instcombine: Migrate memmove optimizations
This patch migrates the memmove optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167687 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp
index c57991b..b4dc93d 100644
--- a/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -978,6 +978,25 @@
}
};
+struct MemMoveOpt : public LibCallOptimization {
+ virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ // These optimizations require DataLayout.
+ if (!TD) return 0;
+
+ FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
+ !FT->getParamType(0)->isPointerTy() ||
+ !FT->getParamType(1)->isPointerTy() ||
+ FT->getParamType(2) != TD->getIntPtrType(*Context))
+ return 0;
+
+ // memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
+ B.CreateMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
+ CI->getArgOperand(2), 1);
+ return CI->getArgOperand(0);
+ }
+};
+
} // End anonymous namespace.
namespace llvm {
@@ -1016,6 +1035,7 @@
// Memory library call optimizations.
MemCmpOpt MemCmp;
MemCpyOpt MemCpy;
+ MemMoveOpt MemMove;
void initOptimizations();
void addOpt(LibFunc::Func F, LibCallOptimization* Opt);
@@ -1066,6 +1086,7 @@
// Memory library call optimizations.
addOpt(LibFunc::memcmp, &MemCmp);
addOpt(LibFunc::memcpy, &MemCpy);
+ addOpt(LibFunc::memmove, &MemMove);
}
Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) {