Merge tag 'byteswap-for-linus-20121219' of git://git.infradead.org/users/dwmw2/byteswap

Pull preparatory gcc intrisics bswap patch from David Woodhouse: "This single patch is effectively a no-op for now. It enables architectures to opt in to using GCC's __builtin_bswapXX() intrinsics for byteswapping, and if we merge this now then the architecture maintainers can enable it for their arch during the next cycle without dependency issues. It's worth making it a par-arch opt-in, because although in *theory* the compiler should never do worse than hand-coded assembler (and of course it also ought to do a lot better on platforms like Atom and PowerPC which have load-and-swap or store-and-swap instructions), that isn't always the case. See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46453 for example." * tag 'byteswap-for-linus-20121219' of git://git.infradead.org/users/dwmw2/byteswap: byteorder: allow arch to opt to use GCC intrinsics for byteswapping

Linus Torvalds committed 13 years ago

Commit 7f2de812 parents 5977107 cf66bb94 files · +45 −3Browse files

Showing the changes to include/uapi/linux (1 of 4 files). Show all

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include/uapi/linux/swab.h+9−3

@@ -45,7 +45,9 @@ · 44 unmodified lines
45	45
46	46	static inline __attribute_const__ __u16 __fswab16(__u16 val)
47	47	{
48		−#ifdef __arch_swab16
	48	+#ifdef __HAVE_BUILTIN_BSWAP16__
	49	+ return __builtin_bswap16(val);
	50	+#elif defined (__arch_swab16)
49	51	return __arch_swab16(val);
50	52	#else
51	53	return ___constant_swab16(val);
@@ -54,7 +56,9 @@ static inline __attribute_const__ __u16 __fswab16(__u16 val) · 2 unmodified lines
54	56
55	57	static inline __attribute_const__ __u32 __fswab32(__u32 val)
56	58	{
57		−#ifdef __arch_swab32
	59	+#ifdef __HAVE_BUILTIN_BSWAP32__
	60	+ return __builtin_bswap32(val);
	61	+#elif defined(__arch_swab32)
58	62	return __arch_swab32(val);
59	63	#else
60	64	return ___constant_swab32(val);
@@ -63,7 +67,9 @@ static inline __attribute_const__ __u32 __fswab32(__u32 val) · 2 unmodified lines
63	67
64	68	static inline __attribute_const__ __u64 __fswab64(__u64 val)
65	69	{
66		−#ifdef __arch_swab64
	70	+#ifdef __HAVE_BUILTIN_BSWAP64__
	71	+ return __builtin_bswap64(val);
	72	+#elif defined (__arch_swab64)
67	73	return __arch_swab64(val);
68	74	#elif defined(__SWAB_64_THRU_32__)
69	75	__u32 h = val >> 32;