Optimize memmove and memset into the LLVM builtins. Note that these
only show up in code from front-ends besides llvm-gcc, like clang.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60287 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 8952747..07c8d94 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -707,6 +707,60 @@
}
};
+//===---------------------------------------===//
+// 'memmove' Optimizations
+
+struct VISIBILITY_HIDDEN MemMoveOpt : public LibCallOptimization {
+ virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ const FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
+ !isa<PointerType>(FT->getParamType(0)) ||
+ !isa<PointerType>(FT->getParamType(1)) ||
+ FT->getParamType(2) != TD->getIntPtrType())
+ return 0;
+
+ // memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
+ Module *M = Caller->getParent();
+ Intrinsic::ID IID = Intrinsic::memmove;
+ const Type *Tys[1];
+ Tys[0] = TD->getIntPtrType();
+ Value *MemMove = Intrinsic::getDeclaration(M, IID, Tys, 1);
+ Value *Dst = CastToCStr(CI->getOperand(1), B);
+ Value *Src = CastToCStr(CI->getOperand(2), B);
+ Value *Size = CI->getOperand(3);
+ Value *Align = ConstantInt::get(Type::Int32Ty, 1);
+ B.CreateCall4(MemMove, Dst, Src, Size, Align);
+ return CI->getOperand(1);
+ }
+};
+
+//===---------------------------------------===//
+// 'memset' Optimizations
+
+struct VISIBILITY_HIDDEN MemSetOpt : public LibCallOptimization {
+ virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ const FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
+ !isa<PointerType>(FT->getParamType(0)) ||
+ FT->getParamType(1) != TD->getIntPtrType() ||
+ FT->getParamType(2) != TD->getIntPtrType())
+ return 0;
+
+ // memset(p, v, n) -> llvm.memset(p, v, n, 1)
+ Module *M = Caller->getParent();
+ Intrinsic::ID IID = Intrinsic::memset;
+ const Type *Tys[1];
+ Tys[0] = TD->getIntPtrType();
+ Value *MemSet = Intrinsic::getDeclaration(M, IID, Tys, 1);
+ Value *Dst = CastToCStr(CI->getOperand(1), B);
+ Value *Val = B.CreateTrunc(CI->getOperand(2), Type::Int8Ty);
+ Value *Size = CI->getOperand(3);
+ Value *Align = ConstantInt::get(Type::Int32Ty, 1);
+ B.CreateCall4(MemSet, Dst, Val, Size, Align);
+ return CI->getOperand(1);
+ }
+};
+
//===----------------------------------------------------------------------===//
// Math Library Optimizations
//===----------------------------------------------------------------------===//
@@ -1197,6 +1251,7 @@
// String and Memory LibCall Optimizations
StrCatOpt StrCat; StrChrOpt StrChr; StrCmpOpt StrCmp; StrNCmpOpt StrNCmp;
StrCpyOpt StrCpy; StrLenOpt StrLen; MemCmpOpt MemCmp; MemCpyOpt MemCpy;
+ MemMoveOpt MemMove; MemSetOpt MemSet;
// Math Library Optimizations
PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
// Integer Optimizations
@@ -1242,6 +1297,8 @@
Optimizations["strlen"] = &StrLen;
Optimizations["memcmp"] = &MemCmp;
Optimizations["memcpy"] = &MemCpy;
+ Optimizations["memmove"] = &MemMove;
+ Optimizations["memset"] = &MemSet;
// Math Library Optimizations
Optimizations["powf"] = &Pow;
@@ -1386,10 +1443,6 @@
// * memcmp(x,y,l) -> cnst
// (if all arguments are constant and strlen(x) <= l and strlen(y) <= l)
//
-// memmove:
-// * memmove(d,s,l,a) -> memcpy(d,s,l,a)
-// (if s is a global constant array)
-//
// pow, powf, powl:
// * pow(exp(x),y) -> exp(x*y)
// * pow(sqrt(x),y) -> pow(x,y*0.5)