commit 21b43885b81a6180e7231e575b5433202582f2fb
author Yaxun (Sam) Liu <yaxun.liu@amd.com> Tue Dec 10 11:55:33 2019 -0500
committer Yaxun (Sam) Liu <yaxun.liu@amd.com> Tue Dec 10 13:56:34 2019 -0500
tree 73660be7786f5d1d252e1d574993ce11efd428d3
parent 7034794b314d9de808de004d22b47f18d134757d

Fix bug 44190 - wrong code with #pragma pack(1)

https://github.com/llvm/llvm-project/commit/5b330e8d6122c336d81dfd11c864e6c6240a381e caused
a regression on s390:

https://bugs.llvm.org/show_bug.cgi?id=44190

we need to copy if if either the argument is non-byval or the argument is underaligned.

Differential Revision: https://reviews.llvm.org/D71282

clang/lib/CodeGen/CGCall.cpp

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 4cf709b..d41516b 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -4005,9 +4005,8 @@
           auto LV = I->getKnownLValue();
           auto AS = LV.getAddressSpace();
 
-          if ((!ArgInfo.getIndirectByVal() &&
-               (LV.getAlignment() >=
-                getContext().getTypeAlignInChars(I->Ty)))) {
+          if (!ArgInfo.getIndirectByVal() ||
+              (LV.getAlignment() < getContext().getTypeAlignInChars(I->Ty))) {
             NeedCopy = true;
           }
           if (!getLangOpts().OpenCL) {