Bug 90547

Summary: [BDW/BSW/SKL Bisected]Piglit/glean@vertprog1-rsq_test_2_(reciprocal_square_root_of_negative_value) fais
Product: Mesa Reporter: lu hua <huax.lu>
Component: Drivers/DRI/i965Assignee: Kenneth Graunke <kenneth>
Status: VERIFIED FIXED QA Contact: Intel 3D Bugs Mailing List <intel-3d-bugs>
Severity: normal    
Priority: high    
Version: git   
Hardware: All   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments: output

Description lu hua 2015-05-21 06:11:30 UTC 
Created attachment 115938 [details]
output

System Environment:
--------------------------
Platform: BSW
Libdrm:		(master)libdrm-2.4.61-1-ge9ea1f42d14e10852f292f3470aee260c7349978
Mesa:		(master)4ee69a97bb0af0cc216539c48b246ea2abf8f208
Xserver:	(master)xorg-server-1.17.0-146-gfc59c8fe8d941b0ec1e98c59bc57b1f97dba149d
Xf86_video_intel:(master)2.99.917-310-ge617c1941c4e5ee90b69221013aab799eace925d 
Libva:		(master)9bfde38f19d81b7f33db8c4c8e80420c9e60429e
Libva_intel_driver:(master)8dda0650b55c467200c34ada127b5d9b54edea5c
Kernel:   (drm-intel-nightly)7e30ba951445ac86f6235a6cf55fc84730c1baf3

Bug detailed description:
-----------------------------
It fails on BDW/BSW/SKL with mesa master branch, it works well on 10.5 branch.

Bisect shows: 42298b05d1ebd8b17b89411723ae13295643e496 is the first bad commit
commit 42298b05d1ebd8b17b89411723ae13295643e496
Author:     Jason Ekstrand <jason.ekstrand@intel.com>
AuthorDate: Thu May 7 15:07:49 2015 -0700
Commit:     Jason Ekstrand <jason.ekstrand@intel.com>
CommitDate: Mon May 18 15:32:00 2015 -0700

    i965: Use NIR by default for vertex shaders on GEN8+

    GLSL IR vs. NIR shader-db results for SIMD8 vertex shaders on Broadwell:

       total instructions in shared programs: 2742062 -> 2681339 (-2.21%)
       instructions in affected programs:     1514770 -> 1454047 (-4.01%)
       helped:                                5813
       HURT:                                  1120

    The gained programs are ARB vertext programs that were previously going
    through the vec4 backend.  Now that we have prog_to_nir, ARB vertex
    programs can go through the scalar backend so they show up as "gained" in
    the shader-db results.

    Acked-by: Kenneth Graunke <kenneth@whitecape.org>
    Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
    Acked-by: Matt Turner <mattst88@gmail.com>


Reproduce steps:
---------------------------- 
1. xinit
2. PIGLIT_TEST='RSQ test 2 (reciprocal square root of negative value)' bin/glean -o -v -v -v -t +vertProg1
Comment 1 Kenneth Graunke 2015-06-04 09:01:07 UTC 
Fix on the list:
http://lists.freedesktop.org/archives/mesa-dev/2015-June/085695.html
Comment 2 Kenneth Graunke 2015-06-05 05:03:37 UTC 
Fixed in master with:

commit 15a12795c6f3edef0e1cbab39b6da3d5b8f64fc3
Author: Kenneth Graunke <kenneth@whitecape.org>
Date:   Thu Jun 4 01:24:07 2015 -0700

    prog_to_nir: Make RSQ properly take the absolute value of its argument.
Comment 3 lu hua 2015-06-08 02:19:08 UTC 
Verified.Fixed.
Comment 4 Gordon Jin 2015-06-12 05:36:02 UTC 
Ken, would you cherry pick this to 10.6?

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