Allow OPpTARGET_MY optimisation for x

Many operators have a special SV allocated in the pad which is used
for return values (the target).  If we make that pad offset point to
a lexical variable, then we can optimise, say, $lexical = "$foo" into
just "$foo", where $lexical is stringify’s ‘target’.  And pp_stringify
doesn’t need to know any better.  We already do that for many ops.

This can be extended to x.  Despite what the comment in op_private
says, list return values do not matter here, because the OPpTARGET_MY
optimisation only happens when the operator is in scalar context.  And
the scalar code paths use TARG and push TARG on to the stack.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/B/Op_private.pm b/lib/B/Op_private.pm
index a09b8ca538..d9dbb8bce6 100644
--- a/lib/B/Op_private.pm
+++ b/lib/B/Op_private.pm
@@ -144,7 +144,7 @@ $bits{$_}{7} = 'OPpPV_IS_UTF8' for qw(dump goto last next redo);
 $bits{$_}{6} = 'OPpREFCOUNTED' for qw(leave leaveeval leavesub leavesublv leavewrite);
 $bits{$_}{6} = 'OPpRUNTIME' for qw(match pushre qr subst substcont);
 $bits{$_}{2} = 'OPpSLICEWARNING' for qw(aslice hslice padav padhv rv2av rv2hv);
-$bits{$_}{4} = 'OPpTARGET_MY' for qw(abs add atan2 chdir chmod chomp chown chr chroot concat cos crypt divide exec exp flock getpgrp getppid getpriority hex i_add i_divide i_modulo i_multiply i_negate i_postdec i_postinc i_subtract index int kill left_shift length link log match mkdir modulo multiply oct ord pow push rand rename right_shift rindex rmdir schomp setpgrp setpriority sin sleep sqrt srand stringify subst subtract symlink system time trans transr unlink unshift utime vec wait waitpid);
+$bits{$_}{4} = 'OPpTARGET_MY' for qw(abs add atan2 chdir chmod chomp chown chr chroot concat cos crypt divide exec exp flock getpgrp getppid getpriority hex i_add i_divide i_modulo i_multiply i_negate i_postdec i_postinc i_subtract index int kill left_shift length link log match mkdir modulo multiply oct ord pow push rand rename repeat right_shift rindex rmdir schomp setpgrp setpriority sin sleep sqrt srand stringify subst subtract symlink system time trans transr unlink unshift utime vec wait waitpid);
 $bits{$_}{5} = 'OPpTRANS_COMPLEMENT' for qw(trans transr);
 $bits{$_}{7} = 'OPpTRANS_DELETE' for qw(trans transr);
 $bits{$_}{0} = 'OPpTRANS_FROM_UTF' for qw(trans transr);