src: remove __builtin_bswap16 call

bnoordhuis · Michael Scovetta · commit dc02563e0536 · 2016-04-02T06:03:50.000Z
Not supported by apple-gcc and I'm not convinced it's worth adding more preprocessor hacks when it should be easy as pie for the compiler to to optimize the byteswap. If it doesn't, fix the compiler. Fixes: nodejs#4284 PR-URL: nodejs#4290 Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
diff --git a/src/util-inl.h b/src/util-inl.h
@@ -199,15 +199,8 @@ TypeName* Unwrap(v8::Local<v8::Object> object) {
 }
 
 void SwapBytes(uint16_t* dst, const uint16_t* src, size_t buflen) {
-  for (size_t i = 0; i < buflen; i++) {
-    // __builtin_bswap16 generates more efficient code with
-    // g++ 4.8 on PowerPC and other big-endian archs
-#ifdef __GNUC__
-    dst[i] = __builtin_bswap16(src[i]);
-#else
+  for (size_t i = 0; i < buflen; i += 1)
     dst[i] = (src[i] << 8) | (src[i] >> 8);
-#endif
-  }
 }
 
 

Original file line number	Diff line number	Diff line change
`@@ -199,15 +199,8 @@ TypeName* Unwrap(v8::Local<v8::Object> object) {`
`199`	`199`	`}`
`200`	`200`
`201`	`201`	`void SwapBytes(uint16_t* dst, const uint16_t* src, size_t buflen) {`
`202`		`- for (size_t i = 0; i < buflen; i++) {`
`203`		`- // __builtin_bswap16 generates more efficient code with`
`204`		`- // g++ 4.8 on PowerPC and other big-endian archs`
`205`		`-#ifdef __GNUC__`
`206`		`- dst[i] = __builtin_bswap16(src[i]);`
`207`		`-#else`
	`202`	`+ for (size_t i = 0; i < buflen; i += 1)`
`208`	`203`	`dst[i] = (src[i] << 8) \| (src[i] >> 8);`
`209`		`-#endif`
`210`		`- }`
`211`	`204`	`}`
`212`	`205`
`213`	`206`