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_io_start(void) |
11 | { |
12 | TCGv_i32 tmp = tcg_const_i32(1); |
13 | tcg_gen_st_i32(tmp, cpu_env, |
14 | offsetof(ArchCPU, parent_obj.can_do_io) - |
15 | offsetof(ArchCPU, env)); |
16 | tcg_temp_free_i32(tmp); |
17 | } |
18 | |
19 | /* |
20 | * cpu->can_do_io is cleared automatically at the beginning of |
21 | * each translation block. The cost is minimal and only paid |
22 | * for -icount, plus it would be very easy to forget doing it |
23 | * in the translator. Therefore, backends only need to call |
24 | * gen_io_start. |
25 | */ |
26 | static inline void gen_io_end(void) |
27 | { |
28 | TCGv_i32 tmp = tcg_const_i32(0); |
29 | tcg_gen_st_i32(tmp, cpu_env, |
30 | offsetof(ArchCPU, parent_obj.can_do_io) - |
31 | offsetof(ArchCPU, env)); |
32 | tcg_temp_free_i32(tmp); |
33 | } |
34 | |
35 | static inline void gen_tb_start(TranslationBlock *tb) |
36 | { |
37 | TCGv_i32 count, imm; |
38 | |
39 | tcg_ctx->exitreq_label = gen_new_label(); |
40 | if (tb_cflags(tb) & CF_USE_ICOUNT) { |
41 | count = tcg_temp_local_new_i32(); |
42 | } else { |
43 | count = tcg_temp_new_i32(); |
44 | } |
45 | |
46 | tcg_gen_ld_i32(count, cpu_env, |
47 | offsetof(ArchCPU, neg.icount_decr.u32) - |
48 | offsetof(ArchCPU, env)); |
49 | |
50 | if (tb_cflags(tb) & CF_USE_ICOUNT) { |
51 | imm = tcg_temp_new_i32(); |
52 | /* We emit a movi with a dummy immediate argument. Keep the insn index |
53 | * of the movi so that we later (when we know the actual insn count) |
54 | * can update the immediate argument with the actual insn count. */ |
55 | tcg_gen_movi_i32(imm, 0xdeadbeef); |
56 | icount_start_insn = tcg_last_op(); |
57 | |
58 | tcg_gen_sub_i32(count, count, imm); |
59 | tcg_temp_free_i32(imm); |
60 | } |
61 | |
62 | tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, tcg_ctx->exitreq_label); |
63 | |
64 | if (tb_cflags(tb) & CF_USE_ICOUNT) { |
65 | tcg_gen_st16_i32(count, cpu_env, |
66 | offsetof(ArchCPU, neg.icount_decr.u16.low) - |
67 | offsetof(ArchCPU, env)); |
68 | gen_io_end(); |
69 | } |
70 | |
71 | tcg_temp_free_i32(count); |
72 | } |
73 | |
74 | static inline void gen_tb_end(TranslationBlock *tb, int num_insns) |
75 | { |
76 | if (tb_cflags(tb) & CF_USE_ICOUNT) { |
77 | /* Update the num_insn immediate parameter now that we know |
78 | * the actual insn count. */ |
79 | tcg_set_insn_param(icount_start_insn, 1, num_insns); |
80 | } |
81 | |
82 | gen_set_label(tcg_ctx->exitreq_label); |
83 | tcg_gen_exit_tb(tb, TB_EXIT_REQUESTED); |
84 | } |
85 | |
86 | #endif |
87 | |