lower calls to abs to inline code, PR2337
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52138 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index cb90bdc..30c9baf 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -984,6 +984,27 @@
return B.CreateZExt(Op, CI->getType());
}
};
+
+//===---------------------------------------===//
+// 'abs', 'labs', 'llabs' Optimizations
+
+struct VISIBILITY_HIDDEN AbsOpt : public LibCallOptimization {
+ virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder &B) {
+ const FunctionType *FT = Callee->getFunctionType();
+ // We require integer(integer) where the types agree.
+ if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
+ FT->getParamType(0) != FT->getReturnType())
+ return 0;
+
+ // abs(x) -> x >s -1 ? x : -x
+ Value *Op = CI->getOperand(1);
+ Value *Pos = B.CreateICmpSGT(Op,ConstantInt::getAllOnesValue(Op->getType()),
+ "ispos");
+ Value *Neg = B.CreateNeg(Op, "neg");
+ return B.CreateSelect(Pos, Op, Neg);
+ }
+};
+
//===---------------------------------------===//
// 'toascii' Optimizations
@@ -1258,7 +1279,8 @@
// Math Library Optimizations
PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
// Integer Optimizations
- FFSOpt FFS; IsDigitOpt IsDigit; IsAsciiOpt IsAscii; ToAsciiOpt ToAscii;
+ FFSOpt FFS; AbsOpt Abs; IsDigitOpt IsDigit; IsAsciiOpt IsAscii;
+ ToAsciiOpt ToAscii;
// Formatting and IO Optimizations
SPrintFOpt SPrintF; PrintFOpt PrintF;
FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
@@ -1328,6 +1350,9 @@
Optimizations["ffs"] = &FFS;
Optimizations["ffsl"] = &FFS;
Optimizations["ffsll"] = &FFS;
+ Optimizations["abs"] = &Abs;
+ Optimizations["labs"] = &Abs;
+ Optimizations["llabs"] = &Abs;
Optimizations["isdigit"] = &IsDigit;
Optimizations["isascii"] = &IsAscii;
Optimizations["toascii"] = &ToAscii;