added bswap and clz inline asm to dr_flac for Watcom builds.

icculus · Mar 15, 2021 · 194725b · 194725b
1 parent fc4ea81
commit 194725b
Showing 1 changed file with 42 additions and 0 deletions.
diff --git a/src/dr_flac.h b/src/dr_flac.h
@@ -884,6 +884,27 @@ drflac_bool32 drflac_next_cuesheet_track(drflac_cuesheet_track_iterator* pIter,
     #if ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))
         #define DRFLAC_HAS_BYTESWAP16_INTRINSIC
     #endif
+#elif defined(__WATCOMC__) && defined(__386__)
+    #define DRFLAC_HAS_BYTESWAP16_INTRINSIC
+    #define DRFLAC_HAS_BYTESWAP32_INTRINSIC
+    #define DRFLAC_HAS_BYTESWAP64_INTRINSIC
+    extern __inline drflac_uint16 _watcom_bswap16(drflac_uint16);
+    extern __inline drflac_uint32 _watcom_bswap32(drflac_uint32);
+    extern __inline drflac_uint64 _watcom_bswap64(drflac_uint64);
+#pragma aux _watcom_bswap16 = \
+    "xchg al, ah" \
+    parm   [ax]   \
+    modify [ax];
+#pragma aux _watcom_bswap32 = \
+    "bswap eax"  \
+    parm   [eax] \
+    modify [eax];
+#pragma aux _watcom_bswap64 = \
+    "bswap eax"     \
+    "bswap edx"     \
+    "xchg eax,edx"  \
+    parm [eax edx]  \
+    modify [eax edx];
 #endif
 
 
@@ -986,6 +1007,8 @@ static DRFLAC_INLINE drflac_uint16 drflac__swap_endian_uint16(drflac_uint16 n)
         return _byteswap_ushort(n);
     #elif defined(__GNUC__) || defined(__clang__)
         return __builtin_bswap16(n);
+    #elif defined(__WATCOMC__) && defined(__386__)
+        return _watcom_bswap16(n);
     #else
         #error "This compiler does not support the byte swap intrinsic."
     #endif
@@ -1002,6 +1025,8 @@ static DRFLAC_INLINE drflac_uint32 drflac__swap_endian_uint32(drflac_uint32 n)
         return _byteswap_ulong(n);
     #elif defined(__GNUC__) || defined(__clang__)
         return __builtin_bswap32(n);
+    #elif defined(__WATCOMC__) && defined(__386__)
+        return _watcom_bswap32(n);
     #else
         #error "This compiler does not support the byte swap intrinsic."
     #endif
@@ -1020,6 +1045,8 @@ static DRFLAC_INLINE drflac_uint64 drflac__swap_endian_uint64(drflac_uint64 n)
         return _byteswap_uint64(n);
     #elif defined(__GNUC__) || defined(__clang__)
         return __builtin_bswap64(n);
+    #elif defined(__WATCOMC__) && defined(__386__)
+        return _watcom_bswap64(n);
     #else
         #error "This compiler does not support the byte swap intrinsic."
     #endif
@@ -1769,6 +1796,9 @@ static drflac_bool32 drflac__find_and_seek_to_next_sync_code(drflac_bs* bs)
 #if  defined(_MSC_VER) && _MSC_VER >= 1400 && (defined(DRFLAC_X64) || defined(DRFLAC_X86))
 #define DRFLAC_IMPLEMENT_CLZ_MSVC
 #endif
+#if  defined(__WATCOMC__) && defined(__386__)
+#define DRFLAC_IMPLEMENT_CLZ_WATCOM
+#endif
 
 static DRFLAC_INLINE drflac_uint32 drflac__clz_software(drflac_cache_t x)
 {
@@ -1847,6 +1877,16 @@ static DRFLAC_INLINE drflac_uint32 drflac__clz_msvc(drflac_cache_t x)
 }
 #endif
 
+#ifdef DRFLAC_IMPLEMENT_CLZ_WATCOM
+static __inline drflac_uint32 drflac__clz_watcom (drflac_uint32);
+#pragma aux drflac__clz_watcom = \
+    "bsr eax, eax" \
+    "xor eax, 31" \
+    parm [eax] nomemory \
+    value [eax] \
+    modify exact [eax] nomemory;
+#endif
+
 static DRFLAC_INLINE drflac_uint32 drflac__clz(drflac_cache_t x)
 {
     // This function assumes at least one bit is set. Checking for 0 needs to be done at a higher level, outside this function.
@@ -1858,6 +1898,8 @@ static DRFLAC_INLINE drflac_uint32 drflac__clz(drflac_cache_t x)
     {
 #ifdef DRFLAC_IMPLEMENT_CLZ_MSVC
         return drflac__clz_msvc(x);
+#elif defined(DRFLAC_IMPLEMENT_CLZ_WATCOM)
+        return drflac__clz_watcom(x);
 #else
         return drflac__clz_software(x);
 #endif