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
