[llvm-branch-commits] [llvm] AMDGPU: Preserve atomicrmw name when specializing address space (PR #102470)

[via llvm-branch-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-llvm-transforms

@llvm/pr-subscribers-backend-amdgpu

Author: Matt Arsenault (arsenm)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/102470.diff


2 Files Affected:

- (modified) llvm/lib/Target/AMDGPU/SIISelLowering.cpp (+2-1) 
- (added) llvm/test/Transforms/AtomicExpand/AMDGPU/expand-atomic-rmw-fadd-flat-specialization-preserve-name.ll (+10) 


``````````diff
diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
index e982f1e643289..7735833b1ad2c 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -16654,12 +16654,13 @@ void SITargetLowering::emitExpandAtomicRMW(AtomicRMWInst *AI) const {
   Builder.CreateBr(PhiBB);
 
   Builder.SetInsertPoint(PhiBB);
-  PHINode *Loaded = Builder.CreatePHI(ValTy, 3, "loaded.phi");
+  PHINode *Loaded = Builder.CreatePHI(ValTy, 3);
   Loaded->addIncoming(LoadedShared, SharedBB);
   Loaded->addIncoming(LoadedPrivate, PrivateBB);
   Loaded->addIncoming(LoadedGlobal, GlobalBB);
   Builder.CreateBr(ExitBB);
 
+  Loaded->takeName(AI);
   AI->replaceAllUsesWith(Loaded);
   AI->eraseFromParent();
 }
diff --git a/llvm/test/Transforms/AtomicExpand/AMDGPU/expand-atomic-rmw-fadd-flat-specialization-preserve-name.ll b/llvm/test/Transforms/AtomicExpand/AMDGPU/expand-atomic-rmw-fadd-flat-specialization-preserve-name.ll
new file mode 100644
index 0000000000000..44cd7097059cd
--- /dev/null
+++ b/llvm/test/Transforms/AtomicExpand/AMDGPU/expand-atomic-rmw-fadd-flat-specialization-preserve-name.ll
@@ -0,0 +1,10 @@
+; RUN: opt -S -mtriple=amdgcn-amd-amdhsa -mcpu=gfx90a -passes=atomic-expand %s | FileCheck %s
+
+; CHECK: %preserve_me = phi float [ %{{[0-9]+}}, %atomicrmw.shared ], [ %loaded.private, %atomicrmw.private ], [ %{{[0-9]+}}, %atomicrmw.global ]
+; CHECK: ret float %preserve_me
+define float @expand_preserve_name(ptr %addr, float %val) {
+  %preserve_me = atomicrmw fadd ptr %addr, float %val seq_cst, !amdgpu.no.fine.grained.memory !0, !amdgpu.ignore.denormal.mode !0
+  ret float %preserve_me
+}
+
+!0 = !{}

``````````

</details>


https://github.com/llvm/llvm-project/pull/102470