Peter Maydell <peter.mayd...@linaro.org> writes: > On 13 July 2017 at 15:19, Alex Bennée <alex.ben...@linaro.org> wrote: >> While an ISB will ensure any raised IRQs happen on the next >> instruction it doesn't cause any to get raised by itself. We can >> therefor use a simple tb exit for ISB instructions and rely on the >> exit_request check at the top of each TB to deal with exiting if >> needed. >> >> Signed-off-by: Alex Bennée <alex.ben...@linaro.org> >> Reviewed-by: Richard Henderson <r...@twiddle.net> >> --- >> target/arm/translate-a64.c | 2 +- >> target/arm/translate.c | 4 ++-- >> 2 files changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c >> index 66139b6046..2ac565eb10 100644 >> --- a/target/arm/translate-a64.c >> +++ b/target/arm/translate-a64.c >> @@ -1393,7 +1393,7 @@ static void handle_sync(DisasContext *s, uint32_t insn, >> * a self-modified code correctly and also to take >> * any pending interrupts immediately. >> */ >> - s->is_jmp = DISAS_UPDATE; >> + gen_goto_tb(s, 0, s->pc); >> return; >> default: >> unallocated_encoding(s); >> diff --git a/target/arm/translate.c b/target/arm/translate.c >> index 493a7b424a..d8892d9ba5 100644 >> --- a/target/arm/translate.c >> +++ b/target/arm/translate.c >> @@ -8168,7 +8168,7 @@ static void disas_arm_insn(DisasContext *s, unsigned >> int insn) >> * self-modifying code correctly and also to take >> * any pending interrupts immediately. >> */ >> - gen_lookup_tb(s); >> + gen_goto_tb(s, 0, s->pc & ~1); >> return; >> default: >> goto illegal_op; >> @@ -10561,7 +10561,7 @@ static int disas_thumb2_insn(CPUARMState *env, >> DisasContext *s, uint16_t insn_hw >> * and also to take any pending interrupts >> * immediately. >> */ >> - gen_lookup_tb(s); >> + gen_goto_tb(s, 0, s->pc & ~1); >> break; >> default: >> goto illegal_op; > > Why do we need to clear the low bit of s->pc for ISB? > s->pc is the actual PC, not the "PC and low bit indicates > Thumb mode" form that jump addresses have.
It's what gen_lookup_tb does to it's PC before the calculated jump. If it can never happen I can get rid of it. -- Alex Bennée
