[Bug 111069] Assertion fails in nir_opt_remove_phis.c during compilation of SPIR-V shader
bugzilla-daemon at freedesktop.org
bugzilla-daemon at freedesktop.org
Thu Jul 4 18:29:50 UTC 2019
https://bugs.freedesktop.org/show_bug.cgi?id=111069
--- Comment #1 from Denis <denys.kostin at globallogic.com> ---
Created attachment 144705
--> https://bugs.freedesktop.org/attachment.cgi?id=144705&action=edit
backtrace_for_the_issue
Hi, thanks for bug report. I made a bisect and attached backtrace with debug
symbols.
Also want to note, that bisect lead to these two commits:
[den at den-pc mesa]$ git bisect good
There are only 'skip'ped commits left to test.
The first bad commit could be any of:
dc349f07b5f9c257f68ecf0cbb89f9722a42233a
b3c6146925595ec3a7eece3afb9ccaad32906d4c
We cannot bisect more!
Commit dc349f07b5f9c257f68ecf0cbb89f9722a42233a failed to build, and commit
below looked the first "bad" commit then
commit b3c6146925595ec3a7eece3afb9ccaad32906d4c (HEAD)
Author: Caio Marcelo de Oliveira Filho <caio.oliveira at intel.com>
Date: Fri Sep 14 11:41:39 2018 -0700
nir: Copy propagation between blocks
Extend the pass to propagate the copies information along the control
flow graph. It performs two walks, first it collects the vars
that were written inside each node. Then it walks applying the copy
propagation using a list of copies previously available. At each node
the list is invalidated according to results from the first walk.
This approach is simpler than a full data-flow analysis, but covers
various cases. If derefs are used for operating on more memory
resources (e.g. SSBOs), the difference from a regular pass is expected
to be more visible -- as the SSA copy propagation pass won't apply to
those.
A full data-flow analysis would handle more scenarios: conditional
breaks in the control flow and merge equivalent effects from multiple
branches (e.g. using a phi node to merge the source for writes to the
same deref). However, as previous commentary in the code stated, its
complexity 'rapidly get out of hand'. The current patch is a good
intermediate step towards more complex analysis.
The 'copies' linked list was modified to use util_dynarray to make it
more convenient to clone it (to handle ifs/loops).
Annotated shader-db results for Skylake:
total instructions in shared programs: 15105796 -> 15105451 (<.01%)
instructions in affected programs: 152293 -> 151948 (-0.23%)
helped: 96
HURT: 17
All the HURTs and many HELPs are one instruction. Looking
at pass by pass outputs, the copy prop kicks in removing a
bunch of loads correctly, which ends up altering what other
other optimizations kick. In those cases the copies would be
propagated after lowering to SSA.
In few HELPs we are actually helping doing more than was
possible previously, e.g. consolidating load_uniforms from
different blocks. Most of those are from
shaders/dolphin/ubershaders/.
total cycles in shared programs: 566048861 -> 565954876 (-0.02%)
cycles in affected programs: 151461830 -> 151367845 (-0.06%)
helped: 2933
HURT: 2950
A lot of noise on both sides.
total loops in shared programs: 4603 -> 4603 (0.00%)
loops in affected programs: 0 -> 0
helped: 0
HURT: 0
total spills in shared programs: 11085 -> 11073 (-0.11%)
spills in affected programs: 23 -> 11 (-52.17%)
helped: 1
HURT: 0
The shaders/dolphin/ubershaders/12.shader_test was able to
pull a couple of loads from inside if statements and reuse
them.
total fills in shared programs: 23143 -> 23089 (-0.23%)
fills in affected programs: 2718 -> 2664 (-1.99%)
helped: 27
HURT: 0
All from shaders/dolphin/ubershaders/.
LOST: 0
GAINED: 0
The other generations follow the same overall shape. The spills and
fills HURTs are all from the same game.
shader-db results for Broadwell.
total instructions in shared programs: 15402037 -> 15401841 (<.01%)
instructions in affected programs: 144386 -> 144190 (-0.14%)
helped: 86
HURT: 9
total cycles in shared programs: 600912755 -> 600902486 (<.01%)
cycles in affected programs: 185662820 -> 185652551 (<.01%)
helped: 2598
HURT: 3053
total loops in shared programs: 4579 -> 4579 (0.00%)
loops in affected programs: 0 -> 0
helped: 0
HURT: 0
total spills in shared programs: 80929 -> 80924 (<.01%)
spills in affected programs: 720 -> 715 (-0.69%)
helped: 1
HURT: 5
total fills in shared programs: 93057 -> 93013 (-0.05%)
fills in affected programs: 3398 -> 3354 (-1.29%)
helped: 27
HURT: 5
LOST: 0
GAINED: 2
:
total cycles in shared programs: 600912755 -> 600902486 (<.01%)
cycles in affected programs: 185662820 -> 185652551 (<.01%)
helped: 2598
HURT: 3053
total loops in shared programs: 4579 -> 4579 (0.00%)
loops in affected programs: 0 -> 0
helped: 0
HURT: 0
total spills in shared programs: 80929 -> 80924 (<.01%)
spills in affected programs: 720 -> 715 (-0.69%)
helped: 1
HURT: 5
total fills in shared programs: 93057 -> 93013 (-0.05%)
fills in affected programs: 3398 -> 3354 (-1.29%)
helped: 27
HURT: 5
LOST: 0
GAINED: 2
shader-db results for Haswell:
total instructions in shared programs: 9231975 -> 9230357 (-0.02%)
instructions in affected programs: 44992 -> 43374 (-3.60%)
helped: 27
HURT: 69
total cycles in shared programs: 87760587 -> 87727502 (-0.04%)
cycles in affected programs: 7720673 -> 7687588 (-0.43%)
helped: 1609
HURT: 1416
total loops in shared programs: 1830 -> 1830 (0.00%)
loops in affected programs: 0 -> 0
helped: 0
HURT: 0
total spills in shared programs: 1988 -> 1692 (-14.89%)
spills in affected programs: 296 -> 0
helped: 1
HURT: 0
total fills in shared programs: 2103 -> 1668 (-20.68%)
fills in affected programs: 438 -> 3 (-99.32%)
helped: 4
HURT: 0
LOST: 0
GAINED: 1
v2: Remove the DISABLE prefix from tests we now pass.
v3: Add comments about missing write_mask handling. (Caio)
Add unreachable when switching on cf_node type. (Jason)
:
total cycles in shared programs: 600912755 -> 600902486 (<.01%)
cycles in affected programs: 185662820 -> 185652551 (<.01%)
helped: 2598
HURT: 3053
total loops in shared programs: 4579 -> 4579 (0.00%)
loops in affected programs: 0 -> 0
helped: 0
HURT: 0
total spills in shared programs: 80929 -> 80924 (<.01%)
spills in affected programs: 720 -> 715 (-0.69%)
helped: 1
HURT: 5
total fills in shared programs: 93057 -> 93013 (-0.05%)
fills in affected programs: 3398 -> 3354 (-1.29%)
helped: 27
HURT: 5
LOST: 0
GAINED: 2
shader-db results for Haswell:
total instructions in shared programs: 9231975 -> 9230357 (-0.02%)
instructions in affected programs: 44992 -> 43374 (-3.60%)
helped: 27
HURT: 69
total cycles in shared programs: 87760587 -> 87727502 (-0.04%)
cycles in affected programs: 7720673 -> 7687588 (-0.43%)
helped: 1609
HURT: 1416
total loops in shared programs: 1830 -> 1830 (0.00%)
loops in affected programs: 0 -> 0
helped: 0
HURT: 0
total spills in shared programs: 1988 -> 1692 (-14.89%)
spills in affected programs: 296 -> 0
helped: 1
HURT: 0
total fills in shared programs: 2103 -> 1668 (-20.68%)
fills in affected programs: 438 -> 3 (-99.32%)
helped: 4
HURT: 0
LOST: 0
GAINED: 1
v2: Remove the DISABLE prefix from tests we now pass.
v3: Add comments about missing write_mask handling. (Caio)
Add unreachable when switching on cf_node type. (Jason)
Properly merge the component information in written map
instead of replacing. (Jason)
Explain how removal from written arrays works. (Jason)
Use mode directly from deref instead of getting the var. (Jason)
v4: Register the local written mode for calls. (Jason)
Prefer cf_node instead of node. (Jason)
Clarify that remove inside iteration only works in backward
iterations. (Jason)
Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>
--
You are receiving this mail because:
You are the assignee for the bug.
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-3d-bugs/attachments/20190704/1b2e2f05/attachment-0001.html>
More information about the intel-3d-bugs
mailing list