- Apply Ard's patch to support multiplication & overflow on both 32bit

  and 64bit machines

2 files changed, 24 insertions, 37 deletions

diff --git a/Zend/zend_multiply.h b/Zend/zend_multiply.h
index 2e6fe6a11a..eda4ca135e 100644
--- a/Zend/zend_multiply.h
+++ b/Zend/zend_multiply.h
@@ -2,7 +2,7 @@
    +----------------------------------------------------------------------+
    | Zend Engine                                                          |
    +----------------------------------------------------------------------+
-   | Copyright (c) 2003-2004 Sascha Schumann                              |
+   | Copyright (c) 1998-2004 Zend Technologies Ltd. (http://www.zend.com) |
    +----------------------------------------------------------------------+
    | This source file is subject to version 2.00 of the Zend license,     |
    | that is bundled with this package in the file LICENSE, and is        |
@@ -12,36 +12,28 @@
    | obtain it through the world-wide-web, please send a note to          |
    | license@zend.com so we can mail you a copy immediately.              |
    +----------------------------------------------------------------------+
-   | Author: Sascha Schumann <sascha@schumann.cx>                         |
+   | Author: Ard Biesheuvel <ard@ard.nu>                                  |
    +----------------------------------------------------------------------+
 */
 
 /* $Id$ */
 
-#if defined(__i386__) && defined(__GNUC__)
+#define HALF   (4*sizeof(long))
+#define UH(b)  ((b) >> HALF)
+#define LH(a)  ((a) & ~(-1L << HALF))
 
-#define ZEND_SIGNED_MULTIPLY_LONG(a, b, lval, dval, usedval) do {	\
-	long __tmpvar; 													\
-	__asm__ ("imul %3,%0\n"											\
-		"adc $0,%1" 												\
-			: "=r"(__tmpvar),"=r"(usedval) 							\
-			: "0"(a), "r"(b), "1"(0));								\
-	if (usedval) (dval) = (double) (a) * (double) (b);				\
-	else (lval) = __tmpvar;											\
+#define ZEND_SIGNED_MULTIPLY_LONG(a, b, lval, dval, usedval) do {		\
+	long __mid,__upr,__res = (a) * (b);									\
+	if (-(long)(a) > 0 && -(long)(b) > 0) { /* overflow intended */		\
+		__mid = UH(-(a))*LH(-(b)) + LH(-(a))*UH(-(b));					\
+		__upr = UH(-(a))*UH(-(b)) + UH(__mid);							\
+	} else {															\
+		__mid = UH(a)*LH(b) + LH(a)*UH(b);								\
+		__upr = UH(a)*UH(b) + UH(__mid);								\
+	}																	\
+	if (((usedval) = !((__upr==-1&&__res<0)||(!__upr&&__res>=0)))) {	\
+		(dval) = (double)(a)*(double)(b);								\
+	} else {															\
+		(lval) = __res;													\
+	}																	\
 } while (0)
-
-#else
-
-#define ZEND_SIGNED_MULTIPLY_LONG(a, b, lval, dval, usedval) do {	\
-	double __tmpvar = (double) (a) * (double) (b);					\
-																	\
-	if (__tmpvar >= LONG_MAX || __tmpvar <= LONG_MIN) {				\
-		(dval) = __tmpvar;											\
-		(usedval) = 1;												\
-	} else {														\
-		(lval) = (a) * (b);											\
-		(usedval) = 0;												\
-	}																\
-} while (0)
-
-#endif
diff --git a/Zend/zend_operators.c b/Zend/zend_operators.c
index 412c3e529f..cbc1235659 100644
--- a/Zend/zend_operators.c
+++ b/Zend/zend_operators.c
@@ -28,6 +28,7 @@
 #include "zend_list.h"
 #include "zend_fast_cache.h"
 #include "zend_API.h"
+#include "zend_multiply.h"
 
 #if 0&&HAVE_BCMATH
 #include "ext/bcmath/number.h"
@@ -803,16 +804,10 @@ ZEND_API int mul_function(zval *result, zval *op1, zval *op2 TSRMLS_DC)
 	zendi_convert_scalar_to_number(op2, op2_copy, result);
 
 	if (op1->type == IS_LONG && op2->type == IS_LONG) {
-		long lval = op1->value.lval * op2->value.lval;
-		
-		/* check for overflow by applying the reverse calculation */
-		if (op1->value.lval != 0 && lval / op1->value.lval != op2->value.lval) {
-			result->value.dval = (double) op1->value.lval * (double) op2->value.lval;
-			result->type = IS_DOUBLE;
-		} else {
-			result->value.lval = lval;
-			result->type = IS_LONG;
-		}
+		long overflow;
+
+		ZEND_SIGNED_MULTIPLY_LONG(op1->value.lval,op2->value.lval, result->value.lval,result->value.dval,overflow);
+		result->type = overflow ? IS_DOUBLE : IS_LONG;	
 		return SUCCESS;
 	}
 	if ((op1->type == IS_DOUBLE && op2->type == IS_LONG)