[RFC PATCH 0/5] RISC-V: Add Half-precision floating point extensions

[Tsukasa OI]

Hi Kito,

Thanks for letting me know.  I think I can rebase or port my work to
Nelson's implementation.

Hi Nelson,

It's good to know that you implemented Zfh.  I think I can port my
Zfhmin patch and testcases based on your work.


My original submission did not contain floating point data pseudo-op in
the assembler (like F, D and Q) and I didn't know .float, .single and
.double are already available on GAS (non arch-specific).  Since
.float16 is currently RISC-V+GNU-specific, it would be nicer if we have
discussion on ... for instance, riscv-asm-manual.


Best Regards,
Tsukasa


On 2022/05/18 10:43, Kito Cheng wrote:
> HI Tsukasa:
> 
> Nelson has ported his zfh implementation from integration branch to
> trunk, did you mind base that on to adding zfhmin?
> 
> On Tue, Jan 11, 2022 at 6:48 PM Tsukasa OI via Binutils
> <binutils@sourceware.org> wrote:
>>
>> This patchset adds support for two recently ratified RISC-V extensions:
>>
>> -   Zfhmin (Half-precision floating point: conversion only)
>> -   Zfh    (Half-precision floating point: full arithmetic)
>>
>> This patchset was intended to be a part of Binutils 2.38 but I was
>> getting too impatient.  I tested this patchset with Spike simulator and
>> tested that a few programs with fp16 was working nicely.  However, this
>> patchset lacks full testsuite.
>>
>> The only reason I didn't make one was simple: all of floating point
>> extensions ('F', 'D' and 'Q') didn't have full testsuite.  Thanks to the
>> fact that this patchset is too late for Binutils 2.38, we have time to
>> add full testsuite for all floating point extensions.
>>
>> Also, this patchset lacks pseudoinstructions (intentionally).  Possible
>> pseudoinstructions to implement later would be:
>>
>> -   fmv.h
>> -   fneg.h
>> -   fabs.h
>>
>> Besides that, we can begin testing 'Zfh' and 'Zfhmin' extensions with
>> this patchset.
>>
>>
>>
>>
>> Tsukasa OI (5):
>>   RISC-V: Add 'Zfh' and 'Zfhmin' extensions
>>   RISC-V: Add insn classes for Zfh/Zfhmin extensions
>>   RISC-V: Add 'Zfh' and 'Zfhmin' instructions
>>   RISC-V: Add 'flh' and 'fsh' macro instructions
>>   RISC-V: Add 'Zfh'/'Zfhmin' conflict message
>>
>>  bfd/elfxx-riscv.c          |  16 +++++-
>>  gas/config/tc-riscv.c      |  10 ++++
>>  include/opcode/riscv-opc.h | 108 +++++++++++++++++++++++++++++++++++++
>>  include/opcode/riscv.h     |   6 +++
>>  opcodes/riscv-opc.c        |  62 +++++++++++++++++++++
>>  5 files changed, 201 insertions(+), 1 deletion(-)
>>
>>
>> base-commit: 9ed5be5650ba7c315cd7cfacccc9208de2f555df
>> --
>> 2.32.0
>>
>