com php-src: Prevent bit shift count wrapping quirkiness on some CPUs for left shift: Zend/zend_operators.c
| From: | ajf@php.net | Date: | Tue, 19 Aug 2014 19:21:23 +0000 |
| Subject: | com php-src: Prevent bit shift count wrapping quirkiness on some CPUs for left shift: Zend/zend_operators.c | ||
| Groups: | php.cvs | ||
| Request: | Send a blank email to php-cvs+get-81842@lists.php.net to get a copy of this message | ||
Commit: b3ba0f6ab018eece2cee391a4b64d9315e801840
Author: Andrea Faulds <ajf@ajf.me> Tue, 19 Aug 2014 20:00:40 +0100
Parents: cb770cdc03cb414ffae34e40f43b8c109af5b0e8
Branches: master
Link: http://git.php.net/?p=php-src.git;a=commitdiff;h=b3ba0f6ab018eece2cee391a4b64d9315e801840
Log:
Prevent bit shift count wrapping quirkiness on some CPUs for left shift
Changed paths:
M Zend/zend_operators.c
Diff:
diff --git a/Zend/zend_operators.c b/Zend/zend_operators.c
index 9821095..61bdbc8 100644
--- a/Zend/zend_operators.c
+++ b/Zend/zend_operators.c
@@ -1493,6 +1493,12 @@ ZEND_API int shift_left_function(zval *result, zval *op1, zval *op2
TSRMLS_DC) /
op1_lval = Z_LVAL_P(op1);
}
+ /* prevent wrapping quirkiness on some processors where << 64 + x == << x */
+ if (Z_LVAL_P(op2) >= SIZEOF_LONG * 8) {
+ ZVAL_LONG(result, 0);
+ return SUCCESS;
+ }
+
if (Z_LVAL_P(op2) < 0) {
zend_error(E_WARNING, "Bit shift by negative number");
ZVAL_FALSE(result);