Hi, Here is the AVX patch for x86-64 psABI proposed at gcc submmit 2008.
H.J. --- On Sun, Jun 15, 2008 at 6:49 PM, Jan Hubicka <[EMAIL PROTECTED]> wrote: >> On Wed, Jun 11, 2008 at 07:49:12AM -0700, H.J. Lu wrote: >> > > I guess we all agree on passing variadic arguments on stack (that is >> > > only those belonging on ...) and rest in registers. It seems easiest in >> > > regard to future register set extensions too. Only negative thing is >> > > that calls to variadic functions will become bit longer, but I guess it >> > > is not big deal. (the fact that register passing conventions are shorter >> > > and variadic functions tends to be called many times was also original >> > > motivation to support register passing on pretty much everything for >> > > varargs in psABI) >> > > >> > >> > There is no precedent for passing named parameters in registers but >> > unnamed parameters on the stack. On IA32 for the __m128 types, we >> > pass ALL __m128 parameters on the stack for varargs functions, not >> > just the unnamed ones. I think we should do the same for x86-64. >> >> Why should the 32-bit ABI influence x86-64 ABI decisions? >> There are clear advantages of passing __m128 named arguments in registers >> (shorter/faster code both on the caller and callee side) and there >> are advantages of passing __m128 unnamed arguments on the stack >> (for va_arg to work, they need to be on the stack, and if they >> are passed in registers, the callee would need to push them >> to the stack). > > For record I would also preffer passing all named AVX arguments in > registers. x86-64 ABI was designed for performance not for backward > compatibility, so it should be consistent with original idea and I think > that ABIs are divergent anough so this won't cause too much of extra > confussion. But I am happy with both solutions. > > Honza >> >> Jakub > -- H.J.
avx-5.patch
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