IRgen/ABI/ARM: Trust the backend to pass vectors correctly for the given ABI.
- Therefore, we can lower out the NEON wrapper structs and pass the vectors
directly. This makes a huge difference in the cleanliness of the IR after
optimization.
- I will trust, but verify, via future ABITest testing (for APCS-GNU, at
least).
llvm-svn: 114618
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 34a6d37..f1da3c3 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -2272,6 +2272,17 @@
if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
+ // NEON vectors are implemented as (theoretically) opaque structures wrapping
+ // the underlying vector type. We trust the backend to pass the underlying
+ // vectors appropriately, so we can unwrap the structs which generally will
+ // lead to much cleaner IR.
+ if (const Type *SeltTy = isSingleElementStruct(Ty, getContext())) {
+ if (SeltTy->isVectorType())
+ return ABIArgInfo::getDirect(CGT.ConvertType(QualType(SeltTy, 0)));
+ }
+
+ // Otherwise, pass by coercing to a structure of the appropriate size.
+ //
// FIXME: This is kind of nasty... but there isn't much choice because the ARM
// backend doesn't support byval.
// FIXME: This doesn't handle alignment > 64 bits.