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Re: [Qemu-devel] [Consult] tilegx: About floating point instructions
From: |
Chen Gang |
Subject: |
Re: [Qemu-devel] [Consult] tilegx: About floating point instructions |
Date: |
Tue, 4 Aug 2015 04:47:11 +0800 |
User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 |
On 8/4/15 00:40, Richard Henderson wrote:
> On 08/01/2015 02:47 AM, Chen Gang wrote:
>> I am just adding floating point instructions (e.g. fsingle_add1),
>> but for me, I can not find any details about them (the ISA
>> documents only give a summary description, but not details), e.g.
>
> The tilegx splits the four/six cycle arithmetic into multiple
> black-box instructions. You need only really implement one of the
> four, with the rest of them being implemented as nops or moves.
>
> Looking at what gcc produces gives the hints:
>
> fdouble_unpack_min min, srca, srcb fdouble_unpack_max max, srca,
> srcb fdouble_add_flags flg, srca, srcb fdouble_addsub max,
> min, flg
> fdouble_pack1 dst, max, flg fdouble_pack2 dst, max, zero
>
> The unpack, addsub, and pack2 insns can be ignored, the add_flags
> insn can perform the whole operation, the pack1 insn performs a move
> from "flg" to "dst".
>
> Similarly for the single-precision:
>
> fsingle_add1 tmp, srca, srcb fsingle_addsub2 tmp, srca, srcb
> fsingle_pack1 flg, tmp fsingle_pack2 dst, tmp, flg
>
> The add1 insn performs the whole operation, the addsub2 and pack1
> insns are ignored, and the pack2 insn is a move from tmp to dst.
>
Thank you very much. I am just analyzing the template file (tilegx.md)
and testsuite executable file (20000603-1.exe) for it. Your information
is really valuable to me! :-)
And still welcome any additional information for it: especially related
details documentations which should be more 'standard' than the third-
party's implementation (e.g. gcc implementation).
I shall try to let qemu tilegx support gcc testsuite successfully within
this month.
Thanks.
--
Chen Gang
Open, share, and attitude like air, water, and life which God blessed
- [Qemu-devel] [Consult] tilegx: About floating point instructions, Chen Gang, 2015/08/01
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions, Richard Henderson, 2015/08/03
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions,
Chen Gang <=
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions, Chen Gang, 2015/08/04
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions, Richard Henderson, 2015/08/04
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions, Chen Gang, 2015/08/05
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions, Chen Gang, 2015/08/08
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions, Chen Gang, 2015/08/08
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions, Chen Gang, 2015/08/08
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions, Chen Gang, 2015/08/11
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions, Chen Gang, 2015/08/13
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions, Chen Gang, 2015/08/15
- Re: [Qemu-devel] [Consult] tilegx: About floating point instructions, Richard Henderson, 2015/08/15