[llvm] [SHT_LLVM_BB_ADDR_MAP][AsmPrinter] Implements PGOAnalysisMap emitting in AsmPrinter with tests. (PR #75202)

via llvm-commits llvm-commits at lists.llvm.org
Tue Dec 12 07:41:00 PST 2023


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-x86

Author: Micah Weston (red1bluelost)

<details>
<summary>Changes</summary>

Uses machine analyses to emit PGOAnalysisMap into the bb-addr-map ELF section. Implements filecheck tests to verify emitting new fields.

## PR Series

The current code for PGOBBAddrMap to be upstreamed is split into five PRs:
1. Object and ObjectYAML - https://github.com/llvm/llvm-project/pull/71750
2. AsmPrinter - (this one) https://github.com/red1bluelost/llvm-project/tree/pgo-bb-addr-map--asm-printer
3. llvm-readobj - https://github.com/red1bluelost/llvm-project/pull/2 or https://github.com/red1bluelost/llvm-project/tree/pgo-bb-addr-map--llvm-readobj
4. llvm obj2yaml - https://github.com/red1bluelost/llvm-project/tree/pgo-bb-addr-map--llvm-obj2yaml


---

Patch is 27.17 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/75202.diff


8 Files Affected:

- (modified) llvm/docs/Extensions.rst (+84) 
- (modified) llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp (+77-2) 
- (modified) llvm/test/CodeGen/X86/basic-block-labels-mir-parse.mir (+6) 
- (modified) llvm/test/CodeGen/X86/basic-block-sections-labels-empty-block.ll (+2) 
- (modified) llvm/test/CodeGen/X86/basic-block-sections-labels-empty-function.ll (+4-2) 
- (modified) llvm/test/CodeGen/X86/basic-block-sections-labels-functions-sections.ll (+26-4) 
- (added) llvm/test/CodeGen/X86/basic-block-sections-labels-pgo-features.ll (+120) 
- (modified) llvm/test/CodeGen/X86/basic-block-sections-labels.ll (+41-4) 


``````````diff
diff --git a/llvm/docs/Extensions.rst b/llvm/docs/Extensions.rst
index 6e94840897832a..5dadc85b2c5341 100644
--- a/llvm/docs/Extensions.rst
+++ b/llvm/docs/Extensions.rst
@@ -451,6 +451,90 @@ Example:
    .uleb128  .LBB_END0_1-.LBB0_1          # BB_1 size
    .byte     y                            # BB_1 metadata
 
+PGO Analysis Map Extra Data
+"""""""""""""""""""""""""""
+
+PGO related analysis data can be emitted after each function within the
+BBAddrMap through the optional ``pgo-analysis-map`` flag. Supported analyses
+currently are Function Entry Count, Basic Block Frequencies, and Branch
+Probabilities.
+
+Each analysis is enabled or disabled via a bit in the feature byte. Currently
+those bits are:
+
+#. Function Entry Count - Number of times the function was called as taken
+   from a PGO profile. This will always be zero if PGO was not used or the
+   function was not encountered in the profile.
+
+#. Basic Block Frequencies - Encoded as raw block frequency value taken from
+   MBFI analysis. This value is an integer that encodes the relative frequency
+   compared to the entry block. More information can be found in
+   'llvm/Support/BlockFrequency.h'.
+
+#. Branch Probabilities - Encoded as raw numerator for branch probability
+   taken from MBPI analysis. This value is the numerator for a fixed point ratio
+   defined in 'llvm/Support/BranchProbability.h'. It indicates the probability
+   that the block is followed by a given successor block during execution.
+
+This extra data requires version 2 or above. This is necessary since successors
+of basic blocks won't know their index but will know their BB ID.
+
+Example of BBAddrMap with PGO data:
+
+.. code-block:: gas
+
+  .section  ".llvm_bb_addr_map","", at llvm_bb_addr_map
+  .byte     2                             # version number
+  .byte     7                             # feature byte - PGO analyses enabled mask
+  .quad     .Lfunc_begin0                 # address of the function
+  .uleb128  4                             # number of basic blocks
+  # BB record for BB_0
+   .uleb128  0                            # BB_0 BB ID
+   .uleb128  .Lfunc_begin0-.Lfunc_begin0  # BB_0 offset relative to function entry (always zero)
+   .uleb128  .LBB_END0_0-.Lfunc_begin0    # BB_0 size
+   .byte     0x18                         # BB_0 metadata (multiple successors)
+  # BB record for BB_1
+   .uleb128  1                            # BB_1 BB ID
+   .uleb128  .LBB0_1-.LBB_END0_0          # BB_1 offset relative to the end of last block (BB_0).
+   .uleb128  .LBB_END0_1-.LBB0_1          # BB_1 size
+   .byte     0x0                          # BB_1 metadata (two successors)
+  # BB record for BB_2
+   .uleb128  2                            # BB_2 BB ID
+   .uleb128  .LBB0_2-.LBB_END1_0          # BB_2 offset relative to the end of last block (BB_1).
+   .uleb128  .LBB_END0_2-.LBB0_2          # BB_2 size
+   .byte     0x0                          # BB_2 metadata (one successor)
+  # BB record for BB_3
+   .uleb128  3                            # BB_3 BB ID
+   .uleb128  .LBB0_3-.LBB_END0_2          # BB_3 offset relative to the end of last block (BB_2).
+   .uleb128  .LBB_END0_3-.LBB0_3          # BB_3 size
+   .byte     0x0                          # BB_3 metadata (zero successors)
+  # PGO Analysis Map
+  .uleb128  1000                          # function entry count (only when enabled)
+  # PGO data record for BB_0
+   .uleb128  1000                         # BB_0 basic block frequency (only when enabled)
+   .uleb128  3                            # BB_0 successors count (only enabled with branch probabilities)
+   .uleb128  1                            # BB_0 successor 1 BB ID (only enabled with branch probabilities)
+   .uleb128  0x22222222                   # BB_0 successor 1 branch probability (only enabled with branch probabilities)
+   .uleb128  2                            # BB_0 successor 2 BB ID (only enabled with branch probabilities)
+   .uleb128  0x33333333                   # BB_0 successor 2 branch probability (only enabled with branch probabilities)
+   .uleb128  3                            # BB_0 successor 3 BB ID (only enabled with branch probabilities)
+   .uleb128  0xaaaaaaaa                   # BB_0 successor 3 branch probability (only enabled with branch probabilities)
+  # PGO data record for BB_1
+   .uleb128  133                          # BB_1 basic block frequency (only when enabled)
+   .uleb128  2                            # BB_1 successors count (only enabled with branch probabilities)
+   .uleb128  2                            # BB_1 successor 1 BB ID (only enabled with branch probabilities)
+   .uleb128  0x11111111                   # BB_1 successor 1 branch probability (only enabled with branch probabilities)
+   .uleb128  3                            # BB_1 successor 2 BB ID (only enabled with branch probabilities)
+   .uleb128  0x11111111                   # BB_1 successor 2 branch probability (only enabled with branch probabilities)
+  # PGO data record for BB_2
+   .uleb128  18                           # BB_2 basic block frequency (only when enabled)
+   .uleb128  1                            # BB_2 successors count (only enabled with branch probabilities)
+   .uleb128  3                            # BB_2 successor 1 BB ID (only enabled with branch probabilities)
+   .uleb128  0xffffffff                   # BB_2 successor 1 branch probability (only enabled with branch probabilities)
+  # PGO data record for BB_3
+   .uleb128  1000                         # BB_3 basic block frequency (only when enabled)
+   .uleb128  0                            # BB_3 successors count (only enabled with branch probabilities)
+
 ``SHT_LLVM_OFFLOADING`` Section (offloading data)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 This section stores the binary data used to perform offloading device linking
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 3a679f1576b7b6..78878d30597ab6 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -40,6 +40,7 @@
 #include "llvm/CodeGen/GCMetadataPrinter.h"
 #include "llvm/CodeGen/LazyMachineBlockFrequencyInfo.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineDominators.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
@@ -139,6 +140,26 @@ static cl::opt<std::string> BasicBlockProfileDump(
              "performed with -basic-block-sections=labels. Enabling this "
              "flag during in-process ThinLTO is not supported."));
 
+// This is a replication of fields of object::PGOAnalysisMap::Features. It
+// should match the order of the fields so that
+// `object::PGOAnalysisMap::Features::decode(PgoAnalysisMapFeatures.getBits())`
+// succeeds.
+enum class PGOMapFeaturesEnum {
+  FuncEntryCount,
+  BBFreq,
+  BrProb,
+};
+static cl::bits<PGOMapFeaturesEnum> PgoAnalysisMapFeatures(
+    "pgo-analysis-map", cl::Hidden, cl::CommaSeparated,
+    cl::values(clEnumValN(PGOMapFeaturesEnum::FuncEntryCount, "func-entry-count",
+                          "Function Entry Count"),
+               clEnumValN(PGOMapFeaturesEnum::BBFreq, "bb-freq",
+                          "Basic Block Frequency"),
+               clEnumValN(PGOMapFeaturesEnum::BrProb, "br-prob",
+                          "Branch Probability")),
+    cl::desc("Enable extended information within the BBAddrMap that is "
+             "extracted from PGO related analysis."));
+
 const char DWARFGroupName[] = "dwarf";
 const char DWARFGroupDescription[] = "DWARF Emission";
 const char DbgTimerName[] = "emit";
@@ -427,6 +448,7 @@ void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<MachineOptimizationRemarkEmitterPass>();
   AU.addRequired<GCModuleInfo>();
   AU.addRequired<LazyMachineBlockFrequencyInfoPass>();
+  AU.addRequired<MachineBranchProbabilityInfo>();
 }
 
 bool AsmPrinter::doInitialization(Module &M) {
@@ -1377,7 +1399,8 @@ void AsmPrinter::emitBBAddrMapSection(const MachineFunction &MF) {
   uint8_t BBAddrMapVersion = OutStreamer->getContext().getBBAddrMapVersion();
   OutStreamer->emitInt8(BBAddrMapVersion);
   OutStreamer->AddComment("feature");
-  OutStreamer->emitInt8(0);
+  auto FeaturesBits = static_cast<uint8_t>(PgoAnalysisMapFeatures.getBits());
+  OutStreamer->emitInt8(FeaturesBits);
   OutStreamer->AddComment("function address");
   OutStreamer->emitSymbolValue(FunctionSymbol, getPointerSize());
   OutStreamer->AddComment("number of basic blocks");
@@ -1407,6 +1430,51 @@ void AsmPrinter::emitBBAddrMapSection(const MachineFunction &MF) {
     OutStreamer->emitULEB128IntValue(getBBAddrMapMetadata(MBB));
     PrevMBBEndSymbol = MBB.getEndSymbol();
   }
+
+  if (FeaturesBits != 0) {
+    assert(BBAddrMapVersion >= 2 &&
+           "PGOAnalysisMap only supports version 2 or later");
+
+    auto FeatEnable =
+        cantFail(object::PGOAnalysisMap::Features::decode(FeaturesBits));
+
+    if (FeatEnable.FuncEntryCount) {
+      OutStreamer->AddComment("function entry count");
+      auto MaybeEntryCount = MF.getFunction().getEntryCount();
+      OutStreamer->emitULEB128IntValue(
+          MaybeEntryCount ? MaybeEntryCount->getCount() : 0);
+    }
+    const MachineBlockFrequencyInfo *MBFI =
+        FeatEnable.BBFreq
+            ? &getAnalysis<LazyMachineBlockFrequencyInfoPass>().getBFI()
+            : nullptr;
+    const MachineBranchProbabilityInfo *MBPI =
+        FeatEnable.BrProb ? &getAnalysis<MachineBranchProbabilityInfo>()
+                          : nullptr;
+
+    if (FeatEnable.BBFreq || FeatEnable.BrProb) {
+      for (const MachineBasicBlock &MBB : MF) {
+        if (FeatEnable.BBFreq) {
+          OutStreamer->AddComment("basic block frequency");
+          OutStreamer->emitULEB128IntValue(
+              MBFI->getBlockFreq(&MBB).getFrequency());
+        }
+        if (FeatEnable.BrProb) {
+          unsigned SuccCount = MBB.succ_size();
+          OutStreamer->AddComment("basic block successor count");
+          OutStreamer->emitULEB128IntValue(SuccCount);
+          for (const MachineBasicBlock *SuccMBB : MBB.successors()) {
+            OutStreamer->AddComment("successor BB ID");
+            OutStreamer->emitULEB128IntValue(SuccMBB->getBBID()->BaseID);
+            OutStreamer->AddComment("successor branch probability");
+            OutStreamer->emitULEB128IntValue(
+                MBPI->getEdgeProbability(&MBB, SuccMBB).getNumerator());
+          }
+        }
+      }
+    }
+  }
+
   OutStreamer->popSection();
 }
 
@@ -1932,8 +2000,15 @@ void AsmPrinter::emitFunctionBody() {
 
   // Emit section containing BB address offsets and their metadata, when
   // BB labels are requested for this function. Skip empty functions.
-  if (MF->hasBBLabels() && HasAnyRealCode)
+  bool HasLabels = MF->hasBBLabels();
+  if (HasLabels && HasAnyRealCode)
     emitBBAddrMapSection(*MF);
+  else if (!HasLabels && HasAnyRealCode &&
+           PgoAnalysisMapFeatures.getBits() != 0)
+    MF->getContext().reportWarning(
+        SMLoc(), "pgo-analysis-map is enabled but the following machine "
+                 "function was does not have labels: " +
+                     MF->getName());
 
   // Emit sections containing instruction and function PCs.
   emitPCSections(*MF);
diff --git a/llvm/test/CodeGen/X86/basic-block-labels-mir-parse.mir b/llvm/test/CodeGen/X86/basic-block-labels-mir-parse.mir
index f11707c719895d..5f124c071801db 100644
--- a/llvm/test/CodeGen/X86/basic-block-labels-mir-parse.mir
+++ b/llvm/test/CodeGen/X86/basic-block-labels-mir-parse.mir
@@ -1,6 +1,12 @@
 # Start after bbsections0-prepare and check that the BB address map is generated.
 # RUN: llc -mtriple x86_64-unknown-linux-gnu -start-after=bbsections-prepare  %s -o - | FileCheck %s -check-prefix=CHECK
 
+# Also verify that this holds for PGO extension
+# RUN: llc -mtriple x86_64-unknown-linux-gnu -start-after=bbsections-prepare -pgo-analysis-map=func-entry-count,bb-freq,br-prob %s -o - | FileCheck %s -check-prefix=CHECK
+# RUN: llc -mtriple x86_64-unknown-linux-gnu -start-after=bbsections-prepare -pgo-analysis-map=func-entry-count %s -o - | FileCheck %s -check-prefix=CHECK
+# RUN: llc -mtriple x86_64-unknown-linux-gnu -start-after=bbsections-prepare -pgo-analysis-map=bb-freq %s -o - | FileCheck %s -check-prefix=CHECK
+# RUN: llc -mtriple x86_64-unknown-linux-gnu -start-after=bbsections-prepare -pgo-analysis-map=br-prob %s -o - | FileCheck %s -check-prefix=CHECK
+
 # How to generate the input:
 # foo.cc
 # int foo(bool k) {
diff --git a/llvm/test/CodeGen/X86/basic-block-sections-labels-empty-block.ll b/llvm/test/CodeGen/X86/basic-block-sections-labels-empty-block.ll
index 8e0f4fa7bc928e..f4b3bc1beb0e2e 100644
--- a/llvm/test/CodeGen/X86/basic-block-sections-labels-empty-block.ll
+++ b/llvm/test/CodeGen/X86/basic-block-sections-labels-empty-block.ll
@@ -1,5 +1,7 @@
 ;; This test verifies that with -gc-empty-basic-blocks SHT_LLVM_BB_ADDR_MAP will not include entries for empty blocks.
 ; RUN: llc < %s -mtriple=x86_64 -O0 -basic-block-sections=labels -gc-empty-basic-blocks | FileCheck --check-prefix=CHECK %s
+;; Additionally test that this holds for pgo extension
+; RUN: llc < %s -mtriple=x86_64 -O0 -basic-block-sections=labels -pgo-analysis-map=bb-freq -gc-empty-basic-blocks | FileCheck --check-prefixes=CHECK %s
 
 define void @foo(i1 zeroext %0) nounwind {
   br i1 %0, label %2, label %empty_block
diff --git a/llvm/test/CodeGen/X86/basic-block-sections-labels-empty-function.ll b/llvm/test/CodeGen/X86/basic-block-sections-labels-empty-function.ll
index 7b7bbb95fb4e21..d2e09884ff1299 100644
--- a/llvm/test/CodeGen/X86/basic-block-sections-labels-empty-function.ll
+++ b/llvm/test/CodeGen/X86/basic-block-sections-labels-empty-function.ll
@@ -1,5 +1,6 @@
 ;; Verify that the BB address map is not emitted for empty functions.
-; RUN: llc < %s -mtriple=x86_64 -basic-block-sections=labels | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64 -basic-block-sections=labels | FileCheck %s --check-prefixes=CHECK,BASIC
+; RUN: llc < %s -mtriple=x86_64 -basic-block-sections=labels -pgo-analysis-map=bb-freq | FileCheck %s --check-prefixes=CHECK,PGO
 
 define void @empty_func() {
 entry:
@@ -19,5 +20,6 @@ entry:
 ; CHECK:	.Lfunc_begin1:
 ; CHECK:		.section	.llvm_bb_addr_map,"o", at llvm_bb_addr_map,.text{{$}}
 ; CHECK-NEXT:		.byte 2			# version
-; CHECK-NEXT:		.byte 0			# feature
+; BASIC-NEXT:		.byte 0			# feature
+; PGO-NEXT:		.byte 2			# feature
 ; CHECK-NEXT:		.quad	.Lfunc_begin1	# function address
diff --git a/llvm/test/CodeGen/X86/basic-block-sections-labels-functions-sections.ll b/llvm/test/CodeGen/X86/basic-block-sections-labels-functions-sections.ll
index b8217bbc00760f..1b31069b67113c 100644
--- a/llvm/test/CodeGen/X86/basic-block-sections-labels-functions-sections.ll
+++ b/llvm/test/CodeGen/X86/basic-block-sections-labels-functions-sections.ll
@@ -1,4 +1,5 @@
-; RUN: llc < %s -mtriple=x86_64 -function-sections -basic-block-sections=labels | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64 -function-sections -basic-block-sections=labels | FileCheck %s --check-prefixes=CHECK,BASIC
+; RUN: llc < %s -mtriple=x86_64 -function-sections -basic-block-sections=labels -pgo-analysis-map=func-entry-count,bb-freq | FileCheck %s --check-prefixes=CHECK,PGO
 
 $_Z4fooTIiET_v = comdat any
 
@@ -11,8 +12,15 @@ define dso_local i32 @_Z3barv() {
 ; CHECK-NEXT:	[[BAR_BEGIN:.Lfunc_begin[0-9]+]]:
 ; CHECK:		.section .llvm_bb_addr_map,"o", at llvm_bb_addr_map,.text._Z3barv{{$}}
 ; CHECK-NEXT:		.byte 2			# version
-; CHECK-NEXT:		.byte 0			# feature
+; BASIC-NEXT:		.byte 0			# feature
+; PGO-NEXT:		.byte 3			# feature
 ; CHECK-NEXT:		.quad [[BAR_BEGIN]]	# function address
+; CHECK-NEXT:		.byte 1			# number of basic blocks
+; CHECK-NEXT:	      	.byte 0			# BB id
+; CHECK-NEXT:	      	.uleb128 .Lfunc_begin0-.Lfunc_begin0
+; CHECK-NEXT:	      	.uleb128 .LBB_END0_0-.Lfunc_begin0
+; CHECK-NEXT:	      	.byte 1
+; PGO-NEXT:		.byte 0			# function entry count
 
 
 define dso_local i32 @_Z3foov() {
@@ -24,8 +32,15 @@ define dso_local i32 @_Z3foov() {
 ; CHECK-NEXT:	[[FOO_BEGIN:.Lfunc_begin[0-9]+]]:
 ; CHECK:		.section  .llvm_bb_addr_map,"o", at llvm_bb_addr_map,.text._Z3foov{{$}}
 ; CHECK-NEXT:		.byte 2			# version
-; CHECK-NEXT:		.byte 0			# feature
+; BASIC-NEXT:		.byte 0			# feature
+; PGO-NEXT:		.byte 3			# feature
 ; CHECK-NEXT:		.quad [[FOO_BEGIN]]	# function address
+; CHECK-NEXT:		.byte 1			# number of basic blocks
+; CHECK-NEXT:	      	.byte 0			# BB id
+; CHECK-NEXT:	      	.uleb128 .Lfunc_begin1-.Lfunc_begin1
+; CHECK-NEXT:	      	.uleb128 .LBB_END1_0-.Lfunc_begin1
+; CHECK-NEXT:	      	.byte 1
+; PGO-NEXT:		.byte 0			# function entry count
 
 
 define linkonce_odr dso_local i32 @_Z4fooTIiET_v() comdat {
@@ -37,5 +52,12 @@ define linkonce_odr dso_local i32 @_Z4fooTIiET_v() comdat {
 ; CHECK-NEXT:	[[FOOCOMDAT_BEGIN:.Lfunc_begin[0-9]+]]:
 ; CHECK:		.section .llvm_bb_addr_map,"Go", at llvm_bb_addr_map,_Z4fooTIiET_v,comdat,.text._Z4fooTIiET_v{{$}}
 ; CHECK-NEXT:		.byte 2				# version
-; CHECK-NEXT:		.byte 0				# feature
+; BASIC-NEXT:		.byte 0				# feature
+; PGO-NEXT:		.byte 3				# feature
 ; CHECK-NEXT:		.quad [[FOOCOMDAT_BEGIN]]	# function address
+; CHECK-NEXT:		.byte 1				# number of basic blocks
+; CHECK-NEXT:	      	.byte 0			# BB id
+; CHECK-NEXT:	      	.uleb128 .Lfunc_begin2-.Lfunc_begin2
+; CHECK-NEXT:	      	.uleb128 .LBB_END2_0-.Lfunc_begin2
+; CHECK-NEXT:	      	.byte 1
+; PGO-NEXT:		.byte 0				# function entry count
diff --git a/llvm/test/CodeGen/X86/basic-block-sections-labels-pgo-features.ll b/llvm/test/CodeGen/X86/basic-block-sections-labels-pgo-features.ll
new file mode 100644
index 00000000000000..4c4cb615e593c7
--- /dev/null
+++ b/llvm/test/CodeGen/X86/basic-block-sections-labels-pgo-features.ll
@@ -0,0 +1,120 @@
+; Check the basic block sections labels option
+; RUN: llc < %s -mtriple=x86_64 -function-sections -unique-section-names=true -basic-block-sections=labels | FileCheck %s --check-prefixes=CHECK,BASIC
+
+;; Also verify this holds for all PGO features enabled
+; RUN: llc < %s -mtriple=x86_64 -function-sections -unique-section-names=true -basic-block-sections=labels -pgo-analysis-map=func-entry-count,bb-freq,br-prob | FileCheck %s --check-prefixes=CHECK,PGO-ALL,PGO-FEC,PGO-BBF,PGO-BRP
+
+;; Also verify that pgo extension only includes the enabled feature
+; RUN: llc < %s -mtriple=x86_64 -function-sections -unique-section-names=true -basic-block-sections=labels -pgo-analysis-map=func-entry-count | FileCheck %s --check-prefixes=CHECK,PGO-FEC,FEC-ONLY
+; RUN: llc < %s -mtriple=x86_64 -function-sections -unique-section-names=true -basic-block-sections=labels -pgo-analysis-map=bb-freq | FileCheck %s --check-prefixes=CHECK,PGO-BBF,BBF-ONLY
+; RUN: llc < %s -mtriple=x86_64 -function-sections -unique-section-names=true -basic-block-sections=labels -pgo-analysis-map=br-prob | FileCheck %s --check-prefixes=CHECK,PGO-BRP,BRP-ONLY
+
+
+define void @_Z3bazb(i1 zeroext, i1 zeroext) personality ptr @__gxx_personality_v0 {
+  br i1 %0, label %3, label %8
+
+3:
+  %4 = invoke i32 @_Z3barv()
+          to label %8 unwind label %6
+  br label %10
+
+6:
+  landingpad { ptr, i32 }
+          catch ptr null
+  br label %12
+
+8:
+  %9 = call i32 @_Z3foov()
+  br i1 %1, label %12, label %10
+
+10:
+  %11 = select i1 %1, ptr blockaddress(@_Z3bazb, %3), ptr blockaddress(@_Z3bazb, %12) ; <ptr> [#uses=1]
+  indirectbr ptr %11, [label %3, label %12]
+
+12:
+  ret void
+}
+
+declare i32 @_Z3barv() #1
+
+declare i32 @_Z3foov() #1
+
+declare i32 @__gxx_personality_v0(...)
+
+; CHECK:	.section .text._Z3bazb,"ax", at progbits{{$}}
+; CHECK-LABEL:	_Z3bazb:
+; CHECK-LABEL:	.Lfunc_begin0:
+; CHECK-LABEL:	.LBB_END0_0:
+; CHECK-LABEL:	.LBB0_1:
+; CHECK-LABEL:	.LBB_END0_1:
+; CHECK-LABEL:	.LBB0_2:
+; CHECK-LABEL:	.LBB_END0_2:
+; CHECK-LABEL:	.LBB0_3:
+; CHECK-LABEL:	.LBB_END0_3:
+; CHECK-LABEL:	.Lfunc_end0:
+
+; CHECK: 	.section	.llvm_bb_addr_map,"o", at llvm_bb_addr_map,.text._Z3bazb{{$}}
+; CHECK-NEXT:   .byte   2		# version
+; BASIC-NEXT:   .byte   0		# feature
+; PGO-ALL-NEXT:	.byte   7		# feature
+; FEC-ONLY-NEXT:.byte   1		# feature
+; BBF-ONLY-NEXT:.byte   2		# feature
+; BRP-ONLY-NEXT:.byte   4		# feature
+; CHECK-NEXT:	.quad	.Lfunc_begin0	# function address
+; CHECK-NEXT:	.byte	6		# number of basic blocks
+; CHECK-NEXT: ...
[truncated]

``````````

</details>


https://github.com/llvm/llvm-project/pull/75202


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