[Qemu-devel] [PATCH, RFC/FYI 0/4] TCG memory access helper changes

[Blue Swirl]

The "faster helper" in the last patch is not so impressive. GCC does
not want to inline the TCG specific helper but performs a tail call
from it to common helper. This results in useless shuffling of
registers and stack, also stack protector gets to kick in the second
time. I tried also to modify the common helper (pass a boolean flag to
select missed case first) but GCC still generated exactly the same
code.

Anyway, patches 1 to 3 could serve as a basis to optimize the
interface between TCG generated code and the memory access helpers
further. For example, coding the helpers in assembly would be
possible. The TLB indices etc. which have been calculated in generated
code could be reused in the access helper.

Blue Swirl (4):
  softmmu: move target alignment definition to configure stage
  softmmu: make unaligned access helper global
  softmmu: move TCG memory access helpers to TCG targets
  softmmu: add a faster helper for TCG

 configure                  |   11 +++++++
 exec-all.h                 |    9 ++++++
 exec.c                     |    6 ++++
 softmmu_template.h         |   73 +++++++++++++++++++++++++++++++++++---------
 target-alpha/mem_helper.c  |   19 ++----------
 target-mips/op_helper.c    |   18 ++++++++---
 target-sparc/cpu.h         |    3 --
 target-sparc/ldst_helper.c |   18 ++---------
 target-xtensa/op_helper.c  |   19 ++++++++----
 tcg/arm/tcg-target.c       |   33 ++++++++++++++------
 tcg/hppa/tcg-target.c      |   31 ++++++++++++++-----
 tcg/i386/tcg-target.c      |   31 ++++++++++++++-----
 tcg/ia64/tcg-target.c      |   31 ++++++++++++++-----
 tcg/mips/tcg-target.c      |   31 ++++++++++++++-----
 tcg/ppc/tcg-target.c       |   31 ++++++++++++++-----
 tcg/ppc64/tcg-target.c     |   31 ++++++++++++++-----
 tcg/s390/tcg-target.c      |   31 ++++++++++++++-----
 tcg/sparc/tcg-target.c     |   31 ++++++++++++++-----
 tci.c                      |   21 +++++++++++++
 19 files changed, 344 insertions(+), 134 deletions(-)

-- 
1.7.10