mips: intreadwrite: remove unnecessary inline asm

GCC actually handles unaligned accesses correctly in all cases
except, absurdly, 32-bit loads on mips64.  The remaining asm is
thus not needed, and removing it results in better code.
Signed-off-by: Mans Rullgard <mans@mansr.com>

libavutil/mips/intreadwrite.h

@@ -24,7 +24,7 @@
 #include <stdint.h>
 #include "config.h"
 
-#if HAVE_INLINE_ASM
+#if ARCH_MIPS64 && HAVE_INLINE_ASM
 
 #define AV_RN32 AV_RN32
 static av_always_inline uint32_t AV_RN32(const void *p)
@@ -38,61 +38,6 @@ static av_always_inline uint32_t AV_RN32(const void *p)
     return v;
 }
 
-#define AV_WN32 AV_WN32
-static av_always_inline void AV_WN32(void *p, uint32_t v)
-{
-    __asm__ ("swl %2, %0  \n\t"
-             "swr %2, %1  \n\t"
-             : "=m"(*(uint32_t *)((uint8_t *)p+3*!HAVE_BIGENDIAN)),
-               "=m"(*(uint32_t *)((uint8_t *)p+3*HAVE_BIGENDIAN))
-             : "r"(v));
-}
-
-#if ARCH_MIPS64
-
-#define AV_RN64 AV_RN64
-static av_always_inline uint64_t AV_RN64(const void *p)
-{
-    uint64_t v;
-    __asm__ ("ldl %0, %1  \n\t"
-             "ldr %0, %2  \n\t"
-             : "=&r"(v)
-             : "m"(*(const uint64_t *)((const uint8_t *)p+7*!HAVE_BIGENDIAN)),
-               "m"(*(const uint64_t *)((const uint8_t *)p+7*HAVE_BIGENDIAN)));
-    return v;
-}
-
-#define AV_WN64 AV_WN64
-static av_always_inline void AV_WN64(void *p, uint64_t v)
-{
-    __asm__ ("sdl %2, %0  \n\t"
-             "sdr %2, %1  \n\t"
-             : "=m"(*(uint64_t *)((uint8_t *)p+7*!HAVE_BIGENDIAN)),
-               "=m"(*(uint64_t *)((uint8_t *)p+7*HAVE_BIGENDIAN))
-             : "r"(v));
-}
-
-#else
-
-#define AV_RN64 AV_RN64
-static av_always_inline uint64_t AV_RN64(const void *p)
-{
-    union { uint64_t v; uint32_t hl[2]; } v;
-    v.hl[0] = AV_RN32(p);
-    v.hl[1] = AV_RN32((const uint8_t *)p + 4);
-    return v.v;
-}
-
-#define AV_WN64 AV_WN64
-static av_always_inline void AV_WN64(void *p, uint64_t v)
-{
-    union { uint64_t v; uint32_t hl[2]; } vv = { v };
-    AV_WN32(p, vv.hl[0]);
-    AV_WN32((uint8_t *)p + 4, vv.hl[1]);
-}
-
-#endif /* ARCH_MIPS64 */
-
-#endif /* HAVE_INLINE_ASM */
+#endif /* ARCH_MIPS64 && HAVE_INLINE_ASM */
 
 #endif /* AVUTIL_MIPS_INTREADWRITE_H */