Ensure that one can store X bytes in a fifo of size X.

[ffmpeg] / libavutil / bswap.h

diff --git a/libavutil/bswap.h b/libavutil/bswap.h
index 4280f808f52320644e7d19256e1898ad74c2840e..b35fb5161334c63518235ab8153e6cafff533835 100644 (file)
--- a/libavutil/bswap.h
+++ b/libavutil/bswap.h
@@ -20,138 +20,78 @@
 
 /**
  * @file bswap.h
- * byte swap.
+ * byte swapping routines
  */
 
-#ifndef __BSWAP_H__
-#define __BSWAP_H__
+#ifndef FFMPEG_BSWAP_H
+#define FFMPEG_BSWAP_H
+
+#include <stdint.h>
+#include "config.h"
+#include "common.h"
 
 #ifdef HAVE_BYTESWAP_H
 #include <byteswap.h>
 #else
 
-#ifdef ARCH_X86_64
-#  define LEGACY_REGS "=Q"
-#else
-#  define LEGACY_REGS "=q"
-#endif
-
-#if defined(ARCH_X86)
-static av_always_inline uint16_t bswap_16(uint16_t x)
-{
-  __asm("rorw $8, %0"   :
-        LEGACY_REGS (x) :
-        "0" (x));
-    return x;
-}
-
-static av_always_inline uint32_t bswap_32(uint32_t x)
+static av_always_inline av_const uint16_t bswap_16(uint16_t x)
 {
-#if __CPU__ != 386
- __asm("bswap   %0":
-      "=r" (x)     :
+#if defined(ARCH_X86)
+    asm("rorw $8, %0" : "+r"(x));
+#elif defined(ARCH_SH4)
+    asm("swap.b %0,%0" : "=r"(x) : "0"(x));
 #else
- __asm("xchgb   %b0,%h0\n"
-      "         rorl    $16,%0\n"
-      "         xchgb   %b0,%h0":
-      LEGACY_REGS (x)                :
+    x= (x>>8) | (x<<8);
 #endif
-      "0" (x));
-  return x;
+    return x;
 }
 
-static inline uint64_t bswap_64(uint64_t x)
+static av_always_inline av_const uint32_t bswap_32(uint32_t x)
 {
-#ifdef ARCH_X86_64
-  __asm("bswap  %0":
-        "=r" (x)   :
-        "0" (x));
-  return x;
+#if defined(ARCH_X86)
+#ifdef HAVE_BSWAP
+    asm("bswap   %0" : "+r" (x));
 #else
-    union {
-        uint64_t ll;
-        struct {
-           uint32_t l,h;
-        } l;
-    } r;
-    r.l.l = bswap_32 (x);
-    r.l.h = bswap_32 (x>>32);
-    return r.ll;
+    asm("rorw    $8,  %w0 \n\t"
+        "rorl    $16, %0  \n\t"
+        "rorw    $8,  %w0"
+        : "+r"(x));
 #endif
-}
-
 #elif defined(ARCH_SH4)
-
-static av_always_inline uint16_t bswap_16(uint16_t x) {
-        __asm__("swap.b %0,%0":"=r"(x):"0"(x));
-        return x;
-}
-
-static av_always_inline uint32_t bswap_32(uint32_t x) {
-        __asm__(
-        "swap.b %0,%0\n"
+    asm("swap.b %0,%0\n"
         "swap.w %0,%0\n"
         "swap.b %0,%0\n"
-        :"=r"(x):"0"(x));
-        return x;
-}
-
-static inline uint64_t bswap_64(uint64_t x)
-{
-    union {
-        uint64_t ll;
-        struct {
-           uint32_t l,h;
-        } l;
-    } r;
-    r.l.l = bswap_32 (x);
-    r.l.h = bswap_32 (x>>32);
-    return r.ll;
-}
-#else
-
-static av_always_inline uint16_t bswap_16(uint16_t x){
-    x= (x>>8) | (x<<8);
-    return x;
-}
-
-#ifdef ARCH_ARM
-static av_always_inline uint32_t bswap_32(uint32_t x){
+        : "=r"(x) : "0"(x));
+#elif defined(ARCH_ARM)
     uint32_t t;
-    __asm__ (
-      "eor %1, %0, %0, ror #16 \n\t"
-      "bic %1, %1, #0xFF0000   \n\t"
-      "mov %0, %0, ror #8      \n\t"
-      "eor %0, %0, %1, lsr #8  \n\t"
-      : "+r"(x), "+r"(t));
-    return x;
-}
-
+    asm ("eor %1, %0, %0, ror #16 \n\t"
+         "bic %1, %1, #0xFF0000   \n\t"
+         "mov %0, %0, ror #8      \n\t"
+         "eor %0, %0, %1, lsr #8  \n\t"
+         : "+r"(x), "+r"(t));
 #elif defined(ARCH_BFIN)
-static av_always_inline uint32_t bswap_32(uint32_t x){
     unsigned tmp;
-    asm("%1 = %0 >> 8 (V);\n\t"
-        "%0 = %0 << 8 (V);\n\t"
-        "%0 = %0 | %1;\n\t"
-        "%0 = PACK(%0.L, %0.H);\n\t"
+    asm("%1 = %0 >> 8 (V);      \n\t"
+        "%0 = %0 << 8 (V);      \n\t"
+        "%0 = %0 | %1;          \n\t"
+        "%0 = PACK(%0.L, %0.H); \n\t"
         : "+d"(x), "=&d"(tmp));
-    return x;
-}
-
 #else
-static av_always_inline uint32_t bswap_32(uint32_t x){
     x= ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF);
     x= (x>>16) | (x<<16);
+#endif
     return x;
 }
-#endif
 
-static inline uint64_t bswap_64(uint64_t x)
+static inline uint64_t av_const bswap_64(uint64_t x)
 {
 #if 0
     x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL);
     x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL);
     return (x>>32) | (x<<32);
+#elif defined(ARCH_X86_64)
+  asm("bswap  %0": "=r" (x) : "0" (x));
+  return x;
 #else
     union {
         uint64_t ll;
@@ -163,7 +103,6 @@ static inline uint64_t bswap_64(uint64_t x)
     return r.ll;
 #endif
 }
-#endif  /* defined(ARCH_X86) */
 
 #endif  /* !HAVE_BYTESWAP_H */
 
@@ -186,4 +125,4 @@ static inline uint64_t bswap_64(uint64_t x)
 #define le2me_64(x) (x)
 #endif
 
-#endif /* __BSWAP_H__ */
+#endif /* FFMPEG_BSWAP_H */