Avoid unnecessary destruction in bc_mul()

This commit is contained in:
Niels Dossche 2024-05-01 21:14:03 +02:00
parent 0cd952d851
commit 34b2116eb5
8 changed files with 21 additions and 18 deletions

View file

@ -242,7 +242,7 @@ PHP_FUNCTION(bcmul)
zend_string *left, *right; zend_string *left, *right;
zend_long scale_param; zend_long scale_param;
bool scale_param_is_null = 1; bool scale_param_is_null = 1;
bc_num first = NULL, second = NULL, result; bc_num first = NULL, second = NULL, result = NULL;
int scale; int scale;
ZEND_PARSE_PARAMETERS_START(2, 3) ZEND_PARSE_PARAMETERS_START(2, 3)
@ -261,8 +261,6 @@ PHP_FUNCTION(bcmul)
scale = (int) scale_param; scale = (int) scale_param;
} }
bc_init_num(&result);
if (php_str2num(&first, ZSTR_VAL(left)) == FAILURE) { if (php_str2num(&first, ZSTR_VAL(left)) == FAILURE) {
zend_argument_value_error(1, "is not well-formed"); zend_argument_value_error(1, "is not well-formed");
goto cleanup; goto cleanup;
@ -273,7 +271,7 @@ PHP_FUNCTION(bcmul)
goto cleanup; goto cleanup;
} }
bc_multiply (first, second, &result, scale); result = bc_multiply (first, second, scale);
RETVAL_NEW_STR(bc_num2str_ex(result, scale)); RETVAL_NEW_STR(bc_num2str_ex(result, scale));

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@ -131,7 +131,13 @@ bc_num bc_sub(bc_num n1, bc_num n2, size_t scale_min);
*(result) = sub_ex; \ *(result) = sub_ex; \
} while (0) } 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); bool bc_divide(bc_num n1, bc_num n2, bc_num *quot, int scale);

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@ -61,7 +61,7 @@ bool bc_divmod(bc_num num1, bc_num num2, bc_num *quot, bc_num *rem, size_t scale
if (quot) { if (quot) {
quotient = bc_copy_num(temp); 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_sub_ex(num1, temp, rem, rscale);
bc_free_num (&temp); bc_free_num (&temp);

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@ -162,7 +162,7 @@ void bc_out_num(bc_num num, int o_base, void (*out_char)(char), bool leading_zer
pre_space = false; pre_space = false;
t_num = bc_copy_num(BCG(_one_)); t_num = bc_copy_num(BCG(_one_));
while (t_num->n_len <= num->n_scale) { 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); fdigit = bc_num2long(frac_part);
bc_int2num(&int_part, fdigit); bc_int2num(&int_part, fdigit);
bc_sub_ex(frac_part, int_part, &frac_part, 0); 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); bc_out_long(fdigit, max_o_digit->n_len, pre_space, out_char);
pre_space = true; 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); bc_free_num (&t_num);
} }

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@ -69,7 +69,7 @@ void bc_raise(bc_num num1, long exponent, bc_num *result, size_t scale)
pwrscale = num1->n_scale; pwrscale = num1->n_scale;
while ((exponent & 1) == 0) { while ((exponent & 1) == 0) {
pwrscale = 2 * pwrscale; pwrscale = 2 * pwrscale;
bc_multiply(power, power, &power, pwrscale); bc_multiply_ex(power, power, &power, pwrscale);
exponent = exponent >> 1; exponent = exponent >> 1;
} }
temp = bc_copy_num(power); 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. */ /* Do the calculation. */
while (exponent > 0) { while (exponent > 0) {
pwrscale = 2 * pwrscale; pwrscale = 2 * pwrscale;
bc_multiply(power, power, &power, pwrscale); bc_multiply_ex(power, power, &power, pwrscale);
if ((exponent & 1) == 1) { if ((exponent & 1) == 1) {
calcscale = pwrscale + calcscale; calcscale = pwrscale + calcscale;
bc_multiply(temp, power, &temp, calcscale); bc_multiply_ex(temp, power, &temp, calcscale);
} }
exponent = exponent >> 1; exponent = exponent >> 1;
} }

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@ -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)) { while (!bc_is_zero(exponent)) {
(void) bc_divmod(exponent, BCG(_two_), &exponent, &parity, 0); (void) bc_divmod(exponent, BCG(_two_), &exponent, &parity, 0);
if (!bc_is_zero(parity)) { 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); (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); (void) bc_modulo(power, modulus, &power, scale);
} }
} }

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@ -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)). 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; bc_num pval;
size_t len1, len2; 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)) { if (bc_is_zero(pval)) {
pval->n_sign = PLUS; pval->n_sign = PLUS;
} }
bc_free_num(prod); return pval;
*prod = pval;
} }

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@ -79,7 +79,7 @@ bool bc_sqrt(bc_num *num, size_t scale)
bc_int2num(&guess, 10); bc_int2num(&guess, 10);
bc_int2num(&guess1, (*num)->n_len); bc_int2num(&guess1, (*num)->n_len);
bc_multiply(guess1, point5, &guess1, 0); bc_multiply_ex(guess1, point5, &guess1, 0);
guess1->n_scale = 0; guess1->n_scale = 0;
bc_raise_bc_exponent(guess, guess1, &guess, 0); bc_raise_bc_exponent(guess, guess1, &guess, 0);
bc_free_num (&guess1); bc_free_num (&guess1);
@ -93,7 +93,7 @@ bool bc_sqrt(bc_num *num, size_t scale)
guess1 = bc_copy_num(guess); guess1 = bc_copy_num(guess);
bc_divide(*num, guess, &guess, cscale); bc_divide(*num, guess, &guess, cscale);
bc_add_ex(guess, guess1, &guess, 0); 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); bc_sub_ex(guess, guess1, &diff, cscale + 1);
if (bc_is_near_zero(diff, cscale)) { if (bc_is_near_zero(diff, cscale)) {
if (cscale < rscale + 1) { if (cscale < rscale + 1) {