This patch fixes problem with passing structures and unions

smaller than register as argument in variadic functions on
big endian architectures.
Differential Revision: http://reviews.llvm.org/D21611


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@273665 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/TargetInfo.cpp

@@ -272,7 +272,8 @@ static Address emitVoidPtrDirectVAArg(CodeGenFunction &CGF,
 
   // If the argument is smaller than a slot, and this is a big-endian
   // target, the argument will be right-adjusted in its slot.
-  if (DirectSize < SlotSize && CGF.CGM.getDataLayout().isBigEndian()) {
+  if (DirectSize < SlotSize && CGF.CGM.getDataLayout().isBigEndian() &&
+      !DirectTy->isStructTy()) {
     Addr = CGF.Builder.CreateConstInBoundsByteGEP(Addr, SlotSize - DirectSize);
   }
 

test/CodeGen/struct-union-BE.c

+// RUN: %clang -O2 -target mips-linux-gnu  -EB -S -emit-llvm %s -o - | FileCheck %s -check-prefix=MIPS
+// RUN: %clang -O2 -target mips64-linux-gnu  -EB -S -emit-llvm %s -o - | FileCheck %s -check-prefix=MIPS64
+// RUN: %clang -O2 -target armeb-linux-gnueabihf -march=armv7a  -EB -S -emit-llvm %s -o - | FileCheck %s -check-prefix=ARM
+
+#include <stdarg.h>
+#include <stdlib.h>
+
+struct tiny {
+  char c;
+};
+
+union data {
+  char c;
+};
+
+void fstr(int n, ...) {
+  struct tiny x;
+  va_list ap;
+  va_start (ap,n);
+  x = va_arg (ap, struct tiny);
+  if (x.c !=  10)
+    abort();
+  va_end (ap);
+// MIPS-NOT: %{{[0-9]+}} = getelementptr inbounds i8, i8* %argp.cur, i32 3
+// MIPS64-NOT: %{{[0-9]+}} = getelementptr inbounds i8, i8* %argp.cur, i64 7
+// ARM-NOT: %{{[0-9]+}} = getelementptr inbounds i8, i8* %argp.cur, i32 3
+}
+
+void funi(int n, ...) {
+  union data x;
+  va_list ap;
+  va_start (ap,n);
+  x = va_arg (ap, union data);
+  if (x.c !=  10)
+    abort();
+  va_end (ap);
+// MIPS-NOT: %{{[0-9]+}} = getelementptr inbounds i8, i8* %argp.cur, i32 3
+// MIPS64-NOT: %{{[0-9]+}} = getelementptr inbounds i8, i8* %argp.cur, i64 7
+// ARM-NOT: %{{[0-9]+}} = getelementptr inbounds i8, i8* %argp.cur, i32 3
+}
+
+void foo() {
+  struct tiny x[3];
+  union data y;
+  x[0].c = 10;
+  fstr(1, x[0]);
+  funi(1, y);
+}