[ARM] Set default alignment to 64bits

Summary:
The maximum alignment used by ARM arch
is 64bits, not 128.

This could cause overaligned memory
access for 128 bit neon vector that
have unpredictable behaviour.

This fixes: https://bugs.llvm.org/show_bug.cgi?id=42668

Reviewers: ostannard, dmgreen, srhines, danalbert, pirama, peter.smith

Reviewed By: pirama, peter.smith

Subscribers: phosek, thegameg, thakis, llvm-commits, carwil, peter.smith, javed.absar, kristof.beyls, cfe-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D65000

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@368288 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Basic/Targets/ARM.cpp b/lib/Basic/Targets/ARM.cpp
index c6834b9fac15bd3bc37fa80042edd67e827c6528..3ae2091f4a0f8274793f17eed0a580a8bdf2b531 100644 (file)
--- a/lib/Basic/Targets/ARM.cpp
+++ b/lib/Basic/Targets/ARM.cpp
@@ -309,8 +309,9 @@ ARMTargetInfo::ARMTargetInfo(const llvm::Triple &Triple,
   setAtomic();
 
   // Maximum alignment for ARM NEON data types should be 64-bits (AAPCS)
+  // as well the default alignment
   if (IsAAPCS && (Triple.getEnvironment() != llvm::Triple::Android))
-    MaxVectorAlign = 64;
+    DefaultAlignForAttributeAligned = 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

diff --git a/test/CodeGenCXX/ARM/exception-alignment.cpp b/test/CodeGenCXX/ARM/exception-alignment.cpp
new file mode 100644 (file)
index 0000000..8fd08df
--- /dev/null
+++ b/test/CodeGenCXX/ARM/exception-alignment.cpp
@@ -0,0 +1,21 @@
+// Bug: https://bugs.llvm.org/show_bug.cgi?id=42668
+// REQUIRES: arm-registered-target
+
+// RUN: %clang_cc1 -triple armv8-arm-none-eabi -emit-llvm -target-cpu generic -Os -fcxx-exceptions -o - -x c++ %s | FileCheck --check-prefixes=CHECK,A8 %s
+// RUN: %clang_cc1 -triple armv8-unknown-linux-android -emit-llvm -target-cpu generic -Os -fcxx-exceptions -o - -x c++ %s | FileCheck --check-prefixes=CHECK,A16 %s
+
+// CHECK: [[E:%[A-z0-9]+]] = tail call i8* @__cxa_allocate_exception
+// CHECK-NEXT: [[BC:%[A-z0-9]+]] = bitcast i8* [[E]] to <2 x i64>*
+// A8-NEXT: store <2 x i64> <i64 1, i64 2>, <2 x i64>* [[BC]], align 8
+// A16-NEXT: store <2 x i64> <i64 1, i64 2>, <2 x i64>* [[BC]], align 16
+#include <arm_neon.h>
+
+int main(void) {
+  try {
+    throw vld1q_u64(((const uint64_t[2]){1, 2}));
+  } catch (uint64x2_t exc) {
+    return 0;
+  }
+  return 1;
+}
+

diff --git a/test/SemaCXX/warn-overaligned-type-thrown.cpp b/test/SemaCXX/warn-overaligned-type-thrown.cpp
index 080101778363711fa2411869b4476258231eb62d..d7468445f8b7925bd12d7744dbfabd63d0db0402 100644 (file)
--- a/test/SemaCXX/warn-overaligned-type-thrown.cpp
+++ b/test/SemaCXX/warn-overaligned-type-thrown.cpp
@@ -2,11 +2,12 @@
 // RUN: %clang_cc1 -triple arm64-apple-ios10 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions -DUNDERALIGNED %s
 // RUN: %clang_cc1 -triple arm64-apple-tvos10 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions -DUNDERALIGNED %s
 // RUN: %clang_cc1 -triple arm64-apple-watchos4 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions -DUNDERALIGNED %s
+// RUN: %clang_cc1 -triple arm-linux-gnueabi -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions  -DUNDERALIGNED %s
 // RUN: %clang_cc1 -triple x86_64-apple-macosx10.14 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s
 // RUN: %clang_cc1 -triple arm64-apple-ios12 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s
 // RUN: %clang_cc1 -triple arm64-apple-tvos12 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s
 // RUN: %clang_cc1 -triple arm64-apple-watchos5 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s
-// RUN: %clang_cc1 -triple arm-linux-gnueabi -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s
+// RUN: %clang_cc1 -triple arm-linux-androideabi -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s
 // RUN: %clang_cc1 -triple aarch64-linux-gnueabi -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s
 // RUN: %clang_cc1 -triple mipsel-linux-gnu -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s
 // RUN: %clang_cc1 -triple mips64el-linux-gnu -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s