From: Gabe Black <gabeblack@google.com>
Date: Wed, 14 Oct 2020 08:09:21 +0000 (-0700)
Subject: misc: Wrap __attribute__((aligned())) in a macro in compiler.hh.
X-Git-Tag: develop-gem5-snapshot~602
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=215e12b884d634dd4866b8222bd5435a511d4de6;p=gem5.git

misc: Wrap __attribute__((aligned())) in a macro in compiler.hh.

This attribute is gcc specific (also implemented by clang for
compatibility), and so should be behind a level of abstraction to make
using different compilers easier.

Change-Id: I7495f011f617268dd7a589dc0bcf1b3b7f515046
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35976
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
---

diff --git a/src/arch/arm/linux/linux.hh b/src/arch/arm/linux/linux.hh
index 5fd6cdc0c..ad773cd3b 100644
--- a/src/arch/arm/linux/linux.hh
+++ b/src/arch/arm/linux/linux.hh
@@ -43,6 +43,7 @@
 #define __ARCH_ARM_LINUX_LINUX_HH__
 
 #include "arch/arm/utility.hh"
+#include "base/compiler.hh"
 #include "kern/linux/linux.hh"
 
 class ArmLinux : public Linux
@@ -219,9 +220,9 @@ class ArmLinux32 : public ArmLinux
         uint32_t  st_gid;
         uint64_t  st_rdev;
         uint8_t   __pad3[4];
-        int64_t   __attribute__ ((aligned (8))) st_size;
+        M5_ALIGNED(8) int64_t st_size;
         uint32_t  st_blksize;
-        uint64_t  __attribute__ ((aligned (8))) st_blocks;
+        M5_ALIGNED(8) uint64_t st_blocks;
         uint32_t  st_atimeX;
         uint32_t  st_atime_nsec;
         uint32_t  st_mtimeX;
diff --git a/src/arch/mips/linux/aligned.hh b/src/arch/mips/linux/aligned.hh
index db4896afa..84157a2d8 100644
--- a/src/arch/mips/linux/aligned.hh
+++ b/src/arch/mips/linux/aligned.hh
@@ -30,18 +30,8 @@
 #define __ARCH_MIPS_LINUX_ALIGNED_HH__
 
 
-/* GCC 3.3.X has a bug in which attributes+typedefs don't work. 3.2.X is fine
- * as in 3.4.X, but the bug is marked will not fix in 3.3.X so here is
- * the work around.
- */
-#if (__GNUC__ == 3 && __GNUC_MINOR__  != 3) || __GNUC__ > 3
-typedef uint64_t uint64_ta __attribute__ ((aligned (8))) ;
-typedef int64_t int64_ta __attribute__ ((aligned (8))) ;
-typedef Addr Addr_a __attribute__ ((aligned (8))) ;
-#else
-#define uint64_ta uint64_t __attribute__ ((aligned (8)))
-#define int64_ta int64_t __attribute__ ((aligned (8)))
-#define Addr_a Addr __attribute__ ((aligned (8)))
-#endif /* __GNUC__ __GNUC_MINOR__ */
+typedef M5_ALIGNED(8) uint64_t uint64_ta;
+typedef M5_ALIGNED(8) int64_t int64_ta;
+typedef M5_ALIGNED(8) Addr Addr_a;
 
 #endif /* __ARCH_MIPS_LINUX_ALIGNED_HH__ */
diff --git a/src/base/compiler.hh b/src/base/compiler.hh
index 4565143b1..643352cd0 100644
--- a/src/base/compiler.hh
+++ b/src/base/compiler.hh
@@ -99,6 +99,9 @@
 #  define M5_LOCAL [[gnu::visibility("hidden")]]
 #  define M5_WEAK [[gnu::weak]]
 
+// Force an alignment for a variable.
+#  define M5_ALIGNED(alignment) [[gnu::aligned(alignment)]]
+
 // Marker for what should be an unreachable point in the code.
 #  define M5_UNREACHABLE __builtin_unreachable()
 
diff --git a/src/base/statistics.hh b/src/base/statistics.hh
index c66454053..2c1b1a121 100644
--- a/src/base/statistics.hh
+++ b/src/base/statistics.hh
@@ -657,7 +657,7 @@ class ScalarBase : public DataWrap<Derived, ScalarInfoProxy>
 
   protected:
     /** The storage of this stat. */
-    char storage[sizeof(Storage)] __attribute__ ((aligned (8)));
+    M5_ALIGNED(8) char storage[sizeof(Storage)];
 
   protected:
     /**
@@ -1878,7 +1878,7 @@ class DistBase : public DataWrap<Derived, DistInfoProxy>
 
   protected:
     /** The storage for this stat. */
-    char storage[sizeof(Storage)] __attribute__ ((aligned (8)));
+    M5_ALIGNED(8) char storage[sizeof(Storage)];
 
   protected:
     /**