LuoYuanke added inline comments.
================
Comment at: llvm/lib/Target/X86/X86InstrFoldTables.cpp:1852
+ { X86::VFCMULCPHZrr, X86::VFCMULCPHZrm, 0 },
+ { X86::VFCMULCSHZrr, X86::VFCMULCSHZrm,
TB_NO_REVERSE },
{ X86::VFMADDPD4Yrr, X86::VFMADDPD4Ymr, 0 },
----------------
craig.topper wrote:
> LuoYuanke wrote:
> > pengfei wrote:
> > > LuoYuanke wrote:
> > > > Why FR32X version is not needed for complex scalar instructions?
> > > Do you mean complex ss/sd? We don't have these instructions.
> > No, I mean we have both X86::XXX and X86::XXX_Int for other instructions.
> > One is FR16X which can be unfolded, one is VR128X which can't. For example,
> > VFNMADD213SHZm and VFNMADD213SHZm_Int.
> The VFCMULCSHZrr instructions produce two 16-bit values packed into the lower
> 32 bits. That would mean we would need a FR32X result, but it couldn't
> interact meaningfully with any other FR32X instruction since its really two
> values.
>
> I think we only have FR32/FR64 instructions for things that have generic IR
> equivalents or that we create from other generic IR operations. Like I think
> we have an FR32 RCP and RSQRT because we can convert float div or 1/sqrt to
> them.
Thanks, Craig. I understand now. :)
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D105269/new/
https://reviews.llvm.org/D105269
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
