Avoid unnecessary destruction in bc_sub()

Author: ndossche

ext/bcmath/bcmath.c

@@ -195,7 +195,7 @@ PHP_FUNCTION(bcsub)
 	zend_string *left, *right;
 	zend_long scale_param;
 	bool scale_param_is_null = 1;
-	bc_num first = NULL, second = NULL, result;
+	bc_num first = NULL, second = NULL, result = NULL;
 	int scale;
 
 	ZEND_PARSE_PARAMETERS_START(2, 3)
@@ -214,8 +214,6 @@ PHP_FUNCTION(bcsub)
 		scale = (int) scale_param;
 	}
 
-	bc_init_num(&result);
-
 	if (php_str2num(&first, ZSTR_VAL(left)) == FAILURE) {
 		zend_argument_value_error(1, "is not well-formed");
 		goto cleanup;
@@ -226,7 +224,7 @@ PHP_FUNCTION(bcsub)
 		goto cleanup;
 	}
 
-	bc_sub (first, second, &result, scale);
+	result = bc_sub (first, second, scale);
 
 	RETVAL_NEW_STR(bc_num2str_ex(result, scale));
 

ext/bcmath/libbcmath/src/bcmath.h

@@ -123,7 +123,13 @@ bc_num bc_add(bc_num n1, bc_num n2, size_t scale_min);
 	*(result) = add_ex;                             \
 } while (0)
 
-void bc_sub(bc_num n1, bc_num n2, bc_num *result, size_t scale_min);
+bc_num bc_sub(bc_num n1, bc_num n2, size_t scale_min);
+
+#define bc_sub_ex(n1, n2, result, scale_min) do {	\
+	bc_num sub_ex = bc_sub(n1, n2, scale_min);		\
+	bc_free_num (result);                           \
+	*(result) = sub_ex;                             \
+} while (0)
 
 void bc_multiply(bc_num n1, bc_num n2, bc_num *prod, size_t scale);
 

ext/bcmath/libbcmath/src/divmod.c

@@ -62,7 +62,7 @@ bool bc_divmod(bc_num num1, bc_num num2, bc_num *quot, bc_num *rem, size_t scale
 		quotient = bc_copy_num(temp);
 	}
 	bc_multiply(temp, num2, &temp, rscale);
-	bc_sub(num1, temp, rem, rscale);
+	bc_sub_ex(num1, temp, rem, rscale);
 	bc_free_num (&temp);
 
 	if (quot) {

ext/bcmath/libbcmath/src/output.c

@@ -79,7 +79,7 @@ void bc_out_num(bc_num num, int o_base, void (*out_char)(char), bool leading_zer
 	int index, fdigit;
 	bool pre_space;
 	stk_rec *digits, *temp;
-	bc_num int_part, frac_part, base, cur_dig, t_num, max_o_digit;
+	bc_num int_part, base, cur_dig, t_num, max_o_digit;
 
 	/* The negative sign if needed. */
 	if (num->n_sign == MINUS) (*out_char)('-');
@@ -120,10 +120,9 @@ void bc_out_num(bc_num num, int o_base, void (*out_char)(char), bool leading_zer
 			digits = NULL;
 			bc_init_num(&int_part);
 			bc_divide(num, BCG(_one_), &int_part, 0);
-			bc_init_num(&frac_part);
 			bc_init_num(&cur_dig);
 			bc_init_num(&base);
-			bc_sub(num, int_part, &frac_part, 0);
+			bc_num frac_part = bc_sub(num, int_part, 0);
 			/* Make the INT_PART and FRAC_PART positive. */
 			int_part->n_sign = PLUS;
 			frac_part->n_sign = PLUS;
@@ -166,7 +165,7 @@ void bc_out_num(bc_num num, int o_base, void (*out_char)(char), bool leading_zer
 					bc_multiply(frac_part, base, &frac_part, num->n_scale);
 					fdigit = bc_num2long(frac_part);
 					bc_int2num(&int_part, fdigit);
-					bc_sub(frac_part, int_part, &frac_part, 0);
+					bc_sub_ex(frac_part, int_part, &frac_part, 0);
 					if (o_base <= 16) {
 						(*out_char)(ref_str[fdigit]);
 					} else {

ext/bcmath/libbcmath/src/recmul.c

@@ -163,7 +163,7 @@ static void _bc_shift_addsub(bc_num accum, bc_num val, int shift, bool sub)
 static void _bc_rec_mul(bc_num u, size_t ulen, bc_num v, size_t vlen, bc_num *prod)
 {
 	bc_num u0, u1, v0, v1;
-	bc_num m1, m2, m3, d1, d2;
+	bc_num m1, m2, m3;
 	size_t n;
 	bool m1zero;
 
@@ -203,10 +203,8 @@ static void _bc_rec_mul(bc_num u, size_t ulen, bc_num v, size_t vlen, bc_num *pr
 
 	/* Calculate sub results ... */
 
-	bc_init_num(&d1);
-	bc_init_num(&d2);
-	bc_sub(u1, u0, &d1, 0);
-	bc_sub(v0, v1, &d2, 0);
+	bc_num d1 = bc_sub(u1, u0, 0);
+	bc_num d2 = bc_sub(v0, v1, 0);
 
 
 	/* Do recursive multiplies and shifted adds. */

ext/bcmath/libbcmath/src/sqrt.c

@@ -94,7 +94,7 @@ bool bc_sqrt(bc_num *num, size_t scale)
 		bc_divide(*num, guess, &guess, cscale);
 		bc_add_ex(guess, guess1, &guess, 0);
 		bc_multiply(guess, point5, &guess, cscale);
-		bc_sub(guess, guess1, &diff, cscale + 1);
+		bc_sub_ex(guess, guess1, &diff, cscale + 1);
 		if (bc_is_near_zero(diff, cscale)) {
 			if (cscale < rscale + 1) {
 				cscale = MIN (cscale * 3, rscale + 1);

ext/bcmath/libbcmath/src/sub.c

@@ -39,7 +39,7 @@
    N2 is subtracted from N1 and the result placed in RESULT.  SCALE_MIN
    is the minimum scale for the result. */
 
-void bc_sub(bc_num n1, bc_num n2, bc_num *result, size_t scale_min)
+bc_num bc_sub(bc_num n1, bc_num n2, size_t scale_min)
 {
 	bc_num diff = NULL;
 
@@ -70,7 +70,5 @@ void bc_sub(bc_num n1, bc_num n2, bc_num *result, size_t scale_min)
 		}
 	}
 
-	/* Clean up and return. */
-	bc_free_num (result);
-	*result = diff;
+	return diff;
 }