File:  [gforth] / gforth / vmgen-ex / mini-inst.vmg
Revision 1.2: download - view: text, annotated - select for diffs
Tue Aug 20 07:59:02 2002 UTC (21 years, 7 months ago) by anton
Branches: MAIN
CVS tags: HEAD
prims2x.fs changes: now supports C code delimited by braces;
                    Forth or C names for primitives depending on [ifdef] vmgen
Documentation changes
adapted vmgen-ex* to earlier prims2x.fs changes

    1: \ mini.inst is generated automatically from mini-inst.vmg and mini-super.vmg
    2: \ example .vmg file
    3: 
    4: \ Copyright (C) 2001 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., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
   21: 
   22: 
   23: \ WARNING: This file is processed by m4. Make sure your identifiers
   24: \ don't collide with m4's (e.g. by undefining them).
   25: 
   26: 
   27: \ comments start with "\ "
   28: 
   29: \ stack definitions:
   30: \E stack data-stack sp Cell
   31: 
   32: \ stack prefix definitions
   33: \E inst-stream stack-prefix #
   34: 
   35: \ type prefix definitions:
   36: \E s" Cell"   single data-stack type-prefix i
   37: \E s" char *" single data-stack type-prefix a
   38: \E s" Inst *" single data-stack type-prefix target
   39: 
   40: \ simple VM instructions:
   41: add ( i1 i2 -- i )
   42: i = i1+i2;
   43: 
   44: sub ( i1 i2 -- i )
   45: i = i1-i2;
   46: 
   47: mul ( i1 i2 -- i )
   48: i = i1*i2;
   49: 
   50: and ( i1 i2 -- i )
   51: i = i1 & i2;
   52: 
   53: or ( i1 i2 -- i )
   54: i = i1 | i2;
   55: 
   56: lessthan ( i1 i2 -- i )
   57: i = i1<i2;
   58: 
   59: equals ( i1 i2 -- i )
   60: i = i1==i2;
   61: 
   62: not ( i1 -- i2 )
   63: i2 = !i1;
   64: 
   65: negate ( i1 -- i2 )
   66: i2 = -i1;
   67: 
   68: lit ( #i -- i )
   69: 
   70: drop ( i -- )
   71: 
   72: print ( i -- )
   73: printf("%ld\n", i);
   74: 
   75: branch ( #target -- )
   76: SET_IP(target);
   77: 
   78: zbranch ( #target i -- )
   79: if (i==0) {
   80:   SET_IP(target);
   81:   INST_TAIL;
   82: }
   83: 
   84: \  The stack is organized as follows:
   85: \  The stack grows downwards; a stack usually looks like this:
   86: 
   87: \  higher addresses
   88: \  --------------------- bottom of stack
   89: \     locals of main
   90: \     return address (points to VM code after call)
   91: \  +->oldfp (NULL)
   92: \  |  intermediate results (e.g., 1 for a call like 1+foo(...))
   93: \  |  arguments passed to the called function
   94: \  |  locals of the called function
   95: \  |  return address (points to VM code after call)
   96: \  +--oldfp                <-- fp
   97: \     intermediate results <-- sp
   98: \  ---------------------- top of stack
   99: \  lower addresses
  100: 
  101: \ The following VM instructions also explicitly reference sp and
  102: \ therefore may have to do something about spTOS caching.
  103: 
  104: call ( #target #iadjust -- targetret aoldfp )
  105: /* IF_spTOS(sp[2] = spTOS);*/ /* unnecessary; vmgen inserts a flush anyway */
  106: targetret = IP;
  107: SET_IP(target);
  108: aoldfp = fp;
  109: sp = (Cell *)(((char *)sp)+iadjust);
  110: fp = (char *)sp;
  111: /* IF_spTOS(spTOS = sp[0]); */ /* dead, thus unnecessary; vmgen copies aoldfp there */
  112: 
  113: return ( #iadjust target afp i1 -- i2 )
  114: /* IF_spTOS(sp[-2] = spTOS); */ /* unnecessary; that stack item is dead */
  115: SET_IP(target);
  116: sp = (Cell *)(((char *)sp)+iadjust);
  117: fp = afp;
  118: i2=i1;
  119: /* IF_spTOS(spTOS = sp[0]); */ /* dead, thus unnecessary; vmgen copies i2 there */
  120: 
  121: \ loadlocal and storelocal access stack items below spTOS, so we can
  122: \ ignore spTOS caching.
  123: 
  124: loadlocal ( #ioffset -- i )
  125: i = *(Cell *)(fp+ioffset);
  126: 
  127: storelocal ( #ioffset i -- )
  128: *(Cell *)(fp+ioffset) = i;
  129: 
  130: end ( i -- )
  131: /* SUPER_END would increment the next BB count (because IP points there);
  132:    this would be a problem if there is no following BB.
  133:    Instead, we do the following to add an end point for the current BB: */
  134: #ifdef VM_PROFILING
  135: block_insert(IP); /* we also do this at compile time, so this is unnecessary */
  136: #endif
  137: return i;
  138: 
  139: include(mini-super.vmg)

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