Joseph Myers via llvm-dev
2021-Jul-13 15:41 UTC
[llvm-dev] [PATCH] Add optional _Float16 support
On Tue, 13 Jul 2021, H.J. Lu wrote:> On Mon, Jul 12, 2021 at 8:59 PM Wang, Pengfei <pengfei.wang at intel.com> wrote: > > > > > Return _Float16 and _Complex _Float16 values in %xmm0/%xmm1 registers. > > > > Can you please explain the behavior here? Is there difference between _Float16 and _Complex _Float16 when return? I.e., > > 1, In which case will _Float16 values return in both %xmm0 and %xmm1? > > 2, For a single _Float16 value, are both real part and imaginary part returned in %xmm0? Or returned in %xmm0 and %xmm1 respectively? > > Here is the v2 patch to add the missing _Float16 bits. The PDF file is at > > https://gitlab.com/x86-psABIs/i386-ABI/-/wikis/Intel386-psABIThis PDF shows _Complex _Float16 as having a size of 2 bytes (should be 4-byte size, 2-byte alignment). It also seems to change double from 4-byte to 8-byte alignment, which is wrong. And it's inconsistent about whether it covers the long double = double (Android) case - it shows that case for _Complex long double but not for long double itself. -- Joseph S. Myers joseph at codesourcery.com
H.J. Lu via llvm-dev
2021-Jul-13 16:24 UTC
[llvm-dev] [PATCH] Add optional _Float16 support
On Tue, Jul 13, 2021 at 8:41 AM Joseph Myers <joseph at codesourcery.com> wrote:> > On Tue, 13 Jul 2021, H.J. Lu wrote: > > > On Mon, Jul 12, 2021 at 8:59 PM Wang, Pengfei <pengfei.wang at intel.com> wrote: > > > > > > > Return _Float16 and _Complex _Float16 values in %xmm0/%xmm1 registers. > > > > > > Can you please explain the behavior here? Is there difference between _Float16 and _Complex _Float16 when return? I.e., > > > 1, In which case will _Float16 values return in both %xmm0 and %xmm1? > > > 2, For a single _Float16 value, are both real part and imaginary part returned in %xmm0? Or returned in %xmm0 and %xmm1 respectively? > > > > Here is the v2 patch to add the missing _Float16 bits. The PDF file is at > > > > https://gitlab.com/x86-psABIs/i386-ABI/-/wikis/Intel386-psABI > > This PDF shows _Complex _Float16 as having a size of 2 bytes (should be > 4-byte size, 2-byte alignment). > > It also seems to change double from 4-byte to 8-byte alignment, which is > wrong. And it's inconsistent about whether it covers the long double > double (Android) case - it shows that case for _Complex long double but > not for long double itself.Here is the v3 patch with the fixes. I also updated the PDF file.> -- > Joseph S. Myers > joseph at codesourcery.com >-- H.J. -------------- next part -------------- A non-text attachment was scrubbed... Name: v3-0001-Add-optional-_Float16-support.patch Type: text/x-patch Size: 7346 bytes Desc: not available URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20210713/54dfaddd/attachment.bin>