[llvm] 01a7c88 - [AMDGPU][LowerBufferFatPointers] Erase dead ptr(7) intrinsics (#160798)

[via llvm-commits]

Author: Krzysztof Drewniak
Date: 2025-09-29T10:46:45-05:00
New Revision: 01a7c880d27b7b594910e03d173819d90d14c421

URL: https://github.com/llvm/llvm-project/commit/01a7c880d27b7b594910e03d173819d90d14c421
DIFF: https://github.com/llvm/llvm-project/commit/01a7c880d27b7b594910e03d173819d90d14c421.diff

LOG: [AMDGPU][LowerBufferFatPointers] Erase dead ptr(7) intrinsics (#160798)

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.

---------

Co-authored-by: Shilei Tian <i at tianshilei.me>

Added: 
    llvm/test/CodeGen/AMDGPU/lower-buffer-fat-pointers-dead-intrinsics.ll

Modified: 
    llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
index d9bfeae52e213..0a5913293238a 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 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();
     } 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..d6198f5000c34
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/lower-buffer-fat-pointers-dead-intrinsics.ll
@@ -0,0 +1,9 @@
+; 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))
+
+; 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