Messages in this thread | | | Date | Tue, 03 Feb 2009 09:23:12 -0800 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH RFC WIP] x86/paravirt: add register-saving thunks to reduce caller register pressure |
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Pavel Machek wrote: >> This patch seeks to alleviate this pressure by introducing wrapper >> thunks that will do the register saving/restoring, so that the >> callsite doesn't need to worry about it, but the callee function can >> be conventional compiler-generated code. In many cases (particularly >> performance-sensitive cases) the callee will be in assembler anyway, >> and need not use the compiler's calling convention. >> >> Standard calling convention is: >> arguments return scratch >> x86-32 eax edx ecx eax ? >> > > esi edi ebp ? >
Those are callee-save, so the caller doesn't need to worry about preserving their values.
> actually standard calling convention is all arguments on stack iirc > but we use regparm=3 for kernel...? >
Yes. "standard" = "standard kernel calling convention"
J
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