31 Jul
2023
31 Jul
'23
11:42 p.m.
On 7/31/23 17:36, Tom Rini wrote:
On Mon, Jul 31, 2023 at 05:27:33PM -0400, Sean Anderson wrote:
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.
Signed-off-by: Sean Anderson sean.anderson@seco.com
This looks like it's synced from the kernel, what tag?
The builtins are synced from v5.15 and they haven't changed since.
--Sean