https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104152
Bug ID: 104152
Summary: ICE with -Ofast -march=armv8.2-a+sve
-msve-vector-bits=scalable
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: gilles.gouaillardet at gmail dot com
Target Milestone: ---
Created attachment 52248
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52248&action=edit
a simple reproducer
The attached reproducer crashes with the trunk branch when -Ofast
-march=armv8.2-a+sve -msve-vector-bits=scalable is used:
FWIW, git bisect points to this commit:
commit ce670e4faafb296d1f1a7828d20f8c8ba4686797
Author: Richard Biener <rguent...@suse.de>
Date: Wed Nov 18 14:17:34 2020 +0100
tree-optimization/97832 - handle associatable chains in SLP discovery
This makes SLP discovery handle associatable (including mixed
plus/minus) chains better by swapping operands across the whole
chain. To work this adds caching of the 'matches' lanes for
failed SLP discovery attempts, thereby fixing a failed SLP
discovery for the slp-pr98855.cc testcase which results in
building an operand from scalars as expected. Unfortunately
this makes us trip over the cost threshold so I'm XFAILing the
testcase for now.
For BB vectorization all this doesn't work because we have no way
to distinguish good from bad associations as we eventually build
operands from scalars and thus not fail in the classical sense.
2021-05-31 Richard Biener <rguent...@suse.de>
PR tree-optimization/97832
* tree-vectorizer.h (_slp_tree::failed): New.
* tree-vect-slp.c (_slp_tree::_slp_tree): Initialize
failed member.
(_slp_tree::~_slp_tree): Free failed.
(vect_build_slp_tree): Retain failed nodes and record
matches in them, copying that back out when running
into a cached fail. Dump start and end of discovery.
(dt_sort_cmp): New.
(vect_build_slp_tree_2): Handle associatable chains
together doing more aggressive operand swapping.
* gcc.dg/vect/pr97832-1.c: New testcase.
* gcc.dg/vect/pr97832-2.c: Likewise.
* gcc.dg/vect/pr97832-3.c: Likewise.
* g++.dg/vect/slp-pr98855.cc: XFAIL.
Here is the stack trace in my environment:
$ g++ -c -Ofast -march=armv8.2-a+sve -msve-vector-bits=scalable -c badaboum.cpp
2>&1 | tee badaboum.log
during GIMPLE pass: vect
badaboum.cpp: In function ?int badaboum(float*, float**)?:
badaboum.cpp:20:5: internal compiler error: in duplicate_and_interleave, at
tree-vect-slp.cc:6188
20 | int badaboum(rvec_ cm_mol, float **tc)
| ^~~~~~~~
0x136d3e7 duplicate_and_interleave(vec_info*, gimple**, tree_node*,
vec<tree_node*, va_heap, vl_ptr> const&, unsigned int, vec<tree_node*, va_heap,
vl_ptr>&)
../../../src/gcc-trunk/gcc/tree-vect-slp.cc:6188
0x136d89b vect_create_constant_vectors
../../../src/gcc-trunk/gcc/tree-vect-slp.cc:6409
0x136d89b vect_schedule_slp_node
../../../src/gcc-trunk/gcc/tree-vect-slp.cc:7114
0x137d363 vect_schedule_scc
../../../src/gcc-trunk/gcc/tree-vect-slp.cc:7426
0x137ddbf vect_schedule_scc
../../../src/gcc-trunk/gcc/tree-vect-slp.cc:7443
0x137ddbf vect_schedule_scc
../../../src/gcc-trunk/gcc/tree-vect-slp.cc:7443
0x137ddbf vect_schedule_scc
../../../src/gcc-trunk/gcc/tree-vect-slp.cc:7443
0x137ddbf vect_schedule_scc
../../../src/gcc-trunk/gcc/tree-vect-slp.cc:7443
0x137e60f vect_schedule_slp(vec_info*, vec<_slp_instance*, va_heap, vl_ptr>
const&)
../../../src/gcc-trunk/gcc/tree-vect-slp.cc:7579
0x1355bc3 vect_transform_loop(_loop_vec_info*, gimple*)
../../../src/gcc-trunk/gcc/tree-vect-loop.cc:9753
0x138aa2b vect_transform_loops
../../../src/gcc-trunk/gcc/tree-vectorizer.cc:1003
0x138aa2b try_vectorize_loop_1
../../../src/gcc-trunk/gcc/tree-vectorizer.cc:1133
0x138aa2b try_vectorize_loop
../../../src/gcc-trunk/gcc/tree-vectorizer.cc:1162
0x138b097 execute
../../../src/gcc-trunk/gcc/tree-vectorizer.cc:1278
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
