On 10/22/2010 07:11 PM, Linus Torvalds wrote: > On Fri, Oct 22, 2010 at 6:20 PM, tip-bot for H. Peter Anvin > <hpa@xxxxxxxxx> wrote: >> >> Checkin d7acb92fea932ad2e7846480aeacddc2c03c8485 made use of fxsaveq >> in fpu_fxsave() if the assembler supports it; this adds >> fxsaveq/fxrstorq to fxrstor_checking() and fxsave_user() as well. > > Hmm. I really think you should be able to do something like this > > #ifdef CONFIG_AS_FXSAVEQ > #define FXSAVEQ_INSN "fxsaveq %[fx]" > #define FXRSTORQ_INSN "fxrstorq %[fx]" > #define FX_EXTRA(ptr) > #else > #define FXSAVEQ_INSN "rex64/fxsave (%[fxr])" > #define FXRSTORQ_INSN "rex64/fxrstor (%[fxr])" > #define FX_EXTRA(ptr) [fxr] "R" (ptr) > #endif > > and then you should be able to write the actual code something like > > asm volatile(FXSAVEQ_INSN > :[fx] "=m" (memory) > :FX_EXTRA(&memory)) > > and > > #define __COMMA_CONCAT(x) ,##x > #define COMMA_CONCAT(x) __COMMA_CONCAT(x) > asm volatile(FXRSTRORQ_INSN > : :[fx] "m" (memory) COMMA_CONCAT(FX_EXTRA(&memory))); > > or something like that (obviously you'll need the exception stuff too there). > > With no #ifdef's in the actual code. Hmm? > Well sure, but it is already encapsulated in 3 inlines. To me, the above is quite frankly quite a bit harder to read than the broken-out form. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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