> > ... define buffer_find_nonzero_offset_inner ...
> > ... define can_use_buffer_find_nonzero_offset_inner ...
>
> > #if defined CONFIG_HAVE_GNU_IFUNC && defined CONFIG_HAVE_AVX2 ...
> > define buffer_find_nonzero_offset_avx2 ...
> > ... define can_use_buffer_find_nonzero_offset_avx2 ...
> > ...
> > This patch use the ifunc mechanism to select the proper function when
> > running, for platform supports AVX2, excute the AVX2 instructions,
> > else, excute the original code.
> >
> > Signed-off-by: Liang Li
> > ---
> > include/qemu-common.h | 28 +++--
> > util/Makefile.objs
On 11/10/2015 03:51 AM, Liang Li wrote:
+__asm__(".type can_use_buffer_find_nonzero_offset, \%gnu_indirect_function");
+__asm__(".type buffer_find_nonzero_offset, \%gnu_indirect_function");
+
+
+void *can_use_buffer_find_nonzero_offset_ifunc(void) \
+ __asm__("can_use_buffer_f
Paolo Bonzini wrote:
>
> The main issue here is that you are not testing whether the compiler
> supports gnu_indirect_function.
>
> I suggest that you start by moving the functions to util/buffer-zero.c
>
> Then the structure should be something like
>
> #ifdef CONFIG_HAVE_AVX2
> #include
> #en
>
> The main issue here is that you are not testing whether the compiler supports
> gnu_indirect_function.
>
> I suggest that you start by moving the functions to util/buffer-zero.c
>
> Then the structure should be something like
>
> #ifdef CONFIG_HAVE_AVX2
> #include
> #endif
>
> ... define
On 10/11/2015 03:51, Liang Li wrote:
> buffer_find_nonzero_offset() is a hot function during live migration.
> Now it use SSE2 intructions for optimization. For platform supports
> AVX2 instructions, use the AVX2 instructions for optimization can help
> to improve the performance about 30% compar
