On Sun, Mar 23, 2008 at 8:09 AM, H.J. Lu <[EMAIL PROTECTED]> wrote: > > 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. >
I think we should align _Decimal64 and _Decimal128 to their natural alignments when passing a function. The same should apply to x86-64 when they are passed on stack. H.J.
