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[FFmpeg-devel] swscale/x86/yuv2rgb: Fix build without SSSE3

Message ID 20200223122256.23402-1-michael@niedermayer.cc
State New
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Series [FFmpeg-devel] swscale/x86/yuv2rgb: Fix build without SSSE3
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Commit Message

Michael Niedermayer Feb. 23, 2020, 12:22 p.m. UTC
From: Parker Ernest <@>

commit fc6a5883d6af8cae0e96af84dda0ad74b360a084 breaks build on
x86_64 CPUs which do not have SSSE3, e.g. AMD Phenom-II

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libswscale/x86/yuv2rgb.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Paul B Mahol Feb. 23, 2020, 12:33 p.m. UTC | #1
lgtm

On 2/23/20, Michael Niedermayer <michael@niedermayer.cc> wrote:
> From: Parker Ernest <@>
>
> commit fc6a5883d6af8cae0e96af84dda0ad74b360a084 breaks build on
> x86_64 CPUs which do not have SSSE3, e.g. AMD Phenom-II
>
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libswscale/x86/yuv2rgb.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/libswscale/x86/yuv2rgb.c b/libswscale/x86/yuv2rgb.c
> index c12e88cbb5..4791e5b93a 100644
> --- a/libswscale/x86/yuv2rgb.c
> +++ b/libswscale/x86/yuv2rgb.c
> @@ -83,6 +83,7 @@ av_cold SwsFunc ff_yuv2rgb_init_x86(SwsContext *c)
>  #if HAVE_X86ASM
>      int cpu_flags = av_get_cpu_flags();
>
> +#if HAVE_SSSE3
>      if (EXTERNAL_SSSE3(cpu_flags)) {
>          switch (c->dstFormat) {
>          case AV_PIX_FMT_RGB32:
> @@ -111,6 +112,7 @@ av_cold SwsFunc ff_yuv2rgb_init_x86(SwsContext *c)
>              return yuv420_rgb15_ssse3;
>          }
>      }
> +#endif
>
>      if (EXTERNAL_MMXEXT(cpu_flags)) {
>          switch (c->dstFormat) {
> --
> 2.17.1
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
James Darnley Feb. 23, 2020, 12:38 p.m. UTC | #2
On 2020-02-23 13:22, Michael Niedermayer wrote:
> From: Parker Ernest <@>
> 
> commit fc6a5883d6af8cae0e96af84dda0ad74b360a084 breaks build on
> x86_64 CPUs which do not have SSSE3, e.g. AMD Phenom-II
> 
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libswscale/x86/yuv2rgb.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/libswscale/x86/yuv2rgb.c b/libswscale/x86/yuv2rgb.c
> index c12e88cbb5..4791e5b93a 100644
> --- a/libswscale/x86/yuv2rgb.c
> +++ b/libswscale/x86/yuv2rgb.c
> @@ -83,6 +83,7 @@ av_cold SwsFunc ff_yuv2rgb_init_x86(SwsContext *c)
>  #if HAVE_X86ASM
>      int cpu_flags = av_get_cpu_flags();
>  
> +#if HAVE_SSSE3
>      if (EXTERNAL_SSSE3(cpu_flags)) {
>          switch (c->dstFormat) {
>          case AV_PIX_FMT_RGB32:
> @@ -111,6 +112,7 @@ av_cold SwsFunc ff_yuv2rgb_init_x86(SwsContext *c)
>              return yuv420_rgb15_ssse3;
>          }
>      }
> +#endif
>  
>      if (EXTERNAL_MMXEXT(cpu_flags)) {
>          switch (c->dstFormat) {
> 

What?  Why doesn't the the EXTERNAL_SSSE3 macro stop the code from
entering that branch?  The #if would only stop the section from being
compiled with --disable-ssse3.  A normal build would still enter that
branch on that CPU.
James Almer Feb. 23, 2020, 1:39 p.m. UTC | #3
On 2/23/2020 9:33 AM, Paul B Mahol wrote:
> lgtm

No, it's not ok. The EXTERNAL_SSSE3() macro should be enough to prevent
any of these functions from running on old CPUs.

It would help actually knowing what kind of failure is the user getting.

> 
> On 2/23/20, Michael Niedermayer <michael@niedermayer.cc> wrote:
>> From: Parker Ernest <@>
>>
>> commit fc6a5883d6af8cae0e96af84dda0ad74b360a084 breaks build on
>> x86_64 CPUs which do not have SSSE3, e.g. AMD Phenom-II
>>
>> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
>> ---
>>  libswscale/x86/yuv2rgb.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/libswscale/x86/yuv2rgb.c b/libswscale/x86/yuv2rgb.c
>> index c12e88cbb5..4791e5b93a 100644
>> --- a/libswscale/x86/yuv2rgb.c
>> +++ b/libswscale/x86/yuv2rgb.c
>> @@ -83,6 +83,7 @@ av_cold SwsFunc ff_yuv2rgb_init_x86(SwsContext *c)
>>  #if HAVE_X86ASM
>>      int cpu_flags = av_get_cpu_flags();
>>
>> +#if HAVE_SSSE3
>>      if (EXTERNAL_SSSE3(cpu_flags)) {
>>          switch (c->dstFormat) {
>>          case AV_PIX_FMT_RGB32:
>> @@ -111,6 +112,7 @@ av_cold SwsFunc ff_yuv2rgb_init_x86(SwsContext *c)
>>              return yuv420_rgb15_ssse3;
>>          }
>>      }
>> +#endif
>>
>>      if (EXTERNAL_MMXEXT(cpu_flags)) {
>>          switch (c->dstFormat) {
>> --
>> 2.17.1
>>
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel@ffmpeg.org
>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>> To unsubscribe, visit link above, or email
>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>
Carl Eugen Hoyos Feb. 23, 2020, 4:03 p.m. UTC | #4
Am So., 23. Feb. 2020 um 13:30 Uhr schrieb Michael Niedermayer
<michael@niedermayer.cc>:
>
> From: Parker Ernest <@>
>
> commit fc6a5883d6af8cae0e96af84dda0ad74b360a084 breaks build on
> x86_64 CPUs which do not have SSSE3, e.g. AMD Phenom-II

Does the commit break build on specific CPUs or specific toolchains?

Carl Eugen
Paul B Mahol Feb. 23, 2020, 5:26 p.m. UTC | #5
On 2/23/20, James Almer <jamrial@gmail.com> wrote:
> On 2/23/2020 9:33 AM, Paul B Mahol wrote:
>> lgtm
>
> No, it's not ok. The EXTERNAL_SSSE3() macro should be enough to prevent
> any of these functions from running on old CPUs.

this is about building.

>
> It would help actually knowing what kind of failure is the user getting.
>
>>
>> On 2/23/20, Michael Niedermayer <michael@niedermayer.cc> wrote:
>>> From: Parker Ernest <@>
>>>
>>> commit fc6a5883d6af8cae0e96af84dda0ad74b360a084 breaks build on
>>> x86_64 CPUs which do not have SSSE3, e.g. AMD Phenom-II
>>>
>>> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
>>> ---
>>>  libswscale/x86/yuv2rgb.c | 2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>> diff --git a/libswscale/x86/yuv2rgb.c b/libswscale/x86/yuv2rgb.c
>>> index c12e88cbb5..4791e5b93a 100644
>>> --- a/libswscale/x86/yuv2rgb.c
>>> +++ b/libswscale/x86/yuv2rgb.c
>>> @@ -83,6 +83,7 @@ av_cold SwsFunc ff_yuv2rgb_init_x86(SwsContext *c)
>>>  #if HAVE_X86ASM
>>>      int cpu_flags = av_get_cpu_flags();
>>>
>>> +#if HAVE_SSSE3
>>>      if (EXTERNAL_SSSE3(cpu_flags)) {
>>>          switch (c->dstFormat) {
>>>          case AV_PIX_FMT_RGB32:
>>> @@ -111,6 +112,7 @@ av_cold SwsFunc ff_yuv2rgb_init_x86(SwsContext *c)
>>>              return yuv420_rgb15_ssse3;
>>>          }
>>>      }
>>> +#endif
>>>
>>>      if (EXTERNAL_MMXEXT(cpu_flags)) {
>>>          switch (c->dstFormat) {
>>> --
>>> 2.17.1
>>>
>>> _______________________________________________
>>> ffmpeg-devel mailing list
>>> ffmpeg-devel@ffmpeg.org
>>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>>
>>> To unsubscribe, visit link above, or email
>>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel@ffmpeg.org
>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>> To unsubscribe, visit link above, or email
>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>>
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
Hendrik Leppkes Feb. 23, 2020, 5:39 p.m. UTC | #6
On Sun, Feb 23, 2020 at 6:26 PM Paul B Mahol <onemda@gmail.com> wrote:
>
> On 2/23/20, James Almer <jamrial@gmail.com> wrote:
> > On 2/23/2020 9:33 AM, Paul B Mahol wrote:
> >> lgtm
> >
> > No, it's not ok. The EXTERNAL_SSSE3() macro should be enough to prevent
> > any of these functions from running on old CPUs.
>
> this is about building.
>

We don't protect other parts of the SIMD code with preprocessor
checks, we only typically do it for AVX2, but not any of the SSE
variants, so at the very least some clarity would be appreciated why
and when this is needed. Because the commit message does not.

- Hendrik
Michael Niedermayer Feb. 23, 2020, 5:58 p.m. UTC | #7
On Sun, Feb 23, 2020 at 05:03:36PM +0100, Carl Eugen Hoyos wrote:
> Am So., 23. Feb. 2020 um 13:30 Uhr schrieb Michael Niedermayer
> <michael@niedermayer.cc>:
> >
> > From: Parker Ernest <@>
> >
> > commit fc6a5883d6af8cae0e96af84dda0ad74b360a084 breaks build on
> > x86_64 CPUs which do not have SSSE3, e.g. AMD Phenom-II
> 
> Does the commit break build on specific CPUs or specific toolchains?

I dont know what the testcase was the author encountered, i just posted
this here as the author wanted me to post it for him.
but a simple
make distclean ; ./configure --disable-ssse3 && make -j32
replicates the build failure here (see below for the errors)

We do have the 
extern void RENAME(ff_yuv_420_rgb32)(x86_reg index, uint8_t *image, const uint8_t *pu_index,
                                     const uint8_t *pv_index, const uint64_t *pointer_c_dither,
                                     const uint8_t *py_2index);
...

under #if HAVE_SSSE3

so i think either that needs to be changed or the code using it needs to be
similarly protected.
the if(...)
is not good enough because it is not something failingh at linking stage but
already before because the compiler has no idea what the identifer even is.
(compared to knowing what it is but not having a implemenetation later, which
 works as disabled code and optimized out references dont fail to link)



libswscale/x86/yuv2rgb.c: In function ‘ff_yuv2rgb_init_x86’:
libswscale/x86/yuv2rgb.c:91:24: error: ‘yuva420_rgb32_ssse3’ undeclared (first use in this function); did you mean ‘yuva420_rgb32_mmx’?
                 return yuva420_rgb32_ssse3;
                        ^~~~~~~~~~~~~~~~~~~
                        yuva420_rgb32_mmx
libswscale/x86/yuv2rgb.c:91:24: note: each undeclared identifier is reported only once for each function it appears in
libswscale/x86/yuv2rgb.c:95:24: error: ‘yuv420_rgb32_ssse3’ undeclared (first use in this function); did you mean ‘yuva420_rgb32_ssse3’?
                 return yuv420_rgb32_ssse3;
                        ^~~~~~~~~~~~~~~~~~
                        yuva420_rgb32_ssse3
libswscale/x86/yuv2rgb.c:99:24: error: ‘yuva420_bgr32_ssse3’ undeclared (first use in this function); did you mean ‘yuva420_rgb32_ssse3’?
                 return yuva420_bgr32_ssse3;
                        ^~~~~~~~~~~~~~~~~~~
                        yuva420_rgb32_ssse3
libswscale/x86/yuv2rgb.c:103:24: error: ‘yuv420_bgr32_ssse3’ undeclared (first use in this function); did you mean ‘yuva420_bgr32_ssse3’?
                 return yuv420_bgr32_ssse3;
                        ^~~~~~~~~~~~~~~~~~
                        yuva420_bgr32_ssse3
libswscale/x86/yuv2rgb.c:105:20: error: ‘yuv420_rgb24_ssse3’ undeclared (first use in this function); did you mean ‘yuv420_rgb32_ssse3’?
             return yuv420_rgb24_ssse3;
                    ^~~~~~~~~~~~~~~~~~
                    yuv420_rgb32_ssse3
libswscale/x86/yuv2rgb.c:107:20: error: ‘yuv420_bgr24_ssse3’ undeclared (first use in this function); did you mean ‘yuv420_rgb24_ssse3’?
             return yuv420_bgr24_ssse3;
                    ^~~~~~~~~~~~~~~~~~
                    yuv420_rgb24_ssse3
libswscale/x86/yuv2rgb.c:109:20: error: ‘yuv420_rgb16_ssse3’ undeclared (first use in this function); did you mean ‘yuv420_rgb24_ssse3’?
             return yuv420_rgb16_ssse3;
                    ^~~~~~~~~~~~~~~~~~
                    yuv420_rgb24_ssse3
libswscale/x86/yuv2rgb.c:111:20: error: ‘yuv420_rgb15_ssse3’ undeclared (first use in this function); did you mean ‘yuv420_rgb16_ssse3’?
             return yuv420_rgb15_ssse3;
                    ^~~~~~~~~~~~~~~~~~
                    yuv420_rgb16_ssse3
ffbuild/common.mak:59: recipe for target 'libswscale/x86/yuv2rgb.o' failed
make: *** [libswscale/x86/yuv2rgb.o] Error 1
make: *** Waiting for unfinished jobs....

[...]
James Almer Feb. 23, 2020, 6:10 p.m. UTC | #8
On 2/23/2020 2:58 PM, Michael Niedermayer wrote:
> On Sun, Feb 23, 2020 at 05:03:36PM +0100, Carl Eugen Hoyos wrote:
>> Am So., 23. Feb. 2020 um 13:30 Uhr schrieb Michael Niedermayer
>> <michael@niedermayer.cc>:
>>>
>>> From: Parker Ernest <@>
>>>
>>> commit fc6a5883d6af8cae0e96af84dda0ad74b360a084 breaks build on
>>> x86_64 CPUs which do not have SSSE3, e.g. AMD Phenom-II
>>
>> Does the commit break build on specific CPUs or specific toolchains?
> 
> I dont know what the testcase was the author encountered, i just posted
> this here as the author wanted me to post it for him.
> but a simple
> make distclean ; ./configure --disable-ssse3 && make -j32
> replicates the build failure here (see below for the errors)
> 
> We do have the 
> extern void RENAME(ff_yuv_420_rgb32)(x86_reg index, uint8_t *image, const uint8_t *pu_index,
>                                      const uint8_t *pv_index, const uint64_t *pointer_c_dither,
>                                      const uint8_t *py_2index);
> ...
> 
> under #if HAVE_SSSE3
> 
> so i think either that needs to be changed or the code using it needs to be
> similarly protected.
> the if(...)
> is not good enough because it is not something failingh at linking stage but
> already before because the compiler has no idea what the identifer even is.
> (compared to knowing what it is but not having a implemenetation later, which
>  works as disabled code and optimized out references dont fail to link)

This would also happen with --disable-mmxext.

IMO, the #if HAVE_* checks should be removed and always include all
three instances of yuv2rgb_template.c.
The actual asm code is always assembled after all, and as Hendrik
mentioned, we only ever make AVX functions or higher optional, mainly
because of assembler support and because disabling such instruction sets
also affects alignment and stride constants across the codebase.

> 
> 
> 
> libswscale/x86/yuv2rgb.c: In function ‘ff_yuv2rgb_init_x86’:
> libswscale/x86/yuv2rgb.c:91:24: error: ‘yuva420_rgb32_ssse3’ undeclared (first use in this function); did you mean ‘yuva420_rgb32_mmx’?
>                  return yuva420_rgb32_ssse3;
>                         ^~~~~~~~~~~~~~~~~~~
>                         yuva420_rgb32_mmx
> libswscale/x86/yuv2rgb.c:91:24: note: each undeclared identifier is reported only once for each function it appears in
> libswscale/x86/yuv2rgb.c:95:24: error: ‘yuv420_rgb32_ssse3’ undeclared (first use in this function); did you mean ‘yuva420_rgb32_ssse3’?
>                  return yuv420_rgb32_ssse3;
>                         ^~~~~~~~~~~~~~~~~~
>                         yuva420_rgb32_ssse3
> libswscale/x86/yuv2rgb.c:99:24: error: ‘yuva420_bgr32_ssse3’ undeclared (first use in this function); did you mean ‘yuva420_rgb32_ssse3’?
>                  return yuva420_bgr32_ssse3;
>                         ^~~~~~~~~~~~~~~~~~~
>                         yuva420_rgb32_ssse3
> libswscale/x86/yuv2rgb.c:103:24: error: ‘yuv420_bgr32_ssse3’ undeclared (first use in this function); did you mean ‘yuva420_bgr32_ssse3’?
>                  return yuv420_bgr32_ssse3;
>                         ^~~~~~~~~~~~~~~~~~
>                         yuva420_bgr32_ssse3
> libswscale/x86/yuv2rgb.c:105:20: error: ‘yuv420_rgb24_ssse3’ undeclared (first use in this function); did you mean ‘yuv420_rgb32_ssse3’?
>              return yuv420_rgb24_ssse3;
>                     ^~~~~~~~~~~~~~~~~~
>                     yuv420_rgb32_ssse3
> libswscale/x86/yuv2rgb.c:107:20: error: ‘yuv420_bgr24_ssse3’ undeclared (first use in this function); did you mean ‘yuv420_rgb24_ssse3’?
>              return yuv420_bgr24_ssse3;
>                     ^~~~~~~~~~~~~~~~~~
>                     yuv420_rgb24_ssse3
> libswscale/x86/yuv2rgb.c:109:20: error: ‘yuv420_rgb16_ssse3’ undeclared (first use in this function); did you mean ‘yuv420_rgb24_ssse3’?
>              return yuv420_rgb16_ssse3;
>                     ^~~~~~~~~~~~~~~~~~
>                     yuv420_rgb24_ssse3
> libswscale/x86/yuv2rgb.c:111:20: error: ‘yuv420_rgb15_ssse3’ undeclared (first use in this function); did you mean ‘yuv420_rgb16_ssse3’?
>              return yuv420_rgb15_ssse3;
>                     ^~~~~~~~~~~~~~~~~~
>                     yuv420_rgb16_ssse3
> ffbuild/common.mak:59: recipe for target 'libswscale/x86/yuv2rgb.o' failed
> make: *** [libswscale/x86/yuv2rgb.o] Error 1
> make: *** Waiting for unfinished jobs....
> 
> [...]
> 
> 
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>
Hendrik Leppkes Feb. 23, 2020, 6:29 p.m. UTC | #9
On Sun, Feb 23, 2020 at 6:58 PM Michael Niedermayer <michaelni@gmx.at> wrote:
>
> On Sun, Feb 23, 2020 at 05:03:36PM +0100, Carl Eugen Hoyos wrote:
> > Am So., 23. Feb. 2020 um 13:30 Uhr schrieb Michael Niedermayer
> > <michael@niedermayer.cc>:
> > >
> > > From: Parker Ernest <@>
> > >
> > > commit fc6a5883d6af8cae0e96af84dda0ad74b360a084 breaks build on
> > > x86_64 CPUs which do not have SSSE3, e.g. AMD Phenom-II
> >
> > Does the commit break build on specific CPUs or specific toolchains?
>
> I dont know what the testcase was the author encountered, i just posted
> this here as the author wanted me to post it for him.
> but a simple
> make distclean ; ./configure --disable-ssse3 && make -j32
> replicates the build failure here (see below for the errors)
>
> We do have the
> extern void RENAME(ff_yuv_420_rgb32)(x86_reg index, uint8_t *image, const uint8_t *pu_index,
>                                      const uint8_t *pv_index, const uint64_t *pointer_c_dither,
>                                      const uint8_t *py_2index);
> ...
>
> under #if HAVE_SSSE3
>
> so i think either that needs to be changed or the code using it needs to be
> similarly protected.

The extern declaration should be removed from that guard then, like
other SIMD code in the codebase.

- Hendrik
James Darnley Feb. 23, 2020, 10:42 p.m. UTC | #10
On 2020-02-23 18:58, Michael Niedermayer wrote:
> On Sun, Feb 23, 2020 at 05:03:36PM +0100, Carl Eugen Hoyos wrote:
>> Am So., 23. Feb. 2020 um 13:30 Uhr schrieb Michael Niedermayer
>> <michael@niedermayer.cc>:
>>>
>>> From: Parker Ernest <@>
>>>
>>> commit fc6a5883d6af8cae0e96af84dda0ad74b360a084 breaks build on
>>> x86_64 CPUs which do not have SSSE3, e.g. AMD Phenom-II
>>
>> Does the commit break build on specific CPUs or specific toolchains?
> 
> I dont know what the testcase was the author encountered, i just posted
> this here as the author wanted me to post it for him.
> but a simple
> make distclean ; ./configure --disable-ssse3 && make -j32
> replicates the build failure here (see below for the errors)

Okay, it breaks the build when you do --disable-sse3.  I see that too.

It is okay to fix that any way you want.  This patch is fine by me but
please don't imply that it fixes a run time error in the commit message,
which is what I first thought.

I see a discussion has sprung up on the best way to fix it so I guess
that has to be resolved first.
Carl Eugen Hoyos Feb. 23, 2020, 11:22 p.m. UTC | #11
Am So., 23. Feb. 2020 um 23:43 Uhr schrieb James Darnley
<james.darnley@gmail.com>:
>
> On 2020-02-23 18:58, Michael Niedermayer wrote:
> > On Sun, Feb 23, 2020 at 05:03:36PM +0100, Carl Eugen Hoyos wrote:
> >> Am So., 23. Feb. 2020 um 13:30 Uhr schrieb Michael Niedermayer
> >> <michael@niedermayer.cc>:
> >>>
> >>> From: Parker Ernest <@>
> >>>
> >>> commit fc6a5883d6af8cae0e96af84dda0ad74b360a084 breaks build on
> >>> x86_64 CPUs which do not have SSSE3, e.g. AMD Phenom-II
> >>
> >> Does the commit break build on specific CPUs or specific toolchains?
> >
> > I dont know what the testcase was the author encountered, i just posted
> > this here as the author wanted me to post it for him.
> > but a simple
> > make distclean ; ./configure --disable-ssse3 && make -j32
> > replicates the build failure here (see below for the errors)
>
> Okay, it breaks the build when you do --disable-sse3.  I see that too.
>
> It is okay to fix that any way you want.  This patch is fine by me but

> please don't imply that it fixes a run time error in the commit message,
> which is what I first thought.

I also feel that mentioning a specific cpu instead of --disable-ssse3 is
misleading.

Carl Eugen
diff mbox series

Patch

diff --git a/libswscale/x86/yuv2rgb.c b/libswscale/x86/yuv2rgb.c
index c12e88cbb5..4791e5b93a 100644
--- a/libswscale/x86/yuv2rgb.c
+++ b/libswscale/x86/yuv2rgb.c
@@ -83,6 +83,7 @@  av_cold SwsFunc ff_yuv2rgb_init_x86(SwsContext *c)
 #if HAVE_X86ASM
     int cpu_flags = av_get_cpu_flags();
 
+#if HAVE_SSSE3
     if (EXTERNAL_SSSE3(cpu_flags)) {
         switch (c->dstFormat) {
         case AV_PIX_FMT_RGB32:
@@ -111,6 +112,7 @@  av_cold SwsFunc ff_yuv2rgb_init_x86(SwsContext *c)
             return yuv420_rgb15_ssse3;
         }
     }
+#endif
 
     if (EXTERNAL_MMXEXT(cpu_flags)) {
         switch (c->dstFormat) {