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bc: simplify representation of 0.5 in sqrt()

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function                                             old     new   delta
zxc_program_exec                                    4012    4149    +137
zdc_program_printStream                              144       -    -144
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/0 up/down: 137/-144)           Total: -7 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-12-29 16:23:34 +01:00
parent 374d2c47ec
commit 8ab209f00e
1 changed files with 15 additions and 10 deletions
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25
miscutils/bc.c
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@ -2157,6 +2157,7 @@ static BC_STATUS zbc_num_sqrt(BcNum *a, BcNum *restrict b, size_t scale)
{ {
BcStatus s; BcStatus s;
BcNum num1, num2, half, f, fprime, *x0, *x1, *temp; BcNum num1, num2, half, f, fprime, *x0, *x1, *temp;
BcDig half_digs[1];
size_t pow, len, digs, digs1, resrdx, req, times = 0; size_t pow, len, digs, digs1, resrdx, req, times = 0;
ssize_t cmp = 1, cmp1 = SSIZE_MAX, cmp2 = SSIZE_MAX; ssize_t cmp = 1, cmp1 = SSIZE_MAX, cmp2 = SSIZE_MAX;
@ -2181,10 +2182,11 @@ static BC_STATUS zbc_num_sqrt(BcNum *a, BcNum *restrict b, size_t scale)
bc_num_init(&num1, len); bc_num_init(&num1, len);
bc_num_init(&num2, len); bc_num_init(&num2, len);
bc_num_init_DEF_SIZE(&half);
half.cap = ARRAY_SIZE(half_digs);
half.num = half_digs;
bc_num_one(&half); bc_num_one(&half);
half.num[0] = 5; half_digs[0] = 5;
half.rdx = 1; half.rdx = 1;
bc_num_init(&f, len); bc_num_init(&f, len);
@ -2247,7 +2249,6 @@ static BC_STATUS zbc_num_sqrt(BcNum *a, BcNum *restrict b, size_t scale)
err: err:
bc_num_free(&fprime); bc_num_free(&fprime);
bc_num_free(&f); bc_num_free(&f);
bc_num_free(&half);
bc_num_free(&num2); bc_num_free(&num2);
bc_num_free(&num1); bc_num_free(&num1);
RETURN_STATUS(s); RETURN_STATUS(s);
@ -2285,7 +2286,7 @@ static BC_STATUS zdc_num_modexp(BcNum *a, BcNum *b, BcNum *c, BcNum *restrict d)
{ {
BcStatus s; BcStatus s;
BcNum base, exp, two, temp; BcNum base, exp, two, temp;
BcDig two_digs[2]; BcDig two_digs[1];
if (c->len == 0) if (c->len == 0)
RETURN_STATUS(bc_error("divide by zero")); RETURN_STATUS(bc_error("divide by zero"));
@ -5125,15 +5126,19 @@ static BC_STATUS zxc_program_num(BcResult *r, BcNum **num)
case XC_RESULT_ARRAY: case XC_RESULT_ARRAY:
case XC_RESULT_ARRAY_ELEM: { case XC_RESULT_ARRAY_ELEM: {
BcVec *v; BcVec *v;
void *p;
v = xc_program_search(r->d.id.name, r->t == XC_RESULT_VAR); v = xc_program_search(r->d.id.name, r->t == XC_RESULT_VAR);
// dc variables are all stacks, so here we have this:
p = bc_vec_top(v);
// TODO: eliminate these stacks for bc-only config?
if (r->t == XC_RESULT_ARRAY_ELEM) { if (r->t == XC_RESULT_ARRAY_ELEM) {
v = bc_vec_top(v); v = p;
if (v->len <= r->d.id.idx) bc_array_expand(v, r->d.id.idx + 1); if (v->len <= r->d.id.idx)
bc_array_expand(v, r->d.id.idx + 1);
*num = bc_vec_item(v, r->d.id.idx); *num = bc_vec_item(v, r->d.id.idx);
} else } else {
*num = bc_vec_top(v); *num = p;
}
break; break;
} }
#if ENABLE_BC #if ENABLE_BC