Bug 76617

Summary:	[SNB/IVB/HSW/BYT/BDW Bisected]Ogles3conform/GL3Tests_shadow_shadow_execution_vert.test fails
Product:	Mesa	Reporter:	lu hua <huax.lu>
Component:	Drivers/DRI/i965	Assignee:	Matt Turner <mattst88>
Status:	VERIFIED FIXED	QA Contact:	Intel 3D Bugs Mailing List <intel-3d-bugs>
Severity:	major
Priority:	high	CC:	eero.t.tamminen, idr
Version:	unspecified
Hardware:	All
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	output

Description lu hua 2014-03-26 06:25:53 UTC

Created attachment 96396 [details]
output

System Environment:
--------------------------
Platform: Haswell
Libdrm:		(master)libdrm-2.4.52-10-g1cb5fc706cf5913d9dee33c939f65a23ecea17a5
Mesa:		(master)7683fce8781ef0169333c5ee1276392d058cfaa8
Xserver:	(master)xorg-server-1.15.99.901-129-gbf087659f0fb747c471e26c5b287c35877818040
Xf86_video_intel:(master)2.99.911-3-g220accd828c5a0054ae9e3b491a434f7a6c750e0
Cairo:		(master)bb17403622e9ea474017e0039af8ee48b2b285db
Libva:		(staging)bf2e1773d4373619232c4c653b8cda19ea329441
Libva_intel_driver:(staging)b1319c7f7cb9d20179b20dac2308330bd0e51ffe
Kernel:	(drm-intel-nightly)84295583b8322f96a187c4fc5cca5dd7d511f57e

Bug detailed description:
-----------------------------
It fails on Sandybridge, Ivybridge, Haswell, Baytrail and broadwell with mesa master branch.It doesn't happen on mesa 10.1 branch.

Bisect shows:9630ba6c6e754b438cf67c7d76ec1c99488df3ba is the first bad commit.
commit 9630ba6c6e754b438cf67c7d76ec1c99488df3ba
Author:     Matt Turner <mattst88@gmail.com>
AuthorDate: Tue Mar 11 13:14:08 2014 -0700
Commit:     Matt Turner <mattst88@gmail.com>
CommitDate: Mon Mar 24 11:06:26 2014 -0700

    i965/vec4: Let dead code eliminate trim dead channels.

    That is, modify

       mad dst, a, b, c

    to be

       mad dst.xyz, a, b, c

    if dst.w is never read.

    total instructions in shared programs: 811869 -> 805582 (-0.77%)
    instructions in affected programs:     168287 -> 162000 (-3.74%)

    Reviewed-by: Eric Anholt <eric@anholt.net>

Reproduce steps:
---------------------------- 
1. xinit
2. ./GTF -width=64 -height=64 -run=GL3Tests/shadow/shadow_execution_vert.test

Comment 1 Matt Turner 2014-03-28 23:50:30 UTC

Thanks for the report. I've sent a patch to at least work around the issue for now.

http://lists.freedesktop.org/archives/mesa-dev/2014-March/056814.html

Comment 2 Matt Turner 2014-03-31 18:24:26 UTC

Fixed: 3a8bd9724196075da76ddcb50eff4867c5a37398

Comment 3 lu hua 2014-04-02 02:35:33 UTC

Verified.Fixed.

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