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[IVDescriptor] Explicitly check for isMinMaxRecurrenceKind in getReductionOpChain. NFC #132025

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Merged
merged 2 commits into from
Mar 20, 2025
Merged

[IVDescriptor] Explicitly check for isMinMaxRecurrenceKind in getReductionOpChain. NFC #132025

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28799f3
[IVDescriptor] Explicitly check for isMinMaxRecurrenceKind in getRedu…
lukel97 Mar 19, 2025
a463ce3
Calculate IsMinMax once
lukel97 Mar 20, 2025
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7 changes: 4 additions & 3 deletions llvm/lib/Analysis/IVDescriptors.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1167,6 +1167,7 @@ SmallVector<Instruction *, 4>
RecurrenceDescriptor::getReductionOpChain(PHINode *Phi, Loop *L) const {
SmallVector<Instruction *, 4> ReductionOperations;
unsigned RedOp = getOpcode();
const bool IsMinMax = isMinMaxRecurrenceKind(Kind);

// Search down from the Phi to the LoopExitInstr, looking for instructions
// with a single user of the correct type for the reduction.
Expand All @@ -1184,15 +1185,15 @@ RecurrenceDescriptor::getReductionOpChain(PHINode *Phi, Loop *L) const {
// more expensive than out-of-loop reductions, and need to be costed more
// carefully.
unsigned ExpectedUses = 1;
if (RedOp == Instruction::ICmp || RedOp == Instruction::FCmp)
if (IsMinMax)
ExpectedUses = 2;

auto getNextInstruction = [&](Instruction *Cur) -> Instruction * {
for (auto *User : Cur->users()) {
Instruction *UI = cast<Instruction>(User);
if (isa<PHINode>(UI))
continue;
if (RedOp == Instruction::ICmp || RedOp == Instruction::FCmp) {
if (IsMinMax) {
// We are expecting a icmp/select pair, which we go to the next select
// instruction if we can. We already know that Cur has 2 uses.
if (isa<SelectInst>(UI))
Expand All @@ -1204,7 +1205,7 @@ RecurrenceDescriptor::getReductionOpChain(PHINode *Phi, Loop *L) const {
return nullptr;
};
auto isCorrectOpcode = [&](Instruction *Cur) {
if (RedOp == Instruction::ICmp || RedOp == Instruction::FCmp) {
if (IsMinMax) {
Value *LHS, *RHS;
return SelectPatternResult::isMinOrMax(
matchSelectPattern(Cur, LHS, RHS).Flavor);
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