From c2209405ecb88db972b91bef4630184c310e31b6 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <sezeroz@gmail.com>
Date: Sat, 24 Mar 2018 22:27:31 +0300
Subject: [PATCH] SDL_endian.h: add Watcom inline asm for SDL_Swap16 and
 SDL_Swap32

---
 include/SDL_endian.h | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/include/SDL_endian.h b/include/SDL_endian.h
index 068da918f..cf2b4422c 100644
--- a/include/SDL_endian.h
+++ b/include/SDL_endian.h
@@ -97,6 +97,12 @@ static __inline__ Uint16 SDL_Swap16(Uint16 x)
 	__asm__("rorw #8,%0" : "=d" (x) :  "0" (x) : "cc");
 	return x;
 }
+#elif defined(__WATCOMC__) && defined(__386__)
+extern _inline Uint16 SDL_Swap16(Uint16);
+#pragma aux SDL_Swap16 = \
+	"xchg al, ah" \
+	parm   [ax]   \
+	modify [ax];
 #else
 static __inline__ Uint16 SDL_Swap16(Uint16 x) {
 	return SDL_static_cast(Uint16, ((x<<8)|(x>>8)));
@@ -132,6 +138,21 @@ static __inline__ Uint32 SDL_Swap32(Uint32 x)
 	__asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0" : "=d" (x) :  "0" (x) : "cc");
 	return x;
 }
+#elif defined(__WATCOMC__) && defined(__386__)
+extern _inline Uint32 SDL_Swap32(Uint32);
+#ifndef __SW_3 /* 486+ */
+#pragma aux SDL_Swap32 = \
+	"bswap eax"  \
+	parm   [eax] \
+	modify [eax];
+#else  /* 386-only */
+#pragma aux SDL_Swap32 = \
+	"xchg al, ah"  \
+	"ror  eax, 16" \
+	"xchg al, ah"  \
+	parm   [eax]   \
+	modify [eax];
+#endif
 #else
 static __inline__ Uint32 SDL_Swap32(Uint32 x) {
 	return SDL_static_cast(Uint32, ((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24)));