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[v2,0/3] powerpc/64: memcmp() optimization

Message ID 1505950480-14830-1-git-send-email-wei.guo.simon@gmail.com (mailing list archive)
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Series powerpc/64: memcmp() optimization | expand

Message

Simon Guo Sept. 20, 2017, 11:34 p.m. UTC 
From: Simon Guo <wei.guo.simon@gmail.com>

There is some room to optimize memcmp() in powerpc 64 bits version for
following 2 cases:
(1) Even src/dst addresses are not aligned with 8 bytes at the beginning,
memcmp() can align them and go with .Llong comparision mode without
fallback to .Lshort comparision mode do compare buffer byte by byte.
(2) VMX instructions can be used to speed up for large size comparision.

This patch set also updates memcmp selftest case to make it compiled and
incorporate large size comparison case.

v1 -> v2:
- update 8bytes unaligned bytes comparison method.
- fix a VMX comparision bug.
- enhanced the original memcmp() selftest.
- add powerpc/64 to subject/commit message.

Simon Guo (3):
  powerpc/64: Align bytes before fall back to .Lshort in powerpc64
    memcmp().
  powerpc/64: enhance memcmp() with VMX instruction for long bytes
    comparision
  powerpc:selftest update memcmp_64 selftest for VMX implementation

 arch/powerpc/include/asm/asm-prototypes.h          |   2 +-
 arch/powerpc/lib/copypage_power7.S                 |   2 +-
 arch/powerpc/lib/memcmp_64.S                       | 181 ++++++++++++++++++++-
 arch/powerpc/lib/memcpy_power7.S                   |   2 +-
 arch/powerpc/lib/vmx-helper.c                      |   2 +-
 .../selftests/powerpc/copyloops/asm/ppc_asm.h      |   2 +-
 .../selftests/powerpc/stringloops/asm/ppc_asm.h    |  31 ++++
 .../testing/selftests/powerpc/stringloops/memcmp.c |  63 ++++---
 8 files changed, 254 insertions(+), 31 deletions(-)