From: Tim Northover <tnorthover@apple.com>
Date: Tue, 14 Oct 2014 20:57:29 +0000 (+0000)
Subject: ARM: set preferred aggregate alignment to 32 universally.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=404920da32ce86e4280a9122b14c2e42764b4a76;p=clang

ARM: set preferred aggregate alignment to 32 universally.

Before, ARM and Thumb mode code had different preferred alignments, which could
lead to some rather unexpected results. There's justification for reducing it
from the default 64-bits (wasted space), but I don't think there is for going
below 32-bits.

There's no actual ABI change here, just to reassure people.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@219720 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 8ecde72422..0ed96eb693 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -638,7 +638,7 @@ public:
     // RegParmMax is inherited from the underlying architecture
     this->LongDoubleFormat = &llvm::APFloat::IEEEdouble;
     if (Triple.getArch() == llvm::Triple::arm) {
-      this->DescriptionString = "e-m:e-p:32:32-i64:64-v128:64:128-n32-S128";
+      this->DescriptionString = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S128";
     } else if (Triple.getArch() == llvm::Triple::x86) {
       this->DescriptionString = "e-m:e-p:32:32-i64:64-n8:16:32-S128";
     } else if (Triple.getArch() == llvm::Triple::x86_64) {
@@ -3757,13 +3757,13 @@ class ARMTargetInfo : public TargetInfo {
       }
     } else {
       if (T.isOSBinFormatMachO())
-        DescriptionString = BigEndian ?
-                              "E-m:o-p:32:32-i64:64-v128:64:128-n32-S64" :
-                              "e-m:o-p:32:32-i64:64-v128:64:128-n32-S64";
+        DescriptionString =
+            BigEndian ? "E-m:o-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+                      : "e-m:o-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64";
       else
-        DescriptionString = BigEndian ?
-                              "E-m:e-p:32:32-i64:64-v128:64:128-n32-S64" :
-                              "e-m:e-p:32:32-i64:64-v128:64:128-n32-S64";
+        DescriptionString =
+            BigEndian ? "E-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+                      : "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64";
     }
 
     // FIXME: Enumerated types are variable width in straight AAPCS.
diff --git a/test/CodeGen/target-data.c b/test/CodeGen/target-data.c
index c374c9d230..ab27a65c57 100644
--- a/test/CodeGen/target-data.c
+++ b/test/CodeGen/target-data.c
@@ -68,7 +68,7 @@
 
 // RUN: %clang_cc1 -triple arm-nacl-gnueabi -o - -emit-llvm %s | \
 // RUN: FileCheck %s -check-prefix=ARM-NACL
-// ARM-NACL: target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-n32-S128"
+// ARM-NACL: target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S128"
 
 // RUN: %clang_cc1 -triple mipsel-nacl -o - -emit-llvm %s | \
 // RUN: FileCheck %s -check-prefix=MIPS-NACL
@@ -132,7 +132,7 @@
 
 // RUN: %clang_cc1 -triple arm-unknown-gnueabi -o - -emit-llvm %s | \
 // RUN: FileCheck %s -check-prefix=ARM
-// ARM: target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-n32-S64"
+// ARM: target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
 
 // RUN: %clang_cc1 -triple thumb-unknown -o - -emit-llvm -target-abi apcs-gnu \
 // RUN: %s | FileCheck %s -check-prefix=THUMB-GNU