AMDGPU: Make ballot intrinsic propagate poison

[arsenm]

No description provided.

[arsenm]

• AMDGPU: Make fma_legacy intrinsic propagate poison #131063
• AMDGPU: Make fmul_legacy intrinsic propagate poison #131062
• AMDGPU: Make ballot intrinsic propagate poison #131061 👈 (View in Graphite)
• AMDGPU: Make fmed3 intrinsic propagate poison #131060
• AMDGPU: Make cvt_pknorm and cvt_pk intrinsics propagate poison #131059
• main

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[llvmbot]

@llvm/pr-subscribers-llvm-transforms

@llvm/pr-subscribers-backend-amdgpu

Author: Matt Arsenault (arsenm)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/131061.diff

2 Files Affected:

• (modified) llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp (+5-1)
• (modified) llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll (+16)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp b/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp
index 5d6f6d0c2c901..083fa2a730fff 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp
@@ -1049,7 +1049,11 @@ GCNTTIImpl::instCombineIntrinsic(InstCombiner &IC, IntrinsicInst &II) const {
     break;
   }
   case Intrinsic::amdgcn_ballot: {
-    if (auto *Src = dyn_cast<ConstantInt>(II.getArgOperand(0))) {
+    Value *Arg = II.getArgOperand(0);
+    if (isa<PoisonValue>(Arg))
+      return IC.replaceInstUsesWith(II, PoisonValue::get(II.getType()));
+
+    if (auto *Src = dyn_cast<ConstantInt>(Arg)) {
       if (Src->isZero()) {
         // amdgcn.ballot(i1 0) is zero.
         return IC.replaceInstUsesWith(II, Constant::getNullValue(II.getType()));
diff --git a/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll b/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll
index cfc0e345aaa3d..91f25576034bb 100644
--- a/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll
+++ b/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll
@@ -2952,6 +2952,22 @@ define i32 @ballot_one_32() {
   ret i32 %b
 }
 
+define i64 @ballot_poison_64() {
+; CHECK-LABEL: @ballot_poison_64(
+; CHECK-NEXT:    ret i64 poison
+;
+  %b = call i64 @llvm.amdgcn.ballot.i64(i1 poison)
+  ret i64 %b
+}
+
+define i32 @ballot_poison_32() {
+; CHECK-LABEL: @ballot_poison_32(
+; CHECK-NEXT:    ret i32 poison
+;
+  %b = call i32 @llvm.amdgcn.ballot.i32(i1 poison)
+  ret i32 %b
+}
+
 ; --------------------------------------------------------------------
 ; llvm.amdgcn.wqm.vote
 ; --------------------------------------------------------------------

[pravinjagtap]

LGTM

[arsenm]

Merge activity

• Mar 14, 12:23 AM EDT: A user started a stack merge that includes this pull request via Graphite.
• Mar 14, 12:31 AM EDT: Graphite rebased this pull request as part of a merge.
• Mar 14, 12:34 AM EDT: Graphite rebased this pull request as part of a merge.
• Mar 14, 12:36 AM EDT: A user merged this pull request with Graphite.