r219720 - ARM: set preferred aggregate alignment to 32 universally.

Tim Northover tnorthover at apple.com
Tue Oct 14 13:57:29 PDT 2014


Author: tnorthover
Date: Tue Oct 14 15:57:29 2014
New Revision: 219720

URL: http://llvm.org/viewvc/llvm-project?rev=219720&view=rev
Log:
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.

Modified:
    cfe/trunk/lib/Basic/Targets.cpp
    cfe/trunk/test/CodeGen/target-data.c

Modified: cfe/trunk/lib/Basic/Targets.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/Targets.cpp?rev=219720&r1=219719&r2=219720&view=diff
==============================================================================
--- cfe/trunk/lib/Basic/Targets.cpp (original)
+++ cfe/trunk/lib/Basic/Targets.cpp Tue Oct 14 15:57:29 2014
@@ -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.

Modified: cfe/trunk/test/CodeGen/target-data.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/target-data.c?rev=219720&r1=219719&r2=219720&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/target-data.c (original)
+++ cfe/trunk/test/CodeGen/target-data.c Tue Oct 14 15:57:29 2014
@@ -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





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