OP_AELEMFASTLEX_STORE - combined sassign/aelemfast_lex

This commit introduces a new OP to replace simple cases of OP_SASSIGN
and OP_AELEMFAST_LEX. (Similar concept to GH #19943)

For example, `my @ary; $ary[0] = "boo"` is currently implemented as:
    7     <2> sassign vKS/2 ->8
    5        <$> const[PV "boo"] s ->6
    -        <1> ex-aelem sKRM*/2 ->7
    6           <0> aelemfast_lex[@ary:1,2] sRM ->7
    -           <0> ex-const s ->-

But now will be turned into:
    6     <1> aelemfastlex_store[@ary:1,2] vKS ->7
    5        <$> const(PV "boo") s ->6
    -        <1> ex-aelem sKRM*/2 ->6
    -           <0> ex-aelemfast_lex sRM ->6
    -           <0> ex-const s ->-

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

2 files changed, 12 insertions, 0 deletions

diff --git a/lib/B/Deparse.pm b/lib/B/Deparse.pm
index 8cd02ce4dc..8895204308 100644
--- a/lib/B/Deparse.pm
+++ b/lib/B/Deparse.pm
@@ -4305,6 +4305,17 @@ sub pp_gv {
     return $self->maybe_qualify("", $self->gv_name($gv));
 }
 
+sub pp_aelemfastlex_store {
+    my $self = shift;
+    my($op, $cx) = @_;
+    my $name = $self->padname($op->targ);
+    $name =~ s/^@/\$/;
+    my $i = $op->private;
+    $i -= 256 if $i > 127;
+    my $val = $self->deparse($op->first, 7);
+    return $self->maybe_parens("${name}[$i] = $val", $cx, 7);
+}
+
 sub pp_aelemfast_lex {
     my $self = shift;
     my($op, $cx) = @_;
diff --git a/lib/B/Op_private.pm b/lib/B/Op_private.pm
index df34dff846..01931ed94f 100644
--- a/lib/B/Op_private.pm
+++ b/lib/B/Op_private.pm
@@ -254,6 +254,7 @@ $bits{aeach}{0} = $bf[0];
 @{$bits{aelem}}{5,4,1,0} = ($bf[8], $bf[8], $bf[1], $bf[1]);
 @{$bits{aelemfast}}{7,6,5,4,3,2,1,0} = ($bf[6], $bf[6], $bf[6], $bf[6], $bf[6], $bf[6], $bf[6], $bf[6]);
 @{$bits{aelemfast_lex}}{7,6,5,4,3,2,1,0} = ($bf[6], $bf[6], $bf[6], $bf[6], $bf[6], $bf[6], $bf[6], $bf[6]);
+@{$bits{aelemfastlex_store}}{7,6,5,4,3,2,1,0} = ($bf[6], $bf[6], $bf[6], $bf[6], $bf[6], $bf[6], $bf[6], $bf[6]);
 $bits{akeys}{0} = $bf[0];
 $bits{alarm}{0} = $bf[0];
 $bits{and}{0} = $bf[0];