[llvm] [AMDGPU][LowerBufferFatPointers] Erase dead ptr(7) intrinsics (PR #160798)

[Krzysztof Drewniak via llvm-commits]

https://github.com/krzysz00 updated https://github.com/llvm/llvm-project/pull/160798

>From a89ea96f1bac93223af3d237e8ad4b9513b5cdec Mon Sep 17 00:00:00 2001
From: Krzysztof Drewniak <Krzysztof.Drewniak at amd.com>
Date: Thu, 25 Sep 2025 23:50:54 +0000
Subject: [PATCH 1/4] [AMDGPU][LowerBufferFatPointers] Erase dead ptr(7)
 intrinsics

Fix a crash that would arise when intrinsics like llvm.masked.load.T.p7
were left in the module when AMDGPULowerBufferFatPointers was applied
and so a captures(none) annotation would be applied to a non-pointer
value, triggering a verifier failure.
---
 .../Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp    |  4 +++-
 .../lower-buffer-fat-pointers-dead-intrinsics.ll      | 11 +++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 llvm/test/CodeGen/AMDGPU/lower-buffer-fat-pointers-dead-intrinsics.ll

diff --git a/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
index d9bfeae52e213..eac3329d00f9b 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
@@ -2562,7 +2562,9 @@ bool AMDGPULowerBufferFatPointers::run(Module &M, const TargetMachine &TM) {
   for (Function *F : NeedsPostProcess)
     Splitter.processFunction(*F);
   for (Function *F : Intrinsics) {
-    if (isRemovablePointerIntrinsic(F->getIntrinsicID())) {
+    // use_empty() can also occor with cases like malked load, which will
+    // have been rewritten out of the module by now but not erased.
+    if (F->use_empty() || isRemovablePointerIntrinsic(F->getIntrinsicID())) {
       F->eraseFromParent();
     } else {
       std::optional<Function *> NewF = Intrinsic::remangleIntrinsicFunction(F);
diff --git a/llvm/test/CodeGen/AMDGPU/lower-buffer-fat-pointers-dead-intrinsics.ll b/llvm/test/CodeGen/AMDGPU/lower-buffer-fat-pointers-dead-intrinsics.ll
new file mode 100644
index 0000000000000..a156ecdc4b53b
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/lower-buffer-fat-pointers-dead-intrinsics.ll
@@ -0,0 +1,11 @@
+; RUN: opt -S -mcpu=gfx900 -amdgpu-lower-buffer-fat-pointers < %s | FileCheck %s
+; RUN: opt -S -mcpu=gfx900 -passes=amdgpu-lower-buffer-fat-pointers < %s | FileCheck %s
+
+target triple = "amdgcn-amd-amdhsa"
+
+; CHECK: @arbitrary
+declare amdgpu_kernel void @arbitrary(ptr addrspace(1))
+
+; COM: This used to cause verifier errors when "lowered"
+declare <4 x i8> @llvm.masked.load.v4i8.p7(ptr addrspace(7) captures(none), i32 immarg, <4 x i1>, <4 x i8>)
+; CHECK-NOT: llvm.masked.load

>From f6d50ffbb0ff400af6d6795e2bab2406cdb11264 Mon Sep 17 00:00:00 2001
From: Krzysztof Drewniak <Krzysztof.Drewniak at amd.com>
Date: Fri, 26 Sep 2025 13:05:34 -0500
Subject: [PATCH 2/4] Change run lines

Co-authored-by: Shilei Tian <i at tianshilei.me>
---
 .../AMDGPU/lower-buffer-fat-pointers-dead-intrinsics.ll     | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/llvm/test/CodeGen/AMDGPU/lower-buffer-fat-pointers-dead-intrinsics.ll b/llvm/test/CodeGen/AMDGPU/lower-buffer-fat-pointers-dead-intrinsics.ll
index a156ecdc4b53b..d6198f5000c34 100644
--- a/llvm/test/CodeGen/AMDGPU/lower-buffer-fat-pointers-dead-intrinsics.ll
+++ b/llvm/test/CodeGen/AMDGPU/lower-buffer-fat-pointers-dead-intrinsics.ll
@@ -1,7 +1,5 @@
-; RUN: opt -S -mcpu=gfx900 -amdgpu-lower-buffer-fat-pointers < %s | FileCheck %s
-; RUN: opt -S -mcpu=gfx900 -passes=amdgpu-lower-buffer-fat-pointers < %s | FileCheck %s
-
-target triple = "amdgcn-amd-amdhsa"
+; RUN: opt -S -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -amdgpu-lower-buffer-fat-pointers < %s | FileCheck %s
+; RUN: opt -S -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -passes=amdgpu-lower-buffer-fat-pointers < %s | FileCheck %s
 
 ; CHECK: @arbitrary
 declare amdgpu_kernel void @arbitrary(ptr addrspace(1))

>From 387e9b7f3044d00967d8590a82d5ec70547f92c9 Mon Sep 17 00:00:00 2001
From: Krzysztof Drewniak <Krzysztof.Drewniak at amd.com>
Date: Fri, 26 Sep 2025 18:05:57 +0000
Subject: [PATCH 3/4] Fix typo

---
 llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
index eac3329d00f9b..de9bc2e77b7fe 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
@@ -2562,7 +2562,7 @@ bool AMDGPULowerBufferFatPointers::run(Module &M, const TargetMachine &TM) {
   for (Function *F : NeedsPostProcess)
     Splitter.processFunction(*F);
   for (Function *F : Intrinsics) {
-    // use_empty() can also occor with cases like malked load, which will
+    // use_empty() can also occor with cases like masked load, which will
     // have been rewritten out of the module by now but not erased.
     if (F->use_empty() || isRemovablePointerIntrinsic(F->getIntrinsicID())) {
       F->eraseFromParent();

>From 520c37cb4b3a03e9fae2fe48caaff23dfd5a01d3 Mon Sep 17 00:00:00 2001
From: Krzysztof Drewniak <Krzysztof.Drewniak at amd.com>
Date: Fri, 26 Sep 2025 18:07:22 +0000
Subject: [PATCH 4/4] Fix the other typo

---
 llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
index de9bc2e77b7fe..0a5913293238a 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
@@ -2562,7 +2562,7 @@ bool AMDGPULowerBufferFatPointers::run(Module &M, const TargetMachine &TM) {
   for (Function *F : NeedsPostProcess)
     Splitter.processFunction(*F);
   for (Function *F : Intrinsics) {
-    // use_empty() can also occor with cases like masked load, which will
+    // use_empty() can also occur with cases like masked load, which will
     // have been rewritten out of the module by now but not erased.
     if (F->use_empty() || isRemovablePointerIntrinsic(F->getIntrinsicID())) {
       F->eraseFromParent();