lang/m2/comp/tmpvar.C

   1 /*
   2  * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
   3  * See the copyright notice in the ACK home directory, in the file "Copyright".
   4  *
   5  * Author: Ceriel J.H. Jacobs
   6  */
   7
   8 /* T E M P O R A R Y   V A R I A B L E S */
   9
  10 /* $Id: tmpvar.C,v 1.14 1994/06/24 12:42:58 ceriel Exp $ */
  11
  12 /*      Code for the allocation and de-allocation of temporary variables,
  13         allowing re-use.
  14         The routines use "ProcScope" instead of "CurrentScope", because
  15         "CurrentScope" also reflects WITH statements, and these scopes do not
  16         have local variabes.
  17 */
  18
  19 #include        "debug.h"
  20
  21 #include        <em_arith.h>
  22 #include        <em_label.h>
  23 #include        <em_code.h>
  24 #include        <em_reg.h>
  25 #include        <alloc.h>
  26 #include        <assert.h>
  27
  28 #include        "LLlex.h"
  29 #include        "def.h"
  30 #include        "type.h"
  31 #include        "scope.h"
  32 #include        "main.h"
  33
  34 struct tmpvar {
  35         struct tmpvar   *t_next;
  36         arith           t_offset;       /* offset from LocalBase */
  37 };
  38
  39 /* STATICALLOCDEF "tmpvar" 10 */
  40
  41 static struct tmpvar    *TmpInts,       /* for integer temporaries */
  42                         *TmpPtrs;       /* for pointer temporaries */
  43 static t_scope  *ProcScope;     /* scope of procedure in which the
  44                                            temporaries are allocated
  45                                         */
  46
  47 TmpOpen(sc) t_scope *sc;
  48 {
  49         /*      Initialize for temporaries in scope "sc".
  50         */
  51         ProcScope = sc;
  52 }
  53
  54 arith
  55 TmpSpace(sz, al)
  56         arith sz;
  57 {
  58         register t_scope *sc = ProcScope;
  59
  60         sc->sc_off = - WA(align(sz - sc->sc_off, al));
  61         return sc->sc_off;
  62 }
  63
  64 STATIC arith
  65 NewTmp(plist, sz, al, regtype)
  66         register struct tmpvar **plist;
  67         arith sz;
  68 {
  69         register arith offset;
  70         register struct tmpvar *tmp;
  71
  72         if (!*plist) {
  73                 offset = TmpSpace(sz, al);
  74                 if (! options['n']) C_ms_reg(offset, sz, regtype, 0);
  75         }
  76         else {
  77                 tmp = *plist;
  78                 offset = tmp->t_offset;
  79                 *plist = tmp->t_next;
  80                 free_tmpvar(tmp);
  81         }
  82         return offset;
  83 }
  84
  85 arith
  86 NewInt()
  87 {
  88         return NewTmp(&TmpInts, int_size, int_align, reg_any);
  89 }
  90
  91 arith
  92 NewPtr()
  93 {
  94         return NewTmp(&TmpPtrs, pointer_size, pointer_align, reg_pointer);
  95 }
  96
  97 STATIC
  98 FreeTmp(plist, off)
  99         struct tmpvar **plist;
 100         arith off;
 101 {
 102         register struct tmpvar *tmp = new_tmpvar();
 103
 104         tmp->t_next = *plist;
 105         tmp->t_offset = off;
 106         *plist = tmp;
 107 }
 108
 109 FreeInt(off)
 110         arith off;
 111 {
 112         FreeTmp(&TmpInts, off);
 113 }
 114
 115 FreePtr(off)
 116         arith off;
 117 {
 118         FreeTmp(&TmpPtrs, off);
 119 }
 120
 121 TmpClose()
 122 {
 123         register struct tmpvar *tmp, *tmp1;
 124
 125         tmp = TmpInts;
 126         while (tmp) {
 127                 tmp1 = tmp;
 128                 tmp = tmp->t_next;
 129                 free_tmpvar(tmp1);
 130         }
 131         tmp = TmpPtrs;
 132         while (tmp) {
 133                 tmp1 = tmp;
 134                 tmp = tmp->t_next;
 135                 free_tmpvar(tmp1);
 136         }
 137         TmpInts = TmpPtrs = 0;
 138 }