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[Qemu-arm] [PATCH v4 00/11] TCG optimizations for 2.10
From: |
Emilio G. Cota |
Subject: |
[Qemu-arm] [PATCH v4 00/11] TCG optimizations for 2.10 |
Date: |
Wed, 26 Apr 2017 23:29:13 -0400 |
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
- [Qemu-arm] [PATCH v4 00/11] TCG optimizations for 2.10,
Emilio G. Cota <=
- [Qemu-arm] [PATCH v4 06/11] target/arm: optimize cross-page direct jumps in softmmu, Emilio G. Cota, 2017/04/26
- [Qemu-arm] [PATCH v4 08/11] target/i386: introduce gen_jr helper to generate lookup_and_goto_ptr, Emilio G. Cota, 2017/04/26
- [Qemu-arm] [PATCH v4 01/11] exec-all: export tb_htable_lookup, Emilio G. Cota, 2017/04/26
- [Qemu-arm] [PATCH v4 11/11] tb-hash: improve tb_jmp_cache hash function in user mode, Emilio G. Cota, 2017/04/26
- [Qemu-arm] [PATCH v4 09/11] target/i386: optimize cross-page direct jumps in softmmu, Emilio G. Cota, 2017/04/26
- [Qemu-arm] [PATCH v4 04/11] tcg: export tcg_gen_lookup_and_goto_ptr, Emilio G. Cota, 2017/04/26
- [Qemu-arm] [PATCH v4 02/11] tcg-runtime: add lookup_tb_ptr helper, Emilio G. Cota, 2017/04/26
- [Qemu-arm] [PATCH v4 03/11] tcg: introduce goto_ptr opcode, Emilio G. Cota, 2017/04/26