On Thu, 8 Jul 2021 at 17:04, Richard Henderson <richard.hender...@linaro.org> wrote: > > On 7/8/21 5:05 AM, Peter Maydell wrote: > > On Wed, 30 Jun 2021 at 19:47, Richard Henderson > > <richard.hender...@linaro.org> wrote: > >> > >> Using gen_goto_tb directly misses the single-step check. > >> > >> Cc: qemu-...@nongnu.org > >> Signed-off-by: Richard Henderson <richard.hender...@linaro.org> > >> --- > >> target/arm/translate.c | 4 ++-- > >> 1 file changed, 2 insertions(+), 2 deletions(-) > >> > >> diff --git a/target/arm/translate.c b/target/arm/translate.c > >> index a0c6cfa902..8cd31feeaa 100644 > >> --- a/target/arm/translate.c > >> +++ b/target/arm/translate.c > >> @@ -8582,7 +8582,7 @@ static bool trans_ISB(DisasContext *s, arg_ISB *a) > >> * self-modifying code correctly and also to take > >> * any pending interrupts immediately. > >> */ > >> - gen_goto_tb(s, 0, s->base.pc_next); > >> + gen_jmp(s, s->base.pc_next); > >> return true; > >> } > >> > >> @@ -8596,7 +8596,7 @@ static bool trans_SB(DisasContext *s, arg_SB *a) > >> * for TCG; MB and end the TB instead. > >> */ > >> tcg_gen_mb(TCG_MO_ALL | TCG_BAR_SC); > >> - gen_goto_tb(s, 0, s->base.pc_next); > >> + gen_jmp(s, s->base.pc_next); > >> return true; > > > > Why isn't it enough here just to set is_jmp to DISAS_NEXT ? > > You mean DISAS_TOO_MANY? That would work, yes. > At the time I was just thinking of replacing one jump with another.
You've implicitly answered my question, which is that the main translator loop code treats DISAS_NEXT as "keep adding insns to the TB" :-) It feels slightly like misuse to use DISAS_TOO_MANY, unless we renamed it to something like DISAS_END_TB (which is what it's actually doing). thanks -- PMM
