mono/jit/regset.c

   1 /*
   2  * regset.c: register set abstraction
   3  *
   4  * Author:
   5  *   Dietmar Maurer (dietmar@ximian.com)
   6  *
   7  * (C) 2001 Ximian, Inc.
   8  */
   9
  10 #include "regset.h"
  11 #include <mono/arch/x86/x86-codegen.h>
  12
  13 MonoRegSet *
  14 mono_regset_new (int max_regs)
  15 {
  16         MonoRegSet *rs;
  17
  18         g_return_val_if_fail (max_regs > 0 && max_regs <= 32, NULL);
  19
  20         rs = g_new0 (MonoRegSet, 1);
  21
  22         rs->max_regs = max_regs;
  23         rs->used_mask = 0;
  24         rs->free_mask = ~rs->used_mask;
  25         rs->reserved_mask = 0;
  26
  27         return rs;
  28 }
  29
  30 void
  31 mono_regset_free (MonoRegSet *rs)
  32 {
  33         g_free (rs);
  34 }
  35
  36 void
  37 mono_regset_reserve_reg (MonoRegSet *rs, int regnum)
  38 {
  39         guint32 ind;
  40
  41         g_return_if_fail (rs != NULL);
  42         g_return_if_fail (rs->max_regs > regnum);
  43
  44         ind = 1 << regnum;
  45
  46         rs->reserved_mask |= ind;
  47 }
  48
  49 int
  50 mono_regset_alloc_reg (MonoRegSet *rs, int regnum, guint8 exclude_mask)
  51 {
  52         guint32 i, ind;
  53
  54         g_return_val_if_fail (rs != NULL, -1);
  55         g_return_val_if_fail (rs->max_regs > regnum, -1);
  56
  57         if (regnum < 0) {
  58                 for (i = 0, ind = 1; i < rs->max_regs; i++, ind = ind << 1) {
  59                         if (exclude_mask & ind)
  60                                 continue;
  61                         if ((rs->free_mask & ind) && !(rs->reserved_mask & ind)) {
  62                                 rs->free_mask &= ~ind;
  63                                 rs->used_mask |= ind;
  64                                 return i;
  65                         }
  66                 }
  67                 return -1;
  68         } else {
  69                 ind = 1 << regnum;
  70
  71                 if (exclude_mask & ind)
  72                         return -1;
  73
  74                 if ((rs->free_mask & ind) && !(rs->reserved_mask & ind)) {
  75                         rs->free_mask &= ~ind;
  76                         rs->used_mask |= ind;
  77                         return regnum;
  78                 }
  79                 return -1;
  80         }
  81 }
  82
  83 void
  84 mono_regset_free_reg (MonoRegSet *rs, int regnum)
  85 {
  86         guint32 ind;
  87
  88         g_return_if_fail (rs != NULL);
  89         g_return_if_fail (rs->max_regs > regnum);
  90
  91         if (regnum < 0)
  92                 return;
  93
  94         ind = 1 << regnum;
  95
  96         g_return_if_fail (rs->free_mask && ind);
  97
  98         rs->free_mask |= ind;
  99 }
 100
 101 gboolean
 102 mono_regset_reg_used (MonoRegSet *rs, int regnum)
 103 {
 104         guint32 ind;
 105
 106         g_return_val_if_fail (rs != NULL, FALSE);
 107         g_return_val_if_fail (rs->max_regs > regnum, FALSE);
 108         g_return_val_if_fail (regnum >= 0, FALSE);
 109
 110         ind = 1 << regnum;
 111
 112         return rs->used_mask & ind;
 113 }
 114
 115