[CodeGen] Don't crash classifying a union of an AVX vector and an int

We forgot to run postMerge after decided that the union had to be
classified as MEMORY.  This left us with Lo == MEMORY and Hi == SSEUp
which is an invalid combination.

This fixes PR24021.

Differential Revision: http://reviews.llvm.org/D10908

llvm-svn: 241666

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/x86_64-arguments-avx.cpp b/clang/test/CodeGenCXX/x86_64-arguments-avx.cpp
index 29e693451d1..2933d9445b7 100644
--- a/clang/test/CodeGenCXX/x86_64-arguments-avx.cpp
+++ b/clang/test/CodeGenCXX/x86_64-arguments-avx.cpp
@@ -50,3 +50,12 @@ UU2 PR23082(UU2 x) {
   return x;
 }
 }
+
+namespace test3 {
+union U {
+  __attribute__((__vector_size__(32))) float f1;
+  int f2;
+};
+// CHECK: define i32 @_ZN5test31fENS_1UE({{.*}}* byval align 32
+int f(U u) { return u.f2; }
+}