[PATCH][FastISel] Let the target decide first if it wants to materialize a constant.

[Chad Rosier]

If you tell me the specific revision, I can give you an answer in 15-20
minutes.

> Dang, that might have been the other commit I made after this to extend
> the addressing modes for AArch64.
> Let me revert that commit first. How long will it take to see the results
> of the revert?
>
> Cheers,
> Juergen
>
> On Aug 14, 2014, at 9:53 AM, Chad Rosier <mcrosier at codeaurora.org> wrote:
>
>> Juergen,
>> Also, I'm seeing a large number of spec2K and spec2K6 failures after
>> this
>> flurry of commits.  I'm not exactly sure which one to blame, but we
>> should
>> consider reverting to fix the nightlies as well as allow for proper
>> review.
>>
>> Chad
>>
>>> So, this was in my list of things to look at but it seems like you
>>> went ahead and committed it without actually waiting for feedback?
>>>
>>> -eric
>>>
>>> On Tue, Aug 12, 2014 at 9:23 AM, Juergen Ributzka <juergen at apple.com>
>>> wrote:
>>>> ping :D
>>>>
>>>> On Aug 7, 2014, at 2:51 PM, Juergen Ributzka <juergen at apple.com>
>>>> wrote:
>>>>
>>>>> Hi @ll,
>>>>>
>>>>> I want to change the order in which FastISel tries to materialize a
>>>>> constant.
>>>>>
>>>>> Originally it would try to use a simple target-independent approach,
>>>>> which can lead to the generation of inefficient code.
>>>>>
>>>>> On X86 this would result in the use of movabsq to materialize any
>>>>> 64bit
>>>>> integer constant - even for simple and small values such as 0 and 1.
>>>>> Also
>>>>> some very funny floating-point materialization could be observed too.
>>>>>
>>>>> On AArch64 it would materialize the constant 0 in a register even the
>>>>> architecture has an actual "zero" register.
>>>>>
>>>>> On ARM it would generate unnecessary mov instructions or not use mvn,
>>>>> etc
>>>>>
>>>>> I want to simply change the order and always asks the target first if
>>>>> it likes to materialize the constant. The patches a pretty simple and
>>>>> straight forward, but since it changes the way how FastISel works
>>>>> with
>>>>> respect to constants I wanted everyone affected by it to have at
>>>>> least
>>>>> a quick look first.
>>>>>
>>>>> Thanks
>>>>>
>>>>> Cheers,
>>>>> Juergen
>>>>>
>>>>> <0001-FastISel-AArch64-Cleanup-constant-materialization-co.patch><0002-FastISel-ARM-Fix-a-bug-in-the-integer-materializatio.patch><0003-FastISel-ARM-Use-MOVT-MOVW-if-the-subtarget-requests.patch><0004-FastISel-X86-Refactor-constant-materialization.-NFCI.patch><0005-FastISel-Let-the-target-decide-first-if-it-wants-to-.patch><0006-FastISel-AArch64-Make-use-of-the-zero-register-when-.patch><0007-FastISel-X86-Emit-more-efficient-instructions-for-in.patch><0008-FastISel-X86-Use-XOR-to-materialize-the-0-value.patch>
>>>>
>>>
>>
>>
>> --
>> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
>> hosted by The Linux Foundation
>>
>
>


-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation