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