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[DAG] isGuaranteedNotToBeUndefOrPoisonForTargetNode - add fallback implementation #86125

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Merged
merged 1 commit into from
Mar 21, 2024
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[DAG] isGuaranteedNotToBeUndefOrPoisonForTargetNode - add fallback implementation #86125

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5 changes: 3 additions & 2 deletions llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5042,8 +5042,9 @@ bool SelectionDAG::isGuaranteedNotToBeUndefOrPoison(SDValue Op,

// If Op can't create undef/poison and none of its operands are undef/poison
// then Op is never undef/poison.
// NOTE: TargetNodes should handle this in themselves in
// isGuaranteedNotToBeUndefOrPoisonForTargetNode.
// NOTE: TargetNodes can handle this in themselves in
// isGuaranteedNotToBeUndefOrPoisonForTargetNode or let
// TargetLowering::isGuaranteedNotToBeUndefOrPoisonForTargetNode handle it.
return !canCreateUndefOrPoison(Op, PoisonOnly, /*ConsiderFlags*/ true,
Depth) &&
all_of(Op->ops(), [&](SDValue V) {
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10 changes: 9 additions & 1 deletion llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
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Expand Up @@ -3786,7 +3786,15 @@ bool TargetLowering::isGuaranteedNotToBeUndefOrPoisonForTargetNode(
Op.getOpcode() == ISD::INTRINSIC_VOID) &&
"Should use isGuaranteedNotToBeUndefOrPoison if you don't know whether Op"
" is a target node!");
return false;

// If Op can't create undef/poison and none of its operands are undef/poison
// then Op is never undef/poison.
return !canCreateUndefOrPoisonForTargetNode(Op, DemandedElts, DAG, PoisonOnly,
/*ConsiderFlags*/ true, Depth) &&
all_of(Op->ops(), [&](SDValue V) {
return DAG.isGuaranteedNotToBeUndefOrPoison(V, PoisonOnly,
Depth + 1);
});
}

bool TargetLowering::canCreateUndefOrPoisonForTargetNode(
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