#ifndef GEN_ICOUNT_H #define GEN_ICOUNT_H #include "exec/exec-all.h" /* Helpers for instruction counting code generation. */ static TCGOp *icount_start_insn; static inline void gen_io_start(void) { TCGv_i32 tmp = tcg_const_i32(1); tcg_gen_st_i32(tmp, cpu_env, offsetof(ArchCPU, parent_obj.can_do_io) - offsetof(ArchCPU, env)); tcg_temp_free_i32(tmp); } static inline void gen_tb_start(const TranslationBlock *tb) { TCGv_i32 count; if (tb_cflags(tb) & CF_USE_ICOUNT) { count = tcg_temp_local_new_i32(); } else { count = tcg_temp_new_i32(); } tcg_gen_ld_i32(count, cpu_env, offsetof(ArchCPU, neg.icount_decr.u32) - offsetof(ArchCPU, env)); if (tb_cflags(tb) & CF_USE_ICOUNT) { /* * We emit a sub with a dummy immediate argument. Keep the insn index * of the sub so that we later (when we know the actual insn count) * can update the argument with the actual insn count. */ tcg_gen_sub_i32(count, count, tcg_constant_i32(0)); icount_start_insn = tcg_last_op(); } /* * Emit the check against icount_decr.u32 to see if we should exit * unless we suppress the check with CF_NOIRQ. If we are using * icount and have suppressed interruption the higher level code * should have ensured we don't run more instructions than the * budget. */ if (tb_cflags(tb) & CF_NOIRQ) { tcg_ctx->exitreq_label = NULL; } else { tcg_ctx->exitreq_label = gen_new_label(); tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, tcg_ctx->exitreq_label); } if (tb_cflags(tb) & CF_USE_ICOUNT) { tcg_gen_st16_i32(count, cpu_env, offsetof(ArchCPU, neg.icount_decr.u16.low) - offsetof(ArchCPU, env)); /* * cpu->can_do_io is cleared automatically here at the beginning of * each translation block. The cost is minimal and only paid for * -icount, plus it would be very easy to forget doing it in the * translator. Doing it here means we don't need a gen_io_end() to * go with gen_io_start(). */ tcg_gen_st_i32(tcg_constant_i32(0), cpu_env, offsetof(ArchCPU, parent_obj.can_do_io) - offsetof(ArchCPU, env)); } tcg_temp_free_i32(count); } static inline void gen_tb_end(const TranslationBlock *tb, int num_insns) { if (tb_cflags(tb) & CF_USE_ICOUNT) { /* * Update the num_insn immediate parameter now that we know * the actual insn count. */ tcg_set_insn_param(icount_start_insn, 2, tcgv_i32_arg(tcg_constant_i32(num_insns))); } if (tcg_ctx->exitreq_label) { gen_set_label(tcg_ctx->exitreq_label); tcg_gen_exit_tb(tb, TB_EXIT_REQUESTED); } } #endif