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[Qemu-devel] [PATCH 0/3] target-arm: cache tbflags in CPUARMState


From: Paolo Bonzini
Subject: [Qemu-devel] [PATCH 0/3] target-arm: cache tbflags in CPUARMState
Date: Wed, 14 Sep 2016 11:56:50 +0200

Computing TranslationBlock flags is pretty expensive on ARM, especially
32-bit.  Because tbflags are computed on every tb lookup, it is not
unlikely to see cpu_get_tb_cpu_state close to the top of the profile
now that QHT makes the hash table much more efficient.

However, most tbflags only change when the EL is switched or after
MSR instructions.  Based on this observation, this series caches these
tbflags in CPUARMState, resulting in a 10-15% speedup on 32-bit code.

Paolo

Paolo Bonzini (3):
  target-arm: introduce cpu_dynamic_tb_cpu_flags
  target-arm: add env->tbflags
  target-arm: cache most tbflags

 target-arm/cpu.c           |  2 ++
 target-arm/cpu.h           | 58 ++++++++++++++++++++++++++++++++--------------
 target-arm/helper.c        |  2 ++
 target-arm/helper.h        |  1 +
 target-arm/op_helper.c     |  7 ++++++
 target-arm/translate-a64.c |  4 ++++
 target-arm/translate.c     | 12 ++++++++--
 target-arm/translate.h     |  1 +
 8 files changed, 68 insertions(+), 19 deletions(-)

-- 
2.7.4




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