mirror of
https://git.planet-casio.com/Vhex-Kernel-Core/fxlibc.git
synced 2024-12-29 13:03:38 +01:00
95 lines
3 KiB
C
95 lines
3 KiB
C
/*
|
|
Copyright (c) 2009 Florian Loitsch
|
|
|
|
Permission is hereby granted, free of charge, to any person
|
|
obtaining a copy of this software and associated documentation
|
|
files (the "Software"), to deal in the Software without
|
|
restriction, including without limitation the rights to use,
|
|
copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
copies of the Software, and to permit persons to whom the
|
|
Software is furnished to do so, subject to the following
|
|
conditions:
|
|
|
|
The above copyright notice and this permission notice shall be
|
|
included in all copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
|
|
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
|
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
|
|
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
|
OTHER DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
#include "diy_fp.h"
|
|
#include "k_comp.h"
|
|
#include "double.h"
|
|
#include "powers.h"
|
|
#include <stdbool.h>
|
|
#include "grisu2.h"
|
|
#include <stdint.h>
|
|
|
|
#define TEN9 1000000000
|
|
|
|
void grisu_round(char* buffer, int len,
|
|
uint64_t delta, uint64_t rest,
|
|
uint64_t ten_kappa, uint64_t wp_w) {
|
|
while (rest < wp_w &&
|
|
delta - rest >= ten_kappa &&
|
|
(rest + ten_kappa < wp_w || /// closer
|
|
wp_w - rest > rest+ten_kappa - wp_w))
|
|
{
|
|
buffer[len-1]--; rest += ten_kappa;
|
|
}
|
|
}
|
|
|
|
void digit_gen(diy_fp_t W, diy_fp_t Mp, diy_fp_t delta,
|
|
char* buffer, int* len, int* K) {
|
|
uint32_t div; int d,kappa; diy_fp_t one, wp_w;
|
|
wp_w = minus(Mp, W);
|
|
one.f = ((uint64_t) 1) << -Mp.e; one.e = Mp.e;
|
|
uint32_t p1 = Mp.f >> -one.e; /// Mp_cut
|
|
uint64_t p2 = Mp.f & (one.f - 1);
|
|
*len = 0; kappa = 10; div = TEN9;
|
|
while (kappa > 0) {
|
|
d = p1 / div;
|
|
if (d || *len) buffer[(*len)++] = '0' + d; /// Mp_inv1
|
|
p1 %= div; kappa--;
|
|
uint64_t tmp = (((uint64_t)p1)<<-one.e)+p2;
|
|
if (tmp <= delta.f) { /// Mp_delta
|
|
*K += kappa;
|
|
grisu_round(buffer, *len, delta.f, tmp, ((uint64_t)div) << -one.e, wp_w.f);
|
|
return;
|
|
}
|
|
div /= 10;
|
|
}
|
|
uint64_t unit = 1;
|
|
while (1) {
|
|
p2 *= 10; delta.f *= 10; unit *= 10;
|
|
d = p2 >> -one.e;
|
|
if (d || *len) buffer[(*len)++] = '0' + d;
|
|
p2 &= one.f - 1; kappa--;
|
|
if (p2 < delta.f) {
|
|
*K += kappa;
|
|
grisu_round(buffer, *len, delta.f, p2, one.f, wp_w.f*unit);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
void grisu2(double v, char* buffer, int* length, int* K) {
|
|
diy_fp_t w_m, w_p;
|
|
int q = 64, alpha = -59, gamma = -56; int pos;
|
|
normalized_boundaries(v, &w_m, &w_p);
|
|
diy_fp_t w = normalize_diy_fp(double2diy_fp(v));
|
|
int mk = k_comp(w_p.e + q, alpha, gamma);
|
|
diy_fp_t c_mk = cached_power(mk);
|
|
diy_fp_t W = multiply(w, c_mk);
|
|
diy_fp_t Wp = multiply(w_p, c_mk);
|
|
diy_fp_t Wm = multiply(w_m, c_mk);
|
|
Wm.f++; Wp.f--;
|
|
diy_fp_t delta = minus(Wp, Wm);
|
|
*K = -mk;
|
|
digit_gen(W, Wp, delta, buffer, length, K);
|
|
}
|