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| author | David Mitchell <davem@iabyn.com> | 2015-10-25 08:41:50 +0000 |
|---|---|---|
| committer | David Mitchell <davem@iabyn.com> | 2015-11-10 13:52:34 +0000 |
| commit | 4c2c31284ee422eca648d182e07205f67a173227 (patch) | |
| tree | 75ed516c3acfcb5c67e98cf201a97d813fbf326e /opcode.h | |
| parent | 230ee21f3e366901ce5769d324124c522df7ce8a (diff) | |
| download | perl-4c2c31284ee422eca648d182e07205f67a173227.tar.gz | |
split pp_predec() from pp_preinc() and improve
pp_preinc() handles both ++$x and --$x (and the integer variants
pp_i_preinc/dec). Split it into two separate functions, as handling
both inc and dec in the same function requires 3 extra conditionals.
At the same time make the code more efficient.
As currently written it:
1) checked for "bad" SVs (such as read-only) and croaked;
2) checked for a IOK-only SV and directly incremented the IVX slot;
3) else called out to sv_inc() to handle the more complex cases.
This commit combines the checks in (1) and (2) into one single big
check of flags, and anything "bad" simply skips the IOK-only code
and calls sv_dec(), which can do its own checking of read-only etc
and croak if necessary. Porting/bench.pl shows the following raw numbers
for ++$x ($x lexical and holding an integer):
before after
-------- --------
Ir 77.0 56.0
Dr 30.0 24.0
Dw 10.0 10.0
COND 12.0 9.0
IND 2.0 2.0
COND_m -0.1 0.0
IND_m 2.0 2.0
Even having split the function into two, the combined size of the two new
functions is smaller than the single previous function.
Diffstat (limited to 'opcode.h')
| -rw-r--r-- | opcode.h | 7 |
1 files changed, 3 insertions, 4 deletions
@@ -22,8 +22,7 @@ #define Perl_pp_chomp Perl_pp_chop #define Perl_pp_schomp Perl_pp_schop #define Perl_pp_i_preinc Perl_pp_preinc -#define Perl_pp_predec Perl_pp_preinc -#define Perl_pp_i_predec Perl_pp_preinc +#define Perl_pp_i_predec Perl_pp_predec #define Perl_pp_i_postinc Perl_pp_postinc #define Perl_pp_postdec Perl_pp_postinc #define Perl_pp_i_postdec Perl_pp_postinc @@ -1013,8 +1012,8 @@ EXT Perl_ppaddr_t PL_ppaddr[] /* or perlvars.h */ Perl_pp_pos, Perl_pp_preinc, Perl_pp_i_preinc, /* implemented by Perl_pp_preinc */ - Perl_pp_predec, /* implemented by Perl_pp_preinc */ - Perl_pp_i_predec, /* implemented by Perl_pp_preinc */ + Perl_pp_predec, + Perl_pp_i_predec, /* implemented by Perl_pp_predec */ Perl_pp_postinc, Perl_pp_i_postinc, /* implemented by Perl_pp_postinc */ Perl_pp_postdec, /* implemented by Perl_pp_postinc */ |