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[X86] Avoid repeated hash lookups (NFC) #131725

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Merged
merged 1 commit into from
Mar 18, 2025
Merged

[X86] Avoid repeated hash lookups (NFC) #131725

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11 changes: 5 additions & 6 deletions llvm/lib/Target/X86/X86PadShortFunction.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -181,10 +181,9 @@ void PadShortFunc::findReturns(MachineBasicBlock *MBB, unsigned int Cycles) {
bool PadShortFunc::cyclesUntilReturn(MachineBasicBlock *MBB,
unsigned int &Cycles) {
// Return cached result if BB was previously visited
DenseMap<MachineBasicBlock*, VisitedBBInfo>::iterator it
= VisitedBBs.find(MBB);
if (it != VisitedBBs.end()) {
VisitedBBInfo BBInfo = it->second;
auto [It, Inserted] = VisitedBBs.try_emplace(MBB);
if (!Inserted) {
VisitedBBInfo BBInfo = It->second;
Cycles += BBInfo.Cycles;
return BBInfo.HasReturn;
}
Expand All @@ -196,15 +195,15 @@ bool PadShortFunc::cyclesUntilReturn(MachineBasicBlock *MBB,
// functions do not count because the called function will be padded,
// if necessary.
if (MI.isReturn() && !MI.isCall()) {
VisitedBBs[MBB] = VisitedBBInfo(true, CyclesToEnd);
It->second = VisitedBBInfo(true, CyclesToEnd);
Cycles += CyclesToEnd;
return true;
}

CyclesToEnd += TSM.computeInstrLatency(&MI);
}

VisitedBBs[MBB] = VisitedBBInfo(false, CyclesToEnd);
It->second = VisitedBBInfo(false, CyclesToEnd);
Cycles += CyclesToEnd;
return false;
}
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