https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87256
--- Comment #5 from Sergei Trofimovich <slyfox at inbox dot ru> ---
(In reply to dave.anglin from comment #3)
> On 2018-09-08 3:11 PM, slyfox at inbox dot ru wrote:
> > -#define NUM_ALG_HASH_ENTRIES 1031
> > +#define NUM_ALG_HASH_ENTRIES 10311
> Does this help the compile time for xxhash?
A bit: it shrinks compile time from 80s to 13s (other targets do it in
sub-second times).
Ran the build against gcc master as:
${HOME}/dev/git/gcc-hppa2.0/gcc/xgcc -B${HOME}/dev/git/gcc-hppa2.0/gcc/ -O2
-pipe -fdiagnostics-show-option -frecord-gcc-switches -Wall -Wextra -Wcast-qual
-Wcast-align -Wshadow -Wstrict-aliasing=1 -Wswitch-enum
-Wdeclaration-after-statement -Wstrict-prototypes -Wundef -c -o xxhash.o
xxhash.c -ftime-report
Before the patch:
Time variable usr sys
wall GGC
expand : 82.20 ( 93%) 0.01 ( 7%) 82.94 (
93%) 4372 kB ( 11%)
TOTAL : 88.11 0.14 89.06
40621 kB
After the patch:
Time variable usr sys
wall GGC
expand : 8.95 ( 68%) 0.00 ( 0%) 8.93 (
67%) 4372 kB ( 11%)
TOTAL : 13.15 0.08 13.24
40623 kB
perf record/report still shows most of time is dominated by synth_mult():
64.59% cc1 cc1 [.] synth_mult
3.00% cc1 cc1 [.] sd_lists_size
