From: Nikita Popov <nikita.ppv@gmail.com>
Date: Thu, 30 Jul 2020 08:17:37 +0000 (+0200)
Subject: Check non-zero in is_power_of_two()
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3690a805c15087f7f04c602e9f3c1e617060c475;p=php

Check non-zero in is_power_of_two()

And assert non-zero in floor_log2().

Fixes DASM_S_RANGE_I in ext/simplexml/tests/021.phpt.
---

diff --git a/ext/opcache/jit/zend_jit_x86.dasc b/ext/opcache/jit/zend_jit_x86.dasc
index 5c827f4b99..107e2c5de8 100644
--- a/ext/opcache/jit/zend_jit_x86.dasc
+++ b/ext/opcache/jit/zend_jit_x86.dasc
@@ -1613,6 +1613,7 @@ static uint32_t ones32(uint32_t x)
 
 static uint32_t floor_log2(uint32_t x)
 {
+	ZEND_ASSERT(x != 0);
 	x |= (x >> 1);
 	x |= (x >> 2);
 	x |= (x >> 4);
@@ -1623,7 +1624,7 @@ static uint32_t floor_log2(uint32_t x)
 
 static zend_bool is_power_of_two(uint32_t x)
 {
-	return !(x & (x - 1));
+	return !(x & (x - 1)) && x != 0;
 }
 
 static zend_bool has_concrete_type(uint32_t value_type)