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Annotation of qemu/roms/openbios/libgcc/multi3.c, revision 1.1.1.1

1.1       root        1: /* muldi3.c extracted from gcc-2.7.2.3/libgcc2.c and
                      2:                           gcc-2.7.2.3/longlong.h which is: */
                      3: /* Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
                      4: 
                      5: This file is part of GNU CC.
                      6: 
                      7: GNU CC is free software; you can redistribute it and/or modify
                      8: it under the terms of the GNU General Public License as published by
                      9: the Free Software Foundation; either version 2, or (at your option)
                     10: any later version.
                     11: 
                     12: GNU CC is distributed in the hope that it will be useful,
                     13: but WITHOUT ANY WARRANTY; without even the implied warranty of
                     14: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     15: GNU General Public License for more details.
                     16: 
                     17: You should have received a copy of the GNU General Public License
                     18: along with GNU CC; see the file COPYING.  If not, write to
                     19: the Free Software Foundation, 51 Franklin St, Fifth Floor, Boston,
                     20: MA 02110-1301, USA. */
                     21: 
                     22: #include "libgcc.h"
                     23: 
                     24: #define BITS_PER_UNIT 8
                     25: #define DI_TYPE_SIZE 64
                     26: 
                     27: #define __BITS4 (DI_TYPE_SIZE / 4)
                     28: #define __ll_B (1L << (DI_TYPE_SIZE / 2))
                     29: #define __ll_lowpart(t) ((UDItype) (t) % __ll_B)
                     30: #define __ll_highpart(t) ((UDItype) (t) / __ll_B)
                     31: 
                     32: #define umul_ppmm(w1, w0, u, v)                                                \
                     33:   do {                                                                 \
                     34:     UDItype __x0, __x1, __x2, __x3;                                    \
                     35:     UDItype __ul, __vl, __uh, __vh;                                    \
                     36:                                                                        \
                     37:     __ul = __ll_lowpart (u);                                           \
                     38:     __uh = __ll_highpart (u);                                          \
                     39:     __vl = __ll_lowpart (v);                                           \
                     40:     __vh = __ll_highpart (v);                                          \
                     41:                                                                        \
                     42:     __x0 = (UDItype) __ul * __vl;                                      \
                     43:     __x1 = (UDItype) __ul * __vh;                                      \
                     44:     __x2 = (UDItype) __uh * __vl;                                      \
                     45:     __x3 = (UDItype) __uh * __vh;                                      \
                     46:                                                                        \
                     47:     __x1 += __ll_highpart (__x0);/* this can't give carry */           \
                     48:     __x1 += __x2;              /* but this indeed can */               \
                     49:     if (__x1 < __x2)           /* did we get it? */                    \
                     50:       __x3 += __ll_B;          /* yes, add it in the proper pos. */    \
                     51:                                                                        \
                     52:     (w1) = __x3 + __ll_highpart (__x1);                                        \
                     53:     (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0);         \
                     54:   } while (0)
                     55: 
                     56: #define __umulsidi3(u, v) \
                     57:   ({TIunion __w;                                                       \
                     58:     umul_ppmm (__w.s.high, __w.s.low, u, v);                           \
                     59:     __w.ll; })
                     60: 
                     61: struct TIstruct {DItype high, low;};
                     62: 
                     63: typedef union
                     64: {
                     65:   struct TIstruct s;
                     66:   TItype ll;
                     67: } TIunion;
                     68: 
                     69: TItype
                     70: __multi3 (TItype u, TItype v)
                     71: {
                     72:   TIunion w;
                     73:   TIunion uu, vv;
                     74: 
                     75:   uu.ll = u,
                     76:   vv.ll = v;
                     77: 
                     78:   w.ll = __umulsidi3 (uu.s.low, vv.s.low);
                     79:   w.s.high += ((UDItype) uu.s.low * (UDItype) vv.s.high
                     80:               + (UDItype) uu.s.high * (UDItype) vv.s.low);
                     81: 
                     82:   return w.ll;
                     83: }

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