intreadwrite.h

   1 /*
   2  * This file is part of FFmpeg.
   3  *
   4  * FFmpeg is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * FFmpeg is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with FFmpeg; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #ifndef AVUTIL_ARM_INTREADWRITE_H
  20 #define AVUTIL_ARM_INTREADWRITE_H
  21
  22 #include <stdint.h>
  23 #include "config.h"
  24 #include "libavutil/attributes.h"
  25
  26 #if HAVE_FAST_UNALIGNED && HAVE_INLINE_ASM && !AV_GCC_VERSION_AT_LEAST(4,7)
  27
  28 #define AV_RN16 AV_RN16
  29 static av_always_inline unsigned AV_RN16(const void *p)
  30 {
  31     const uint8_t *q = p;
  32     unsigned v;
  33 #if !AV_GCC_VERSION_AT_LEAST(4,6)
  34     __asm__ ("ldrh %0, %1" : "=r"(v) : "m"(*(const uint16_t *)q));
  35 #elif defined __thumb__
  36     __asm__ ("ldrh %0, %1" : "=r"(v) : "m"(q[0]), "m"(q[1]));
  37 #else
  38     __asm__ ("ldrh %0, %1" : "=r"(v) : "Uq"(q[0]), "m"(q[1]));
  39 #endif
  40     return v;
  41 }
  42
  43 #define AV_WN16 AV_WN16
  44 static av_always_inline void AV_WN16(void *p, uint16_t v)
  45 {
  46     __asm__ ("strh %1, %0" : "=m"(*(uint16_t *)p) : "r"(v));
  47 }
  48
  49 #define AV_RN32 AV_RN32
  50 static av_always_inline uint32_t AV_RN32(const void *p)
  51 {
  52     const struct __attribute__((packed)) { uint32_t v; } *q = p;
  53     uint32_t v;
  54     __asm__ ("ldr  %0, %1" : "=r"(v) : "m"(*q));
  55     return v;
  56 }
  57
  58 #define AV_WN32 AV_WN32
  59 static av_always_inline void AV_WN32(void *p, uint32_t v)
  60 {
  61     __asm__ ("str  %1, %0" : "=m"(*(uint32_t *)p) : "r"(v));
  62 }
  63
  64 #if HAVE_ASM_MOD_Q
  65
  66 #define AV_RN64 AV_RN64
  67 static av_always_inline uint64_t AV_RN64(const void *p)
  68 {
  69     const struct __attribute__((packed)) { uint32_t v; } *q = p;
  70     uint64_t v;
  71     __asm__ ("ldr   %Q0, %1  \n\t"
  72              "ldr   %R0, %2  \n\t"
  73              : "=&r"(v)
  74              : "m"(q[0]), "m"(q[1]));
  75     return v;
  76 }
  77
  78 #define AV_WN64 AV_WN64
  79 static av_always_inline void AV_WN64(void *p, uint64_t v)
  80 {
  81     __asm__ ("str  %Q2, %0  \n\t"
  82              "str  %R2, %1  \n\t"
  83              : "=m"(*(uint32_t*)p), "=m"(*((uint32_t*)p+1))
  84              : "r"(v));
  85 }
  86
  87 #endif /* HAVE_ASM_MOD_Q */
  88
  89 #endif /* HAVE_INLINE_ASM */
  90
  91 #endif /* AVUTIL_ARM_INTREADWRITE_H */