gen-icount.h

   1 /* Helpers for instruction counting code generation.  */
   2
   3 static TCGArg *icount_arg;
   4 static int icount_label;
   5
   6 static inline void gen_icount_start(void)
   7 {
   8     TCGv_i32 count;
   9
  10     if (!use_icount)
  11         return;
  12
  13     icount_label = gen_new_label();
  14     /* FIXME: This generates lousy code.  We can't use tcg_new_temp because
  15        count needs to live over the conditional branch.  To workaround this
  16        we allow the target to supply a convenient register temporary.  */
  17 #ifndef ICOUNT_TEMP
  18     count = tcg_temp_local_new_i32();
  19 #else
  20     count = ICOUNT_TEMP;
  21 #endif
  22     tcg_gen_ld_i32(count, cpu_env, offsetof(CPUState, icount_decr.u32));
  23     /* This is a horrid hack to allow fixing up the value later.  */
  24     icount_arg = gen_opparam_ptr + 1;
  25     tcg_gen_subi_i32(count, count, 0xdeadbeef);
  26
  27     tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, icount_label);
  28     tcg_gen_st16_i32(count, cpu_env, offsetof(CPUState, icount_decr.u16.low));
  29 #ifndef ICOUNT_TEMP
  30     tcg_temp_free_i32(count);
  31 #endif
  32 }
  33
  34 static void gen_icount_end(TranslationBlock *tb, int num_insns)
  35 {
  36     if (use_icount) {
  37         *icount_arg = num_insns;
  38         gen_set_label(icount_label);
  39         tcg_gen_exit_tb((long)tb + 2);
  40     }
  41 }
  42
  43 static void inline gen_io_start(void)
  44 {
  45     TCGv_i32 tmp = tcg_const_i32(1);
  46     tcg_gen_st_i32(tmp, cpu_env, offsetof(CPUState, can_do_io));
  47     tcg_temp_free_i32(tmp);
  48 }
  49
  50 static inline void gen_io_end(void)
  51 {
  52     TCGv_i32 tmp = tcg_const_i32(0);
  53     tcg_gen_st_i32(tmp, cpu_env, offsetof(CPUState, can_do_io));
  54     tcg_temp_free_i32(tmp);
  55 }
  56