Fix x86-64 byval passing to specify the alignment even when the code

generator will give it something sufficient.  This is important because
the mid-level optimizer doesn't know what alignment is required otherwise.

llvm-svn: 131879

1 files changed, 4 insertions, 7 deletions

diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 73526fbfdd0..5ac5ea4ac40 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -1315,13 +1315,10 @@ ABIArgInfo X86_64ABIInfo::getIndirectResult(QualType Ty) const {
   if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
 
-  // Compute the byval alignment. We trust the back-end to honor the
-  // minimum ABI alignment for byval, to make cleaner IR.
-  const unsigned MinABIAlign = 8;
-  unsigned Align = getContext().getTypeAlign(Ty) / 8;
-  if (Align > MinABIAlign)
-    return ABIArgInfo::getIndirect(Align);
-  return ABIArgInfo::getIndirect(0);
+  // Compute the byval alignment. We specify the alignment of the byval in all
+  // cases so that the mid-level optimizer knows the alignment of the byval.
+  unsigned Align = std::max(getContext().getTypeAlign(Ty) / 8, 8U);
+  return ABIArgInfo::getIndirect(Align);
 }
 
 /// Get16ByteVectorType - The ABI specifies that a value should be passed in an