Dave Martin df0e74da6d ARM: 7173/1: Add optimised swahb32() byteswap helper for v6 and above ... ARMv6 and later processors have the REV16 instruction, which swaps the bytes within each halfword of a register value. This is already used to implement swab16(), but since the native operation performaed by REV16 is actually swahb32(), this patch renames the existing swab16() helper accordingly and defines __arch_swab16() in terms of it. This allows calls to both swab16() and swahb32() to be optimised. The compiler's generated code might improve someday, but as of 4.5.2 the code generated for pure C implementing these 16-bit bytesswaps remains pessimal. swahb32() is useful for converting 32-bit Thumb instructions between integer and memory representation on BE8 platforms (among other uses). Signed-off-by: Dave Martin <dave.martin@linaro.org> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>		2011-12-06 11:15:26 +00:00
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asm	ARM: 7173/1: Add optimised swahb32() byteswap helper for v6 and above	2011-12-06 11:15:26 +00:00