From: Marc Bennewitz <marc-bennewitz@arcor.de>
Date: Mon, 28 Apr 2014 17:58:10 +0000 (+0200)
Subject: Improved logarithm of base 2 and 10 of standard math functions
X-Git-Tag: PRE_PHPNG_MERGE~4^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b547e1358d3846fad4cd0c86e2d2e9f5a9039b35;p=php

Improved logarithm of base 2 and 10 of standard math functions
---

diff --git a/ext/standard/config.m4 b/ext/standard/config.m4
index c1f5aff7c2..e1f9941790 100644
--- a/ext/standard/config.m4
+++ b/ext/standard/config.m4
@@ -337,7 +337,7 @@ fi
 dnl
 dnl Check for available functions
 dnl
-AC_CHECK_FUNCS(getcwd getwd asinh acosh atanh log1p hypot glob strfmon nice fpclass isinf isnan mempcpy strpncpy)
+AC_CHECK_FUNCS(getcwd getwd asinh acosh atanh log1p log2 hypot glob strfmon nice fpclass isinf isnan mempcpy strpncpy)
 AC_FUNC_FNMATCH	
 
 dnl
diff --git a/ext/standard/math.c b/ext/standard/math.c
index 72f6d51c6f..b33b6e28da 100644
--- a/ext/standard/math.c
+++ b/ext/standard/math.c
@@ -697,22 +697,35 @@ PHP_FUNCTION(log1p)
 PHP_FUNCTION(log)
 {
 	double num, base = 0;
-	
+
 	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "d|d", &num, &base) == FAILURE) {
 		return;
 	}
+
 	if (ZEND_NUM_ARGS() == 1) {
 		RETURN_DOUBLE(log(num));
 	}
-	if (base <= 0.0) {
-		php_error_docref(NULL TSRMLS_CC, E_WARNING, "base must be greater than 0");				
-		RETURN_FALSE;
+
+#ifdef HAVE_LOG2
+	if (base == 2.0) {
+		RETURN_DOUBLE(log2(num));
+	}
+#endif
+
+	if (base == 10.0) {
+		RETURN_DOUBLE(log10(num));
 	}
-	if (base == 1) {
+
+	if (base == 1.0) {
 		RETURN_DOUBLE(php_get_nan());
-	} else {
-		RETURN_DOUBLE(log(num) / log(base));
 	}
+
+	if (base <= 0.0) {
+		php_error_docref(NULL TSRMLS_CC, E_WARNING, "base must be greater than 0");
+		RETURN_FALSE;
+	}
+
+	RETURN_DOUBLE(log(num) / log(base));
 }
 /* }}} */