From 34b2116eb506c1e4d7ad51a5c8acc9dbe4afe70c Mon Sep 17 00:00:00 2001
From: Niels Dossche <7771979+nielsdos@users.noreply.github.com>
Date: Wed, 1 May 2024 21:14:03 +0200
Subject: [PATCH] Avoid unnecessary destruction in bc_mul()

---
 ext/bcmath/bcmath.c                 | 6 ++----
 ext/bcmath/libbcmath/src/bcmath.h   | 8 +++++++-
 ext/bcmath/libbcmath/src/divmod.c   | 2 +-
 ext/bcmath/libbcmath/src/output.c   | 4 ++--
 ext/bcmath/libbcmath/src/raise.c    | 6 +++---
 ext/bcmath/libbcmath/src/raisemod.c | 4 ++--
 ext/bcmath/libbcmath/src/recmul.c   | 5 ++---
 ext/bcmath/libbcmath/src/sqrt.c     | 4 ++--
 8 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/ext/bcmath/bcmath.c b/ext/bcmath/bcmath.c
index d6b8ae4d59e..b353ea0a7b8 100644
--- a/ext/bcmath/bcmath.c
+++ b/ext/bcmath/bcmath.c
@@ -242,7 +242,7 @@ PHP_FUNCTION(bcmul)
 	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)
@@ -261,8 +261,6 @@ PHP_FUNCTION(bcmul)
 		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;
@@ -273,7 +271,7 @@ PHP_FUNCTION(bcmul)
 		goto cleanup;
 	}
 
-	bc_multiply (first, second, &result, scale);
+	result = bc_multiply (first, second, scale);
 
 	RETVAL_NEW_STR(bc_num2str_ex(result, scale));
 
diff --git a/ext/bcmath/libbcmath/src/bcmath.h b/ext/bcmath/libbcmath/src/bcmath.h
index 83e867546cc..09c1985d2cb 100644
--- a/ext/bcmath/libbcmath/src/bcmath.h
+++ b/ext/bcmath/libbcmath/src/bcmath.h
@@ -131,7 +131,13 @@ bc_num bc_sub(bc_num n1, bc_num n2, size_t scale_min);
 	*(result) = sub_ex;                             \
 } while (0)
 
-void bc_multiply(bc_num n1, bc_num n2, bc_num *prod, size_t scale);
+bc_num bc_multiply(bc_num n1, bc_num n2, size_t scale);
+
+#define bc_multiply_ex(n1, n2, result, scale_min) do {	\
+	bc_num mul_ex = bc_multiply(n1, n2, scale_min); \
+	bc_free_num (result);                           \
+	*(result) = mul_ex;                             \
+} while (0)
 
 bool bc_divide(bc_num n1, bc_num n2, bc_num *quot, int scale);
 
diff --git a/ext/bcmath/libbcmath/src/divmod.c b/ext/bcmath/libbcmath/src/divmod.c
index 3dab0104c87..662e5600cb2 100644
--- a/ext/bcmath/libbcmath/src/divmod.c
+++ b/ext/bcmath/libbcmath/src/divmod.c
@@ -61,7 +61,7 @@ bool bc_divmod(bc_num num1, bc_num num2, bc_num *quot, bc_num *rem, size_t scale
 	if (quot) {
 		quotient = bc_copy_num(temp);
 	}
-	bc_multiply(temp, num2, &temp, rscale);
+	bc_multiply_ex(temp, num2, &temp, rscale);
 	bc_sub_ex(num1, temp, rem, rscale);
 	bc_free_num (&temp);
 
diff --git a/ext/bcmath/libbcmath/src/output.c b/ext/bcmath/libbcmath/src/output.c
index 699e2ab3b6a..ee3e726c87c 100644
--- a/ext/bcmath/libbcmath/src/output.c
+++ b/ext/bcmath/libbcmath/src/output.c
@@ -162,7 +162,7 @@ void bc_out_num(bc_num num, int o_base, void (*out_char)(char), bool leading_zer
 				pre_space = false;
 				t_num = bc_copy_num(BCG(_one_));
 				while (t_num->n_len <= num->n_scale) {
-					bc_multiply(frac_part, base, &frac_part, num->n_scale);
+					bc_multiply_ex(frac_part, base, &frac_part, num->n_scale);
 					fdigit = bc_num2long(frac_part);
 					bc_int2num(&int_part, fdigit);
 					bc_sub_ex(frac_part, int_part, &frac_part, 0);
@@ -172,7 +172,7 @@ void bc_out_num(bc_num num, int o_base, void (*out_char)(char), bool leading_zer
 						bc_out_long(fdigit, max_o_digit->n_len, pre_space, out_char);
 						pre_space = true;
 					}
-					bc_multiply(t_num, base, &t_num, 0);
+					bc_multiply_ex(t_num, base, &t_num, 0);
 				}
 				bc_free_num (&t_num);
 			}
diff --git a/ext/bcmath/libbcmath/src/raise.c b/ext/bcmath/libbcmath/src/raise.c
index 61d64ace947..390f4d6935c 100644
--- a/ext/bcmath/libbcmath/src/raise.c
+++ b/ext/bcmath/libbcmath/src/raise.c
@@ -69,7 +69,7 @@ void bc_raise(bc_num num1, long exponent, bc_num *result, size_t scale)
 	pwrscale = num1->n_scale;
 	while ((exponent & 1) == 0) {
 		pwrscale = 2 * pwrscale;
-		bc_multiply(power, power, &power, pwrscale);
+		bc_multiply_ex(power, power, &power, pwrscale);
 		exponent = exponent >> 1;
 	}
 	temp = bc_copy_num(power);
@@ -79,10 +79,10 @@ void bc_raise(bc_num num1, long exponent, bc_num *result, size_t scale)
 	/* Do the calculation. */
 	while (exponent > 0) {
 		pwrscale = 2 * pwrscale;
-		bc_multiply(power, power, &power, pwrscale);
+		bc_multiply_ex(power, power, &power, pwrscale);
 		if ((exponent & 1) == 1) {
 			calcscale = pwrscale + calcscale;
-			bc_multiply(temp, power, &temp, calcscale);
+			bc_multiply_ex(temp, power, &temp, calcscale);
 		}
 		exponent = exponent >> 1;
 	}
diff --git a/ext/bcmath/libbcmath/src/raisemod.c b/ext/bcmath/libbcmath/src/raisemod.c
index d4a2d01f3ed..caf1a090f98 100644
--- a/ext/bcmath/libbcmath/src/raisemod.c
+++ b/ext/bcmath/libbcmath/src/raisemod.c
@@ -72,10 +72,10 @@ raise_mod_status bc_raisemod(bc_num base, bc_num expo, bc_num mod, bc_num *resul
 		while (!bc_is_zero(exponent)) {
 			(void) bc_divmod(exponent, BCG(_two_), &exponent, &parity, 0);
 			if (!bc_is_zero(parity)) {
-				bc_multiply(temp, power, &temp, scale);
+				bc_multiply_ex(temp, power, &temp, scale);
 				(void) bc_modulo(temp, modulus, &temp, scale);
 			}
-			bc_multiply(power, power, &power, scale);
+			bc_multiply_ex(power, power, &power, scale);
 			(void) bc_modulo(power, modulus, &power, scale);
 		}
 	}
diff --git a/ext/bcmath/libbcmath/src/recmul.c b/ext/bcmath/libbcmath/src/recmul.c
index ea4c64300f0..127330ba3ae 100644
--- a/ext/bcmath/libbcmath/src/recmul.c
+++ b/ext/bcmath/libbcmath/src/recmul.c
@@ -253,7 +253,7 @@ static void _bc_rec_mul(bc_num u, size_t ulen, bc_num v, size_t vlen, bc_num *pr
    the result being MIN(N2 scale+N1 scale, MAX (SCALE, N2 scale, N1 scale)).
    */
 
-void bc_multiply(bc_num n1, bc_num n2, bc_num *prod, size_t scale)
+bc_num bc_multiply(bc_num n1, bc_num n2, size_t scale)
 {
 	bc_num pval;
 	size_t len1, len2;
@@ -276,6 +276,5 @@ void bc_multiply(bc_num n1, bc_num n2, bc_num *prod, size_t scale)
 	if (bc_is_zero(pval)) {
 		pval->n_sign = PLUS;
 	}
-	bc_free_num(prod);
-	*prod = pval;
+	return pval;
 }
diff --git a/ext/bcmath/libbcmath/src/sqrt.c b/ext/bcmath/libbcmath/src/sqrt.c
index 6be595deb4f..995bf076b54 100644
--- a/ext/bcmath/libbcmath/src/sqrt.c
+++ b/ext/bcmath/libbcmath/src/sqrt.c
@@ -79,7 +79,7 @@ bool bc_sqrt(bc_num *num, size_t scale)
 		bc_int2num(&guess, 10);
 
 		bc_int2num(&guess1, (*num)->n_len);
-		bc_multiply(guess1, point5, &guess1, 0);
+		bc_multiply_ex(guess1, point5, &guess1, 0);
 		guess1->n_scale = 0;
 		bc_raise_bc_exponent(guess, guess1, &guess, 0);
 		bc_free_num (&guess1);
@@ -93,7 +93,7 @@ bool bc_sqrt(bc_num *num, size_t scale)
 		guess1 = bc_copy_num(guess);
 		bc_divide(*num, guess, &guess, cscale);
 		bc_add_ex(guess, guess1, &guess, 0);
-		bc_multiply(guess, point5, &guess, cscale);
+		bc_multiply_ex(guess, point5, &guess, cscale);
 		bc_sub_ex(guess, guess1, &diff, cscale + 1);
 		if (bc_is_near_zero(diff, cscale)) {
 			if (cscale < rscale + 1) {