diff options
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineAddSub.cpp | 53 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/fast-math.ll | 10 |
2 files changed, 53 insertions, 10 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/lib/Transforms/InstCombine/InstCombineAddSub.cpp index 3c5781c..7595da0 100644 --- a/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -44,7 +44,7 @@ namespace { } void set(const APFloat& C); - + void negate(); bool isZero() const { return isInt() ? !IntVal : getFpVal().isZero(); } @@ -79,6 +79,14 @@ namespace { bool isInt() const { return !IsFp; } + // If the coefficient is represented by an integer, promote it to a + // floating point. + void convertToFpType(const fltSemantics &Sem); + + // Construct an APFloat from a signed integer. + // TODO: We should get rid of this function when APFloat can be constructed + // from an *SIGNED* integer. + APFloat createAPFloatFromInt(const fltSemantics &Sem, int Val); private: bool IsFp; @@ -206,7 +214,31 @@ void FAddendCoef::set(const APFloat& C) { IsFp = BufHasFpVal = true; } -void FAddendCoef::operator=(const FAddendCoef& That) { +void FAddendCoef::convertToFpType(const fltSemantics &Sem) { + if (!isInt()) + return; + + APFloat *P = getFpValPtr(); + if (IntVal > 0) + new(P) APFloat(Sem, IntVal); + else { + new(P) APFloat(Sem, 0 - IntVal); + P->changeSign(); + } + IsFp = BufHasFpVal = true; +} + +APFloat FAddendCoef::createAPFloatFromInt(const fltSemantics &Sem, int Val) { + if (Val >= 0) + return APFloat(Sem, Val); + + APFloat T(Sem, 0 - Val); + T.changeSign(); + + return T; +} + +void FAddendCoef::operator=(const FAddendCoef &That) { if (That.isInt()) set(That.IntVal); else @@ -225,13 +257,13 @@ void FAddendCoef::operator+=(const FAddendCoef &That) { if (isInt()) { const APFloat &T = That.getFpVal(); - set(T); - getFpVal().add(APFloat(T.getSemantics(), IntVal), RndMode); + convertToFpType(T.getSemantics()); + getFpVal().add(T, RndMode); return; } APFloat &T = getFpVal(); - T.add(APFloat(T.getSemantics(), That.IntVal), RndMode); + T.add(createAPFloatFromInt(T.getSemantics(), That.IntVal), RndMode); } void FAddendCoef::operator-=(const FAddendCoef &That) { @@ -246,13 +278,13 @@ void FAddendCoef::operator-=(const FAddendCoef &That) { if (isInt()) { const APFloat &T = That.getFpVal(); - set(T); - getFpVal().subtract(APFloat(T.getSemantics(), IntVal), RndMode); + convertToFpType(T.getSemantics()); + getFpVal().subtract(T, RndMode); return; } APFloat &T = getFpVal(); - T.subtract(APFloat(T.getSemantics(), IntVal), RndMode); + T.subtract(createAPFloatFromInt(T.getSemantics(), IntVal), RndMode); } void FAddendCoef::operator*=(const FAddendCoef &That) { @@ -275,11 +307,12 @@ void FAddendCoef::operator*=(const FAddendCoef &That) { isInt() ? That.getFpVal().getSemantics() : getFpVal().getSemantics(); if (isInt()) - set(APFloat(Semantic, IntVal)); + convertToFpType(Semantic); APFloat &F0 = getFpVal(); if (That.isInt()) - F0.multiply(APFloat(Semantic, That.IntVal), APFloat::rmNearestTiesToEven); + F0.multiply(createAPFloatFromInt(Semantic, That.IntVal), + APFloat::rmNearestTiesToEven); else F0.multiply(That.getFpVal(), APFloat::rmNearestTiesToEven); diff --git a/test/Transforms/InstCombine/fast-math.ll b/test/Transforms/InstCombine/fast-math.ll index 47f1ec4..edcbcc7 100644 --- a/test/Transforms/InstCombine/fast-math.ll +++ b/test/Transforms/InstCombine/fast-math.ll @@ -130,6 +130,16 @@ define double @fail2(double %f1, double %f2) { ; CHECK: ret } +; c1 * x - x => (c1 - 1.0) * x +define float @fold13(float %x) { + %mul = fmul fast float %x, 7.000000e+00 + %sub = fsub fast float %mul, %x + ret float %sub +; CHECK: fold13 +; CHECK: fmul fast float %x, 6.000000e+00 +; CHECK: ret +} + ; ========================================================================= ; ; Testing-cases about fmul begin |