aboutsummaryrefslogtreecommitdiff
path: root/llvm/lib/CodeGen/SelectionDAG
diff options
context:
space:
mode:
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG')
-rw-r--r--llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp84
-rw-r--r--llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp32
2 files changed, 82 insertions, 34 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index c5c3866..b47274b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -18870,27 +18870,38 @@ SDValue DAGCombiner::visitFPOW(SDNode *N) {
static SDValue foldFPToIntToFP(SDNode *N, const SDLoc &DL, SelectionDAG &DAG,
const TargetLowering &TLI) {
- // We only do this if the target has legal ftrunc. Otherwise, we'd likely be
- // replacing casts with a libcall. We also must be allowed to ignore -0.0
- // because FTRUNC will return -0.0 for (-1.0, -0.0), but using integer
- // conversions would return +0.0.
+ // We can fold the fpto[us]i -> [us]itofp pattern into a single ftrunc.
+ // If NoSignedZerosFPMath is enabled, this is a direct replacement.
+ // Otherwise, for strict math, we must handle edge cases:
+ // 1. For unsigned conversions, use FABS to handle negative cases. Take -0.0
+ // as example, it first becomes integer 0, and is converted back to +0.0.
+ // FTRUNC on its own could produce -0.0.
+
// FIXME: We should be able to use node-level FMF here.
- // TODO: If strict math, should we use FABS (+ range check for signed cast)?
EVT VT = N->getValueType(0);
- if (!TLI.isOperationLegal(ISD::FTRUNC, VT) ||
- !DAG.getTarget().Options.NoSignedZerosFPMath)
+ if (!TLI.isOperationLegal(ISD::FTRUNC, VT))
return SDValue();
// fptosi/fptoui round towards zero, so converting from FP to integer and
// back is the same as an 'ftrunc': [us]itofp (fpto[us]i X) --> ftrunc X
SDValue N0 = N->getOperand(0);
if (N->getOpcode() == ISD::SINT_TO_FP && N0.getOpcode() == ISD::FP_TO_SINT &&
- N0.getOperand(0).getValueType() == VT)
- return DAG.getNode(ISD::FTRUNC, DL, VT, N0.getOperand(0));
+ N0.getOperand(0).getValueType() == VT) {
+ if (DAG.getTarget().Options.NoSignedZerosFPMath)
+ return DAG.getNode(ISD::FTRUNC, DL, VT, N0.getOperand(0));
+ }
if (N->getOpcode() == ISD::UINT_TO_FP && N0.getOpcode() == ISD::FP_TO_UINT &&
- N0.getOperand(0).getValueType() == VT)
- return DAG.getNode(ISD::FTRUNC, DL, VT, N0.getOperand(0));
+ N0.getOperand(0).getValueType() == VT) {
+ if (DAG.getTarget().Options.NoSignedZerosFPMath)
+ return DAG.getNode(ISD::FTRUNC, DL, VT, N0.getOperand(0));
+
+ // Strict math: use FABS to handle negative inputs correctly.
+ if (TLI.isFAbsFree(VT)) {
+ SDValue Abs = DAG.getNode(ISD::FABS, DL, VT, N0.getOperand(0));
+ return DAG.getNode(ISD::FTRUNC, DL, VT, Abs);
+ }
+ }
return SDValue();
}
@@ -19340,8 +19351,10 @@ SDValue DAGCombiner::visitFMinMax(SDNode *N) {
EVT VT = N->getValueType(0);
const SDNodeFlags Flags = N->getFlags();
unsigned Opc = N->getOpcode();
- bool PropagatesNaN = Opc == ISD::FMINIMUM || Opc == ISD::FMAXIMUM;
- bool IsMin = Opc == ISD::FMINNUM || Opc == ISD::FMINIMUM;
+ bool PropAllNaNsToQNaNs = Opc == ISD::FMINIMUM || Opc == ISD::FMAXIMUM;
+ bool PropOnlySNaNsToQNaNs = Opc == ISD::FMINNUM || Opc == ISD::FMAXNUM;
+ bool IsMin =
+ Opc == ISD::FMINNUM || Opc == ISD::FMINIMUM || Opc == ISD::FMINIMUMNUM;
SelectionDAG::FlagInserter FlagsInserter(DAG, N);
// Constant fold.
@@ -19356,34 +19369,53 @@ SDValue DAGCombiner::visitFMinMax(SDNode *N) {
if (const ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1)) {
const APFloat &AF = N1CFP->getValueAPF();
- // minnum(X, nan) -> X
- // maxnum(X, nan) -> X
- // minimum(X, nan) -> nan
- // maximum(X, nan) -> nan
- if (AF.isNaN())
- return PropagatesNaN ? N->getOperand(1) : N->getOperand(0);
+ // minnum(X, qnan) -> X
+ // maxnum(X, qnan) -> X
+ // minnum(X, snan) -> qnan
+ // maxnum(X, snan) -> qnan
+ // minimum(X, nan) -> qnan
+ // maximum(X, nan) -> qnan
+ // minimumnum(X, nan) -> X
+ // maximumnum(X, nan) -> X
+ if (AF.isNaN()) {
+ if (PropAllNaNsToQNaNs || (AF.isSignaling() && PropOnlySNaNsToQNaNs)) {
+ if (AF.isSignaling())
+ return DAG.getConstantFP(AF.makeQuiet(), SDLoc(N), VT);
+ return N->getOperand(1);
+ }
+ return N->getOperand(0);
+ }
// In the following folds, inf can be replaced with the largest finite
// float, if the ninf flag is set.
if (AF.isInfinity() || (Flags.hasNoInfs() && AF.isLargest())) {
- // minnum(X, -inf) -> -inf
- // maxnum(X, +inf) -> +inf
+ // minnum(X, -inf) -> -inf (ignoring sNaN -> qNaN propagation)
+ // maxnum(X, +inf) -> +inf (ignoring sNaN -> qNaN propagation)
// minimum(X, -inf) -> -inf if nnan
// maximum(X, +inf) -> +inf if nnan
- if (IsMin == AF.isNegative() && (!PropagatesNaN || Flags.hasNoNaNs()))
+ // minimumnum(X, -inf) -> -inf
+ // maximumnum(X, +inf) -> +inf
+ if (IsMin == AF.isNegative() &&
+ (!PropAllNaNsToQNaNs || Flags.hasNoNaNs()))
return N->getOperand(1);
// minnum(X, +inf) -> X if nnan
// maxnum(X, -inf) -> X if nnan
- // minimum(X, +inf) -> X
- // maximum(X, -inf) -> X
- if (IsMin != AF.isNegative() && (PropagatesNaN || Flags.hasNoNaNs()))
+ // minimum(X, +inf) -> X (ignoring quieting of sNaNs)
+ // maximum(X, -inf) -> X (ignoring quieting of sNaNs)
+ // minimumnum(X, +inf) -> X if nnan
+ // maximumnum(X, -inf) -> X if nnan
+ if (IsMin != AF.isNegative() && (PropAllNaNsToQNaNs || Flags.hasNoNaNs()))
return N->getOperand(0);
}
}
+ // There are no VECREDUCE variants of FMINIMUMNUM or FMAXIMUMNUM
+ if (Opc == ISD::FMINIMUMNUM || Opc == ISD::FMAXIMUMNUM)
+ return SDValue();
+
if (SDValue SD = reassociateReduction(
- PropagatesNaN
+ PropAllNaNsToQNaNs
? (IsMin ? ISD::VECREDUCE_FMINIMUM : ISD::VECREDUCE_FMAXIMUM)
: (IsMin ? ISD::VECREDUCE_FMIN : ISD::VECREDUCE_FMAX),
Opc, SDLoc(N), VT, N0, N1, Flags))
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 175753f..6c11c5b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -234,6 +234,19 @@ static bool dontUseFastISelFor(const Function &Fn) {
});
}
+static bool maintainPGOProfile(const TargetMachine &TM,
+ CodeGenOptLevel OptLevel) {
+ if (OptLevel != CodeGenOptLevel::None)
+ return true;
+ if (TM.getPGOOption()) {
+ const PGOOptions &Options = *TM.getPGOOption();
+ return Options.Action == PGOOptions::PGOAction::IRUse ||
+ Options.Action == PGOOptions::PGOAction::SampleUse ||
+ Options.CSAction == PGOOptions::CSPGOAction::CSIRUse;
+ }
+ return false;
+}
+
namespace llvm {
//===--------------------------------------------------------------------===//
@@ -395,6 +408,7 @@ SelectionDAGISel::~SelectionDAGISel() { delete CurDAG; }
void SelectionDAGISelLegacy::getAnalysisUsage(AnalysisUsage &AU) const {
CodeGenOptLevel OptLevel = Selector->OptLevel;
+ bool RegisterPGOPasses = maintainPGOProfile(Selector->TM, Selector->OptLevel);
if (OptLevel != CodeGenOptLevel::None)
AU.addRequired<AAResultsWrapperPass>();
AU.addRequired<GCModuleInfo>();
@@ -403,15 +417,15 @@ void SelectionDAGISelLegacy::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<TargetLibraryInfoWrapperPass>();
AU.addRequired<TargetTransformInfoWrapperPass>();
AU.addRequired<AssumptionCacheTracker>();
- if (UseMBPI && OptLevel != CodeGenOptLevel::None)
- AU.addRequired<BranchProbabilityInfoWrapperPass>();
+ if (UseMBPI && RegisterPGOPasses)
+ AU.addRequired<BranchProbabilityInfoWrapperPass>();
AU.addRequired<ProfileSummaryInfoWrapperPass>();
// AssignmentTrackingAnalysis only runs if assignment tracking is enabled for
// the module.
AU.addRequired<AssignmentTrackingAnalysis>();
AU.addPreserved<AssignmentTrackingAnalysis>();
- if (OptLevel != CodeGenOptLevel::None)
- LazyBlockFrequencyInfoPass::getLazyBFIAnalysisUsage(AU);
+ if (RegisterPGOPasses)
+ LazyBlockFrequencyInfoPass::getLazyBFIAnalysisUsage(AU);
MachineFunctionPass::getAnalysisUsage(AU);
}
@@ -464,6 +478,7 @@ void SelectionDAGISel::initializeAnalysisResults(
(void)MatchFilterFuncName;
#endif
+ bool RegisterPGOPasses = maintainPGOProfile(TM, OptLevel);
TII = MF->getSubtarget().getInstrInfo();
TLI = MF->getSubtarget().getTargetLowering();
RegInfo = &MF->getRegInfo();
@@ -474,7 +489,7 @@ void SelectionDAGISel::initializeAnalysisResults(
auto *PSI = MAMP.getCachedResult<ProfileSummaryAnalysis>(*Fn.getParent());
BlockFrequencyInfo *BFI = nullptr;
FAM.getResult<BlockFrequencyAnalysis>(Fn);
- if (PSI && PSI->hasProfileSummary() && OptLevel != CodeGenOptLevel::None)
+ if (PSI && PSI->hasProfileSummary() && RegisterPGOPasses)
BFI = &FAM.getResult<BlockFrequencyAnalysis>(Fn);
FunctionVarLocs const *FnVarLocs = nullptr;
@@ -492,7 +507,7 @@ void SelectionDAGISel::initializeAnalysisResults(
// into account). That's unfortunate but OK because it just means we won't
// ask for passes that have been required anyway.
- if (UseMBPI && OptLevel != CodeGenOptLevel::None)
+ if (UseMBPI && RegisterPGOPasses)
FuncInfo->BPI = &FAM.getResult<BranchProbabilityAnalysis>(Fn);
else
FuncInfo->BPI = nullptr;
@@ -518,6 +533,7 @@ void SelectionDAGISel::initializeAnalysisResults(MachineFunctionPass &MFP) {
(void)MatchFilterFuncName;
#endif
+ bool RegisterPGOPasses = maintainPGOProfile(TM, OptLevel);
TII = MF->getSubtarget().getInstrInfo();
TLI = MF->getSubtarget().getTargetLowering();
RegInfo = &MF->getRegInfo();
@@ -528,7 +544,7 @@ void SelectionDAGISel::initializeAnalysisResults(MachineFunctionPass &MFP) {
AC = &MFP.getAnalysis<AssumptionCacheTracker>().getAssumptionCache(Fn);
auto *PSI = &MFP.getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
BlockFrequencyInfo *BFI = nullptr;
- if (PSI && PSI->hasProfileSummary() && OptLevel != CodeGenOptLevel::None)
+ if (PSI && PSI->hasProfileSummary() && RegisterPGOPasses)
BFI = &MFP.getAnalysis<LazyBlockFrequencyInfoPass>().getBFI();
FunctionVarLocs const *FnVarLocs = nullptr;
@@ -549,7 +565,7 @@ void SelectionDAGISel::initializeAnalysisResults(MachineFunctionPass &MFP) {
// into account). That's unfortunate but OK because it just means we won't
// ask for passes that have been required anyway.
- if (UseMBPI && OptLevel != CodeGenOptLevel::None)
+ if (UseMBPI && RegisterPGOPasses)
FuncInfo->BPI =
&MFP.getAnalysis<BranchProbabilityInfoWrapperPass>().getBPI();
else
generated by cgit v1.1 at 2025-10-10 21:31:51 +0000