2015-10-22 15:30 GMT+02:00 Martell Malone <[email protected]>: > The reason I am asking is because there is a calling convention bug for > mingw-w64 and clang that is only present on x86_64. > > Are you sure there are no differences from a Linux target?
Yes, I am. At least at that time I made x64 target ready, it used the 80-bit floating-point too. Nevertheless it is most naturally to use same floating-point precision for x64 as used for x87, as targets need to be remain compatible here. So not sure what ABI difference to Clang exists here? I don't see such issue on gcc-side. > > On Thursday, October 22, 2015, Kai Tietz <[email protected]> wrote: >> >> Hi guys, >> >> 2015-10-22 12:54 GMT+02:00 Martell Malone <[email protected]>: >> > Hi guys, >> > >> > Can someone confirm the format of long double for the x86_x64 target of >> > mingw-w64. >> > >> > Under i686 it is x87 80 bit precision >> > But under x86_64? >> >> It is also 80 bit precision. We kept it the same as for linux x86_64 >> targets.In general this is already an extension of x64 ABI, as for the >> MS' compiler 'long double' has just 64-bit precision. >> >> >> > Is it sse2 128 or 80 bit or is it still x87 >> >> We use for 80 bit still x87 opcodes. Indeed it could be an >> improvement to use a soft-emu using sse2 instructions and just >> down-scale to 80-bit precision from it. At least for x86_64 this >> might be indeed a speed-improvement in some cases. >> >> > Kind regards >> > Martell >> >> Regards, >> Kai >> ------------------------------------------------------------------------------ _______________________________________________ Mingw-w64-public mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
