[PATCH v3 0/5] sparc64: Optimize fls and __fls
From: Vijay Kumar
Date: Fri Oct 06 2017 - 12:55:24 EST
SPARC provides lzcnt instruction (with VIS3) which can be used to
optimize fls, __fls and fls64 functions. For the systems that supports
lzcnt instruction, we now do boot time patching to use sparc
optimized fls, __fls and fls64 functions.
- Using ENTRY(), ENDPROC() for assembler functions.
- Removed BITS_PER_LONG from __fls.
- Using generic fls64().
- Replaced lzcnt instruction with .word directive.
- Fixed delay slot issue.
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