[X86] _MM_ALIGN16 attribute support for non-windows targets

[zvi]

Summary

This patch adds support for the _MM_ALIGN16 attribute on non-windows targets. This aligns Clang with ICC which supports the attribute on all targets.

Fixes PR28056

[zvi]

Thanks the suggestion, David. I did not realize attribute is supported by Windows targets.

Zvi

From: David Majnemer [mailto:[e-mail]]
Sent: Thursday, June 09, 2016 17:48
To: [e-mail]; Rackover, Zvi <[e-mail]>
Cc: Aboud, Amjad <[e-mail]>; [e-mail]; [e-mail]; [e-mail]
Subject: Re: [PATCH] D21173: [X86] _MM_ALIGN16 attribute support for non-windows targets

[zvi]

Following David Majnemer's suggestion on cfe-commits: I would just use the attribute spelling, no need for two definitions

[mkuper]

LGTM

lib/Headers/xmmintrin.h

 ///    set to zero.
 static __inline__ int __DEFAULT_FN_ATTRS
 _mm_movemask_ps(__m128 __a)
 {
   return __builtin_ia32_movmskps((__v4sf)__a);
 }
 
 
-#ifdef _MSC_VER
-#define _MM_ALIGN16 __declspec(align(16))
-#endif
+#define _MM_ALIGN16 __attribute__((aligned(16)))
 
 #define _MM_SHUFFLE(z, y, x, w) (((z) << 6) | ((y) << 4) | ((x) << 2) | (w))
 
 #define _MM_EXCEPT_INVALID    (0x0001)
 #define _MM_EXCEPT_DENORM     (0x0002)
 #define _MM_EXCEPT_DIV_ZERO   (0x0004)
 #define _MM_EXCEPT_OVERFLOW   (0x0008)
 #define _MM_EXCEPT_UNDERFLOW  (0x0010)

test/Headers/xmmintrin.c

 // RUN: %clang_cc1 %s -ffreestanding -triple x86_64-apple-macosx10.9.0 -emit-llvm -o - | FileCheck %s
 //
 // RUN: rm -rf %t
 // RUN: %clang_cc1 %s -ffreestanding -triple x86_64-apple-macosx10.9.0 -emit-llvm -o - \
 // RUN:     -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -isystem %S/Inputs/include \
 // RUN:     | FileCheck %s
 // REQUIRES: x86-registered-target
 #include <xmmintrin.h>
 
+// CHECK: @c = common global i8 0, align 16
+_MM_ALIGN16 char c;
+
 // Make sure the last step of _mm_cvtps_pi16 converts <4 x i32> to <4 x i16> by
 // checking that clang emits PACKSSDW instead of PACKSSWB.
 
 // CHECK: define i64 @test_mm_cvtps_pi16
 // CHECK: call x86_mmx @llvm.x86.mmx.packssdw
 
 __m64 test_mm_cvtps_pi16(__m128 a) {
   return _mm_cvtps_pi16(a);