ARM64: Do not expand variadic HFA/HVA arguments with the Darwin ABI.

Unlike the standard AAPCS64 ABI, variadic arguments are always passed on the
stack with the Darwin ABI, and this was not being considered when deciding
whether to expand HFA/HVA arguments in a call. An HFA argument with a "float"
base type was being expanded into separate "float" arguments, each of which
was then extended to a double, resulting in a serious mismatch from what is
expected by the va_arg implementation. <rdar://problem/15777067>

llvm-svn: 206729

1 files changed, 6 insertions, 0 deletions

diff --git a/clang/test/CodeGen/arm64-arguments.c b/clang/test/CodeGen/arm64-arguments.c
index c5e489fd856..b2de08dbe68 100644
--- a/clang/test/CodeGen/arm64-arguments.c
+++ b/clang/test/CodeGen/arm64-arguments.c
@@ -640,6 +640,12 @@ float test_hfa(int n, ...) {
   return h.d;
 }
 
+float test_hfa_call(struct HFA *a) {
+// CHECK-LABEL: define float @test_hfa_call(%struct.HFA* %a)
+// CHECK: call float (i32, ...)* @test_hfa(i32 1, [2 x double] {{.*}})
+  test_hfa(1, *a);
+}
+
 struct TooBigHFA {
   float a, b, c, d, e;
 };