In perl.git, the branch blead has been updated
<http://perl5.git.perl.org/perl.git/commitdiff/e791f90a39908c06e138681e3ceb8504cf71c52b?hp=8818afe890a4339f1db505ea767e5150ecbd0aa6>
- Log -----------------------------------------------------------------
commit e791f90a39908c06e138681e3ceb8504cf71c52b
Author: Father Chrysostomos <spr...@cpan.org>
Date: Tue Oct 14 21:56:25 2014 -0700
Change OA_DANGEROUS description in regen/opcode*
âHas side effectsâ can be misleading. The OA_DANGEROUS flag is only
used by the common-vars search that checks to see whether it is possi-
ble to skip making temporary copies.
We have to make copies in cases like this:
($a,$b) = func();
because func() could return ($b,$a).
If any op on either side is marked OA_DANGEROUS and not handled spe-
cially in op.c:S_aassign_scommon_vars, then it is assumed it could
return a scalar that is also elsewhere in the list, so a temp copy
is needed.
(I think some of the existing ops with this flag could drop it.)
M regen/opcode.pl
M regen/opcodes
commit f5b5c2a37af8753575a60bff8620560576946b4a
Author: Father Chrysostomos <spr...@cpan.org>
Date: Mon Oct 13 20:37:29 2014 -0700
Simplify double-nextstate optimisation
Executing two nextstate ops in a row is equivalent to executing just
the second, so the peephole optimiser eliminates one of them.
The double-nextstate optimisation seems to have been written under
the assumption that the current op cannot be elided from the op_next
change, which is untrue, as we have oldop (the previous op in
the chain).
If the current op and the one following it are both nextstate ops,
then the contents of the second are moved over to the first and the
second is nulled. Then current_op->op_next is adjusted to skip over
the newly-nulled op.
The the next op in the chain, the one that the first nextstate op now
points to, is processed.
The result is that every other nextstate in sequence of three or more
would be elided:
1 <;> nextstate(main 1 -e:1) v ->2
- <0> ex-const v ->-
- <0> null v ->-
- <0> ex-const v ->2
2 <;> nextstate(main 1 -e:1) v:{ ->3
- <0> ex-const v ->-
- <0> null v ->-
- <0> ex-const v ->3
3 <;> nextstate(main 1 -e:1) v:{ ->4
- <0> ex-const v ->-
- <0> null v ->-
- <0> ex-const v ->4
4 <;> nextstate(main 1 -e:1) v:{ ->5
We donât need to go through the complication of making the first next-
state equivalent to the second. Just null the first one and adjust
the previous opâs pointer (oldop->op_next) to point to the second one.
Now all consecutive nextstates get nulled except the last:
- <0> ex-nextstate v ->-
- <0> ex-const v ->-
- <0> ex-nextstate v ->-
- <0> ex-const v ->-
- <0> ex-nextstate v ->-
- <0> ex-const v ->-
- <0> ex-nextstate v ->-
- <0> ex-const v ->-
- <0> ex-nextstate v ->1
- <0> ex-const v ->-
- <0> ex-nextstate v ->1
- <0> ex-const v ->1
1 <;> nextstate(main 1 -e:1) v:{ ->2
The only visible difference this makes is in B::Deparse output, but
this changed in 5.14 when the optimisation was first introduced, so I
think changing it again is acceptable:
$ perl5.12.4 -MO=Deparse -e 'use strict; 0; use warnings; 0'
use strict 'refs';
'???';
use warnings;
'???';
-e syntax OK
$ perl5.14.4 -MO=Deparse -e 'use strict; 0; use warnings; 0'
use warnings;
use strict 'refs';
'???';
;
'???';
-e syntax OK
$ ./perl -Ilib -MO=Deparse -e 'use strict; 0; use warnings; 0'
;
'???';
use warnings;
use strict;
'???';
-e syntax OK
M ext/B/t/optree_specials.t
M lib/B/Deparse.t
M op.c
M t/op/opt.t
-----------------------------------------------------------------------
Summary of changes:
ext/B/t/optree_specials.t | 48 +++++++++++++++++++++++------------------------
lib/B/Deparse.t | 2 +-
op.c | 41 +++-------------------------------------
regen/opcode.pl | 2 +-
regen/opcodes | 2 +-
t/op/opt.t | 8 +++++++-
6 files changed, 37 insertions(+), 66 deletions(-)
diff --git a/ext/B/t/optree_specials.t b/ext/B/t/optree_specials.t
index f22b77f..652b5ab 100644
--- a/ext/B/t/optree_specials.t
+++ b/ext/B/t/optree_specials.t
@@ -45,9 +45,9 @@ checkOptree ( name => 'BEGIN',
# 1 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$ ->2
# 3 <1> require sK/1 ->4
# 2 <$> const[PV "strict.pm"] s/BARE ->3
-# 4 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$ ->5
+# - <0> ex-nextstate v ->4
# - <@> lineseq K ->-
-# - <0> null ->5
+# 4 <;> nextstate(B::Concise -275 Concise.pm:356) :*,&,{,x*,x&,x$,$
->5
# 9 <1> entersub[t1] KS*/TARG,STRICT ->a
# 5 <0> pushmark s ->6
# 6 <$> const[PV "strict"] sM ->7
@@ -59,9 +59,9 @@ checkOptree ( name => 'BEGIN',
# b <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$ ->c
# d <1> require sK/1 ->e
# c <$> const[PV "strict.pm"] s/BARE ->d
-# e <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$ ->f
+# - <0> ex-nextstate v ->e
# - <@> lineseq K ->-
-# - <0> null ->f
+# e <;> nextstate(B::Concise -265 Concise.pm:367) :*,&,x*,x&,x$,$ ->f
# j <1> entersub[t1] KS*/TARG,STRICT ->k
# f <0> pushmark s ->g
# g <$> const[PV "strict"] sM ->h
@@ -73,9 +73,9 @@ checkOptree ( name => 'BEGIN',
# l <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$ ->m
# n <1> require sK/1 ->o
# m <$> const[PV "warnings.pm"] s/BARE ->n
-# o <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$ ->p
+# - <0> ex-nextstate v ->o
# - <@> lineseq K ->-
-# - <0> null ->p
+# o <;> nextstate(B::Concise -254 Concise.pm:386) :*,&,{,x*,x&,x$,$
->p
# t <1> entersub[t1] KS*/TARG,STRICT ->u
# p <0> pushmark s ->q
# q <$> const[PV "warnings"] sM ->r
@@ -95,9 +95,9 @@ EOT_EOT
# 1 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$ ->2
# 3 <1> require sK/1 ->4
# 2 <$> const(PV "strict.pm") s/BARE ->3
-# 4 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$ ->5
+# - <0> ex-nextstate v ->4
# - <@> lineseq K ->-
-# - <0> null ->5
+# 4 <;> nextstate(B::Concise -275 Concise.pm:356) :*,&,{,x*,x&,x$,$
->5
# 9 <1> entersub[t1] KS*/TARG,STRICT ->a
# 5 <0> pushmark s ->6
# 6 <$> const(PV "strict") sM ->7
@@ -109,9 +109,9 @@ EOT_EOT
# b <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$ ->c
# d <1> require sK/1 ->e
# c <$> const(PV "strict.pm") s/BARE ->d
-# e <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$ ->f
+# - <0> ex-nextstate v ->e
# - <@> lineseq K ->-
-# - <0> null ->f
+# e <;> nextstate(B::Concise -265 Concise.pm:367) :*,&,x*,x&,x$,$ ->f
# j <1> entersub[t1] KS*/TARG,STRICT ->k
# f <0> pushmark s ->g
# g <$> const(PV "strict") sM ->h
@@ -123,9 +123,9 @@ EOT_EOT
# l <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$ ->m
# n <1> require sK/1 ->o
# m <$> const(PV "warnings.pm") s/BARE ->n
-# o <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$ ->p
+# - <0> ex-nextstate v ->o
# - <@> lineseq K ->-
-# - <0> null ->p
+# o <;> nextstate(B::Concise -254 Concise.pm:386) :*,&,{,x*,x&,x$,$
->p
# t <1> entersub[t1] KS*/TARG,STRICT ->u
# p <0> pushmark s ->q
# q <$> const(PV "warnings") sM ->r
@@ -241,7 +241,7 @@ checkOptree ( name => 'all of BEGIN END INIT CHECK
UNITCHECK -exec',
# 1 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$
# 2 <$> const[PV "strict.pm"] s/BARE
# 3 <1> require sK/1
-# 4 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$
+# 4 <;> nextstate(B::Concise -275 Concise.pm:356) :*,&,{,x*,x&,x$,$
# 5 <0> pushmark s
# 6 <$> const[PV "strict"] sM
# 7 <$> const[PV "refs"] sM
@@ -252,7 +252,7 @@ checkOptree ( name => 'all of BEGIN END INIT CHECK
UNITCHECK -exec',
# b <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$
# c <$> const[PV "strict.pm"] s/BARE
# d <1> require sK/1
-# e <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$
+# e <;> nextstate(B::Concise -265 Concise.pm:367) :*,&,x*,x&,x$,$
# f <0> pushmark s
# g <$> const[PV "strict"] sM
# h <$> const[PV "refs"] sM
@@ -263,7 +263,7 @@ checkOptree ( name => 'all of BEGIN END INIT CHECK
UNITCHECK -exec',
# l <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$
# m <$> const[PV "warnings.pm"] s/BARE
# n <1> require sK/1
-# o <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$
+# o <;> nextstate(B::Concise -254 Concise.pm:386) :*,&,{,x*,x&,x$,$
# p <0> pushmark s
# q <$> const[PV "warnings"] sM
# r <$> const[PV "qw"] sM
@@ -300,7 +300,7 @@ EOT_EOT
# 1 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$
# 2 <$> const(PV "strict.pm") s/BARE
# 3 <1> require sK/1
-# 4 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$
+# 4 <;> nextstate(B::Concise -275 Concise.pm:356) :*,&,{,x*,x&,x$,$
# 5 <0> pushmark s
# 6 <$> const(PV "strict") sM
# 7 <$> const(PV "refs") sM
@@ -311,7 +311,7 @@ EOT_EOT
# b <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$
# c <$> const(PV "strict.pm") s/BARE
# d <1> require sK/1
-# e <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$
+# e <;> nextstate(B::Concise -265 Concise.pm:367) :*,&,x*,x&,x$,$
# f <0> pushmark s
# g <$> const(PV "strict") sM
# h <$> const(PV "refs") sM
@@ -322,7 +322,7 @@ EOT_EOT
# l <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$
# m <$> const(PV "warnings.pm") s/BARE
# n <1> require sK/1
-# o <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$
+# o <;> nextstate(B::Concise -254 Concise.pm:386) :*,&,{,x*,x&,x$,$
# p <0> pushmark s
# q <$> const(PV "warnings") sM
# r <$> const(PV "qw") sM
@@ -369,7 +369,7 @@ checkOptree ( name => 'regression test for patch 25352',
# 1 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$
# 2 <$> const[PV "strict.pm"] s/BARE
# 3 <1> require sK/1
-# 4 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$
+# 4 <;> nextstate(B::Concise -275 Concise.pm:356) :*,&,{,x*,x&,x$,$
# 5 <0> pushmark s
# 6 <$> const[PV "strict"] sM
# 7 <$> const[PV "refs"] sM
@@ -380,7 +380,7 @@ checkOptree ( name => 'regression test for patch 25352',
# b <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$
# c <$> const[PV "strict.pm"] s/BARE
# d <1> require sK/1
-# e <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$
+# e <;> nextstate(B::Concise -265 Concise.pm:367) :*,&,x*,x&,x$,$
# f <0> pushmark s
# g <$> const[PV "strict"] sM
# h <$> const[PV "refs"] sM
@@ -391,7 +391,7 @@ checkOptree ( name => 'regression test for patch 25352',
# l <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$
# m <$> const[PV "warnings.pm"] s/BARE
# n <1> require sK/1
-# o <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$
+# o <;> nextstate(B::Concise -254 Concise.pm:386) :*,&,{,x*,x&,x$,$
# p <0> pushmark s
# q <$> const[PV "warnings"] sM
# r <$> const[PV "qw"] sM
@@ -403,7 +403,7 @@ EOT_EOT
# 1 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$
# 2 <$> const(PV "strict.pm") s/BARE
# 3 <1> require sK/1
-# 4 <;> nextstate(B::Concise -275 Concise.pm:356) v:*,&,{,x*,x&,x$,$
+# 4 <;> nextstate(B::Concise -275 Concise.pm:356) :*,&,{,x*,x&,x$,$
# 5 <0> pushmark s
# 6 <$> const(PV "strict") sM
# 7 <$> const(PV "refs") sM
@@ -414,7 +414,7 @@ EOT_EOT
# b <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$
# c <$> const(PV "strict.pm") s/BARE
# d <1> require sK/1
-# e <;> nextstate(B::Concise -265 Concise.pm:367) v:*,&,x*,x&,x$,$
+# e <;> nextstate(B::Concise -265 Concise.pm:367) :*,&,x*,x&,x$,$
# f <0> pushmark s
# g <$> const(PV "strict") sM
# h <$> const(PV "refs") sM
@@ -425,7 +425,7 @@ EOT_EOT
# l <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$
# m <$> const(PV "warnings.pm") s/BARE
# n <1> require sK/1
-# o <;> nextstate(B::Concise -254 Concise.pm:386) v:*,&,{,x*,x&,x$,$
+# o <;> nextstate(B::Concise -254 Concise.pm:386) :*,&,{,x*,x&,x$,$
# p <0> pushmark s
# q <$> const(PV "warnings") sM
# r <$> const(PV "qw") sM
diff --git a/lib/B/Deparse.t b/lib/B/Deparse.t
index 0046ce1..8a7a425 100644
--- a/lib/B/Deparse.t
+++ b/lib/B/Deparse.t
@@ -338,8 +338,8 @@ tr/\x{345}/\x{370}/;
1;
####
# Constants in a block
+# CONTEXT no warnings;
{
- no warnings;
'???';
2;
}
diff --git a/op.c b/op.c
index 50346bf..2217307 100644
--- a/op.c
+++ b/op.c
@@ -11881,44 +11881,9 @@ Perl_rpeep(pTHX_ OP *o)
nextop = nextop->op_next;
if (nextop && (nextop->op_type == OP_NEXTSTATE)) {
- COP *firstcop = (COP *)o;
- COP *secondcop = (COP *)nextop;
- /* We want the COP pointed to by o (and anything else) to
- become the next COP down the line. */
- cop_free(firstcop);
-
- firstcop->op_next = secondcop->op_next;
-
- /* Now steal all its pointers, and duplicate the other
- data. */
- firstcop->cop_line = secondcop->cop_line;
-#ifdef USE_ITHREADS
- firstcop->cop_stashoff = secondcop->cop_stashoff;
- firstcop->cop_file = secondcop->cop_file;
-#else
- firstcop->cop_stash = secondcop->cop_stash;
- firstcop->cop_filegv = secondcop->cop_filegv;
-#endif
- firstcop->cop_hints = secondcop->cop_hints;
- firstcop->cop_seq = secondcop->cop_seq;
- firstcop->cop_warnings = secondcop->cop_warnings;
- firstcop->cop_hints_hash = secondcop->cop_hints_hash;
-
-#ifdef USE_ITHREADS
- secondcop->cop_stashoff = 0;
- secondcop->cop_file = NULL;
-#else
- secondcop->cop_stash = NULL;
- secondcop->cop_filegv = NULL;
-#endif
- secondcop->cop_warnings = NULL;
- secondcop->cop_hints_hash = NULL;
-
- /* If we use op_null(), and hence leave an ex-COP, some
- warnings are misreported. For example, the compile-time
- error in 'use strict; no strict refs;' */
- secondcop->op_type = OP_NULL;
- secondcop->op_ppaddr = PL_ppaddr[OP_NULL];
+ op_null(o);
+ if (oldop)
+ oldop->op_next = nextop;
}
}
break;
diff --git a/regen/opcode.pl b/regen/opcode.pl
index 10c708b..402929f 100755
--- a/regen/opcode.pl
+++ b/regen/opcode.pl
@@ -1082,7 +1082,7 @@ my %opflags = (
'T' => 8 | 16, # ... which may be lexical
'i' => 0, # always produces integer (unused since
e7311069)
'I' => 32, # has corresponding int op
- 'd' => 64, # danger, unknown side effects
+ 'd' => 64, # danger, make temp copy in list assignment
'u' => 128, # defaults to $_
);
diff --git a/regen/opcodes b/regen/opcodes
index 07910ed..1e55ecb 100644
--- a/regen/opcodes
+++ b/regen/opcodes
@@ -23,7 +23,7 @@
# needs a target - t (OA_TARGET)
# target can be in a pad - T (OA_TARGET|OA_TARGLEX)
# has a corresponding integer version - I (OA_OTHERINT)
-# has side effects - d (OA_DANGEROUS)
+# make temp copy in list assignment - d (OA_DANGEROUS)
# uses $_ if no argument given - u (OA_DEFGV)
# Values for the operands are:
diff --git a/t/op/opt.t b/t/op/opt.t
index 71eedcf..aa73fd7 100644
--- a/t/op/opt.t
+++ b/t/op/opt.t
@@ -9,7 +9,7 @@ BEGIN {
@INC = '../lib';
}
-plan 19;
+plan 20;
use B qw 'svref_2object OPpASSIGN_COMMON';
@@ -56,6 +56,12 @@ for (['CONSTANT', sub { join "foo", "bar" }, 0,
"bar" ],
}
+# nextstate multiple times becoming one nextstate
+
+is svref_2object(sub { 0;0;0;0;0;0;time })->START->next->name, 'time',
+ 'multiple nextstates become one';
+
+
# split to array
for(['@pkgary' , '@_' ],
--
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