From a747dfc8c574ce97e66459394b9315d1129932e7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Grubbstr=C3=B6m=20=28Grubba=29?=
<grubba@grubba.org>
Date: Thu, 28 Jun 2012 20:14:50 +0200
Subject: [PATCH] Compiler: Fix too aggressive optimization of empty foreach.
---
src/treeopt.in | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/src/treeopt.in b/src/treeopt.in
index 58836ae9f4..cebe145de0 100644
--- a/src/treeopt.in
+++ b/src/treeopt.in
@@ -1063,8 +1063,21 @@ F_DO(-, 0 = +[node_is_true($$)]):
// No body -- No reason to loop...
-F_FOREACH(F_VAL_LVAL(0, *), -):
- F_POP_VALUE($0, -);
+F_FOREACH(F_VAL_LVAL(0 = +[!($$->node_info & (OPT_SIDE_EFFECT|OPT_ASSIGNMENT))],
+ 1 = +[($$->token != ':')]), -):
+{
+ // Note: We still need to set the loop variable as if the last
+ // turn of the loop has executed, in case it is used later.
+ $$ = mknode(F_POP_VALUE,
+ mknode('?',
+ mkefuncallnode("sizeof", $0),
+ mknode(':',
+ mknode(F_ASSIGN,
+ mknode(F_INDEX, $0, mkintnode(-1)), $1),
+ NULL)),
+ 0);
+}
+;
F_LOOP(0, -):
F_POP_VALUE($0, -);
--
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