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* byteorder: only use linux/swab.hHarvey Harrison2009-01-061-222/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The first step to make swab.h a regular header that will include an asm/swab.h with arch overrides. Avoid the gratuitous differences introduced in the new linux/swab.h by naming the ___constant_swabXX bits and __fswabXX bits exactly as found in the old implementation in byteorder/swab[b].h Use this new swab.h in byteorder/[big|little]_endian.h and remove the two old swab headers. Although the inclusion of asm/byteorder.h looks strange in linux/swab.h, this will allow each arch to move the actual arch overrides for the swab bits in an asm file and then the includes can be cleaned up without requiring a flag day for all arches at once. Keep providing __fswabXX in case some userspace was using them directly, but the revised __swabXX should be used instead in any new code and will always do constant folding not dependent on the optimization level, which means the __constant versions can be phased out in-kernel. Arches that use the old-style arch macros will lose their optimized versions until they move to the new style, but at least they will still compile. Many arches have already moved and the patches to move the remaining arches are trivial. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix constant folding and poor optimization in byte swapping codeTrent Piepho2007-05-081-39/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Constant folding does not work for the swabXX() byte swapping functions, and the C versions optimize poorly. Attempting to initialize a global variable to swab16(0x1234) or put something like "case swab32(42):" in a switch statement will not compile. It can work, swab.h just isn't doing it correctly. This patch fixes that. Contrary to the comment in asm-i386/byteorder.h, gcc does not recognize the "C" version of swab16 and turn it into efficient code. gcc can do this, just not with the current code. The simple function: u16 foo(u16 x) { return swab16(x); } Would compile to: movzwl %ax, %eax movl %eax, %edx shrl $8, %eax sall $8, %edx orl %eax, %edx With this patch, it will compile to: rolw $8, %ax I also attempted to document the maze different macros/inline functions that are used to create the final product. Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Cc: Francois-Rene Rideau <fare@tunes.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] remove gcc-2 checksAndrew Morton2006-01-081-1/+1
| | | | | | | | | | | | | Remove various things which were checking for gcc-1.x and gcc-2.x compilers. From: Adrian Bunk <bunk@stusta.de> Some documentation updates and removes some code paths for gcc < 3.2. Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+192
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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