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Groups > linux.kernel > #1740961

[PATCH v2 0/2] sparc64: Optimize fls, fls64 and __fls

From Vijay Kumar <vijay.ac.kumar@oracle.com>
Newsgroups linux.kernel
Subject [PATCH v2 0/2] sparc64: Optimize fls, fls64 and __fls
Date 2017-09-27 21:30 +0200
Message-ID <uuqbU-7c0-7@gated-at.bofh.it> (permalink)
Organization linux.* mail to news gateway

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SPARC provides lzcnt instruction (with VIS3) which can be used to
optimize fls, fls64 and __fls functions. For the systems that supports 
lzcnt instruction, we now do boot time patching to use sparc
optimized fls, fls64 and __fls functions.

v1->v2: 
 - Fixed delay slot issue pointed by Rob Gardner in patch 2/2.

Vijay Kumar (2):
  sparc64: Define SPARC default fls and __fls
  sparc64: Use lzcnt instruction for fls and __fls

 arch/sparc/Makefile                |    1 +
 arch/sparc/include/asm/bitops_64.h |    7 +-
 arch/sparc/kernel/head_64.S        |    2 +
 arch/sparc/lib/Makefile            |    4 +
 arch/sparc/lib/NG4fls.S            |   31 +++++++++
 arch/sparc/lib/NG4patch.S          |    9 +++
 arch/sparc/lib/fls.S               |  126 ++++++++++++++++++++++++++++++++++++
 7 files changed, 177 insertions(+), 3 deletions(-)
 create mode 100644 arch/sparc/lib/NG4fls.S
 create mode 100644 arch/sparc/lib/fls.S

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[PATCH v2 0/2] sparc64: Optimize fls, fls64 and __fls Vijay Kumar <vijay.ac.kumar@oracle.com> - 2017-09-27 21:30 +0200

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