvm::setProfMetadata(Instruction *TI, ArrayRef<uint64_t> EdgeCounts,
                            uint64_t MaxCount) {
   auto Weights = downscaleWeights(EdgeCounts, MaxCount);
 
-  LLVM_DEBUG(dbgs() << "Weight is: "; for (const auto &W
-                                           : Weights) {
+  LLVM_DEBUG(dbgs() << "Weight is: "; for (const auto &W : Weights) {
     dbgs() << W << " ";
-  } dbgs() << "\n";);
+  } dbgs() << "\n");
 
   misexpect::checkExpectAnnotations(*TI, Weights, /*IsFrontend=*/false);
 
   setBranchWeights(*TI, Weights, /*IsExpected=*/false);
+
   if (EmitBranchProbability) {
     std::string BrCondStr = getBranchCondString(TI);
     if (BrCondStr.empty())
diff --git a/llvm/test/Instrumentation/InstrProfiling/amdgpu-contiguous-counters.ll b/llvm/test/Instrumentation/InstrProfiling/amdgpu-contiguous-counters.ll
new file mode 100644
index 0000000000000..95ce5c30f7f53
--- /dev/null
+++ b/llvm/test/Instrumentation/InstrProfiling/amdgpu-contiguous-counters.ll
@@ -0,0 +1,41 @@
+;; Test that AMDGPU targets use contiguous counter allocation with CUID-based naming.
+;; This avoids linker reordering issues where individual __profc_* symbols could be
+;; placed in any order within the section.
+
+; RUN: opt %s -mtriple=amdgcn-amd-amdhsa -passes=instrprof -S | FileCheck %s
+
+;; Simulate a module with CUID (as generated by HIP compilation)
+ at __hip_cuid_abc123 = addrspace(1) global i8 0
+
+ at __profn_kernel1 = private constant [7 x i8] c"kernel1"
+ at __profn_kernel2 = private constant [7 x i8] c"kernel2"
+
+;; Check that contiguous counter array is created with CUID suffix
+; CHECK: @__profc_all_abc123 = protected addrspace(1) global [{{[0-9]+}} x i64] zeroinitializer, section "__llvm_prf_cnts_abc123", align 8
+
+;; Check that contiguous uniform counter array is created for divergence tracking
+; CHECK: @__profu_all_abc123 = protected addrspace(1) global [{{[0-9]+}} x i64] zeroinitializer, section "__llvm_prf_ucnts_abc123", align 8
+
+;; Check that individual __profc_kernel* symbols are NOT created (contiguous mode)
+; CHECK-NOT: @__profc_kernel1
+; CHECK-NOT: @__profc_kernel2
+
+define amdgpu_kernel void @kernel1() {
+  call void @llvm.instrprof.increment(ptr @__profn_kernel1, i64 12345, i32 2, i32 0)
+  call void @llvm.instrprof.increment(ptr @__profn_kernel1, i64 12345, i32 2, i32 1)
+  ret void
+}
+
+define amdgpu_kernel void @kernel2() {
+  call void @llvm.instrprof.increment(ptr @__profn_kernel2, i64 67890, i32 1, i32 0)
+  ret void
+}
+
+declare void @llvm.instrprof.increment(ptr, i64, i32, i32)
+
+;; Check that __llvm_offload_prf_<CUID> structure is created with 8 pointers
+; CHECK: @__llvm_offload_prf_abc123 = addrspace(1) constant { ptr addrspace(1), ptr addrspace(1), ptr addrspace(1), ptr addrspace(1), ptr addrspace(1), ptr addrspace(1), ptr addrspace(1), ptr addrspace(1) }
+
+;; Per-function data symbols are aliases into the contiguous __profd_all array
+; CHECK: @__profd_kernel1 = protected alias
+; CHECK: @__profd_kernel2 = protected alias
diff --git a/llvm/test/Instrumentation/InstrProfiling/amdgpu-uniform-counters.ll b/llvm/test/Instrumentation/InstrProfiling/amdgpu-uniform-counters.ll
new file mode 100644
index 0000000000000..d326ef67b613a
--- /dev/null
+++ b/llvm/test/Instrumentation/InstrProfiling/amdgpu-uniform-counters.ll
@@ -0,0 +1,31 @@
+;; Test that AMDGPU targets generate uniform counter instrumentation for
+;; divergence tracking. This enables PGO to detect which blocks execute
+;; uniformly (all lanes active) vs divergently (partial wave execution).
+
+; RUN: opt %s -mtriple=amdgcn-amd-amdhsa -passes=instrprof -S | FileCheck %s
+
+ at __hip_cuid_test123 = addrspace(1) global i8 0
+ at __profn_test_kernel = private constant [11 x i8] c"test_kernel"
+
+define amdgpu_kernel void @test_kernel() {
+  call void @llvm.instrprof.increment(ptr @__profn_test_kernel, i64 12345, i32 1, i32 0)
+  ret void
+}
+
+declare void @llvm.instrprof.increment(ptr, i64, i32, i32)
+
+;; Check that uniform counter array is created
+; CHECK: @__profu_all_test123 = protected addrspace(1) global
+
+;; Check that ballot intrinsic is used to get active mask
+; CHECK: call i32 @llvm.amdgcn.ballot.i32(i1 true)
+
+;; Check that ctpop is used to count active lanes
+; CHECK: call i32 @llvm.ctpop.i32
+
+;; Check that uniformity check compares active mask to full wave mask (0xFFFFFFFF)
+; CHECK: icmp eq i32 %{{.*}}, -1
+
+;; Check that uniform counter is conditionally updated based on uniformity
+;; The atomic wave leader mode uses a branch on isUniform
+; CHECK: br i1 %isUniform, label %uniform_then
diff --git a/llvm/test/Instrumentation/InstrProfiling/coverage.ll b/llvm/test/Instrumentation/InstrProfiling/coverage.ll
index 08cbcaa962b76..75fd18a94940d 100644
--- a/llvm/test/Instrumentation/InstrProfiling/coverage.ll
+++ b/llvm/test/Instrumentation/InstrProfiling/coverage.ll
@@ -5,12 +5,12 @@ target triple = "aarch64-unknown-linux-gnu"
 
 @__profn_foo = private constant [3 x i8] c"foo"
 ; CHECK: @__profc_foo = private global [1 x i8] c"\FF", section "__llvm_prf_cnts", comdat, align 1
-; CHECK: @__profd_foo = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i32 } { i64 {{.*}}, i64 {{.*}}, i64 sub (i64 ptrtoint (ptr @__profc_foo to i64)
-; BINARY: @__profd_foo = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i32 } { i64 {{.*}}, i64 {{.*}}, i64 ptrtoint (ptr @__profc_foo to i64),
+; CHECK: @__profd_foo = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i16, i32 } { i64 {{.*}}, i64 {{.*}}, i64 sub (i64 ptrtoint (ptr @__profc_foo to i64)
+; BINARY: @__profd_foo = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i16, i32 } { i64 {{.*}}, i64 {{.*}}, i64 ptrtoint (ptr @__profc_foo to i64),
 @__profn_bar = private constant [3 x i8] c"bar"
 ; CHECK: @__profc_bar = private global [1 x i8] c"\FF", section "__llvm_prf_cnts", comdat, align 1
-; CHECK: @__profd_bar = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i32 } { i64 {{.*}}, i64 {{.*}}, i64 sub (i64 ptrtoint (ptr @__profc_bar to i64)
-; BINARY: @__profd_bar = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i32 } { i64 {{.*}}, i64 {{.*}}, i64 ptrtoint (ptr @__profc_bar to i64),
+; CHECK: @__profd_bar = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i16, i32 } { i64 {{.*}}, i64 {{.*}}, i64 sub (i64 ptrtoint (ptr @__profc_bar to i64)
+; BINARY: @__profd_bar = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i16, i32 } { i64 {{.*}}, i64 {{.*}}, i64 ptrtoint (ptr @__profc_bar to i64),
 
 ; CHECK: @__llvm_prf_nm = {{.*}} section "__llvm_prf_names"
 ; BINARY: @__llvm_prf_nm ={{.*}} section "__llvm_covnames"
diff --git a/llvm/test/Instrumentation/InstrProfiling/inline-data-var-create.ll b/llvm/test/Instrumentation/InstrProfiling/inline-data-var-create.ll
index 456103164378e..b8c2bc2f04f9f 100644
--- a/llvm/test/Instrumentation/InstrProfiling/inline-data-var-create.ll
+++ b/llvm/test/Instrumentation/InstrProfiling/inline-data-var-create.ll
@@ -7,17 +7,18 @@
 
 target triple = "x86_64-unknown-linux-gnu"
 
-; INLINEFIRST: @__profd_foo = private global{{.*}}zeroinitializer, i32 21
-; INLINEFIRST: @__profd_bar = private global{{.*}}zeroinitializer, i32 23
-; INLINEFIRST: @__profd_foobar = private global{{.*}}zeroinitializer, i32 99
-
-; INLINEAFTER: @__profd_foobar = private global{{.*}}zeroinitializer, i32 99
-; INLINEAFTER: @__profd_foo = private global{{.*}}zeroinitializer, i32 21
-; INLINEAFTER: @__profd_bar = private global{{.*}}zeroinitializer, i32 23
-
-; NOINLINE: @__profd_foobar = private global{{.*}}zeroinitializer, i32 99
-; NOINLINE: @__profd_foo = private global{{.*}}zeroinitializer, i32 21
-; NOINLINE: @__profd_bar = private global{{.*}}zeroinitializer, i32 23
+;; Note: struct layout is { ..., i32, [3 x i16], i16, i32 } where i16 is NumOffloadProfilingThreads
+; INLINEFIRST: @__profd_foo = private global{{.*}}i16 0, i32 21
+; INLINEFIRST: @__profd_bar = private global{{.*}}i16 0, i32 23
+; INLINEFIRST: @__profd_foobar = private global{{.*}}i16 0, i32 99
+
+; INLINEAFTER: @__profd_foobar = private global{{.*}}i16 0, i32 99
+; INLINEAFTER: @__profd_foo = private global{{.*}}i16 0, i32 21
+; INLINEAFTER: @__profd_bar = private global{{.*}}i16 0, i32 23
+
+; NOINLINE: @__profd_foobar = private global{{.*}}i16 0, i32 99
+; NOINLINE: @__profd_foo = private global{{.*}}i16 0, i32 21
+; NOINLINE: @__profd_bar = private global{{.*}}i16 0, i32 23
 
 declare void @llvm.instrprof.increment(ptr %0, i64 %1, i32 %2, i32 %3)
 declare void @llvm.instrprof.mcdc.parameters(ptr %0, i64 %1, i32 %2)
diff --git a/llvm/test/Instrumentation/InstrProfiling/platform.ll b/llvm/test/Instrumentation/InstrProfiling/platform.ll
index 9c76a5caf2a51..eaccf6681a426 100644
--- a/llvm/test/Instrumentation/InstrProfiling/platform.ll
+++ b/llvm/test/Instrumentation/InstrProfiling/platform.ll
@@ -9,26 +9,38 @@
 ; RUN: opt < %s -mtriple=x86_64-pc-windows -passes=instrprof -S | FileCheck %s -check-prefix=WINDOWS
 ; RUN: opt < %s -mtriple=powerpc64-ibm-aix-xcoff -passes=instrprof -S | FileCheck %s -check-prefix=AIX
 ; RUN: opt < %s -mtriple=arm-elf -passes=instrprof -S | FileCheck %s -check-prefix=BAREMETAL
+; RUN: opt < %s -mtriple=amdgcn-amd-amdhsa -passes=instrprof -S | FileCheck %s -check-prefix=AMDGPU
 
 @__profn_foo = private constant [3 x i8] c"foo"
 ; MACHO-NOT: __profn_foo
 ; ELF-NOT: __profn_foo
 ; WINDOWS-NOT: __profn_foo
 ; AIX-NOT: __profn_foo
+; AMDGPU-NOT: __profn_foo
 
 ; MACHO: @__profc_foo = private global [1 x i64] zeroinitializer, section "__DATA,__llvm_prf_cnts", align 8
 ; ELF: @__profc_foo = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", comdat, align 8
 ; WINDOWS: @__profc_foo = private global [1 x i64] zeroinitializer, section ".lprfc$M", align 8
 ; AIX: @__profc_foo = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", align 8
+;; AMDGPU uses contiguous counter allocation with hash-based naming when no CUID
+; AMDGPU: @__profc_all_{{[0-9]+}} = protected addrspace(1) global [{{[0-9]+}} x i64] zeroinitializer, section "__llvm_prf_cnts_{{[0-9]+}}", align 8
+; AMDGPU: @__profu_all_{{[0-9]+}} = protected addrspace(1) global [{{[0-9]+}} x i64] zeroinitializer, section "__llvm_prf_ucnts_{{[0-9]+}}", align 8
 
 ; MACHO: @__profd_foo = private {{.*}}, section "__DATA,__llvm_prf_data,regular,live_support", align 8
 ; ELF: @__profd_foo = private {{.*}}, section "__llvm_prf_data", comdat($__profc_foo), align 8
 ; WINDOWS: @__profd_foo = private global {{.*}}, section ".lprfd$M", align 8
 ; AIX: @__profd_foo = private {{.*}}, section "__llvm_prf_data", align 8
-
 ; ELF: @__llvm_prf_nm = private constant [{{.*}} x i8] c"{{.*}}", section "{{.*}}__llvm_prf_names"{{.*}}, align 1
 ; WINDOWS: @__llvm_prf_nm = private constant [{{.*}} x i8] c"{{.*}}", section "{{.*}}lprfn$M", align 1
 ; AIX: @__llvm_prf_nm = private constant [{{.*}} x i8] c"{{.*}}", section "{{.*}}__llvm_prf_names", align 1
+;; AMDGPU uses CUID-suffixed names section
+; AMDGPU: @__llvm_prf_nm_{{[0-9]+}} = protected addrspace(1) constant [{{.*}} x i8] c"{{.*}}", section "__llvm_prf_names", align 1
+
+;; Check for __llvm_offload_prf_<CUID> structure (replaces start/stop symbols for AMDGPU)
+; AMDGPU: @__llvm_offload_prf_{{[0-9]+}} = addrspace(1) constant { ptr addrspace(1), ptr addrspace(1), ptr addrspace(1), ptr addrspace(1), ptr addrspace(1), ptr addrspace(1), ptr addrspace(1), ptr addrspace(1) }
+
+;; AMDGPU uses per-TU contiguous allocation, so @__profd_foo is an alias
+; AMDGPU: @__profd_foo = protected alias
 
 define void @foo() {
   call void @llvm.instrprof.increment(ptr @__profn_foo, i64 0, i32 1, i32 0)
@@ -37,6 +49,10 @@ define void @foo() {
 
 declare void @llvm.instrprof.increment(ptr, i64, i32, i32)
 
+;; Start/stop symbols are NOT created for AMDGPU with contiguous allocation
+; AMDGPU-NOT: @__start___llvm_prf_cnts
+; AMDGPU-NOT: @__stop___llvm_prf_cnts
+
 ;; Emit registration functions for platforms that don't find the
 ;; symbols by their sections.
 
@@ -48,6 +64,7 @@ declare void @llvm.instrprof.increment(ptr, i64, i32, i32)
 ; WINDOWS-NOT: define internal void @__llvm_profile_register_functions
 ; AIX-NOT: define internal void @__llvm_profile_register_functions
 ; BAREMETAL-NOT: define internal void @__llvm_profile_register_functions
+; AMDGPU-NOT: define internal void @__llvm_profile_register_functions
 
 ;; PR38340: When dynamic registration is used, we had a bug where we'd register
 ;; something that's not a __profd_* variable.
@@ -60,3 +77,4 @@ declare void @llvm.instrprof.increment(ptr, i64, i32, i32)
 ; WINDOWS-NOT: define internal void @__llvm_profile_init
 ; AIX-NOT: define internal void @__llvm_profile_init
 ; BAREMETAL-NOT: define internal void @__llvm_profile_init
+; AMDGPU-NOT: define internal void @__llvm_profile_init
diff --git a/llvm/test/Transforms/PGOProfile/comdat_internal.ll b/llvm/test/Transforms/PGOProfile/comdat_internal.ll
index 1bad0db1b4762..a3d7def15c516 100644
--- a/llvm/test/Transforms/PGOProfile/comdat_internal.ll
+++ b/llvm/test/Transforms/PGOProfile/comdat_internal.ll
@@ -13,9 +13,9 @@ $foo = comdat any
 ; CHECK: @__llvm_profile_raw_version = hidden constant i64 {{[0-9]+}}, comdat
 ; CHECK-NOT: __profn__stdin__foo
 ; CHECK: @__profc__stdin__foo.[[#FOO_HASH]] = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", comdat, align 8
-; CHECK: @__profd__stdin__foo.[[#FOO_HASH]] = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i32 } { i64 {{.*}}, i64 [[#FOO_HASH]], i64 sub (i64 ptrtoint (ptr @__profc__stdin__foo.742261418966908927 to i64), i64 ptrtoint (ptr @__profd__stdin__foo.742261418966908927 to i64)), i64 0, ptr null
+; CHECK: @__profd__stdin__foo.[[#FOO_HASH]] = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i16, i32 } { i64 {{.*}}, i64 [[#FOO_HASH]], i64 sub (i64 ptrtoint (ptr @__profc__stdin__foo.742261418966908927 to i64), i64 ptrtoint (ptr @__profd__stdin__foo.742261418966908927 to i64)), i64 0, ptr null
 ; CHECK-NOT: @foo
-; CHECK-SAME: , ptr null, i32 1, [3 x i16] zeroinitializer, i32 0 }, section "__llvm_prf_data", comdat($__profc__stdin__foo.[[#FOO_HASH]]), align 8
+; CHECK-SAME: , ptr null, i32 1, [3 x i16] zeroinitializer, i16 0, i32 0 }, section "__llvm_prf_data", comdat($__profc__stdin__foo.[[#FOO_HASH]]), align 8
 ; CHECK: @__llvm_prf_nm
 ; CHECK: @llvm.compiler.used
 
diff --git a/llvm/test/Transforms/PGOProfile/instrprof_burst_sampling_fast.ll b/llvm/test/Transforms/PGOProfile/instrprof_burst_sampling_fast.ll
index 56d8364d8f543..7a333362ce9ba 100644
--- a/llvm/test/Transforms/PGOProfile/instrprof_burst_sampling_fast.ll
+++ b/llvm/test/Transforms/PGOProfile/instrprof_burst_sampling_fast.ll
@@ -14,7 +14,7 @@ $__llvm_profile_raw_version = comdat any
 
 ; SAMPLE-VAR: @__llvm_profile_sampling = thread_local global i16 0, comdat
 ; SAMPLE-VAR: @__profc_f = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", comdat, align 8
-; SAMPLE-VAR: @__profd_f = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i32 } { i64 -3706093650706652785, i64 12884901887, i64 sub (i64 ptrtoint (ptr @__profc_f to i64), i64 ptrtoint (ptr @__profd_f to i64)), i64 0, ptr @f.local, ptr null, i32 1, [3 x i16] zeroinitializer, i32 0 }, section "__llvm_prf_data", comdat($__profc_f), align 8
+; SAMPLE-VAR: @__profd_f = private global { i64, i64, i64, i64, ptr, ptr, i32, [3 x i16], i16, i32 } { i64 -3706093650706652785, i64 12884901887, i64 sub (i64 ptrtoint (ptr @__profc_f to i64), i64 ptrtoint (ptr @__profd_f to i64)), i64 0, ptr @f.local, ptr null, i32 1, [3 x i16] zeroinitializer, i16 0, i32 0 }, section "__llvm_prf_data", comdat($__profc_f), align 8
 ; SAMPLE-VAR: @__llvm_prf_nm = private constant {{.*}}, section "__llvm_prf_names", align 1
 ; SAMPLE-VAR: @llvm.compiler.used = appending global [2 x ptr] [ptr @__llvm_profile_sampling, ptr @__profd_f], section "llvm.metadata"
 ; SAMPLE-VAR: @llvm.used = appending global [1 x ptr] [ptr @__llvm_prf_nm], section "llvm.metadata"
diff --git a/llvm/test/tools/llvm-profdata/profile-version.test b/llvm/test/tools/llvm-profdata/profile-version.test
index e811699ac63ed..7f627cb89c7d0 100644
--- a/llvm/test/tools/llvm-profdata/profile-version.test
+++ b/llvm/test/tools/llvm-profdata/profile-version.test
@@ -2,7 +2,7 @@ Test the profile version.
 
 RUN: llvm-profdata merge -o %t.profdata %p/Inputs/basic.proftext
 RUN: llvm-profdata show --profile-version %t.profdata | FileCheck %s
-CHECK: Profile version: 13
+CHECK: Profile version: 14
 
 RUN: llvm-profdata merge -o %t.prev.profdata %p/Inputs/basic.proftext --write-prev-version
 RUN: llvm-profdata show --profile-version %t.prev.profdata | FileCheck %s --check-prefix=PREV
diff --git a/llvm/tools/llvm-profdata/llvm-profdata.cpp b/llvm/tools/llvm-profdata/llvm-profdata.cpp
index 74c4732ca129a..774fb46c5b1cd 100644
--- a/llvm/tools/llvm-profdata/llvm-profdata.cpp
+++ b/llvm/tools/llvm-profdata/llvm-profdata.cpp
@@ -31,6 +31,7 @@
 #include "llvm/Support/BalancedPartitioning.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Discriminator.h"
+#include "llvm/Support/Endian.h"
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Format.h"
@@ -354,6 +355,11 @@ static cl::opt<unsigned> MemprofGenerateRandomHotnessSeed(
     cl::sub(MergeSubcommand),
     cl::desc("Random hotness seed to use (0 to generate new seed)"));
 
+static cl::opt<unsigned> OffloadDeviceWaveSize(
+    "wave-size", cl::init(32), cl::sub(MergeSubcommand),
+    cl::desc("Wave size for AMDGPU offload profiling uniformity detection "
+             "(32 for gfx10/gfx11, 64 for gfx9). Default: 32"));
+
 // Options specific to overlap subcommand.
 static cl::opt<std::string> BaseFilename(cl::Positional, cl::Required,
                                          cl::desc("<base profile file>"),
@@ -655,11 +661,15 @@ struct WriterContext {
 
   WriterContext(bool IsSparse, std::mutex &ErrLock,
                 SmallSet<instrprof_error, 4> &WriterErrorCodes,
-                uint64_t ReservoirSize = 0, uint64_t MaxTraceLength = 0)
+                uint64_t ReservoirSize = 0, uint64_t MaxTraceLength = 0,
+                unsigned WaveSize = 0)
       : Writer(IsSparse, ReservoirSize, MaxTraceLength, DoWritePrevVersion,
                MemProfVersionRequested, MemProfFullSchema,
                MemprofGenerateRandomHotness, MemprofGenerateRandomHotnessSeed),
-        ErrLock(ErrLock), WriterErrorCodes(WriterErrorCodes) {}
+        ErrLock(ErrLock), WriterErrorCodes(WriterErrorCodes) {
+    if (WaveSize > 0)
+      Writer.setOffloadWaveSize(WaveSize);
+  }
 };
 
 /// Computer the overlap b/w profile BaseFilename and TestFileName,
@@ -690,6 +700,62 @@ static void overlapInput(const std::string &BaseFilename,
   }
 }
 
+/// Read uniform counters from a .unifcnts file.
+/// Returns true if the file was successfully read, false otherwise.
+/// The uniform counters are stored in UniformCounters vector.
+static bool readUniformCountersFile(StringRef ProfileFilename,
+                                    std::vector<uint64_t> &UniformCounters) {
+  // Construct the .unifcnts filename by replacing the extension
+  SmallString<256> UniformFilename(ProfileFilename);
+  sys::path::replace_extension(UniformFilename, "unifcnts");
+
+  // Try to open the file
+  auto BufferOrErr = MemoryBuffer::getFile(UniformFilename);
+  if (!BufferOrErr) {
+    // File doesn't exist or can't be read - this is not an error,
+    // just means no uniform counters are available
+    return false;
+  }
+
+  auto &Buffer = *BufferOrErr.get();
+  const char *Data = Buffer.getBufferStart();
+  size_t Size = Buffer.getBufferSize();
+
+  // Minimum size: 4 uint64_t header fields
+  if (Size < 4 * sizeof(uint64_t))
+    return false;
+
+  // Read header
+  uint64_t Magic = support::endian::read64le(Data);
+  uint64_t Version = support::endian::read64le(Data + 8);
+  uint64_t NumCounters = support::endian::read64le(Data + 16);
+  uint64_t CountersSize = support::endian::read64le(Data + 24);
+
+  // Verify magic number
+  const uint64_t ExpectedMagic = 0x55434E5450524F46ULL; // "UCNTPROF"
+  if (Magic != ExpectedMagic)
+    return false;
+
+  // Verify version
+  if (Version != 1)
+    return false;
+
+  // Verify size
+  size_t ExpectedSize = 4 * sizeof(uint64_t) + CountersSize;
+  if (Size < ExpectedSize)
+    return false;
+
+  // Read counters
+  UniformCounters.resize(NumCounters);
+  const char *CounterData = Data + 4 * sizeof(uint64_t);
+  for (uint64_t i = 0; i < NumCounters; ++i) {
+    UniformCounters[i] =
+        support::endian::read64le(CounterData + i * sizeof(uint64_t));
+  }
+
+  return true;
+}
+
 /// Load an input into a writer context.
 static void
 loadInput(const WeightedFile &Input, SymbolRemapper *Remapper,
@@ -820,11 +886,50 @@ loadInput(const WeightedFile &Input, SymbolRemapper *Remapper,
     return;
   }
 
+  // Try to read uniform counters file for AMDGPU divergence tracking
+  std::vector<uint64_t> UniformCounters;
+  bool HasUniformCounters =
+      readUniformCountersFile(Input.Filename, UniformCounters);
+  size_t UniformCounterOffset = 0;
+
   for (auto &I : *Reader) {
     if (Remapper)
       I.Name = (*Remapper)(I.Name);
     const StringRef FuncName = I.Name;
     bool Reported = false;
+
+    // If we have uniform counters and this is an offload profile, compute
+    // uniformity from the uniform/total counter ratio
+    if (HasUniformCounters && I.NumOffloadProfilingThreads > 0) {
+      size_t NumCounters = I.Counts.size();
+      if (UniformCounterOffset + NumCounters <= UniformCounters.size()) {
+        // Compute uniformity bits from uniform counter ratio
+        size_t NumBlocks = NumCounters / (I.NumOffloadProfilingThreads + 1);
+        I.UniformityBits.resize((NumBlocks + 7) / 8, 0xFF); // Default: uniform
+
+        for (size_t BlockIdx = 0; BlockIdx < NumBlocks; ++BlockIdx) {
+          uint64_t TotalCount = 0;
+          uint64_t UniformCount = 0;
+
+          // Sum across all slots for this block
+          for (size_t Slot = 0; Slot < I.NumOffloadProfilingThreads; ++Slot) {
+            size_t Idx = BlockIdx * (I.NumOffloadProfilingThreads + 1) + Slot;
+            TotalCount += I.Counts[Idx];
+            UniformCount += UniformCounters[UniformCounterOffset + Idx];
+          }
+
+          // Compute uniformity ratio (90% threshold)
+          bool IsUniform =
+              (TotalCount == 0) || ((double)UniformCount / TotalCount >= 0.9);
+          if (!IsUniform) {
+            I.UniformityBits[BlockIdx / 8] &= ~(1 << (BlockIdx % 8));
+          }
+        }
+
+        UniformCounterOffset += NumCounters;
+      }
+    }
+
     WC->Writer.addRecord(std::move(I), Input.Weight, [&](Error E) {
       if (Reported) {
         consumeError(std::move(E));
@@ -1043,7 +1148,7 @@ static void mergeInstrProfile(const WeightedFileVector &Inputs,
   for (unsigned I = 0; I < NumThreads; ++I)
     Contexts.emplace_back(std::make_unique<WriterContext>(
         OutputSparse, ErrorLock, WriterErrorCodes, TraceReservoirSize,
-        MaxTraceLength));
+        MaxTraceLength, OffloadDeviceWaveSize));
 
   if (NumThreads == 1) {
     for (const auto &Input : Inputs)
@@ -1477,8 +1582,8 @@ static void supplementInstrProfile(const WeightedFileVector &Inputs,
   // Read instr profile.
   std::mutex ErrorLock;
   SmallSet<instrprof_error, 4> WriterErrorCodes;
-  auto WC = std::make_unique<WriterContext>(OutputSparse, ErrorLock,
-                                            WriterErrorCodes);
+  auto WC = std::make_unique<WriterContext>(
+      OutputSparse, ErrorLock, WriterErrorCodes, 0, 0, OffloadDeviceWaveSize);
   loadInput(Inputs[0], nullptr, nullptr, /*ProfiledBinary=*/"", WC.get());
   if (WC->Errors.size() > 0)
     exitWithError(std::move(WC->Errors[0].first), InstrFilename);
@@ -2979,6 +3084,16 @@ static int showInstrProfile(ShowFormat SFormat, raw_fd_ostream &OS) {
           OS << (I == Start ? "" : ", ") << Func.Counts[I];
         }
         OS << "]\n";
+
+        // Show uniformity bits if present
+        if (!Func.UniformityBits.empty()) {
+          OS << "    Block uniformity: [";
+          for (size_t I = Start, E = Func.Counts.size(); I < E; ++I) {
+            bool IsUniform = Func.isBlockUniform(I);
+            OS << (I == Start ? "" : ", ") << (IsUniform ? "U" : "D");
+          }
+          OS << "]\n";
+        }
       }
 
       if (ShowIndirectCallTargets) {



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