dataflow.c

   1 /**
   2  * Author: Humberto Naves (hsnaves@gmail.com)
   3  */
   4
   5 #include "code.h"
   6 #include "utils.h"
   7
   8 const uint32 regmask_localvars[NUM_REGMASK] = { 0x43FFFFFE, 0x00000000 };
   9
  10 static
  11 void mark_ssavar (struct ssavar *var, enum ssavartype type, int num)
  12 {
  13   element useel, phiel;
  14   struct value *val;
  15
  16   var->info = num;
  17   var->type = type;
  18   useel = list_head (var->uses);
  19   while (useel) {
  20     struct operation *use = element_getvalue (useel);
  21     if (use->type == OP_PHI) {
  22       phiel = list_head (use->operands);
  23       while (phiel) {
  24         struct value *val = element_getvalue (phiel);
  25         if (val->val.variable->type == SSAVAR_UNK) {
  26           mark_ssavar (val->val.variable, type, num);
  27         }
  28         phiel = element_next (phiel);
  29       }
  30       val = list_headvalue (use->results);
  31       if (val->val.variable->type == SSAVAR_UNK)
  32         mark_ssavar (val->val.variable, type, num);
  33     }
  34     useel = element_next (useel);
  35   }
  36
  37   if (var->def->type == OP_PHI) {
  38     phiel = list_head (var->def->operands);
  39     while (phiel) {
  40       struct value *val = element_getvalue (phiel);
  41       if (val->val.variable->type == SSAVAR_UNK) {
  42         mark_ssavar (val->val.variable, type, num);
  43       }
  44       phiel = element_next (phiel);
  45     }
  46   }
  47 }
  48
  49 void extract_variables (struct subroutine *sub)
  50 {
  51   element varel;
  52   int count = 0;
  53
  54   varel = list_head (sub->ssavars);
  55   while (varel) {
  56     struct ssavar *var = element_getvalue (varel);
  57     if (var->type == SSAVAR_UNK) {
  58       if (IS_BIT_SET (regmask_localvars, var->name.val.intval)) {
  59         if (var->def->type == OP_START) {
  60           mark_ssavar (var, SSAVAR_ARGUMENT, var->name.val.intval);
  61         } else if (var->def->type == OP_CALL && var->name.val.intval != REGISTER_GPR_V0 &&
  62                    var->name.val.intval != REGISTER_GPR_V1) {
  63           var->type = SSAVAR_INVALID;
  64         } else {
  65           int istemp = FALSE;
  66
  67           if (list_size (var->uses) <= 1) {
  68             struct operation *op = list_headvalue (var->uses);
  69             if (op) {
  70               if (op->type != OP_PHI)
  71                 istemp = TRUE;
  72             } else {
  73               istemp = TRUE;
  74             }
  75           }
  76
  77           if (var->def->type == OP_MOVE || var->def->type == OP_INSTRUCTION) {
  78             if (var->def->type == OP_INSTRUCTION) {
  79               if (var->def->info.iop.loc->insn->flags & (INSN_LOAD | INSN_STORE | INSN_BRANCH))
  80                 istemp = FALSE;
  81             }
  82           } else {
  83             istemp = FALSE;
  84           }
  85
  86           if (istemp) {
  87             var->def->status |= OP_STAT_DEFERRED;
  88             var->type = SSAVAR_TEMP;
  89             var->info = 0;
  90           } else {
  91             mark_ssavar (var, SSAVAR_LOCAL, ++count);
  92           }
  93         }
  94       } else {
  95         var->type = SSAVAR_ARGUMENT;
  96       }
  97     }
  98     varel = element_next (varel);
  99   }
 100 }