[Qemu-devel] [PATCH v6 0/7] TCG global variables clean-up

[Evgeny Voevodin <e.voevodin@samsung.com>]

This set of patches moves global variables to tcg_ctx:
gen_opc_ptr
gen_opparam_ptr
gen_opc_buf
gen_opparam_buf

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:
v5->v6:
Fixed broken patches.
Rebased.
v4->v5:
Rebased.
Fixed authorship.
All patches are reviewed-by Richard Henderson <rth@twiddle.net>
v3->v4:
Rebased.
Added target-cris/translate.c: Code style clean-up
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 Voevodin (7):
  target-cris/translate.c: Code style clean-up
  tcg/tcg.h: Duplicate global TCG variables in TCGContext
  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.
  TCG: Remove unused global variables

 gen-icount.h                  |    2 +-
 target-alpha/translate.c      |   10 +-
 target-arm/translate.c        |   10 +-
 target-cris/translate.c       | 5040 +++++++++++++++++++++--------------------
 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, 2859 insertions(+), 2817 deletions(-)

-- 
1.7.9.5