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| author | Denys Vlasenko <vda.linux@googlemail.com> | 2018-12-29 16:23:34 +0100 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2018-12-29 16:23:34 +0100 |
| commit | 8ab209f00ebfc9afeeed70bc950817a2567e7389 (patch) | |
| tree | 30b5b3bea0812de5bab45db7c1837bc54ef6b725 /miscutils | |
| parent | 374d2c47ec956b43ced2879cd8305db616625103 (diff) | |
| download | busybox-8ab209f00ebfc9afeeed70bc950817a2567e7389.tar.gz | |
bc: simplify representation of 0.5 in sqrt()
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>
Diffstat (limited to 'miscutils')
| -rw-r--r-- | miscutils/bc.c | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/miscutils/bc.c b/miscutils/bc.c index 500d97123..081e48ba8 100644 --- a/miscutils/bc.c +++ b/miscutils/bc.c @@ -2157,6 +2157,7 @@ static BC_STATUS zbc_num_sqrt(BcNum *a, BcNum *restrict b, size_t scale) { BcStatus s; BcNum num1, num2, half, f, fprime, *x0, *x1, *temp; + BcDig half_digs[1]; size_t pow, len, digs, digs1, resrdx, req, times = 0; 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(&num2, len); - bc_num_init_DEF_SIZE(&half); + half.cap = ARRAY_SIZE(half_digs); + half.num = half_digs; bc_num_one(&half); - half.num[0] = 5; + half_digs[0] = 5; half.rdx = 1; bc_num_init(&f, len); @@ -2247,7 +2249,6 @@ static BC_STATUS zbc_num_sqrt(BcNum *a, BcNum *restrict b, size_t scale) err: bc_num_free(&fprime); bc_num_free(&f); - bc_num_free(&half); bc_num_free(&num2); bc_num_free(&num1); RETURN_STATUS(s); @@ -2285,7 +2286,7 @@ static BC_STATUS zdc_num_modexp(BcNum *a, BcNum *b, BcNum *c, BcNum *restrict d) { BcStatus s; BcNum base, exp, two, temp; - BcDig two_digs[2]; + BcDig two_digs[1]; if (c->len == 0) 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_ELEM: { BcVec *v; - + void *p; 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) { - v = bc_vec_top(v); - if (v->len <= r->d.id.idx) bc_array_expand(v, r->d.id.idx + 1); + v = p; + 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); - } else - *num = bc_vec_top(v); + } else { + *num = p; + } break; } #if ENABLE_BC |