Annotation of gforth/386.h, revision 1.12
1.1 anton 1: /*
1.11 anton 2: This is the machine-specific part for Intel 386 compatible processors
3:
4: Copyright (C) 1995 Free Software Foundation, Inc.
5:
6: This file is part of Gforth.
1.1 anton 7:
1.11 anton 8: Gforth is free software; you can redistribute it and/or
9: modify it under the terms of the GNU General Public License
10: as published by the Free Software Foundation; either version 2
11: of the License, or (at your option) any later version.
12:
13: This program is distributed in the hope that it will be useful,
14: but WITHOUT ANY WARRANTY; without even the implied warranty of
15: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16: GNU General Public License for more details.
17:
18: You should have received a copy of the GNU General Public License
19: along with this program; if not, write to the Free Software
20: Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
1.1 anton 21: */
22:
1.7 anton 23: #include "32bit.h"
1.1 anton 24:
1.7 anton 25: /* indirect threading is faster on the 486, on the 386 direct
26: threading is probably faster. Therefore we leave defining
27: DIRECT_THREADED to configure */
1.1 anton 28:
1.3 anton 29: /* define this if the processor cannot exploit instruction-level
1.4 anton 30: parallelism (no pipelining or too few registers) */
1.3 anton 31: #define CISC_NEXT
32:
1.9 anton 33: /* 386 and below have no cache, 486 has a shared cache, and the
34: Pentium probably employs hardware cache consistency, so
35: flush-icache is a noop */
1.10 pazsan 36: #define FLUSH_ICACHE(addr,size)
1.9 anton 37:
1.1 anton 38: #ifdef DIRECT_THREADED
1.10 pazsan 39:
40: #define CALL 0xe8 /* call */
41: #define JMP 0xe9 /* jmp */
42: #define GETCFA(reg) ({ asm("popl %0" : "=r" (reg)); (int)reg -= 5;});
43:
1.1 anton 44: /* PFA gives the parameter field address corresponding to a cfa */
45: #define PFA(cfa) (((Cell *)cfa)+2)
46: /* PFA1 is a special version for use just after a NEXT1 */
47: #define PFA1(cfa) PFA(cfa)
48: /* CODE_ADDRESS is the address of the code jumped to through the code field */
1.2 pazsan 49: #define CODE_ADDRESS(cfa) \
1.5 anton 50: ({long _cfa = (long)(cfa); (Label)(_cfa+*((long *)(_cfa+1))+5);})
1.1 anton 51: /* MAKE_CF creates an appropriate code field at the cfa; ca is the code address */
1.2 pazsan 52: #define MAKE_CF(cfa,ca) ({long _cfa = (long)(cfa); \
53: long _ca = (long)(ca); \
1.10 pazsan 54: *(char *)_cfa = CALL; \
1.2 pazsan 55: *(long *)(_cfa+1) = _ca-(_cfa+5);})
1.1 anton 56:
57: /* this is the point where the does code starts if label points to the
58: * jump dodoes */
1.2 pazsan 59: #define DOES_HANDLER_SIZE 8
1.12 ! pazsan 60: #define DOES_CODE(xt) \
! 61: ({ long _xt = (long)(CODE_ADDRESS(xt)); \
! 62: (((*(unsigned char *)(xt)) == CALL) && \
! 63: ((*(unsigned char *)_xt) == JMP) && \
! 64: ((long)(CODE_ADDRESS(_xt)) == (long)symbols[DODOES])) ? \
! 65: _xt+DOES_HANDLER_SIZE : 0L; })
1.1 anton 66:
67: /* this is a special version of DOES_CODE for use in dodoes */
1.12 ! pazsan 68: #define DOES_CODE1(label) (CODE_ADDRESS(label)+DOES_HANDLER_SIZE)
1.1 anton 69:
70: /* this stores a jump dodoes at addr */
1.10 pazsan 71: #define MAKE_DOES_CF(addr,doesp) ({long _addr = (long)(addr); \
72: long _doesp = (long)(doesp)-8; \
73: *(char *)_addr = CALL; \
74: *(long *)(_addr+1) = _doesp-(_addr+5);})
75:
76: #define MAKE_DOES_HANDLER(addr) ({long _addr = (long)(addr); \
77: long _dodo = (long)symbols[DODOES]; \
78: *(char *)_addr = JMP; \
79: *(long *)(_addr+1) = _dodo-(_addr+5);})
1.1 anton 80: #endif
1.4 anton 81:
82: #ifdef FORCE_REG
1.8 anton 83: #if (__GNUC__==2 && defined(__GNUC_MINOR__) && __GNUC_MINOR__==5)
84: /* i.e. gcc-2.5.x */
85: /* this works with 2.5.7; nothing works with 2.5.8 */
1.4 anton 86: #define IPREG asm("%esi")
87: #define SPREG asm("%edi")
88: #ifdef USE_TOS
89: #define CFAREG asm("%ecx")
90: #else
91: #define CFAREG asm("%edx")
92: #endif
1.8 anton 93: #else /* gcc-version */
94: /* this works with 2.6.3 (and quite well, too) */
95: /* since this is not very demanding, it's the default for other gcc versions */
1.10 pazsan 96: #if defined(USE_TOS) && !defined(CFA_NEXT)
97: #define IPREG asm("%ebx")
98: #else
1.8 anton 99: #define SPREG asm("%ebx")
1.10 pazsan 100: #endif /* USE_TOS && !CFA_NEXT */
1.8 anton 101: #endif /* gcc-version */
1.4 anton 102: #endif /* FORCE_REG */
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