Bug 51705 - [Bisected IVB]Oglc glsl-bif-tex-texture(basic.texture.sampler1DShadow.set2-mips) regressed
Summary: [Bisected IVB]Oglc glsl-bif-tex-texture(basic.texture.sampler1DShadow.set2-mi...
Status: CLOSED WONTFIX
Alias: None
Product: Mesa
Classification: Unclassified
Component: Drivers/DRI/i965 (show other bugs)
Version: git
Hardware: All Linux (All)
: medium major
Assignee: Kenneth Graunke
QA Contact: Intel 3D Bugs Mailing List
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-07-03 20:42 UTC by lu hua
Modified: 2015-06-16 02:36 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:


Attachments
output (675.96 KB, text/plain)
2012-08-07 07:51 UTC, lu hua
Details

Description lu hua 2012-07-03 20:42:04 UTC
System Environment:
--------------------------
Arch:             x86_64
Platform:         Ivybridge
Libdrm:		(master)libdrm-2.4.37
Mesa:		(master)f34764ea5308221dc35479bd118142a0e249049c
Xserver:(master)xorg-server-1.12.0-233-gdae317e7265007b38012244722e3b3a06e904ed5
Xf86_video_intel:(master)2.19.0-375-gaffdebcb2d09cd8fdc5aadb2d8df3193587e4a06
Libva:		(staging)f12f80371fb534e6bbf248586b3c17c298a31f4e
Libva_intel_driver:(staging)82fa52510a37ab645daaa3bb7091ff5096a20d0b
Kernel:	(drm-intel-next-queued) 146937e5828ede495e11ba3a6f4a01b36b7166dc

Bug detailed description:
---------------------
It fails on Ivybridge with mesa master and 8.0 branch.

Following cases also fail:
glsl-bif-tex-texture(basic.textureOffset.sampler1DShadow.set1)
glsl-bif-tex-texture(basic.texture.sampler1DShadow.set1)
glsl-bif-tex-texture(basic.texture.sampler1DShadow.set2-mips)

The last known good commit:4bfdc8313592ec8a8794d6b7bc33a5c44df34ed4.
The last known bad commit:f34764ea5308221dc35479bd118142a0e249049c.

Visual Report:
ID      |ACCELERA|DB      |REND_T  |SURF_T  |C_BUF_T |BUF_S   |RED_S   |
     114|       1|       1|      gl|  wipbpx|    rgba|      32|       8|

GREEN_S |BLUE_S  |ALPHA_S |DEPTH_S |STENC_S |ACCUM_S |SPL_BUF |SAMPLES |
       8|       8|       8|      24|       8|      64|       0|       0|

SRGB    |TEX_RGB |TEX_RGBA|CAVEAT  |SWAP    |M_PBUF_W|M_PBUF_H|M_PBUF_P
      -1|       0|       0|    slow|   undef|       0|       0|       0

Reproduce steps:
----------------------------
1. start x
2. ./oglconform -z -suite all -v 2 -D 114 -test glsl-bif-tex-texture \ basic.texture.sampler1DShadow.set2-mips
Comment 1 Kenneth Graunke 2012-08-02 21:24:45 UTC
Most of the oglc glsl-bif-tex tests have had fairly random results for me.  In other words, it sometimes passes, and sometimes fails.  I've spent weeks looking into this already, with no progress.

While we want to fix this, I'm skeptical that it's actually a regression, so I've lowered the priority.
Comment 2 lu hua 2012-08-07 07:50:49 UTC
Bisect shows: 5b83bdc154ec8d607a4c4d96171d0128e51abaec is the first bad commit
commit 5b83bdc154ec8d607a4c4d96171d0128e51abaec
Author: Kenneth Graunke <kenneth@whitecape.org>
Date:   Sat Jun 16 02:08:13 2012 -0700

    i965: Fix brw_swap_cmod() for LE/GE comparisons.

    The idea here is to rewrite comparisons like 2 >= x with x <= 2; we want
    to simply exchange arguments, not negate the condition.  If equality was
    part of the original comparison, it should remain part of the swapped
    version.

    This is the true cause of bug #50298.  It didn't manifest itself on
    Sandybridge because we embed the conditional modifier in the IF
    instruction rather than emitting a CMP.  All other platforms use CMP.

    It also didn't manifest itself on the master branch because commit
    be5f27a84d ("glsl: Refine the loop instruction counting.") papered over
    the problem.

    NOTE: This is a candidate for stable release branches.

    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50298
    Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
    Reviewed-by: Eric Anholt <eric@anholt.net>
Comment 3 lu hua 2012-08-07 07:51:27 UTC
Created attachment 65222 [details]
output
Comment 4 lu hua 2012-08-07 07:53:42 UTC
I run it 20 cycles, It fails 20 times.
system environment:
Mesa:  (master)61b62c007a7941e9b45e83440e932160a597e0e1
Kernel:(drm-intel-next-queued) ab3951eb74e7c33a2f5b7b64d72e82f1eea61571


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