 dcb8e75870
			
		
	
	
		dcb8e75870
		
	
	
	
	
		
			
			Instead of using -1 as end of chain, use 0, and link through the 0 entry as a fully circular double-linked list. Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Signed-off-by: Richard Henderson <rth@twiddle.net>
		
			
				
	
	
		
			80 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			80 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef GEN_ICOUNT_H
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| #define GEN_ICOUNT_H
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| 
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| #include "qemu/timer.h"
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| 
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| /* Helpers for instruction counting code generation.  */
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| 
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| static int icount_start_insn_idx;
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| static TCGLabel *icount_label;
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| static TCGLabel *exitreq_label;
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| 
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| static inline void gen_tb_start(TranslationBlock *tb)
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| {
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|     TCGv_i32 count, flag, imm;
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| 
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|     exitreq_label = gen_new_label();
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|     flag = tcg_temp_new_i32();
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|     tcg_gen_ld_i32(flag, cpu_env,
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|                    offsetof(CPUState, tcg_exit_req) - ENV_OFFSET);
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|     tcg_gen_brcondi_i32(TCG_COND_NE, flag, 0, exitreq_label);
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|     tcg_temp_free_i32(flag);
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| 
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|     if (!(tb->cflags & CF_USE_ICOUNT)) {
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|         return;
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|     }
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| 
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|     icount_label = gen_new_label();
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|     count = tcg_temp_local_new_i32();
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|     tcg_gen_ld_i32(count, cpu_env,
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|                    -ENV_OFFSET + offsetof(CPUState, icount_decr.u32));
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| 
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|     imm = tcg_temp_new_i32();
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|     /* We emit a movi with a dummy immediate argument. Keep the insn index
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|      * of the movi so that we later (when we know the actual insn count)
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|      * can update the immediate argument with the actual insn count.  */
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|     icount_start_insn_idx = tcg_op_buf_count();
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|     tcg_gen_movi_i32(imm, 0xdeadbeef);
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| 
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|     tcg_gen_sub_i32(count, count, imm);
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|     tcg_temp_free_i32(imm);
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| 
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|     tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, icount_label);
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|     tcg_gen_st16_i32(count, cpu_env,
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|                      -ENV_OFFSET + offsetof(CPUState, icount_decr.u16.low));
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|     tcg_temp_free_i32(count);
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| }
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| 
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| static void gen_tb_end(TranslationBlock *tb, int num_insns)
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| {
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|     gen_set_label(exitreq_label);
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|     tcg_gen_exit_tb((uintptr_t)tb + TB_EXIT_REQUESTED);
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| 
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|     if (tb->cflags & CF_USE_ICOUNT) {
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|         /* Update the num_insn immediate parameter now that we know
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|          * the actual insn count.  */
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|         tcg_set_insn_param(icount_start_insn_idx, 1, num_insns);
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|         gen_set_label(icount_label);
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|         tcg_gen_exit_tb((uintptr_t)tb + TB_EXIT_ICOUNT_EXPIRED);
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|     }
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| 
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|     /* Terminate the linked list.  */
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|     tcg_ctx.gen_op_buf[tcg_ctx.gen_op_buf[0].prev].next = 0;
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| }
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| 
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| static inline void gen_io_start(void)
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| {
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|     TCGv_i32 tmp = tcg_const_i32(1);
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|     tcg_gen_st_i32(tmp, cpu_env, -ENV_OFFSET + offsetof(CPUState, can_do_io));
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|     tcg_temp_free_i32(tmp);
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| }
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| 
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| static inline void gen_io_end(void)
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| {
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|     TCGv_i32 tmp = tcg_const_i32(0);
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|     tcg_gen_st_i32(tmp, cpu_env, -ENV_OFFSET + offsetof(CPUState, can_do_io));
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|     tcg_temp_free_i32(tmp);
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| }
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| 
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| #endif
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