From: Nikita Popov <nikic@php.net>
Date: Sun, 5 Jun 2016 21:00:32 +0000 (+0200)
Subject: Fix SSA NOP removal
X-Git-Tag: php-7.1.0alpha1~20
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7b4618e396917e3bd89e6a4d05402d3715dc701c;p=php

Fix SSA NOP removal

NOPs need to be tracked in the shiftlist as well, as there may be
jumps to NOPs.
---

diff --git a/ext/opcache/Optimizer/dfa_pass.c b/ext/opcache/Optimizer/dfa_pass.c
index 3be638eb92..2ebbfbd141 100644
--- a/ext/opcache/Optimizer/dfa_pass.c
+++ b/ext/opcache/Optimizer/dfa_pass.c
@@ -142,6 +142,7 @@ static void zend_ssa_remove_nops(zend_op_array *op_array, zend_ssa *ssa)
 			i = b->start;
 			b->start = target;
 			while (i < end) {
+				shiftlist[i] = i - target;
 				if (EXPECTED(op_array->opcodes[i].opcode != ZEND_NOP) ||
 				   /*keep NOP to support ZEND_VM_SMART_BRANCH */
 				   (i > 0 &&
@@ -165,7 +166,6 @@ static void zend_ssa_remove_nops(zend_op_array *op_array, zend_ssa *ssa)
 					if (i != target) {
 						op_array->opcodes[target] = op_array->opcodes[i];
 						ssa->ops[target] = ssa->ops[i];
-						shiftlist[i] = i - target;
 					}
 					target++;
 				}
diff --git a/ext/opcache/tests/ssa_bug_002.phpt b/ext/opcache/tests/ssa_bug_002.phpt
new file mode 100644
index 0000000000..9ff6f799f4
--- /dev/null
+++ b/ext/opcache/tests/ssa_bug_002.phpt
@@ -0,0 +1,16 @@
+--TEST--
+Incorrect NOP removal on jump to NOP
+--FILE--
+<?php
+
+function test(int $i) : int {
+    if ($i == 1) {
+        $x = $i + 1;
+    }
+    return $i;
+}
+var_dump(test(42));
+
+?>
+--EXPECT--
+int(42)