[llvm] r317753 - AMDGPU: Merge BUFFER_LOAD_DWORD_OFFSET into x2, x4

[Olsak, Marek via llvm-commits]

Hi Michel,


I had looked at the issue and it seems variable indexing has always been somewhat broken in LLVM and this commit uncovered the bug.


Marek

________________________________
From: Michel Dänzer <michel at daenzer.net>
Sent: Thursday, November 9, 2017 5:11:46 PM
To: Olsak, Marek
Cc: llvm-commits at lists.llvm.org
Subject: Re: [llvm] r317753 - AMDGPU: Merge BUFFER_LOAD_DWORD_OFFSET into x2, x4


Hi Marek,


On 09/11/17 02:52 AM, Marek Olsak via llvm-commits wrote:
> Author: mareko
> Date: Wed Nov  8 17:52:36 2017
> New Revision: 317753
>
> URL: http://llvm.org/viewvc/llvm-project?rev=317753&view=rev
> Log:
> AMDGPU: Merge BUFFER_LOAD_DWORD_OFFSET into x2, x4

This change broke a bunch of
spec at glsl-1{1,2}0 at execution@variable-indexing at vs-varying-array-mat4-index-*
tests on my Tonga, e.g.

PIGLIT TEST: 73 - vs-varying-array-mat4-index-col-wr
Probe color at (10,10)
  Expected: 0.000000 1.000000 0.000000
  Observed: 1.000000 0.000000 0.000000
Test failure on line 99
Probe color at (25,10)
  Expected: 0.000000 1.000000 0.000000
  Observed: 1.000000 0.000000 0.000000
Test failure on line 107
Probe color at (40,10)
  Expected: 0.000000 1.000000 0.000000
  Observed: 1.000000 0.000000 0.000000
Test failure on line 115
[...]


These tests consistently pass without this change and fail with it.


I'm attaching the dump of an affected shader with and without this
change. Let me know if you need more information.


--
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer
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