include/exec/gen-icount.h

   1 #ifndef GEN_ICOUNT_H
   2 #define GEN_ICOUNT_H
   3
   4 #include "qemu/timer.h"
   5
   6 /* Helpers for instruction counting code generation.  */
   7
   8 static TCGOp *icount_start_insn;
   9
  10 static inline void gen_tb_start(TranslationBlock *tb)
  11 {
  12     TCGv_i32 count, imm;
  13
  14     tcg_ctx->exitreq_label = gen_new_label();
  15     if (tb_cflags(tb) & CF_USE_ICOUNT) {
  16         count = tcg_temp_local_new_i32();
  17     } else {
  18         count = tcg_temp_new_i32();
  19     }
  20
  21     tcg_gen_ld_i32(count, cpu_env,
  22                    -ENV_OFFSET + offsetof(CPUState, icount_decr.u32));
  23
  24     if (tb_cflags(tb) & CF_USE_ICOUNT) {
  25         imm = tcg_temp_new_i32();
  26         /* We emit a movi with a dummy immediate argument. Keep the insn index
  27          * of the movi so that we later (when we know the actual insn count)
  28          * can update the immediate argument with the actual insn count.  */
  29         tcg_gen_movi_i32(imm, 0xdeadbeef);
  30         icount_start_insn = tcg_last_op();
  31
  32         tcg_gen_sub_i32(count, count, imm);
  33         tcg_temp_free_i32(imm);
  34     }
  35
  36     tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, tcg_ctx->exitreq_label);
  37
  38     if (tb_cflags(tb) & CF_USE_ICOUNT) {
  39         tcg_gen_st16_i32(count, cpu_env,
  40                          -ENV_OFFSET + offsetof(CPUState, icount_decr.u16.low));
  41     }
  42
  43     tcg_temp_free_i32(count);
  44 }
  45
  46 static inline void gen_tb_end(TranslationBlock *tb, int num_insns)
  47 {
  48     if (tb_cflags(tb) & CF_USE_ICOUNT) {
  49         /* Update the num_insn immediate parameter now that we know
  50          * the actual insn count.  */
  51         tcg_set_insn_param(icount_start_insn, 1, num_insns);
  52     }
  53
  54     gen_set_label(tcg_ctx->exitreq_label);
  55     tcg_gen_exit_tb((uintptr_t)tb + TB_EXIT_REQUESTED);
  56 }
  57
  58 static inline void gen_io_start(void)
  59 {
  60     TCGv_i32 tmp = tcg_const_i32(1);
  61     tcg_gen_st_i32(tmp, cpu_env, -ENV_OFFSET + offsetof(CPUState, can_do_io));
  62     tcg_temp_free_i32(tmp);
  63 }
  64
  65 static inline void gen_io_end(void)
  66 {
  67     TCGv_i32 tmp = tcg_const_i32(0);
  68     tcg_gen_st_i32(tmp, cpu_env, -ENV_OFFSET + offsetof(CPUState, can_do_io));
  69     tcg_temp_free_i32(tmp);
  70 }
  71
  72 #endif