Performance hit in qemu-system-ppc

[Howard Spoelstra]

 Hi,

I noticed a considerable (~20%) slowdown in the cpu performance of
qemu-system-ppc.
Bisecting led me to this commit:

d03f140804b345a85973976506492027f703d82d is the first bad commit
commit d03f140804b345a85973976506492027f703d82d
Author: Richard Henderson <richard.hender...@linaro.org>
Date:   Mon Dec 9 13:49:58 2019 -0800

    cputlb: Move body of cpu_ldst_template.h out of line

    With the tracing hooks, the inline functions are no longer
    so simple.  Once out-of-line, the current tlb_entry lookup
    is redundant with the one in the main load/store_helper.

    This also begins the introduction of a new target facing
    interface, with suffix *_mmuidx_ra.  This is not yet
    official because the interface is not done for user-only.

    Use abi_ptr instead of target_ulong in preparation for
    user-only; the two types are identical for softmmu.

    What remains in cpu_ldst_template.h are the expansions
    for _code, _data, and MMU_MODE<N>_SUFFIX.

    Tested-by: Philippe Mathieu-Daudé <phi...@redhat.com>
    Signed-off-by: Richard Henderson <richard.hender...@linaro.org>

 accel/tcg/cputlb.c               | 116 ++++++++++++++++++++++++++++++++++++
 include/exec/cpu_ldst.h          |  25 +++++++-
 include/exec/cpu_ldst_template.h | 125
++++++++-------------------------------
 3 files changed, 166 insertions(+), 100 deletions(-)

Thanks for looking into this issue,
Howard