tree 2a20f707e1c7711f773e05746e5d8342bc576137
parent 2cfcf8a8313bd9bdb54d62ca4ea581f130869aca
author Maciej W. Rozycki <macro@linux-mips.org> 1428099900 +0100
committer Ralf Baechle <ralf@linux-mips.org> 1428448152 +0200

MIPS: bitops.h: Avoid inline asm for constant FLS

GCC is smart enough to substitute the final result for FLS calculations
as implemented in the fallback C code we have in `__fls' and `fls'
applied to constant values.  The presence of inline asm defeats the
compiler though, forcing it to emit extraneous CLZ/DCLZ calculation for
processors that support these instructions.

Use `__builtin_constant_p' then to avoid inline asm altogether for
constants.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9681/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>