From: Javed Absar <javed.absar@arm.com>
Date: Wed, 7 Jun 2017 10:02:02 +0000 (+0000)
Subject: [ARM] Fix Neon vector type alignment to 64-bit
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1f8a87749fa3809736ee58d9904112aeed0e4702;p=clang

[ARM] Fix Neon vector type alignment to 64-bit

This is restricted version of patch - https://reviews.llvm.org/D33205
that I reverted as it was leading to ABI breaks on darwin etc.
This patch restricts the fix to AAPCS (Android remains 128-bit).
Reviewed by: Renato Golin, Stephen Hines
Differential Revision: https://reviews.llvm.org/D33786



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@304889 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index f939bfb339..a304a78354 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -5385,6 +5385,10 @@ public:
     // ARM has atomics up to 8 bytes
     setAtomic();
 
+    // Maximum alignment for ARM NEON data types should be 64-bits (AAPCS)
+    if (IsAAPCS && (Triple.getEnvironment() != llvm::Triple::Android))
+       MaxVectorAlign = 64;
+
     // Do force alignment of members that follow zero length bitfields.  If
     // the alignment of the zero-length bitfield is greater than the member
     // that follows it, `bar', `bar' will be aligned as the  type of the
diff --git a/test/CodeGen/neon-aapcs-align.c b/test/CodeGen/neon-aapcs-align.c
new file mode 100644
index 0000000000..4b7e5ff4d3
--- /dev/null
+++ b/test/CodeGen/neon-aapcs-align.c
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -triple armv7a-none-eabi -target-feature +neon -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=AAPCS
+// RUN: %clang_cc1 -triple armv7a-none-gnueabi -target-feature +neon -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=AAPCS
+// RUN: %clang_cc1 -triple armv7a-none-freebsd -target-feature +neon -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=AAPCS
+
+// RUN: %clang_cc1 -triple armv7a-apple-ios -target-feature +neon -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=DEFAULT
+// RUN: %clang_cc1 -triple armv7a-none-android -target-feature +neon -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=DEFAULT
+// RUN: %clang_cc1 -triple armv7a-none-androideabi -target-feature +neon -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=DEFAULT
+
+#include <arm_neon.h>
+// Neon types have 64-bit alignment
+int32x4_t gl_b;
+void t3(int32x4_t *src) {
+// CHECK: @t3
+  gl_b = *src;
+// AAPCS: store <4 x i32> {{%.*}}, <4 x i32>* @gl_b, align 8
+// DEFAULT: store <4 x i32> {{%.*}}, <4 x i32>* @gl_b, align 16
+}