[llvm-branch-commits] [llvm] [AMDGPU] Remove dead function metadata after amdgpu-lower-kernel-arguments (PR #126147)

[Scott Linder via llvm-branch-commits]

https://github.com/slinder1 created https://github.com/llvm/llvm-project/pull/126147

The verifier ensures function !dbg metadata is unique across the module,
so ensure the old nameless function we leave behind doesn't violate
this invariant.

Removing the function via e.g. eraseFromParent seems like a better
option, but doesn't seem to be legal from a FunctionPass.

>From bc50ff180b53b9b65cc14f2f873edffd733845e0 Mon Sep 17 00:00:00 2001
From: Scott Linder <Scott.Linder at amd.com>
Date: Wed, 5 Feb 2025 22:56:55 +0000
Subject: [PATCH] [AMDGPU] Remove dead function metadata after
 amdgpu-lower-kernel-arguments

The verifier ensures function !dbg metadata is unique across the module,
so ensure the old nameless function we leave behind doesn't violate
this invariant.

Removing the function via e.g. eraseFromParent seems like a better
option, but doesn't seem to be legal from a FunctionPass.
---
 llvm/lib/Target/AMDGPU/AMDGPULowerKernelArguments.cpp       | 1 +
 .../CodeGen/AMDGPU/preload-implicit-kernargs-debug-info.ll  | 6 +++---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPULowerKernelArguments.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerKernelArguments.cpp
index e9d009baa20af29..09412d1b0f1cc96 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULowerKernelArguments.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULowerKernelArguments.cpp
@@ -132,6 +132,7 @@ class PreloadKernelArgInfo {
     NF->setAttributes(AL);
     F.replaceAllUsesWith(NF);
     F.setCallingConv(CallingConv::C);
+    F.clearMetadata();
 
     return NF;
   }
diff --git a/llvm/test/CodeGen/AMDGPU/preload-implicit-kernargs-debug-info.ll b/llvm/test/CodeGen/AMDGPU/preload-implicit-kernargs-debug-info.ll
index fe110cbcafc465d..4b47a218f1be45b 100644
--- a/llvm/test/CodeGen/AMDGPU/preload-implicit-kernargs-debug-info.ll
+++ b/llvm/test/CodeGen/AMDGPU/preload-implicit-kernargs-debug-info.ll
@@ -1,7 +1,7 @@
-; RUN: not --crash opt -mtriple=amdgcn-amd-amdhsa -mcpu=gfx940 -passes='amdgpu-attributor,function(amdgpu-lower-kernel-arguments)' -amdgpu-kernarg-preload-count=16 -S < %s 2>&1 | FileCheck %s
+; RUN: opt -mtriple=amdgcn-amd-amdhsa -mcpu=gfx940 -passes='amdgpu-attributor,function(amdgpu-lower-kernel-arguments)' -amdgpu-kernarg-preload-count=16 -S < %s 2>&1 | FileCheck %s
 
-; CHECK: function declaration may only have a unique !dbg attachment
-; CHECK-NEXT: ptr @0
+; CHECK: define amdgpu_kernel void @preload_block_count_x{{.*}} !dbg ![[#]]
+; CHECK-NOT: declare void @0{{.*}} !dbg ![[#]]
 
 define amdgpu_kernel void @preload_block_count_x(ptr addrspace(1) %out) !dbg !4 {
   %imp_arg_ptr = call ptr addrspace(4) @llvm.amdgcn.implicitarg.ptr()