File:  [gforth] / gforth / Attic / 386.h
Revision 1.12: download - view: text, annotated - select for diffs
Tue Jul 16 20:57:05 1996 UTC (24 years, 6 months ago) by pazsan
Branches: MAIN
CVS tags: HEAD
SPECIAL: to create special "state-smart" words

    1: /*
    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.
    7: 
    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.
   21: */
   22: 
   23: #include "32bit.h"
   24: 
   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 */
   28: 
   29: /* define this if the processor cannot exploit instruction-level
   30:    parallelism (no pipelining or too few registers) */
   31: #define CISC_NEXT
   32: 
   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 */
   36: #define FLUSH_ICACHE(addr,size)
   37: 
   38: #ifdef DIRECT_THREADED
   39: 
   40: #define CALL 0xe8 /* call */
   41: #define JMP  0xe9 /* jmp  */
   42: #define GETCFA(reg)  ({ asm("popl %0" : "=r" (reg)); (int)reg -= 5;});
   43: 
   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 */
   49: #define CODE_ADDRESS(cfa) \
   50:     ({long _cfa = (long)(cfa); (Label)(_cfa+*((long *)(_cfa+1))+5);})
   51: /* MAKE_CF creates an appropriate code field at the cfa; ca is the code address */
   52: #define MAKE_CF(cfa,ca)	({long _cfa = (long)(cfa); \
   53:                           long _ca  = (long)(ca); \
   54: 			  *(char *)_cfa = CALL; \
   55: 			  *(long *)(_cfa+1) = _ca-(_cfa+5);})
   56: 
   57: /* this is the point where the does code starts if label points to the
   58:  * jump dodoes */
   59: #define DOES_HANDLER_SIZE       8
   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; })
   66: 
   67: /* this is a special version of DOES_CODE for use in dodoes */
   68: #define DOES_CODE1(label)      (CODE_ADDRESS(label)+DOES_HANDLER_SIZE)
   69: 
   70: /* this stores a jump dodoes at addr */
   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);})
   80: #endif
   81: 
   82: #ifdef FORCE_REG
   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 */
   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
   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 */
   96: #if defined(USE_TOS) && !defined(CFA_NEXT)
   97: #define IPREG asm("%ebx")
   98: #else
   99: #define SPREG asm("%ebx")
  100: #endif /* USE_TOS && !CFA_NEXT */
  101: #endif /* gcc-version */
  102: #endif /* FORCE_REG */

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