historical/m0-applesillicon.git/xnu-qemu-arm64-5.1.0/roms/openbios/libgcc/multi3.c
2024-01-16 11:20:27 -06:00

83 lines
2.4 KiB
C

/* muldi3.c extracted from gcc-2.7.2.3/libgcc2.c and
gcc-2.7.2.3/longlong.h which is: */
/* Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
This file is part of GNU CC.
GNU CC 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; either version 2, or (at your option)
any later version.
GNU CC 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 GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 51 Franklin St, Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "libgcc.h"
#define BITS_PER_UNIT 8
#define DI_TYPE_SIZE 64
#define __BITS4 (DI_TYPE_SIZE / 4)
#define __ll_B (1L << (DI_TYPE_SIZE / 2))
#define __ll_lowpart(t) ((UDItype) (t) % __ll_B)
#define __ll_highpart(t) ((UDItype) (t) / __ll_B)
#define umul_ppmm(w1, w0, u, v) \
do { \
UDItype __x0, __x1, __x2, __x3; \
UDItype __ul, __vl, __uh, __vh; \
\
__ul = __ll_lowpart (u); \
__uh = __ll_highpart (u); \
__vl = __ll_lowpart (v); \
__vh = __ll_highpart (v); \
\
__x0 = (UDItype) __ul * __vl; \
__x1 = (UDItype) __ul * __vh; \
__x2 = (UDItype) __uh * __vl; \
__x3 = (UDItype) __uh * __vh; \
\
__x1 += __ll_highpart (__x0);/* this can't give carry */ \
__x1 += __x2; /* but this indeed can */ \
if (__x1 < __x2) /* did we get it? */ \
__x3 += __ll_B; /* yes, add it in the proper pos. */ \
\
(w1) = __x3 + __ll_highpart (__x1); \
(w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0); \
} while (0)
#define __umulsidi3(u, v) \
({TIunion __w; \
umul_ppmm (__w.s.high, __w.s.low, u, v); \
__w.ll; })
struct TIstruct {DItype high, low;};
typedef union
{
struct TIstruct s;
TItype ll;
} TIunion;
TItype
__multi3 (TItype u, TItype v)
{
TIunion w;
TIunion uu, vv;
uu.ll = u,
vv.ll = v;
w.ll = __umulsidi3 (uu.s.low, vv.s.low);
w.s.high += ((UDItype) uu.s.low * (UDItype) vv.s.high
+ (UDItype) uu.s.high * (UDItype) vv.s.low);
return w.ll;
}