strength reduce exp2 into ldexp, rdar://5852514

llvm-svn: 50586
This commit is contained in:
Chris Lattner 2008-05-02 18:43:35 +00:00
parent 3b33e2544a
commit 5f0563ceb6
2 changed files with 90 additions and 1 deletions

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@ -837,6 +837,53 @@ struct VISIBILITY_HIDDEN PowOpt : public LibCallOptimization {
}
};
//===---------------------------------------===//
// 'exp2' Optimizations
struct VISIBILITY_HIDDEN Exp2Opt : public LibCallOptimization {
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder &B) {
const FunctionType *FT = Callee->getFunctionType();
// Just make sure this has 1 argument of FP type, which matches the
// result type.
if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
!FT->getParamType(0)->isFloatingPoint())
return 0;
Value *Op = CI->getOperand(1);
// Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x)) if sizeof(x) <= 32
// Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x)) if sizeof(x) < 32
Value *LdExpArg = 0;
if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
LdExpArg = B.CreateSExt(OpC->getOperand(0), Type::Int32Ty, "tmp");
} else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
LdExpArg = B.CreateZExt(OpC->getOperand(0), Type::Int32Ty, "tmp");
}
if (LdExpArg) {
const char *Name;
if (Op->getType() == Type::FloatTy)
Name = "ldexpf";
else if (Op->getType() == Type::DoubleTy)
Name = "ldexp";
else
Name = "ldexpl";
Constant *One = ConstantFP::get(APFloat(1.0f));
if (Op->getType() != Type::FloatTy)
One = ConstantExpr::getFPExtend(One, Op->getType());
Module *M = Caller->getParent();
Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
Op->getType(), Type::Int32Ty,NULL);
return B.CreateCall2(Callee, One, LdExpArg);
}
return 0;
}
};
//===---------------------------------------===//
// Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
@ -1205,7 +1252,7 @@ namespace {
StrCatOpt StrCat; StrChrOpt StrChr; StrCmpOpt StrCmp; StrNCmpOpt StrNCmp;
StrCpyOpt StrCpy; StrLenOpt StrLen; MemCmpOpt MemCmp; MemCpyOpt MemCpy;
// Math Library Optimizations
PowOpt Pow; UnaryDoubleFPOpt UnaryDoubleFP;
PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
// Integer Optimizations
FFSOpt FFS; IsDigitOpt IsDigit; IsAsciiOpt IsAscii; ToAsciiOpt ToAscii;
// Formatting and IO Optimizations
@ -1253,6 +1300,10 @@ void SimplifyLibCalls::InitOptimizations() {
Optimizations["powf"] = &Pow;
Optimizations["pow"] = &Pow;
Optimizations["powl"] = &Pow;
Optimizations["exp2l"] = &Exp2;
Optimizations["exp2"] = &Exp2;
Optimizations["exp2f"] = &Exp2;
#ifdef HAVE_FLOORF
Optimizations["floor"] = &UnaryDoubleFP;
#endif

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@ -0,0 +1,38 @@
; RUN: llvm-as < %s | opt -simplify-libcalls | llvm-dis | grep {call.*ldexp} | count 4
; rdar://5852514
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin8"
define double @t1(i32 %x) nounwind {
entry:
%tmp12 = sitofp i32 %x to double ; <double> [#uses=1]
%exp2 = tail call double @exp2( double %tmp12 ) ; <double> [#uses=1]
ret double %exp2
}
define float @t4(i8 zeroext %x) nounwind {
entry:
%tmp12 = uitofp i8 %x to float ; <float> [#uses=1]
%tmp3 = tail call float @exp2f( float %tmp12 ) nounwind readonly ; <float> [#uses=1]
ret float %tmp3
}
declare float @exp2f(float) nounwind readonly
define double @t3(i16 zeroext %x) nounwind {
entry:
%tmp12 = uitofp i16 %x to double ; <double> [#uses=1]
%exp2 = tail call double @exp2( double %tmp12 ) ; <double> [#uses=1]
ret double %exp2
}
define double @t2(i16 signext %x) nounwind {
entry:
%tmp12 = sitofp i16 %x to double ; <double> [#uses=1]
%exp2 = tail call double @exp2( double %tmp12 ) ; <double> [#uses=1]
ret double %exp2
}
declare double @exp2(double)