src/patches/ffmpeg-6.0-mathpops-clip-constants-used-with-shift.patch

   1 From effadce6c756247ea8bae32dc13bb3e6f464f0eb Mon Sep 17 00:00:00 2001
   2 From: =?utf8?q?R=C3=A9mi=20Denis-Courmont?= <remi@remlab.net>
   3 Date: Sun, 16 Jul 2023 18:18:02 +0300
   4 Subject: [PATCH] avcodec/x86/mathops: clip constants used with shift
   5  instructions within inline assembly
   6
   7 Fixes assembling with binutil as >= 2.41
   8
   9 Signed-off-by: James Almer <jamrial@gmail.com>
  10 ---
  11  libavcodec/x86/mathops.h | 26 +++++++++++++++++++++++---
  12  1 file changed, 23 insertions(+), 3 deletions(-)
  13
  14 diff --git a/libavcodec/x86/mathops.h b/libavcodec/x86/mathops.h
  15 index 6298f5ed19..ca7e2dffc1 100644
  16 --- a/libavcodec/x86/mathops.h
  17 +++ b/libavcodec/x86/mathops.h
  18 @@ -35,12 +35,20 @@
  19  static av_always_inline av_const int MULL(int a, int b, unsigned shift)
  20  {
  21      int rt, dummy;
  22 +    if (__builtin_constant_p(shift))
  23      __asm__ (
  24          "imull %3               \n\t"
  25          "shrdl %4, %%edx, %%eax \n\t"
  26          :"=a"(rt), "=d"(dummy)
  27 -        :"a"(a), "rm"(b), "ci"((uint8_t)shift)
  28 +        :"a"(a), "rm"(b), "i"(shift & 0x1F)
  29      );
  30 +    else
  31 +        __asm__ (
  32 +            "imull %3               \n\t"
  33 +            "shrdl %4, %%edx, %%eax \n\t"
  34 +            :"=a"(rt), "=d"(dummy)
  35 +            :"a"(a), "rm"(b), "c"((uint8_t)shift)
  36 +        );
  37      return rt;
  38  }
  39
  40 @@ -113,19 +121,31 @@ __asm__ volatile(\
  41  // avoid +32 for shift optimization (gcc should do that ...)
  42  #define NEG_SSR32 NEG_SSR32
  43  static inline  int32_t NEG_SSR32( int32_t a, int8_t s){
  44 +    if (__builtin_constant_p(s))
  45      __asm__ ("sarl %1, %0\n\t"
  46           : "+r" (a)
  47 -         : "ic" ((uint8_t)(-s))
  48 +         : "i" (-s & 0x1F)
  49      );
  50 +    else
  51 +        __asm__ ("sarl %1, %0\n\t"
  52 +               : "+r" (a)
  53 +               : "c" ((uint8_t)(-s))
  54 +        );
  55      return a;
  56  }
  57
  58  #define NEG_USR32 NEG_USR32
  59  static inline uint32_t NEG_USR32(uint32_t a, int8_t s){
  60 +    if (__builtin_constant_p(s))
  61      __asm__ ("shrl %1, %0\n\t"
  62           : "+r" (a)
  63 -         : "ic" ((uint8_t)(-s))
  64 +         : "i" (-s & 0x1F)
  65      );
  66 +    else
  67 +        __asm__ ("shrl %1, %0\n\t"
  68 +               : "+r" (a)
  69 +               : "c" ((uint8_t)(-s))
  70 +        );
  71      return a;
  72  }
  73
  74 --
  75 2.25.1
  76