cosmopolitan/libc/runtime/valist.c

52 lines
2.7 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/macros.h"
#include "libc/runtime/valist.h"
static void *__va_arg_mem(struct __va *ap, size_t sz, size_t align) {
void *r = (void *)ROUNDUP((intptr_t)ap->overflow_arg_area, align);
ap->overflow_arg_area = (void *)ROUNDUP((intptr_t)r + sz, 8);
return r;
}
void *__va_arg(struct __va *ap, size_t sz, unsigned align, unsigned k) {
void *r;
switch (k) {
case 0:
if (ap->gp_offset < 48) {
r = (char *)ap->reg_save_area + ap->gp_offset;
ap->gp_offset += 8;
return r;
} else {
return __va_arg_mem(ap, sz, align);
}
case 1:
if (ap->fp_offset < 112) {
r = (char *)ap->reg_save_area + ap->fp_offset;
ap->fp_offset += 8;
return r;
} else {
return __va_arg_mem(ap, sz, align);
}
default:
return __va_arg_mem(ap, sz, align);
}
}