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- A little bit cleaning of pow(), and 12 bytes less memory (wow)

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This commit is contained in:
Jeroen van Wolffelaar
2001-08-04 13:11:17 +00:00
parent fff883689e
commit 8803bbaa80
1 changed files with 14 additions and 12 deletions
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26
ext/standard/math.c
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@@ -378,8 +378,8 @@ PHP_FUNCTION(pi)
/* }}} */
/* {{{ proto number pow(number lbase, number lexponent)
Returns lbase raised to the power of lexponent. Returns
/* {{{ proto number pow(number base, number exponent)
Returns base raised to the power of exponent. Returns
integer result when possible. */
PHP_FUNCTION(pow)
@@ -390,8 +390,7 @@ PHP_FUNCTION(pow)
zval **zbase, **zexp;
long lbase,lexp;
double dval,dbase,pos_result;
long result = 1;
double dval;
if (ZEND_NUM_ARGS() != 2) {
WRONG_PARAM_COUNT;
@@ -407,15 +406,15 @@ PHP_FUNCTION(pow)
if (Z_TYPE_PP(zexp) == IS_DOUBLE) {
/* pow(?,float), this is the ^^ case */
dbase = Z_TYPE_PP(zbase) == IS_LONG ? (double) Z_LVAL_PP(zbase)
: Z_DVAL_PP(zbase);
if ( dbase <= 0.0 ) {
convert_to_double_ex(zbase);
if ( Z_DVAL_PP(zbase) <= 0.0 ) {
/* Note that with the old behaviour, php pow() returned bogus
results. Try pow(-1,2.5) in PHP <= 4.0.6 ... */
php_error(E_WARNING,"Trying to raise a nonpositive value to a broken power");
RETURN_FALSE;
}
RETURN_DOUBLE(exp(log(dbase) * Z_DVAL_PP(zexp)));
RETURN_DOUBLE(exp(log(Z_DVAL_PP(zbase)) * Z_DVAL_PP(zexp)));
}
/* pow(?,int), this is the ** case */
@@ -439,8 +438,8 @@ PHP_FUNCTION(pow)
RETURN_DOUBLE(0.0);
}
} else { /* lbase < 0.0 */
pos_result = exp(log(-Z_DVAL_PP(zbase)) * (double)lexp);
RETURN_DOUBLE(lexp & 1 ? -pos_result : pos_result);
dval = exp(log(-Z_DVAL_PP(zbase)) * (double)lexp);
RETURN_DOUBLE(lexp & 1 ? -dval : dval);
}
}
@@ -475,14 +474,17 @@ PHP_FUNCTION(pow)
RETURN_DOUBLE(((lexp & 1) && lbase<0) ? -dval : dval);
}
Z_TYPE_P(return_value) = IS_LONG;
Z_LVAL_P(return_value) = 1;
/* loop runs at most log(log(LONG_MAX)) times, i.e. ~ 5 */
while (lexp > 0) {
if (lexp & 1) /* odd */
result *= lbase;
Z_LVAL_P(return_value) *= lbase;
lexp >>= 1;
lbase *= lbase;
}
RETURN_LONG(result);
/* return */
}
}