abies Wed Mar 10 10:57:51 2004 EDT
Modified files:
/php-src/ext/standard math.c
Log:
Don't use fp arithmetic for int results
# FP arithmetic is not accurate enough on 64-bit archs
# This patch relies on ZEND_SIGNED_MULTIPLY_LONG(),
# so that should be fixed as well.
http://cvs.php.net/diff.php/php-src/ext/standard/math.c?r1=1.110&r2=1.111&ty=u
Index: php-src/ext/standard/math.c
diff -u php-src/ext/standard/math.c:1.110 php-src/ext/standard/math.c:1.111
--- php-src/ext/standard/math.c:1.110 Thu Jan 8 03:17:33 2004
+++ php-src/ext/standard/math.c Wed Mar 10 10:57:49 2004
@@ -19,10 +19,11 @@
+----------------------------------------------------------------------+
*/
-/* $Id: math.c,v 1.110 2004/01/08 08:17:33 andi Exp $ */
+/* $Id: math.c,v 1.111 2004/03/10 15:57:49 abies Exp $ */
#include "php.h"
#include "php_math.h"
+#include "zend_multiply.h"
#include <math.h>
#include <float.h>
@@ -449,22 +450,38 @@
convert_scalar_to_number(zexp TSRMLS_CC);
/* if both base and exponent were longs, we'll try to get a long out */
- wantlong = Z_TYPE_P(zbase) == IS_LONG
- && Z_TYPE_P(zexp ) == IS_LONG && Z_LVAL_P(zexp) >= 0;
-
+ if (Z_TYPE_P(zbase) == IS_LONG && Z_TYPE_P(zexp) == IS_LONG && Z_LVAL_P(zexp)
>= 0) {
+ long l1 = 1, l2 = Z_LVAL_P(zbase), i = Z_LVAL_P(zexp);
+
+ if (i == 0) {
+ RETURN_LONG(1L);
+ } else if (l2 == 0) {
+ RETURN_LONG(0);
+ }
+
+ /* calculate pow(long,long) in O(log exp) operations, bail if overflow
*/
+ while (i >= 1) {
+ int overflow;
+ double dval;
+
+ if (i % 2) {
+ --i;
+ ZEND_SIGNED_MULTIPLY_LONG(l1,l2,l1,dval,overflow);
+ if (overflow) RETURN_DOUBLE(dval * pow(l2,i));
+ } else {
+ i /= 2;
+ ZEND_SIGNED_MULTIPLY_LONG(l2,l2,l2,dval,overflow);
+ if (overflow) RETURN_DOUBLE((double)l1 * pow(dval,i));
+ }
+ if (i == 0) {
+ RETURN_LONG(l1);
+ }
+ }
+ }
convert_to_double(zbase);
convert_to_double(zexp);
- /* go ahead and calculate things. */
- dval = pow(Z_DVAL_P(zbase),Z_DVAL_P(zexp));
-
- /* if we wanted a long, and dval < LONG_MAX, it must be a long. */
- if (wantlong && zend_finite(dval) && dval <= (double)LONG_MAX) {
- RETURN_LONG((long)dval);
- }
-
- /* otherwise just return the double. */
- RETURN_DOUBLE(dval);
+ RETURN_DOUBLE( pow(Z_DVAL_P(zbase),Z_DVAL_P(zexp)) );
}
/* }}} */
--
PHP CVS Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php
