From cc9c1ed14e876d724107fe72f74dcac71a003fbc Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 19 Aug 2014 18:56:26 +0100 Subject: [PATCH] target-arm: A64: Avoid duplicate exit_tb(0) in non-linked goto_tb If gen_goto_tb() decides not to link the two TBs, then the fallback path generates unnecessary code: * if singlestep is enabled then we generate unreachable code after the gen_exception_internal(EXCP_DEBUG) * if singlestep is disabled then we will generate exit_tb(0) twice, once in gen_goto_tb() and once coming out of the main loop with is_jmp set to DISAS_JUMP Correct these deficiencies by only emitting exit_tb() in the non-singlestep case, in which case we can use DISAS_TB_JUMP to suppress the main-loop exit_tb(). Signed-off-by: Peter Maydell Reviewed-by: Edgar E. Iglesias --- target-arm/translate-a64.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index 2e21948..21a997f 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -234,9 +234,10 @@ static inline void gen_goto_tb(DisasContext *s, int n, uint64_t dest) gen_a64_set_pc_im(dest); if (s->singlestep_enabled) { gen_exception_internal(EXCP_DEBUG); + } else { + tcg_gen_exit_tb(0); + s->is_jmp = DISAS_TB_JUMP; } - tcg_gen_exit_tb(0); - s->is_jmp = DISAS_JUMP; } } -- 2.7.4