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From: Vijay Kumar <vijay.ac.kumar@oracle.com>
To: davem@davemloft.net
Cc: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org,
	babu.moger@oracle.com, rob.gardner@oracle.com
Subject: [PATCH v2 0/2] sparc64: Optimize fls, fls64 and __fls
Date: Wed, 27 Sep 2017 13:25:24 -0600	[thread overview]
Message-ID: <1506540326-9604-1-git-send-email-vijay.ac.kumar@oracle.com> (raw)

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

             reply	other threads:[~2017-09-27 19:25 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-27 19:25 Vijay Kumar [this message]
2017-09-27 19:25 ` [PATCH v2 1/2] sparc64: Define SPARC default fls " Vijay Kumar
2017-09-27 19:50   ` Sam Ravnborg
2017-09-27 19:59     ` Sam Ravnborg
2017-09-27 19:25 ` [PATCH v2 2/2] sparc64: Use lzcnt instruction for " Vijay Kumar
2017-09-27 19:56   ` Sam Ravnborg
2017-09-27 20:29     ` Vijay Kumar
2017-09-27 21:02     ` David Miller
2017-09-27 21:45     ` Anthony Yznaga
2017-09-27 22:10       ` David Miller

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