LXR qemu/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
   8static TCGOp *icount_start_insn;
   9
  10static 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
  46static 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(tb, TB_EXIT_REQUESTED);
  56}
  57
  58static 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
  65static 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
  73