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, 0x00000003 };
   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     struct operation *op = var->def;
  58
  59     if (var->type == SSAVAR_UNK) {
  60       if (IS_BIT_SET (regmask_localvars, var->name.val.intval)) {
  61         if (op->type == OP_START) {
  62           mark_ssavar (var, SSAVAR_ARGUMENT, var->name.val.intval);
  63         } else if (op->type == OP_CALL && var->name.val.intval != REGISTER_GPR_V0 &&
  64                    var->name.val.intval != REGISTER_GPR_V1) {
  65           mark_ssavar (var, SSAVAR_INVALID, 0);
  66         } else {
  67
  68           if (op->type == OP_MOVE || op->type == OP_INSTRUCTION) {
  69             if (!(var->status & (VAR_STAT_PHIARG | VAR_STAT_ASMARG))) {
  70               if (list_size (var->uses) <= 1) {
  71                 op->status |= OP_STAT_DEFERRED;
  72               }
  73             }
  74
  75             if (op->type == OP_INSTRUCTION) {
  76               if (op->info.iop.loc->insn->flags & (INSN_LOAD | INSN_STORE))
  77                 op->status &= ~OP_STAT_DEFERRED;
  78               else if ((op->info.iop.loc->insn->flags & (INSN_BRANCH)) &&
  79                        !op->info.iop.loc->branchalways)
  80                 op->status &= ~OP_STAT_DEFERRED;
  81             }
  82           }
  83
  84           if (op->status & OP_STAT_DEFERRED) {
  85             var->type = SSAVAR_TEMP;
  86             var->info = 0;
  87           } else {
  88             mark_ssavar (var, SSAVAR_LOCAL, ++count);
  89           }
  90         }
  91       } else {
  92         mark_ssavar (var, SSAVAR_ARGUMENT, var->name.val.intval);
  93       }
  94     }
  95     varel = element_next (varel);
  96   }
  97 }