[llvm] 17c7c2e - [DAG] Add missing Depth argument to isGuaranteedNotToBeUndefOrPoison calls inside SimplifyDemanded methods (#149550)

[via llvm-commits]

Author: Simon Pilgrim
Date: 2025-07-20T13:06:55+01:00
New Revision: 17c7c2ebe850b705df0fee4f1160d72097c6cb8f

URL: https://github.com/llvm/llvm-project/commit/17c7c2ebe850b705df0fee4f1160d72097c6cb8f
DIFF: https://github.com/llvm/llvm-project/commit/17c7c2ebe850b705df0fee4f1160d72097c6cb8f.diff

LOG: [DAG] Add missing Depth argument to isGuaranteedNotToBeUndefOrPoison calls inside SimplifyDemanded methods (#149550)

Ensure we don't exceed the maximum recursion depth

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
    llvm/test/CodeGen/X86/pr62286.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index e0597988e8907..37fddcf943681 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -778,7 +778,7 @@ SDValue TargetLowering::SimplifyMultipleUseDemandedBits(
   case ISD::FREEZE: {
     SDValue N0 = Op.getOperand(0);
     if (DAG.isGuaranteedNotToBeUndefOrPoison(N0, DemandedElts,
-                                             /*PoisonOnly=*/false))
+                                             /*PoisonOnly=*/false, Depth + 1))
       return N0;
     break;
   }
@@ -3369,7 +3369,8 @@ bool TargetLowering::SimplifyDemandedVectorElts(
   case ISD::FREEZE: {
     SDValue N0 = Op.getOperand(0);
     if (TLO.DAG.isGuaranteedNotToBeUndefOrPoison(N0, DemandedElts,
-                                                 /*PoisonOnly=*/false))
+                                                 /*PoisonOnly=*/false,
+                                                 Depth + 1))
       return TLO.CombineTo(Op, N0);
 
     // TODO: Replace this with the general fold from DAGCombiner::visitFREEZE

diff  --git a/llvm/test/CodeGen/X86/pr62286.ll b/llvm/test/CodeGen/X86/pr62286.ll
index 2d1b7fcbf0239..9728e130333c4 100644
--- a/llvm/test/CodeGen/X86/pr62286.ll
+++ b/llvm/test/CodeGen/X86/pr62286.ll
@@ -42,10 +42,10 @@ define i64 @PR62286(i32 %a) {
 ; AVX2-LABEL: PR62286:
 ; AVX2:       # %bb.0:
 ; AVX2-NEXT:    vmovd %edi, %xmm0
-; AVX2-NEXT:    vpaddd %xmm0, %xmm0, %xmm1
-; AVX2-NEXT:    vpslldq {{.*#+}} xmm0 = zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3]
-; AVX2-NEXT:    vpand {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0, %xmm0
-; AVX2-NEXT:    vpblendd {{.*#+}} xmm0 = xmm1[0],xmm0[1,2,3]
+; AVX2-NEXT:    vpslldq {{.*#+}} xmm1 = zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,zero,xmm0[0,1,2,3]
+; AVX2-NEXT:    vpaddd %xmm0, %xmm0, %xmm0
+; AVX2-NEXT:    vpand {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm1, %xmm1
+; AVX2-NEXT:    vpor %xmm0, %xmm1, %xmm0
 ; AVX2-NEXT:    vpmovsxdq %xmm0, %ymm0
 ; AVX2-NEXT:    vextracti128 $1, %ymm0, %xmm1
 ; AVX2-NEXT:    vpaddq %xmm1, %xmm0, %xmm0