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Postings from November 2003
Dave Mitchell wrote:
> > >
> > > my ($A, $B);
> > > $B = ($A = '' . foo()) . "y";
> > > $D = ($C = '' . foo()) . "y";
> > > print "$A,$B\n"; # xy,xy
> > > print "$C,$D\n"; # x,xy
> > >
> > > sub foo { "x" }
> >
> > Ouch.
> > I can reproduce it with 5.6.1, but not with 5.5.3.
> > Looks like an optree optimization problem.
>
> Both the inner and outer OP_CONCATs have the TEMP target optimised away;
> the inner one uses the lexical as the target instead, and the outer one is
> STACKED, so it uses the previous result as the target (which happens to be
> the lexical).
I'm tempted to apply the fix below. (Look closer.)
Thoughts ?
Index: opcode.pl
===================================================================
--- opcode.pl (revision 2824)
+++ opcode.pl (working copy)
@@ -537,7 +537,7 @@
i_add integer addition (+) ck_null ifsT2 S S
subtract subtraction (-) ck_null IfsT2 S S
i_subtract integer subtraction (-) ck_null ifsT2 S S
-concat concatenation (.) or string ck_concat fsT2 S S
+concat concatenation (.) or string ck_concat fst2 S S
stringify string ck_fun fsT@ S
left_shift left bitshift (<<) ck_bitop fsT2 S S
End of fix.
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