Transform calls to memcpy into llvm.memcpy calls, patch by Eli Friedman.
llvm-svn: 46433
diff --git a/llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp b/llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp
index 0bd3f84..1f2a1b0 100644
--- a/llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp
@@ -919,6 +919,36 @@
}
} memcmpOptimizer;
+/// This LibCallOptimization will simplify a call to the memcpy library
+/// function. It simply converts them into calls to llvm.memcpy.*;
+/// the resulting call should be optimized later.
+/// @brief Simplify the memcpy library function.
+struct VISIBILITY_HIDDEN MemCpyOptimization : public LibCallOptimization {
+public:
+ MemCpyOptimization() : LibCallOptimization("memcpy",
+ "Number of 'memcpy' calls simplified") {}
+
+ /// @brief Make sure that the "memcpy" function has the right prototype
+ virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
+ const FunctionType *FT = F->getFunctionType();
+ const Type* voidPtr = PointerType::getUnqual(Type::Int8Ty);
+ return FT->getReturnType() == voidPtr && FT->getNumParams() == 3 &&
+ FT->getParamType(0) == voidPtr &&
+ FT->getParamType(1) == voidPtr &&
+ FT->getParamType(2) == SLC.getIntPtrType();
+ }
+
+ /// @brief Perform the memcpy optimization
+ virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
+ Value *MemcpyOps[] = {
+ CI->getOperand(1), CI->getOperand(2), CI->getOperand(3),
+ ConstantInt::get(Type::Int32Ty, 1) // align = 1 always.
+ };
+ new CallInst(SLC.get_memcpy(), MemcpyOps, MemcpyOps + 4, "", CI);
+ // memcpy always returns the destination
+ return ReplaceCallWith(CI, CI->getOperand(1));
+ }
+} MemCpyOptimizer;
/// This LibCallOptimization will simplify a call to the memcpy library
/// function by expanding it out to a single store of size 0, 1, 2, 4, or 8