AMDGPU: Make fmed3 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
• AMDGPU: Make fmed3 intrinsic propagate poison #131060 👈 (View in Graphite)
• 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/131060.diff

2 Files Affected:

• (modified) llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp (+5)
• (modified) llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll (+24)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp b/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp
index 75b79b129d358..5d6f6d0c2c901 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp
@@ -826,6 +826,11 @@ GCNTTIImpl::instCombineIntrinsic(InstCombiner &IC, IntrinsicInst &II) const {
     Value *Src1 = II.getArgOperand(1);
     Value *Src2 = II.getArgOperand(2);
 
+    for (Value *Src : {Src0, Src1, Src2}) {
+      if (isa<PoisonValue>(Src))
+        return IC.replaceInstUsesWith(II, Src);
+    }
+
     // Checking for NaN before canonicalization provides better fidelity when
     // mapping other operations onto fmed3 since the order of operands is
     // unchanged.
diff --git a/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll b/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll
index 14f31280cc878..cfc0e345aaa3d 100644
--- a/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll
+++ b/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll
@@ -2113,6 +2113,30 @@ define float @fmed3_0_1_undef_f32() {
   ret float %med
 }
 
+define float @fmed3_poison_x_y_f32(float %x, float %y) {
+; CHECK-LABEL: @fmed3_poison_x_y_f32(
+; CHECK-NEXT:    ret float poison
+;
+  %med3 = call float @llvm.amdgcn.fmed3.f32(float poison, float %x, float %y)
+  ret float %med3
+}
+
+define float @fmed3_x_poison_y_f32(float %x, float %y) {
+; CHECK-LABEL: @fmed3_x_poison_y_f32(
+; CHECK-NEXT:    ret float poison
+;
+  %med3 = call float @llvm.amdgcn.fmed3.f32(float %x, float poison, float %y)
+  ret float %med3
+}
+
+define float @fmed3_x_y_poison_f32(float %x, float %y) {
+; CHECK-LABEL: @fmed3_x_y_poison_f32(
+; CHECK-NEXT:    ret float poison
+;
+  %med3 = call float @llvm.amdgcn.fmed3.f32(float %x, float %y, float poison)
+  ret float %med3
+}
+
 ; --------------------------------------------------------------------
 ; llvm.amdgcn.icmp
 ; --------------------------------------------------------------------

[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, 12:28 AM EDT: Graphite rebased this pull request as part of a merge.
• Mar 14, 12:30 AM EDT: A user merged this pull request with Graphite.