[FFmpeg-trac] #4474(build system:new): Some inline asm code does not compile on Haiku 32-bit with GCC 4

[FFmpeg]

#4474: Some inline asm code does not compile on Haiku 32-bit with GCC 4
-------------------------------------+-------------------------------------
             Reporter:  Timothy_Gu   |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:  build
              Version:  git-master   |  system
             Keywords:  haiku        |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------

Comment (by Timothy_Gu):

 But back to `vf_noise.c`. If I comment out
 [https://github.com/FFmpeg/FFmpeg/blob/master/libavfilter/x86/vf_noise.c#L93-L96
 this part] compilation succeeds. But if I even call any function
 (including a noop function I created) with a variable as argument
 compilation fails.

 A reduced test case is below:

 {{{
 #!c
 // gcc -m32 -fPIC -fomit-frame-pointer
 void noop()
 {}

 void line_noise_avg_mmx(int src)
 {
     int var = 0;

     __asm__ volatile(
             "addl #2, %0"
             :: "r" (src+1), "r" (src+2), "r" (src+3), "r" (src+4),
                "r" (src+5), "g" (src+6)
             : "%eax"
         );

     // Doesn't compile on Haiku.
     // noop(var);
     noop(); // this compiles
 }
 }}}

 The odd thing is that GCC on Ubuntu (4.8.2) and on haiku (4.8.4) generates
 the exact same assembly with `noop()`, but Haiku errors out on
 `noop(var)`.

 GCC on Ubuntu seems to add these two instructions right after the exit of
 inline asm:

 {{{
         movl 28(%esp),  %eax   # 28(%esp) seems to be `var`
         movl    %eax , (%esp)
 }}}

 and Haiku GCC for some reason is simply too dumb to figure ''this'' out of
 everything, out.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/4474#comment:10>
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