From fafafbaf705adfdf05ff97b6ab5149ba4ee3c039 Mon Sep 17 00:00:00 2001
From: Rick Delaney <rick@consumercontact.com>
Date: Sun, 6 Jan 2008 09:14:39 -0500
Subject: [PATCH] Big slowdown in 5.10 @_ parameter passing Message-ID:
 <20080106191439.GF13935@bort.ca>

p4raw-id: //depot/perl@32891
---
 op.c | 110 +++++++++++++++++++++++++++++++++++++------------------------------
 1 file changed, 61 insertions(+), 49 deletions(-)

diff --git a/op.c b/op.c
index a732aa4..af52a3a 100644
--- a/op.c
+++ b/op.c
@@ -3992,6 +3992,7 @@ Perl_newASSIGNOP(pTHX_ I32 flags, OP *left, I32 optype, OP *right)
 	static const char no_list_state[] = "Initialization of state variables"
 	    " in list context currently forbidden";
 	OP *curop;
+	bool maybe_common_vars = TRUE;
 
 	PL_modcount = 0;
 	/* Grandfathering $[ assignment here.  Bletch.*/
@@ -4009,6 +4010,65 @@ Perl_newASSIGNOP(pTHX_ I32 flags, OP *left, I32 optype, OP *right)
 	o = newBINOP(OP_AASSIGN, flags, list(force_list(right)), curop);
 	o->op_private = (U8)(0 | (flags >> 8));
 
+	if ((left->op_type == OP_LIST
+	     || (left->op_type == OP_NULL && left->op_targ == OP_LIST)))
+	{
+	    OP* lop = ((LISTOP*)left)->op_first;
+	    maybe_common_vars = FALSE;
+	    while (lop) {
+		if (lop->op_type == OP_PADSV ||
+		    lop->op_type == OP_PADAV ||
+		    lop->op_type == OP_PADHV ||
+		    lop->op_type == OP_PADANY) {
+		    if (!(lop->op_private & OPpLVAL_INTRO))
+			maybe_common_vars = TRUE;
+
+		    if (lop->op_private & OPpPAD_STATE) {
+			if (left->op_private & OPpLVAL_INTRO) {
+			    /* Each variable in state($a, $b, $c) = ... */
+			}
+			else {
+			    /* Each state variable in
+			       (state $a, my $b, our $c, $d, undef) = ... */
+			}
+			yyerror(no_list_state);
+		    } else {
+			/* Each my variable in
+			   (state $a, my $b, our $c, $d, undef) = ... */
+		    }
+		} else if (lop->op_type == OP_UNDEF ||
+			   lop->op_type == OP_PUSHMARK) {
+		    /* undef may be interesting in
+		       (state $a, undef, state $c) */
+		} else {
+		    /* Other ops in the list. */
+		    maybe_common_vars = TRUE;
+		}
+		lop = lop->op_sibling;
+	    }
+	}
+	else if ((left->op_private & OPpLVAL_INTRO)
+		&& (   left->op_type == OP_PADSV
+		    || left->op_type == OP_PADAV
+		    || left->op_type == OP_PADHV
+		    || left->op_type == OP_PADANY))
+	{
+	    maybe_common_vars = FALSE;
+	    if (left->op_private & OPpPAD_STATE) {
+		/* All single variable list context state assignments, hence
+		   state ($a) = ...
+		   (state $a) = ...
+		   state @a = ...
+		   state (@a) = ...
+		   (state @a) = ...
+		   state %a = ...
+		   state (%a) = ...
+		   (state %a) = ...
+		*/
+		yyerror(no_list_state);
+	    }
+	}
+
 	/* PL_generation sorcery:
 	 * an assignment like ($a,$b) = ($c,$d) is easier than
 	 * ($a,$b) = ($c,$a), since there is no need for temporary vars.
@@ -4023,7 +4083,7 @@ Perl_newASSIGNOP(pTHX_ I32 flags, OP *left, I32 optype, OP *right)
 	 * to store these values, evil chicanery is done with SvUVX().
 	 */
 
-	{
+	if (maybe_common_vars) {
 	    OP *lastop = o;
 	    PL_generation++;
 	    for (curop = LINKLIST(o); curop != o; curop = LINKLIST(curop)) {
@@ -4084,54 +4144,6 @@ Perl_newASSIGNOP(pTHX_ I32 flags, OP *left, I32 optype, OP *right)
 		o->op_private |= OPpASSIGN_COMMON;
 	}
 
-	if ((left->op_type == OP_LIST
-	     || (left->op_type == OP_NULL && left->op_targ == OP_LIST))) {
-	    OP* lop = ((LISTOP*)left)->op_first;
-	    while (lop) {
-		if (lop->op_type == OP_PADSV ||
-		    lop->op_type == OP_PADAV ||
-		    lop->op_type == OP_PADHV ||
-		    lop->op_type == OP_PADANY) {
-		    if (lop->op_private & OPpPAD_STATE) {
-			if (left->op_private & OPpLVAL_INTRO) {
-			    /* Each variable in state($a, $b, $c) = ... */
-			}
-			else {
-			    /* Each state variable in
-			       (state $a, my $b, our $c, $d, undef) = ... */
-			}
-			yyerror(no_list_state);
-		    } else {
-			/* Each my variable in
-			   (state $a, my $b, our $c, $d, undef) = ... */
-		    }
-		} else {
-		    /* Other ops in the list. undef may be interesting in
-		       (state $a, undef, state $c) */
-		}
-		lop = lop->op_sibling;
-	    }
-	}
-	else if (((left->op_private & (OPpLVAL_INTRO | OPpPAD_STATE))
-		    == (OPpLVAL_INTRO | OPpPAD_STATE))
-		&& (   left->op_type == OP_PADSV
-		    || left->op_type == OP_PADAV
-		    || left->op_type == OP_PADHV
-		    || left->op_type == OP_PADANY))
-	{
-	    /* All single variable list context state assignments, hence
-	       state ($a) = ...
-	       (state $a) = ...
-	       state @a = ...
-	       state (@a) = ...
-	       (state @a) = ...
-	       state %a = ...
-	       state (%a) = ...
-	       (state %a) = ...
-	    */
-	    yyerror(no_list_state);
-	}
-
 	if (right && right->op_type == OP_SPLIT && !PL_madskills) {
 	    OP* tmpop = ((LISTOP*)right)->op_first;
 	    if (tmpop && (tmpop->op_type == OP_PUSHRE)) {
-- 
1.8.3.1