diff options
| author | Karl Williamson <khw@cpan.org> | 2020-01-22 16:06:32 -0700 |
|---|---|---|
| committer | Karl Williamson <khw@cpan.org> | 2020-01-23 15:55:24 -0700 |
| commit | c3ee6e27c2c06543aeaeba21f2516ad52cfbd1b2 (patch) | |
| tree | 041c4ad0b5d3b95a1749c5e5ca68fd347d7ffcfa /numeric.c | |
| parent | efc92487e399906bf9520deb444b349cbe03f4f0 (diff) | |
| download | perl-c3ee6e27c2c06543aeaeba21f2516ad52cfbd1b2.tar.gz | |
grok_bin_oct_hex: Add some branch predictions
This led to about a 7% improvement, number of branches went 2.3kk->1.9kk
in perf, thanks to Sergey Aleynikov. cachegrind shows:
Key:
Ir Instruction read
Dr Data read
Dw Data write
COND conditional branches
IND indirect branches
_m branch predict miss
The numbers represent raw counts per loop iteration.
eight_hex_digits
87654321
blead latest Ratio %
----- ------ -------
Ir 306.0 297.0 103.0
Dr 76.0 76.0 100.0
Dw 41.0 39.0 105.1
COND 26.0 26.0 100.0
IND 2.0 2.0 100.0
COND_m 0.1 0.0 Inf
IND_m 3.0 3.0 100.0
Diffstat (limited to 'numeric.c')
| -rw-r--r-- | numeric.c | 16 |
1 files changed, 8 insertions, 8 deletions
@@ -429,42 +429,42 @@ Perl_grok_bin_oct_hex(pTHX_ const char *start, case 0: return 0; default: - if (! _generic_isCC(*s, class_bit)) break; + if (UNLIKELY(! _generic_isCC(*s, class_bit))) break; value = (value << shift) | XDIGIT_VALUE(*s); s++; /* FALLTHROUGH */ case 7: - if (! _generic_isCC(*s, class_bit)) break; + if (UNLIKELY(! _generic_isCC(*s, class_bit))) break; value = (value << shift) | XDIGIT_VALUE(*s); s++; /* FALLTHROUGH */ case 6: - if (! _generic_isCC(*s, class_bit)) break; + if (UNLIKELY(! _generic_isCC(*s, class_bit))) break; value = (value << shift) | XDIGIT_VALUE(*s); s++; /* FALLTHROUGH */ case 5: - if (! _generic_isCC(*s, class_bit)) break; + if (UNLIKELY(! _generic_isCC(*s, class_bit))) break; value = (value << shift) | XDIGIT_VALUE(*s); s++; /* FALLTHROUGH */ case 4: - if (! _generic_isCC(*s, class_bit)) break; + if (UNLIKELY(! _generic_isCC(*s, class_bit))) break; value = (value << shift) | XDIGIT_VALUE(*s); s++; /* FALLTHROUGH */ case 3: - if (! _generic_isCC(*s, class_bit)) break; + if (UNLIKELY(! _generic_isCC(*s, class_bit))) break; value = (value << shift) | XDIGIT_VALUE(*s); s++; /* FALLTHROUGH */ case 2: - if (! _generic_isCC(*s, class_bit)) break; + if (UNLIKELY(! _generic_isCC(*s, class_bit))) break; value = (value << shift) | XDIGIT_VALUE(*s); s++; /* FALLTHROUGH */ case 1: - if (! _generic_isCC(*s, class_bit)) break; + if (UNLIKELY(! _generic_isCC(*s, class_bit))) break; value = (value << shift) | XDIGIT_VALUE(*s); if (LIKELY(len <= 8)) { |