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| author | David Mitchell <davem@iabyn.com> | 2016-11-15 08:27:48 +0000 |
|---|---|---|
| committer | David Mitchell <davem@iabyn.com> | 2016-11-16 09:54:33 +0000 |
| commit | a0833292cfd2e6c3e7390b655122d7e033b70793 (patch) | |
| tree | 725028ef67a9fb9382e49498a75aa79b6096b700 /t/perf | |
| parent | 90303eefab11f53890ba7378a38c90ca58b20072 (diff) | |
| download | perl-a0833292cfd2e6c3e7390b655122d7e033b70793.tar.gz | |
optimise $ref1 = $ref2 better
When assigning to a ref, the old referent is mortalised if its refcount
is 1, to avoid a premature free on things like $r = $$r or $r = $r->[0].
For the shortcut case where $ref1 and $ref2 are simple refs (no magic etc)
it's possible to do the assign then SvREFCNT_dec() the old value without
having to mortalise it. Which is faster.
Even when it doesn't have to be mortalised (RC > 1) this commit makes it
slightly faster as it no longer calls sv_unref_flags().
Conversely, this commit also makes the short-cut integer assign code path
infinitesimally slower.
Diffstat (limited to 't/perf')
| -rw-r--r-- | t/perf/benchmarks | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/t/perf/benchmarks b/t/perf/benchmarks index 6dfe442d3c..8306b1fcff 100644 --- a/t/perf/benchmarks +++ b/t/perf/benchmarks @@ -891,6 +891,16 @@ setup => 'my $x = 1;', code => '$x = "abc"', }, + 'expr::sassign::lex_rv' => { + desc => 'lexical $ref1 = $ref2;', + setup => 'my $r1 = []; my $r = $r1;', + code => '$r = $r1;', + }, + 'expr::sassign::lex_rv1' => { + desc => 'lexical $ref1 = $ref2; where $$ref1 gets freed', + setup => 'my $r1 = []; my $r', + code => '$r = []; $r = $r1;', + }, |