Re: [Qemu-devel] [PATCH v3 0/6] TCG global variables clean-up

[Blue Swirl]

On Mon, Oct 29, 2012 at 9:14 AM, Evgeny Voevodin <address@hidden> wrote:
> This set of patches moves global variables to tcg_ctx:
> gen_opc_ptr
> gen_opparam_ptr
> gen_opc_buf
> gen_opparam_buf

Patches don't apply, please rebase. Also checkpatch.pl complains about tabs.

>
> Build tested for all targets.
> Execution tested on Exynos4210 target.
>
> After this patchset was aplied, I noticed 0.7% speed-up of code generation.
> Probably, this is due to better data caching.
>
> Here is the test procedure:
> 1. Boot Linux Kernel 5 times.
> 2. For each iteration wait while "JIT cycles" is stable for ~10 seconds
> 3. Write down the "cycles/op"
>
> Here are the results (tested on gcc-4.6):
>
> Before clean-up:
> min: 731.5
> max: 734.8
> avg: 733.0
> standard deviation: ~2 ~= 0.2%
>
> Average cycles/op = 733 +- 2
>
>
>
> After clean-up:
> min: 725.0
> max: 730.5
> avg: 727.8
> standard deviation: ~3 ~= 0.4%
>
> Average cycles/op = 728 +- 3
> Speed-up of TCG code generation = 0.7%
>
> Changelog:
> v2->v3:
> Removed tcg_cur_ctx since it gives slow-down on gcc-4.5.
> Rebased.
> v1->v2:
> Introduced TCGContext *tcg_cur_ctx global to use in those places where we 
> don't
> have an interface to pass pointer to tcg_ctx.
> Code style clean-up
>
> Evgeny (2):
>   tcg/tcg.h: Duplicate global TCG variables in TCGContext
>   TCG: Remove unused global variables
>
> Evgeny Voevodin (4):
>   TCG: Use gen_opc_ptr from context instead of global variable.
>   TCG: Use gen_opparam_ptr from context instead of global variable.
>   TCG: Use gen_opc_buf from context instead of global variable.
>   TCG: Use gen_opparam_buf from context instead of global variable.
>
>  gen-icount.h                  |    2 +-
>  target-alpha/translate.c      |   10 +-
>  target-arm/translate.c        |   10 +-
>  target-cris/translate.c       |   13 +-
>  target-i386/translate.c       |   10 +-
>  target-lm32/translate.c       |   13 +-
>  target-m68k/translate.c       |   10 +-
>  target-microblaze/translate.c |   13 +-
>  target-mips/translate.c       |   11 +-
>  target-openrisc/translate.c   |   13 +-
>  target-ppc/translate.c        |   11 +-
>  target-s390x/translate.c      |   11 +-
>  target-sh4/translate.c        |   10 +-
>  target-sparc/translate.c      |   10 +-
>  target-unicore32/translate.c  |   10 +-
>  target-xtensa/translate.c     |    8 +-
>  tcg/optimize.c                |   62 ++++----
>  tcg/tcg-op.h                  |  324 
> ++++++++++++++++++++---------------------
>  tcg/tcg.c                     |   85 ++++++-----
>  tcg/tcg.h                     |   10 +-
>  translate-all.c               |    3 -
>  21 files changed, 326 insertions(+), 323 deletions(-)
>
> --
> 1.7.9.5
>