[llvm] r276051 - AMDGPU: Change fdiv lowering based on !fpmath metadata

[Matt Arsenault via llvm-commits]

On 07/25/2016 06:02 PM, Marek Olšák wrote:
> On Tue, Jul 26, 2016 at 2:56 AM, Matt Arsenault
> <Matthew.Arsenault at amd.com> wrote:
>> On 07/25/2016 05:51 PM, Marek Olšák via llvm-commits wrote:
>>> The commit actually regresses code quality a lot on Tonga:
>>>
>>> Totals from affected shaders:
>>> VGPRS: 488066 -> 504815 (3.43 %)
>>> Spilled VGPRs: 278 -> 361 (29.86 %)
>>> Scratch VGPRs: 1060 -> 1144 (7.92 %) dwords per thread
>>> Code Size: 26675564 -> 28796812 (7.95 %) bytes
>>> Max Waves: 105039 -> 102285 (-2.62 %)
>>>
>>> Marek
>>>
>>>
>> Do you have an example testcase?
> I see this in the asm diff:
>
> -       v_rsq_f32_e32
> +       v_sqrt_f32_e32
> +       v_cmp_gt_f32_e64
> +       v_cndmask_b32_e32
> +       v_mul_f32_e32
> +       v_rcp_f32_e32
>
> I guess that's better than a test case?
>
> Marek
This might be a correct change, so I'm not 100% sure without seeing the IR