https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109192
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
Last reconfirmed| |2023-03-20
Summary|[13 Regression] timeout |[13 Regression] timeout
|with -O3 -fno-var-tracking |with -O3 since r13-5579
|since r13-5579 |
Priority|P3 |P1
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed - this has nothing to do with -fno-var-tracking btw but reproduces
with just -O3 vs -O2. An interrupted (after a minute) perf profile shows
+ 55.46% 0.66% 1769 cc1 cc1 [.]
operator_cast::op1_range #
+ 48.68% 0.05% 141 cc1 cc1 [.]
operator_cast::fold_range #
+ 48.63% 3.06% 8238 cc1 cc1 [.]
operator_cast::fold_range #
+ 27.27% 1.18% 3160 cc1 cc1 [.]
irange::set_nonzero_bits #
+ 25.39% 1.68% 4512 cc1 cc1 [.]
irange::set_range_from_nonzero_bits #
+ 21.08% 0.74% 1998 cc1 cc1 [.]
irange::get_nonzero_bits #
+ 20.34% 14.24% 38289 cc1 cc1 [.]
irange::get_nonzero_bits_from_range
and we're in the 'thread'(200) pass
NEXT_PASS (pass_fre, false /* may_iterate */);
/* After late FRE we rewrite no longer addressed locals into SSA
form if possible. */
NEXT_PASS (pass_thread_jumps, /*first=*/false);
NEXT_PASS (pass_dominator, false /* may_peel_loop_headers_p */);
NEXT_PASS (pass_strlen);
interrupting gives a backtrace like
#2 0x000000000196ec95 in gori_compute::compute_operand_range (
this=this@entry=0x47bd5e0, r=..., stmt=<gimple_assign 0x7f9b81bbe5f0>,
lhs=..., name=name@entry=<ssa_name 0x7f9b81b21ab0 373>, src=...,
rel=<optimized out>)
at /space/rguenther/src/gcc/gcc/gimple-range-gori.cc:700
...
#211 0x000000000196f37b in gori_compute::compute_operand_range (
this=this@entry=0x47bd5e0, r=...,
stmt=stmt@entry=<gimple_cond 0x7f9b81bac5a0>, lhs=...,
name=name@entry=<ssa_name 0x7f9b81b21ab0 373>, src=...,
rel=<optimized out>)
at /space/rguenther/src/gcc/gcc/gimple-range-gori.cc:702
#212 0x0000000001970ec9 in gori_compute::outgoing_edge_range_p (
this=this@entry=0x47bd5e0, r=...,
e=e@entry=<edge 0x7f9b81dddba0 (122 -> 126)>,
name=name@entry=<ssa_name 0x7f9b81b21ab0 373>, q=...)
at /space/rguenther/src/gcc/gcc/gimple-range-gori.cc:1358
#213 0x0000000000e4aa79 in path_range_query::compute_ranges_in_block (
this=this@entry=0x7fff9c936a40,
bb=bb@entry=<basic_block 0x7f9b81ba7ba0 (122)>)
at /space/rguenther/src/gcc/gcc/gimple-range-path.cc:454
so 200 frames worth of recursion (just luck from some random gdb attach).
There are just 201 BBs in the function (func_36.constprop) and 1525
SSA names, so this seems to be quadraticness / missed caching.
