https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89963
Bug ID: 89963
Summary: Compile-time hog when compiling
gcc/testsuite/gcc.dg/autopar/uns-outer-6.c
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Keywords: compile-time-hog
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: asolokha at gmx dot com
Target Milestone: ---
At least gcc-9.0.0-alpha20190331 (r270048) and gcc 8.3 take indefinite time
when compiling gcc/testsuite/gcc.dg/autopar/uns-outer-6.c w/ -O1 (-O2, -O3,
-Ofast) -fexceptions -floop-nest-optimize -fnon-call-exceptions -ftree-pre.
The profile almost fully consists of calls into libgmp and libisl, like:
20.80% libgmp.so.10.3.2 [.] __gmpn_mul_1
13.27% libisl.so.19.1.0 [.] isl_tab_pivot
10.71% libgmp.so.10.3.2 [.] __gmpz_mul
8.60% libgmp.so.10.3.2 [.] __gmpz_divexact
4.21% libgmp.so.10.3.2 [.] __gmpn_gcd_1
3.63% libgmp.so.10.3.2 [.] __gmpz_aorsmul_1
3.08% libgmp.so.10.3.2 [.] __gmpz_gcd
2.52% libisl.so.19.1.0 [.] isl_seq_gcd
2.37% libgmp.so.10.3.2 [.] __gmpn_divexact_1
2.12% libgmp.so.10.3.2 [.] __gmpz_cmpabs
1.96% libgmp.so.10.3.2 [.] __gmpn_divexact
1.91% libgmp.so.10.3.2 [.] __gmpn_modexact_1_odd
1.84% libgmp.so.10.3.2 [.] __gmpn_submul_1
1.64% libisl.so.19.1.0 [.] isl_seq_abs_min_non_zero
1.60% libgmp.so.10.3.2 [.] __gmpz_cmp_ui
1.31% libisl.so.19.1.0 [.] isl_seq_scale_down
1.29% libgmp.so.10.3.2 [.] __gmpz_addmul
1.08% libisl.so.19.1.0 [.] isl_tab_row_is_redundant
1.03% libgmp.so.10.3.2 [.] __gmpn_copyi
0.98% libgmp.so.10.3.2 [.] __gmpn_addmul_1
0.80% libisl.so.19.1.0 [.] __gmpz_mul@plt
0.63% libisl.so.19.1.0 [.] __gmpz_addmul@plt
0.61% libisl.so.19.1.0 [.] __gmpz_divexact@plt
(trimmed)
So I'm not sure wheter it's a gcc, gmp or isl bug after all. I have gmp 6.1.2
and isl 0.20 installed. I also cannot reproduce this on godbolt.
