From 47316d294571673a8dbf1e9e435893e2660f46a8 Mon Sep 17 00:00:00 2001
From: "Arnold D. Robbins" <arnold@skeeve.com>
Date: Mon, 26 Mar 2018 10:45:01 +0300
Subject: [PATCH] Remove the tail recursion optimization(refix).

---
 awkgram.c | 27 ++-------------------------
 1 file changed, 2 insertions(+), 25 deletions(-)

diff --git a/awkgram.c b/awkgram.c
index 52821eab..d3c4e830 100644
--- a/awkgram.c
+++ b/awkgram.c
@@ -2820,20 +2820,9 @@ regular_loop:
 			(yyval) = list_create((yyvsp[-3]));
 			(void) list_prepend((yyval), instruction(Op_push_i));
 			(yyval)->nexti->memory = dupnode(Nnull_string);
-		} else {
-			if (do_optimize
-				&& (yyvsp[-1])->lasti->opcode == Op_func_call
-				&& strcmp((yyvsp[-1])->lasti->func_name, in_function) == 0
-			) {
-				/* Do tail recursion optimization. Tail
-				 * call without a return value is recognized
-				 * in mk_function().
-				 */
-				((yyvsp[-1])->lasti + 1)->tail_call = true;
-			}
-
+		} else
 			(yyval) = list_append((yyvsp[-1]), (yyvsp[-3]));
-		}
+
 		(yyval) = add_pending_comment((yyval));
 	  }
 #line 2840 "awkgram.c" /* yacc.c:1646  */
@@ -7156,18 +7145,6 @@ mk_function(INSTRUCTION *fi, INSTRUCTION *def)
 	thisfunc = fi->func_body;
 	assert(thisfunc != NULL);
 
-	if (do_optimize && def->lasti->opcode == Op_pop) {
-		/* tail call which does not return any value. */
-
-		INSTRUCTION *t;
-
-		for (t = def->nexti; t->nexti != def->lasti; t = t->nexti)
-			;
-		if (t->opcode == Op_func_call
-		    && strcmp(t->func_name, thisfunc->vname) == 0)
-			(t + 1)->tail_call = true;
-	}
-
 	/* add any pre-function comment to start of action for profile.c  */
 
 	if (function_comment != NULL) {
-- 
2.19.1