v3 for context: https://lists.gnu.org/archive/html/qemu-devel/2017-04/msg04795.html
Changes from v3: - Added reviewed-by tags. - Added a couple of suggested-by tags that I forgot to add in v3 regarding lookup_and_goto_ptr and i386's implementation of goto_ptr. - lookup_tb_ptr + Dropped the unnecessary exit_request check, as suggested by Paolo and Richard. + Only get the CPU state if we get a tb from the jmp_cache, as suggested by Richard. + Added tb_htable_lookup if we miss in tb_jmp_cache, as suggested by Richard. This requires an extra patch to export tb_htable_lookup. - goto_ptr: add IMPL(has_goto_ptr), as pointed out by Richard. - target/arm: added a comment about gen_jr. See the v3 thread for why it is needed. - target/i386: use TCGV_UNUSED instead of (ab)using NULL on a TCGv, as suggested by Richard. Also took his suggestion to simplify the addition of jr + cs_base. To minimize churn I renamed gen_eob_worker to do_gen_eob_worker, which takes the newly added argument. I have *not* re-run all experiments, because it takes several hours and performance hasn't changed much from v3, as can be seen in these two charts: * spec06int user-mode, test input, v2.9.0 baseline: http://imgur.com/ME2eMq1 * spec06int softmmu, test input, v3 baseline: http://imgur.com/Clolu9Z The perf differences are mostly due to adding the htable check. Note that its impact is small, since tb_jmp_cache has a %hit rate in the high 90's. You can inspect/fetch the changes at: https://github.com/cota/qemu/tree/tcg-opt-v4 Thanks, Emilio