On Sun, Mar 23, 2008 at 11:41:00PM +1100, Ben Elliston wrote: > > DFP is beyond i386 psABI. Gcc aligns _Decimal32 to 4 byte, _Decimal64 to 8 > > bytes > > and _Decimal128 to 16bytes. The question is what is the best alignment for > > them > > when passing to a functions. > > The original work I did for the x86-64 backend placed them at that > alignment because that is the required alignment for loading those > values into SSE registers. Right?
That is a good question. For x86, _Decimal128 is passed on stack and aligned at 4 byte. For x86-64, _Decimal128 is passed in SSE registers. An implementation of _Decimal128 in 32bit may want to use SSE registers. H.J.
