Implement OP_PADSV_STORE - combined sassign/padsv OP

This commit introduces a new OP to replace simple cases
of OP_SASSIGN and OP_PADSV.

For example, 'my $x = 1' is currently implemented as:

1  <;> nextstate(main 1 -e:1) v:{
2  <$> const(IV 1) s
3  <0> padsv[$x:1,2] sRM*/LVINTRO
4  <2> sassign vKS/2

But now will be turned into:

1  <;> nextstate(main 1 -e:1) v:{
2  <$> const(IV 1) s
3  <1> padsv_store[$x:1,2] vKMS/LVINTRO

This intended to be a transparent performance optimization.
It should be applicable for RHS optrees of varying complexity.

2 files changed, 18 insertions, 5 deletions

diff --git a/lib/B/Deparse.pm b/lib/B/Deparse.pm
index ca37d110b2..52eec0f77f 100644
--- a/lib/B/Deparse.pm
+++ b/lib/B/Deparse.pm
@@ -7,7 +7,7 @@
 # This is based on the module of the same name by Malcolm Beattie,
 # but essentially none of his code remains.
 
-package B::Deparse 1.67;
+package B::Deparse 1.68;
 use strict;
 use Carp;
 use B qw(class main_root main_start main_cv svref_2object opnumber perlstring
@@ -3092,6 +3092,18 @@ sub pp_isa { binop(@_, "isa", 15) }
 sub pp_sassign { binop(@_, "=", 7, SWAP_CHILDREN) }
 sub pp_aassign { binop(@_, "=", 7, SWAP_CHILDREN | LIST_CONTEXT) }
 
+sub pp_padsv_store {
+    my $self = shift;
+    my ($op, $cx, $forbid_parens, @args) = @_;
+    my $targ = $op->targ;
+    my $var = $self->maybe_my($op, $cx, $self->padname($targ),
+                           $self->padname_sv($targ),
+                           $forbid_parens);
+
+    my $val = $self->deparse($op->first, 7);
+    return $self->maybe_parens("$var = $val", $cx, 7);
+}
+
 sub pp_smartmatch {
     my ($self, $op, $cx) = @_;
     if (($op->flags & OPf_SPECIAL) && $self->{expand} < 2) {
diff --git a/lib/B/Op_private.pm b/lib/B/Op_private.pm
index afa1e80f79..84befff941 100644
--- a/lib/B/Op_private.pm
+++ b/lib/B/Op_private.pm
@@ -134,7 +134,7 @@ $bits{$_}{6} = 'OPpINDEX_BOOLNEG' for qw(index rindex);
 $bits{$_}{1} = 'OPpITER_REVERSED' for qw(enteriter iter);
 $bits{$_}{7} = 'OPpLVALUE' for qw(leave leaveloop);
 $bits{$_}{6} = 'OPpLVAL_DEFER' for qw(aelem helem multideref);
-$bits{$_}{7} = 'OPpLVAL_INTRO' for qw(aelem aslice cond_expr delete enteriter entersub gvsv helem hslice list lvavref lvref lvrefslice multiconcat multideref padav padhv padrange padsv pushmark refassign rv2av rv2gv rv2hv rv2sv split);
+$bits{$_}{7} = 'OPpLVAL_INTRO' for qw(aelem aslice cond_expr delete enteriter entersub gvsv helem hslice list lvavref lvref lvrefslice multiconcat multideref padav padhv padrange padsv padsv_store pushmark refassign rv2av rv2gv rv2hv rv2sv split);
 $bits{$_}{2} = 'OPpLVREF_ELEM' for qw(lvref refassign);
 $bits{$_}{3} = 'OPpLVREF_ITER' for qw(lvref refassign);
 $bits{$_}{3} = 'OPpMAYBE_LVSUB' for qw(aassign aelem akeys aslice av2arylen avhvswitch helem hslice keys kvaslice kvhslice multideref padav padhv pos rv2av rv2gv rv2hv substr values vec);
@@ -145,7 +145,7 @@ $bits{$_}{4} = 'OPpOPEN_IN_RAW' for qw(backtick open);
 $bits{$_}{7} = 'OPpOPEN_OUT_CRLF' for qw(backtick open);
 $bits{$_}{6} = 'OPpOPEN_OUT_RAW' for qw(backtick open);
 $bits{$_}{6} = 'OPpOUR_INTRO' for qw(enteriter gvsv rv2av rv2hv rv2sv split);
-$bits{$_}{6} = 'OPpPAD_STATE' for qw(lvavref lvref padav padhv padsv pushmark refassign);
+$bits{$_}{6} = 'OPpPAD_STATE' for qw(lvavref lvref padav padhv padsv padsv_store pushmark refassign);
 $bits{$_}{7} = 'OPpPV_IS_UTF8' for qw(dump goto last next redo);
 $bits{$_}{6} = 'OPpREFCOUNTED' for qw(leave leaveeval leavesub leavesublv leavewrite);
 $bits{$_}{2} = 'OPpSLICEWARNING' for qw(aslice hslice padav padhv rv2av rv2hv);
@@ -465,6 +465,7 @@ $bits{ord}{0} = $bf[0];
 $bits{padhv}{0} = 'OPpPADHV_ISKEYS';
 @{$bits{padrange}}{6,5,4,3,2,1,0} = ($bf[5], $bf[5], $bf[5], $bf[5], $bf[5], $bf[5], $bf[5]);
 @{$bits{padsv}}{5,4} = ($bf[8], $bf[8]);
+$bits{padsv_store}{0} = $bf[0];
 @{$bits{pipe_op}}{3,2,1,0} = ($bf[4], $bf[4], $bf[4], $bf[4]);
 $bits{pop}{0} = $bf[0];
 $bits{pos}{0} = $bf[0];
@@ -830,7 +831,7 @@ our %ops_using = (
     OPpLIST_GUESSED          => [qw(list)],
     OPpLVALUE                => [qw(leave leaveloop)],
     OPpLVAL_DEFER            => [qw(aelem helem multideref)],
-    OPpLVAL_INTRO            => [qw(aelem aslice cond_expr delete enteriter entersub gvsv helem hslice list lvavref lvref lvrefslice multiconcat multideref padav padhv padrange padsv pushmark refassign rv2av rv2gv rv2hv rv2sv split)],
+    OPpLVAL_INTRO            => [qw(aelem aslice cond_expr delete enteriter entersub gvsv helem hslice list lvavref lvref lvrefslice multiconcat multideref padav padhv padrange padsv padsv_store pushmark refassign rv2av rv2gv rv2hv rv2sv split)],
     OPpLVREF_ELEM            => [qw(lvref refassign)],
     OPpMAYBE_LVSUB           => [qw(aassign aelem akeys aslice av2arylen avhvswitch helem hslice keys kvaslice kvhslice multideref padav padhv pos rv2av rv2gv rv2hv substr values vec)],
     OPpMAYBE_TRUEBOOL        => [qw(blessed padhv ref rv2hv)],
@@ -840,7 +841,7 @@ our %ops_using = (
     OPpOPEN_IN_CRLF          => [qw(backtick open)],
     OPpOUR_INTRO             => [qw(enteriter gvsv rv2av rv2hv rv2sv split)],
     OPpPADHV_ISKEYS          => [qw(padhv)],
-    OPpPAD_STATE             => [qw(lvavref lvref padav padhv padsv pushmark refassign)],
+    OPpPAD_STATE             => [qw(lvavref lvref padav padhv padsv padsv_store pushmark refassign)],
     OPpPV_IS_UTF8            => [qw(dump goto last next redo)],
     OPpREFCOUNTED            => [qw(leave leaveeval leavesub leavesublv leavewrite)],
     OPpREPEAT_DOLIST         => [qw(repeat)],