https://github.com/arsenm updated https://github.com/llvm/llvm-project/pull/173248
>From 57ea81cd9cbfa369402f54c6288908ec31e6cfe5 Mon Sep 17 00:00:00 2001 From: Matt Arsenault <[email protected]> Date: Mon, 22 Dec 2025 12:29:29 +0100 Subject: [PATCH] ValueTracking: Avoid calling computeKnownFPClass on matched constant The fmul case already tries to match a literal value, we don't need to match it twice. --- llvm/include/llvm/Support/KnownFPClass.h | 4 ++++ llvm/lib/Analysis/ValueTracking.cpp | 10 ++++++---- llvm/lib/Support/KnownFPClass.cpp | 4 ++++ 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/llvm/include/llvm/Support/KnownFPClass.h b/llvm/include/llvm/Support/KnownFPClass.h index b3c18bcf6b34b..a34e5eb7a1698 100644 --- a/llvm/include/llvm/Support/KnownFPClass.h +++ b/llvm/include/llvm/Support/KnownFPClass.h @@ -19,6 +19,7 @@ #include <optional> namespace llvm { +class APFloat; struct KnownFPClass { /// Floating-point classes the value could be one of. @@ -28,6 +29,9 @@ struct KnownFPClass { /// definitely set or false if the sign bit is definitely unset. std::optional<bool> SignBit; + KnownFPClass() = default; + KnownFPClass(const APFloat &C); + bool operator==(KnownFPClass Other) const { return KnownFPClasses == Other.KnownFPClasses && SignBit == Other.SignBit; } diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index c4ad71f668506..d657883634df2 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -4920,8 +4920,7 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts, assert(Depth <= MaxAnalysisRecursionDepth && "Limit Search Depth"); if (auto *CFP = dyn_cast<ConstantFP>(V)) { - Known.KnownFPClasses = CFP->getValueAPF().classify(); - Known.SignBit = CFP->isNegative(); + Known = KnownFPClass(CFP->getValueAPF()); return; } @@ -5723,8 +5722,6 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts, Known.knownNot(fcNegative); KnownFPClass KnownLHS, KnownRHS; - computeKnownFPClass(Op->getOperand(1), DemandedElts, fcAllFlags, KnownRHS, - Q, Depth + 1); const APFloat *CRHS; if (match(Op->getOperand(1), m_APFloat(CRHS))) { @@ -5741,6 +5738,11 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts, int MinKnownExponent = ilogb(*CRHS); if (MinKnownExponent >= MantissaBits) Known.knownNot(fcSubnormal); + + KnownRHS = KnownFPClass(*CRHS); + } else { + computeKnownFPClass(Op->getOperand(1), DemandedElts, fcAllFlags, KnownRHS, + Q, Depth + 1); } computeKnownFPClass(Op->getOperand(0), DemandedElts, fcAllFlags, KnownLHS, diff --git a/llvm/lib/Support/KnownFPClass.cpp b/llvm/lib/Support/KnownFPClass.cpp index 43fb2e7108d2b..88de3a57ba415 100644 --- a/llvm/lib/Support/KnownFPClass.cpp +++ b/llvm/lib/Support/KnownFPClass.cpp @@ -12,10 +12,14 @@ //===----------------------------------------------------------------------===// #include "llvm/Support/KnownFPClass.h" +#include "llvm/ADT/APFloat.h" #include "llvm/Support/ErrorHandling.h" using namespace llvm; +KnownFPClass::KnownFPClass(const APFloat &C) + : KnownFPClasses(C.classify()), SignBit(C.isNegative()) {} + /// Return true if it's possible to assume IEEE treatment of input denormals in /// \p F for \p Val. static bool inputDenormalIsIEEE(DenormalMode Mode) { _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
