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 int icount_start_insn_idx;
   9 static TCGLabel *icount_label;
  10 static TCGLabel *exitreq_label;
  11
  12 static inline void gen_tb_start(TranslationBlock *tb)
  13 {
  14     TCGv_i32 count, flag, imm;
  15
  16     exitreq_label = gen_new_label();
  17     flag = tcg_temp_new_i32();
  18     tcg_gen_ld_i32(flag, cpu_env,
  19                    offsetof(CPUState, tcg_exit_req) - ENV_OFFSET);
  20     tcg_gen_brcondi_i32(TCG_COND_NE, flag, 0, exitreq_label);
  21     tcg_temp_free_i32(flag);
  22
  23     if (!(tb->cflags & CF_USE_ICOUNT)) {
  24         return;
  25     }
  26
  27     icount_label = gen_new_label();
  28     count = tcg_temp_local_new_i32();
  29     tcg_gen_ld_i32(count, cpu_env,
  30                    -ENV_OFFSET + offsetof(CPUState, icount_decr.u32));
  31
  32     imm = tcg_temp_new_i32();
  33     /* We emit a movi with a dummy immediate argument. Keep the insn index
  34      * of the movi so that we later (when we know the actual insn count)
  35      * can update the immediate argument with the actual insn count.  */
  36     icount_start_insn_idx = tcg_op_buf_count();
  37     tcg_gen_movi_i32(imm, 0xdeadbeef);
  38
  39     tcg_gen_sub_i32(count, count, imm);
  40     tcg_temp_free_i32(imm);
  41
  42     tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, icount_label);
  43     tcg_gen_st16_i32(count, cpu_env,
  44                      -ENV_OFFSET + offsetof(CPUState, icount_decr.u16.low));
  45     tcg_temp_free_i32(count);
  46 }
  47
  48 static void gen_tb_end(TranslationBlock *tb, int num_insns)
  49 {
  50     gen_set_label(exitreq_label);
  51     tcg_gen_exit_tb((uintptr_t)tb + TB_EXIT_REQUESTED);
  52
  53     if (tb->cflags & CF_USE_ICOUNT) {
  54         /* Update the num_insn immediate parameter now that we know
  55          * the actual insn count.  */
  56         tcg_set_insn_param(icount_start_insn_idx, 1, num_insns);
  57         gen_set_label(icount_label);
  58         tcg_gen_exit_tb((uintptr_t)tb + TB_EXIT_ICOUNT_EXPIRED);
  59     }
  60
  61     /* Terminate the linked list.  */
  62     tcg_ctx.gen_op_buf[tcg_ctx.gen_last_op_idx].next = -1;
  63 }
  64
  65 static inline void gen_io_start(void)
  66 {
  67     TCGv_i32 tmp = tcg_const_i32(1);
  68     tcg_gen_st_i32(tmp, cpu_env, -ENV_OFFSET + offsetof(CPUState, can_do_io));
  69     tcg_temp_free_i32(tmp);
  70 }
  71
  72 static inline void gen_io_end(void)
  73 {
  74     TCGv_i32 tmp = tcg_const_i32(0);
  75     tcg_gen_st_i32(tmp, cpu_env, -ENV_OFFSET + offsetof(CPUState, can_do_io));
  76     tcg_temp_free_i32(tmp);
  77 }
  78
  79 #endif