Add support for the llvm.memmove intrinsic

Patch graciously contributed by Reid Spencer!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11355 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 13 insertions, 0 deletions

diff --git a/lib/CodeGen/IntrinsicLowering.cpp b/lib/CodeGen/IntrinsicLowering.cpp
index 48ae01540b..6eaaafa2e2 100644
--- a/lib/CodeGen/IntrinsicLowering.cpp
+++ b/lib/CodeGen/IntrinsicLowering.cpp
@@ -71,6 +71,19 @@ void DefaultIntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
                  CI->getName(), CI);
     break;
   }
+  case Intrinsic::memmove: {
+    // The memmove intrinsic take an extra alignment argument that the memcpy
+    // libc function does not.
+    const FunctionType *CFT = Callee->getFunctionType();
+    FunctionType *FT =
+      FunctionType::get(*CFT->param_begin(), 
+           std::vector<const Type*>(CFT->param_begin(), CFT->param_end()-1),
+                        false);
+    Function *MemMove = M->getOrInsertFunction("memmove", FT);
+    new CallInst(MemMove, std::vector<Value*>(CI->op_begin()+1, CI->op_end()-1),
+                 CI->getName(), CI);
+    break;
+  }
   }
 
   assert(CI->use_empty() &&