search

Perl / perl5

🐪 The Perl programming language
https://dev.perl.org/perl5/
Other
1.95k stars 554 forks source link

10 ms loss, 4.5 MB big charclass_invlists.h is parsed and discarded in all .obj files #22678

Open bulk88 opened 3 days ago

bulk88 commented 3 days ago

Description

Using Windows Strace, I notice the CC is pulling in the 4.5 MB charclass_invlists.h in every single .o file. %99.99 percent of it will be discarded by the CPP, but the compile time lost is measurable. Not including a formal patch since which integer const macro defs become global and which stay in that 4.5 MB .h isnt my expertise.

executing cl -c -I.. -Ifull -nologo -GF -W3 -MD -I.\include -I. -I.. -DWIN32 -D_CONSOLE -DNO_STRICT -DWIN64 -D_CRT_SECURE_NO_DEPRECATE -D_CRT_NONSTDC_NO_DEPRECATE -D_WINSOCK_DEPRECATED_NO_WARNINGS -DPERLDLL -DPERL_CORE -O1 -Zi -GL -fp:precise -DPERL_TEXTMODE_SCRIPTS -DMULTIPLICITY -DPERL_IMPLICIT_SYS -DUSE_PERLIO -Fo..\av.obj -Fd..\av.pdb ..\av.c

BEFORE

Exit code      : 0
Elapsed time   : 0.50
Kernel time    : 0.06 (12.5%)
User time      : 0.44 (87.5%)
page fault #   : 11127
Working set    : 29992 KB
Paged pool     : 394 KB
Non-paged pool : 11 KB
Page file size : 164400 KB
Exit code      : 0
Elapsed time   : 0.48
Kernel time    : 0.05 (9.8%)
User time      : 0.41 (84.7%)
page fault #   : 11109
Working set    : 29944 KB
Paged pool     : 394 KB
Non-paged pool : 11 KB
Page file size : 164392 KB
Exit code      : 0
Elapsed time   : 0.49
Kernel time    : 0.09 (19.1%)
User time      : 0.39 (79.4%)
page fault #   : 11118
Working set    : 29956 KB
Paged pool     : 394 KB
Non-paged pool : 11 KB
Page file size : 164396 KB

AFTER

Exit code      : 0
Elapsed time   : 0.43
Kernel time    : 0.06 (14.5%)
User time      : 0.34 (79.6%)
page fault #   : 11108
Working set    : 29920 KB
Paged pool     : 394 KB
Non-paged pool : 11 KB
Page file size : 164332 KB
Exit code      : 0
Elapsed time   : 0.42
Kernel time    : 0.08 (18.4%)
User time      : 0.34 (80.9%)
page fault #   : 10903
Working set    : 29908 KB
Paged pool     : 394 KB
Non-paged pool : 11 KB
Page file size : 164328 KB
Exit code      : 0
Elapsed time   : 0.42
Kernel time    : 0.03 (7.4%)
User time      : 0.36 (84.6%)
page fault #   : 10905
Working set    : 29924 KB
Paged pool     : 394 KB
Non-paged pool : 11 KB
Page file size : 164336 KB

experiment patch for perl.h that saved 10 ms


#include "handy.h"
#if defined(PERL_IN_UTF8_C) || defined(PERL_IN_REGCOMP_C) \
    || defined(PERL_IN_XSUB_RE) || defined(PERL_IN_REGEXEC_C)
#   include "charclass_invlists.h"
#endif

#ifndef MAX_FOLD_FROMS
  #define MAX_FOLD_FROMS 3
#endif

#ifndef NUM_ANYOF_CODE_POINTS
#define NUM_ANYOF_CODE_POINTS   (1 << 8)
#endif

Steps to Reproduce

Use strace on a C compiler process, watch it read with IO calls the 4.5 MB charclass_invlists.h file, to the end, when compiling every single perl .o file.

Expected behavior

Do not #include that file by default in perl headers. Only .c files that want it should #include it. which should be a very small count.

Perl configuration

perl 5.41.5