Bug 107743

Summary:	GFXBench5 Tesselation benchmark: 10% perf regression
Product:	Mesa	Reporter:	Mark Janes <mark.a.janes>
Component:	Drivers/DRI/i965	Assignee:	Jason Ekstrand <jason>
Status:	RESOLVED DUPLICATE	QA Contact:	Intel 3D Bugs Mailing List <intel-3d-bugs>
Severity:	normal
Priority:	medium	CC:	caio.oliveira
Version:	unspecified	Keywords:	bisected, regression
Hardware:	Other
OS:	All
See Also:	https://bugs.freedesktop.org/show_bug.cgi?id=107510 https://bugs.freedesktop.org/show_bug.cgi?id=107706
Whiteboard:
i915 platform:		i915 features:

Description Mark Janes 2018-08-29 21:18:58 UTC

bisect in progress between 	6027d354d1d and 	45b5f5fa25b

Comment 1 Mark Janes 2018-08-29 22:10:58 UTC

8d8222461f9d7f497d657c2c0eff70820986429b is the first bad commit
commit 8d8222461f9d7f497d657c2c0eff70820986429b
Author: Jason Ekstrand <jason.ekstrand@intel.com>
Date:   Mon Jul 23 22:20:41 2018 -0700
    intel/nir: Enable nir_opt_find_array_copies
    
    We have to be a bit careful with this one because we want it to run in
    the optimization loop but only in the first brw_nir_optimize call.
    Later calls assume that we've lowered away copy_deref instructions and
    we don't want to introduce any more.
    
    Shader-db results on Kaby Lake:
    
        total instructions in shared programs: 15176942 -> 15176942 (0.00%)
        instructions in affected programs: 0 -> 0
        helped: 0
        HURT: 0
    
    In spite of the lack of any shader-db improvement, this patch completely
    eliminates spilling in the Batman: Arkham City tessellation shaders.
    This is because we are now able to detect that the temporary array
    created by DXVK for storing TCS inputs is a copy of the input arrays and
    use indirect URB reads instead of making a copy of 4.5 KiB of input data
    and then indirecting on it with if-ladders.
    
    Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>

Comment 2 Mark Janes 2018-08-31 17:00:16 UTC

Not sure how I missed that this was written up a bit earlier...

*** This bug has been marked as a duplicate of bug 107706 ***

Comment 3 Eero Tamminen 2019-01-30 13:25:52 UTC

Moving duplicate to a bug that's still open (Timothy closed newer and re-opened the older bug).

*** This bug has been marked as a duplicate of bug 107510 ***

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