strength reduce exp2 into ldexp, rdar://5852514
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50586 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index e9c089d..d43a181 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -838,6 +838,53 @@
};
//===---------------------------------------===//
+// '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'
struct VISIBILITY_HIDDEN UnaryDoubleFPOpt : public LibCallOptimization {
@@ -1205,7 +1252,7 @@
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 @@
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