On 01/21/16 16:07, James Greenhalgh wrote:
> On Thu, Jan 21, 2016 at 01:58:31PM -0600, Evandro Menezes wrote:
>> Hi, James.
>>
>> On 01/21/16 03:24, James Greenhalgh wrote:
>>> On Wed, Jan 06, 2016 at 02:44:47PM -0600, Evandro Menezes wrote:
>>>> On 01/06/2016 06:04 AM, Wilco Dijkstra wrote:
>>>>>> Here's what I had in mind when I inquired about distinguishing FCMP from
>>>>>> FCCMP.  As you can see in the patch, Exynos is the only target that
>>>>>> cares about it, but I wonder if ThunderX or Xgene would too.
>>>>>>
>>>>>> What do you think?
>>>>> The new attributes look fine (I've got a similar outstanding change), however
>>>>> please don't add them to non-AArch64 cores. We only need it for thunderx.md,
>>>>> cortex-a53.md, cortex-a57.md, xgene1.md and exynos-m1.md.
>>>>          Add support for the FCCMP insn types
>>>>
>>>>          2016-01-04  Evandro Menezes  <e.menezes@samsung.com>
>>>>
>>>>          gcc/
>>>>              * config/aarch64/aarch64.md (fccmp): Change insn type.
>>>>              (fccmpe): Likewise.
>>>>              * config/aarch64/thunderx.md (thunderx_fcmp): Add
>>>>     "fccmp{s,d}" types.
>>>>              * config/arm/cortex-a53.md (cortex_a53_fpalu): Likewise.
>>>>              * config/arm/cortex-a57.md (cortex_a57_fp_cmp): Likewise.
>>>>              * config/arm/xgene1.md (xgene1_fcmp): Likewise.
>>>>              * config/arm/exynos-m1.md (exynos_m1_fp_ccmp): New insn
>>>>     reservation.
>>>>              * config/arm/types.md (fccmps): Add new insn type.
>>>>              (fccmpd): Likewise.
>>>>
>>>> Got it.  Here's an updated patch.  Again, assuming that your
>>>> original patch is in place.  Perhaps you can build on it.
>>> If we don't have any targets which care about the fccmps/fccmpd split in
>>> the code base, do we really need it? Can we just follow the example of
>>> fcsel?
>> The Exynos M1 does care about the difference between FCMP and FCCMP,
>> as can be seen in the patch.
>> More explicitly:
>>
>>     (define_insn_reservation "exynos_m1_fp_cmp" 4
>>        (and (eq_attr "tune" "exynosm1")
>>             (eq_attr "type" "fcmps, fcmpd"))
>>        "em1_nmisc")
>>
>>     (define_insn_reservation "exynos_m1_fp_ccmp" 7
>>        (and (eq_attr "tune" "exynosm1")
>>             (eq_attr "type" "fccmps, fccmpd"))
>>        "em1_st, em1_nmisc")
>>
> I think I was unclear. Your exynos-m1 model cares about splitting fcmp[s/d]
> and fccmp, but it doesn't care about splitting fccmp in to fccmps/fccmpd. It
> is the split to fccmps/fccmpd that I think is unneccesary at this time.

Indeed.  However, it seems to me that the jury is still out about the 
{s,d} suffix, isn't it?  Otherwise, whatever others deem better.  I 
myself am agnostic about it.

>>>> diff --git a/gcc/config/arm/types.md b/gcc/config/arm/types.md
>>>> index 321ff89..daf7162 100644
>>>> --- a/gcc/config/arm/types.md
>>>> +++ b/gcc/config/arm/types.md
>>>> @@ -70,6 +70,7 @@
>>>>   ; f_rint[d,s]        double/single floating point rount to integral.
>>>>   ; f_store[d,s]       double/single store to memory.  Used for VFP unit.
>>>>   ; fadd[d,s]          double/single floating-point scalar addition.
>>>> +; fccmp[d,s]         double/single floating-point conditional compare.
>>> Can we follow the convention fcsel uses of calling out "From ARMv8-A:"
>>> for this type?
>> I'm not sure I follow.  Though I didn't refer to the ISA spec, I
>> used the description from it for the *fccmp* type.
> Something like:
>
> ; fccmp    From ARMv8-A: floating point conditional compare.
>
> Just to capture that this instruction is only available for cores implementing
> ARMv8-A.


Got it.

Let me try this again:

    Add support for the FCCMP insn types

    2016-01-21  Evandro Menezes  <e.menezes@samsung.com>

    gcc/
             * config/aarch64/aarch64.md (fccmp): Change insn type.
             (fccmpe): Likewise.
             * config/aarch64/thunderx.md (thunderx_fcmp): Add
    "fccmp{s,d}" types.
             * config/arm/cortex-a53.md (cortex_a53_fpalu): Likewise.
             * config/arm/cortex-a57.md (cortex_a57_fp_cmp): Likewise.
             * config/arm/xgene1.md (xgene1_fcmp): Likewise.
             * config/arm/exynos-m1.md (exynos_m1_fp_ccmp): New insn
    reservation.
             * config/arm/types.md (fccmps): Add new insn type.
             (fccmpd): Likewise.


Thank you,

-- 
Evandro Menezes