http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53037
--- Comment #12 from H.J. Lu <hjl.tools at gmail dot com> 2012-04-19 20:15:55 UTC --- Created attachment 27197 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27197 A patch I got [hjl@gnu-6 pr53037]$ cat x.i typedef unsigned long long __u64 __attribute__((aligned(4),warn_if_not_aligned(8))); struct foo1 { int i1; int i2; int i3; __u64 x; }; struct foo2 { int i1; int i2; int i3; __u64 x; } __attribute__((aligned(8))); struct foo3 { int i1; int i2; __u64 x; } __attribute__((aligned(8))); struct foo4 { int i1; int i3; __u64 x; }; union bar1 { int i1; int i3; __u64 x; }; union bar2 { int i1; int i3; __u64 x; } __attribute__((aligned(8))); [hjl@gnu-6 pr53037]$ make x.s /export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc -B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -mx32 -Wall -S x.i x.i:10:1: warning: alignment 32 of ‘struct foo1’ is less than 64 [enabled by default] }; ^ x.i:10:1: warning: ‘x’ offset 12 in ‘struct foo1’ isn't aligned to 8 [enabled by default] }; ^ x.i:18:1: warning: ‘x’ offset 12 in ‘struct foo2’ isn't aligned to 8 [enabled by default] } __attribute__((aligned(8))); ^ x.i:32:1: warning: alignment 32 of ‘struct foo4’ is less than 64 [enabled by default] }; ^ x.i:39:1: warning: alignment 32 of ‘union bar1’ is less than 64 [enabled by default] }; ^ [hjl@gnu-6 pr53037]$
