u-boot/include/asm-generic/bitops
Sean Anderson 726a802fda arm: Use builtins for ffs/fls
Since ARMv5, the clz instruction allows for efficient implementation of
ffs/fls with builtins. Until ARMv7 (with Thumb-2), this instruction is
only available in ARM mode. LTO makes it difficult to force specific
functions to be in ARM mode, as it is effectively a form of very
aggressive inlining. To work around this, fls/ffs are implemented in
assembly for ARMv5 and ARMv6 when compiling U-Boot in Thumb mode.
Overall, this saves around 75 bytes per call.

This code is synced with v5.15 of the Linux kernel.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
2023-08-17 16:39:20 -04:00
..
__ffs.h include: Add generic bitops headers 2015-11-05 10:51:57 -05:00
__fls.h include: Add generic bitops headers 2015-11-05 10:51:57 -05:00
builtin-__ffs.h arm: Use builtins for ffs/fls 2023-08-17 16:39:20 -04:00
builtin-__fls.h arm: Use builtins for ffs/fls 2023-08-17 16:39:20 -04:00
builtin-ffs.h arm: Use builtins for ffs/fls 2023-08-17 16:39:20 -04:00
builtin-fls.h arm: Use builtins for ffs/fls 2023-08-17 16:39:20 -04:00
fls.h include: Add generic bitops headers 2015-11-05 10:51:57 -05:00
fls64.h include: Add generic bitops headers 2015-11-05 10:51:57 -05:00