https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85964
Martin Liška <marxin at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2018-05-29
CC| |ebotcazou at gcc dot gnu.org,
| |law at gcc dot gnu.org,
| |marxin at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Started when we introduced GCC unroll pragma: r255973. Changing 128 to 32, then
it takes ~5s on a Haswell machine.
time report:
time gcc pr85954.c -c -ftracer -fno-guess-branch-probability -O3 -ftime-report
Time variable usr sys wall
GGC
phase setup : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
1247 kB ( 6%)
phase opt and generate : 5.42 (100%) 0.02 (100%) 5.44 (100%)
21204 kB ( 94%)
phase finalize : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
0 kB ( 0%)
CFG verifier : 0.02 ( 0%) 0.00 ( 0%) 0.02 ( 0%)
0 kB ( 0%)
tree CFG cleanup : 3.40 ( 63%) 0.00 ( 0%) 3.43 ( 63%)
773 kB ( 3%)
tree VRP : 0.01 ( 0%) 0.00 ( 0%) 0.03 ( 1%)
1605 kB ( 7%)
tree copy propagation : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
23 kB ( 0%)
tree PTA : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
0 kB ( 0%)
tree SSA rewrite : 0.02 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
0 kB ( 0%)
tree SSA incremental : 0.17 ( 3%) 0.00 ( 0%) 0.16 ( 3%)
2336 kB ( 10%)
tree operand scan : 0.00 ( 0%) 0.00 ( 0%) 0.02 ( 0%)
645 kB ( 3%)
dominator optimization : 0.07 ( 1%) 0.01 ( 50%) 0.06 ( 1%)
1834 kB ( 8%)
backwards jump threading : 1.49 ( 27%) 0.00 ( 0%) 1.49 ( 27%)
0 kB ( 0%)
tree FRE : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
2 kB ( 0%)
tree loop invariant motion : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
0 kB ( 0%)
complete unrolling : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
2741 kB ( 12%)
tree vectorization : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
1412 kB ( 6%)
tree SSA verifier : 0.03 ( 1%) 0.00 ( 0%) 0.04 ( 1%)
0 kB ( 0%)
tree STMT verifier : 0.03 ( 1%) 0.00 ( 0%) 0.02 ( 0%)
0 kB ( 0%)
tree strlen optimization : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
0 kB ( 0%)
dominance frontiers : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
0 kB ( 0%)
dominance computation : 0.02 ( 0%) 0.01 ( 50%) 0.01 ( 0%)
0 kB ( 0%)
loop init : 0.04 ( 1%) 0.00 ( 0%) 0.02 ( 0%)
128 kB ( 1%)
CPROP : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
20 kB ( 0%)
tracer : 0.03 ( 1%) 0.00 ( 0%) 0.02 ( 0%)
7352 kB ( 33%)
combiner : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
105 kB ( 0%)
tree loop if-conversion : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
663 kB ( 3%)
rest of compilation : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
387 kB ( 2%)
repair loop structures : 0.01 ( 0%) 0.00 ( 0%) 0.02 ( 0%)
0 kB ( 0%)
TOTAL : 5.43 0.02 5.45
22612 kB
Extra diagnostic checks enabled; compiler may run slowly.
Configure with --enable-checking=release to disable checks.
real 0m5.468s
user 0m5.441s
sys 0m0.027s
Perf report:
# Overhead Command Shared Object Symbol
# ........ ....... ................
...........................................................................................................................................................................................................
#
31.15% cc1 cc1 [.] et_splay
13.65% cc1 cc1 [.] fsm_find_thread_path
8.80% cc1 cc1 [.] iterate_fix_dominators
4.75% cc1 cc1 [.]
hash_table<default_hash_traits<basic_block_def*>,
xcallocator>::find_empty_slot_for_expand
3.38% cc1 cc1 [.] thread_jumps::handle_phi
2.78% cc1 cc1 [.]
thread_jumps::fsm_find_control_statement_thread_paths
2.70% cc1 cc1 [.] bitmap_set_bit
2.47% cc1 cc1 [.] graphds_dfs
2.33% cc1 cc1 [.] et_root
2.01% cc1 cc1 [.]
hash_table<default_hash_traits<basic_block_def*>, xcallocator>::expand
1.81% cc1 cc1 [.] et_below
1.39% cc1 libc-2.27.so [.] _int_malloc
1.35% cc1 cc1 [.] add_edge
