Fix a bug for rL312641.
rL312641 Allowed llvm.memcpy/memset/memmove to be tail calls when parent
function return the intrinsics's first argument. However on arm-none-eabi
platform, llvm.memcpy will be expanded to __aeabi_memcpy which doesn't
have return value. The fix is to check the libcall name after expansion
to match "memcpy/memset/memmove" before allowing those intrinsic to be
tail calls.
llvm-svn: 312799
diff --git a/llvm/lib/CodeGen/Analysis.cpp b/llvm/lib/CodeGen/Analysis.cpp
index f561577..876cca4 100644
--- a/llvm/lib/CodeGen/Analysis.cpp
+++ b/llvm/lib/CodeGen/Analysis.cpp
@@ -565,13 +565,20 @@
return false;
const Value *RetVal = Ret->getOperand(0), *CallVal = I;
- // Intrinsic like llvm.memcpy has no return value, but will return the
- // first argument if it is expanded as libcall.
+ // Intrinsic like llvm.memcpy has no return value, but the expanded
+ // libcall may or may not have return value. On most platforms, it
+ // will be expanded as memcpy in libc, which returns the first
+ // argument. On other platforms like arm-none-eabi, memcpy may be
+ // expanded as library call without return value, like __aeabi_memcpy.
const CallInst *Call = cast<CallInst>(I);
if (Function *F = Call->getCalledFunction()) {
Intrinsic::ID IID = F->getIntrinsicID();
- if ((IID == Intrinsic::memcpy || IID == Intrinsic::memmove ||
- IID == Intrinsic::memset) &&
+ if (((IID == Intrinsic::memcpy &&
+ TLI.getLibcallName(RTLIB::MEMCPY) == StringRef("memcpy")) ||
+ (IID == Intrinsic::memmove &&
+ TLI.getLibcallName(RTLIB::MEMMOVE) == StringRef("memmove")) ||
+ (IID == Intrinsic::memset &&
+ TLI.getLibcallName(RTLIB::MEMSET) == StringRef("memset"))) &&
RetVal == Call->getArgOperand(0))
return true;
}