[Qemu-devel] [PATCH 1/2] linux-user: Define target alignment size

[Laurent Vivier <laurent@vivier.eu>]

Datatype alignment can be found using following application:

int main(void)
{
	printf("alignof(short) %ld\n", __alignof__(short));
	printf("alignof(int) %ld\n", __alignof__(int));
	printf("alignof(long) %ld\n", __alignof__(long));
	printf("alignof(long long) %ld\n", __alignof__(long long));
}

This patch includes following alignments:

i386

   alignof(short) 2
   alignof(int) 4
   alignof(long) 4
   alignof(long long) 8

 x86_64

   alignof(short) 2
   alignof(int) 4
   alignof(long) 8
   alignof(long long) 8

 arm

   alignof(short) 2
   alignof(int) 4
   alignof(long) 4
   alignof(long long) 4

 m68k (680x0)

   alignof(short) 2
   alignof(int) 2
   alignof(long) 2
   alignof(long long) 2

 mips

   alignof(short) 2
   alignof(int) 4
   alignof(long) 4
   alignof(long long) 8

 ppc

   alignof(short) 2
   alignof(int) 4
   alignof(long) 4
   alignof(long long) 8

for other targets, use by default (2,4,4,8).

Please, update for your favorite target...

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
v2: compute align size for each basic datatype

 configure  |   13 +++++++++++++
 cpu-defs.h |   14 ++++++++++----
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/configure b/configure
index 25381e5..efc6fa4 100755
--- a/configure
+++ b/configure
@@ -2919,6 +2919,10 @@ target_nptl="no"
 interp_prefix1=`echo "$interp_prefix" | sed "s/%M/$target_arch2/g"`
 echo "CONFIG_QEMU_INTERP_PREFIX=\"$interp_prefix1\"" >> $config_target_mak
 gdb_xml_files=""
+target_short_alignment=2
+target_int_alignment=4
+target_long_alignment=4
+target_long_long_alignment=8
 
 TARGET_ARCH="$target_arch2"
 TARGET_BASE_ARCH=""
@@ -2931,6 +2935,7 @@ case "$target_arch2" in
   x86_64)
     TARGET_BASE_ARCH=i386
     target_phys_bits=64
+    target_long_alignment=8
   ;;
   alpha)
     target_phys_bits=64
@@ -2942,6 +2947,7 @@ case "$target_arch2" in
     target_nptl="yes"
     gdb_xml_files="arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml"
     target_phys_bits=32
+    target_long_long_alignment=4
   ;;
   cris)
     target_nptl="yes"
@@ -2951,6 +2957,9 @@ case "$target_arch2" in
     bflt="yes"
     gdb_xml_files="cf-core.xml cf-fp.xml"
     target_phys_bits=32
+    target_int_alignment=2
+    target_long_alignment=2
+    target_long_long_alignment=2
   ;;
   microblaze)
     bflt="yes"
@@ -3029,6 +3038,10 @@ case "$target_arch2" in
     exit 1
   ;;
 esac
+echo "TARGET_SHORT_ALIGNMENT=$target_short_alignment" >> $config_target_mak
+echo "TARGET_INT_ALIGNMENT=$target_int_alignment" >> $config_target_mak
+echo "TARGET_LONG_ALIGNMENT=$target_long_alignment" >> $config_target_mak
+echo "TARGET_LONG_LONG_ALIGNMENT=$target_long_long_alignment" >> $config_target_mak
 echo "TARGET_ARCH=$TARGET_ARCH" >> $config_target_mak
 target_arch_name="`echo $TARGET_ARCH | tr '[:lower:]' '[:upper:]'`"
 echo "TARGET_$target_arch_name=y" >> $config_target_mak
diff --git a/cpu-defs.h b/cpu-defs.h
index 8d4bf86..98c6718 100644
--- a/cpu-defs.h
+++ b/cpu-defs.h
@@ -37,16 +37,22 @@
 
 #define TARGET_LONG_SIZE (TARGET_LONG_BITS / 8)
 
+typedef int16_t target_short __attribute__ ((aligned(TARGET_SHORT_ALIGNMENT)));
+typedef uint16_t target_ushort __attribute__((aligned(TARGET_SHORT_ALIGNMENT)));
+typedef int32_t target_int __attribute__((aligned(TARGET_INT_ALIGNMENT)));
+typedef uint32_t target_uint __attribute__((aligned(TARGET_INT_ALIGNMENT)));
+typedef int64_t target_long_long __attribute__((aligned(TARGET_LONG_LONG_ALIGNMENT)));
+typedef uint64_t target_ulong_long __attribute__((aligned(TARGET_LONG_LONG_ALIGNMENT)));
 /* target_ulong is the type of a virtual address */
 #if TARGET_LONG_SIZE == 4
-typedef int32_t target_long;
-typedef uint32_t target_ulong;
+typedef int32_t target_long __attribute__((aligned(TARGET_LONG_ALIGNMENT)));
+typedef uint32_t target_ulong __attribute__((aligned(TARGET_LONG_ALIGNMENT)));
 #define TARGET_FMT_lx "%08x"
 #define TARGET_FMT_ld "%d"
 #define TARGET_FMT_lu "%u"
 #elif TARGET_LONG_SIZE == 8
-typedef int64_t target_long;
-typedef uint64_t target_ulong;
+typedef int64_t target_long __attribute__((aligned(TARGET_LONG_ALIGNMENT)));
+typedef uint64_t target_ulong __attribute__((aligned(TARGET_LONG_ALIGNMENT)));
 #define TARGET_FMT_lx "%016" PRIx64
 #define TARGET_FMT_ld "%" PRId64
 #define TARGET_FMT_lu "%" PRIu64
-- 
1.7.1