1Devel::GoFaster(3)    User Contributed Perl Documentation   Devel::GoFaster(3)
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NAME

6       Devel::GoFaster - optimise executable Perl ops
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SYNOPSIS

9           use Devel::GoFaster;
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11           use Devel::GoFaster "global";
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DESCRIPTION

14       This module implements some optimisations in compiled Perl code, which
15       should make it run slightly faster without visibly affecting behaviour.
16       The optimisations are applied at the peephole optimisation step,
17       augmenting Perl's built-in optimisations.
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19       Code to be made faster does not need to be written in any special way;
20       this module can generally be applied to code that was not written with
21       it in mind.  However, to help with situations where the op munging
22       causes trouble (such as with the deparser), there is some selectivity
23       in which code gets the optimisations.  Whether to apply these
24       optimisations is decided for each subroutine as a whole: it cannot be
25       enabled or disabled for just part of a subroutine.  There is a global
26       control, defaulting to off, and lexically-scoped local control which
27       takes precedence over the global control.
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29       Because the optimisations are applied in the peephole optimiser, not
30       affecting primary compilation, they are invisible to most modules that
31       muck around with op trees during compilation.  So this module should
32       play nicely with modules that use custom ops and the like.  However,
33       anything that examines the ops of a complete compiled subroutine is
34       liable to see the non-standard optimised ops from this module, and may
35       have a problem.  In particular, the deparser can't correctly deparse
36       code that has been affected by this module.  If such problems affect a
37       particular subroutine, the lexical control can be used to disable non-
38       standard optimisation of that subroutine alone.
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40       This module tries quite hard to not visibly fail, so that it should be
41       generally safe to use its pragmata.  If circumstances make it
42       impossible to apply optimisations that would sometimes be available,
43       the module will silently leave code unoptimised.  In particular,
44       because all the optimisations are necessarily implemented using XS
45       code, on any system that can't build or load XS modules this module's
46       pragmata effectively become no-ops.  No particular optimisations are
47       guaranteed by invoking this module.
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PRAGMATA

50       use Devel::GoFaster
51           Locally enable the optimisations of this module.  Subroutines
52           compiled in the lexical scope of this pragma will get the non-
53           standard optimisations, regardless of the global pragma state.
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55       no Devel::GoFaster
56           Locally disable the optimisations of this module.  Subroutines
57           compiled in the lexical scope of this pragma will not get the non-
58           standard optimisations, regardless of the global pragma state.
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60       use Devel::GoFaster "global"
61           Globally enable the optimisations of this module.  Subroutines
62           compiled after this pragma has been encountered will get the non-
63           standard optimisations, except where locally overridden.
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65       no Devel::GoFaster "global"
66           Globally disable the optimisations of this module (which is the
67           default state).  Subroutines compiled after this pragma has been
68           encountered will not get the non-standard optimisations, except
69           where locally overridden.
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BUGS

72       As noted above, this module is liable to break anything that examines
73       the ops of a complete compiled subroutine, such as the deparser.
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AUTHOR

76       Andrew Main (Zefram) <zefram@fysh.org>
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79       Copyright (C) 2015, 2017 Andrew Main (Zefram) <zefram@fysh.org>
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LICENSE

82       This module is free software; you can redistribute it and/or modify it
83       under the same terms as Perl itself.
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87perl v5.32.0                      2020-07-28                Devel::GoFaster(3)
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