On 4/1/20 9:28 AM, Richard Sandiford wrote:
> How important is it to describe the flags operation as a compare though?
> Could we instead use an unspec with three inputs, and keep it as :CC?
> That would still allow special-case matching for zero operands.
I'm not sure.
My guess is that the only
Richard Henderson writes:
> On 3/31/20 11:34 AM, Richard Sandiford wrote:
>>> +(define_insn "*cmp3_carryinC"
>>> + [(set (reg:CC CC_REGNUM)
>>> + (compare:CC
>>> + (ANY_EXTEND:
>>> + (match_operand:GPI 0 "register_operand" "r"))
>>> + (plus:
>>> + (ANY_EXTEND:
>>> +
On Tue, Mar 31, 2020 at 03:44:51PM -0700, Richard Henderson wrote:
> If we add more CC modes, does that mean that we have to improve SELECT_CC_MODE
> to match those patterns? Or do we add new CC modes just so that combine's use
> of SELECT_CC_MODE *cannot* match them?
Adding new CC modes isn't
On 3/31/20 11:34 AM, Richard Sandiford wrote:
>> +(define_insn "*cmp3_carryinC"
>> + [(set (reg:CC CC_REGNUM)
>> +(compare:CC
>> + (ANY_EXTEND:
>> +(match_operand:GPI 0 "register_operand" "r"))
>> + (plus:
>> +(ANY_EXTEND:
>> + (match_operand:GPI 1
Richard Henderson writes:
> Duplicate all usub_*_carryinC, but use xzr for the output when we
> only require the flags output. The signed versions use sign_extend
> instead of zero_extend for combine's benefit.
>
> These will be used shortly for TImode comparisons.
>
> *
On 3/22/20 12:30 PM, Segher Boessenkool wrote:
> Hi!
>
> On Fri, Mar 20, 2020 at 07:42:25PM -0700, Richard Henderson via Gcc-patches
> wrote:
>> Duplicate all usub_*_carryinC, but use xzr for the output when we
>> only require the flags output. The signed versions use sign_extend
>> instead of
Hi!
On Fri, Mar 20, 2020 at 07:42:25PM -0700, Richard Henderson via Gcc-patches
wrote:
> Duplicate all usub_*_carryinC, but use xzr for the output when we
> only require the flags output. The signed versions use sign_extend
> instead of zero_extend for combine's benefit.
You actually use
Duplicate all usub_*_carryinC, but use xzr for the output when we
only require the flags output. The signed versions use sign_extend
instead of zero_extend for combine's benefit.
These will be used shortly for TImode comparisons.
* config/aarch64/aarch64.md (cmp3_carryinC): New.
