| Message ID | E1ooSWU-000FE4-9D@rmk-PC.armlinux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ARM: findbit assembly updates | expand |
diff --git a/arch/arm/lib/findbit.S b/arch/arm/lib/findbit.S index 4c584bc4704b..256e095d490b 100644 --- a/arch/arm/lib/findbit.S +++ b/arch/arm/lib/findbit.S @@ -170,7 +170,11 @@ ENDPROC(_find_next_bit_be) * One or more bits in the LSB of r3 are assumed to be set. */ .L_found: -#if __LINUX_ARM_ARCH__ >= 5 +#if __LINUX_ARM_ARCH__ >= 7 + rbit r3, r3 @ reverse bits + clz r3, r3 @ count high zero bits + add r0, r2, r3 @ add offset of first set bit +#elif __LINUX_ARM_ARCH__ >= 5 rsb r0, r3, #0 and r3, r3, r0 @ mask out lowest bit set clz r3, r3 @ count high zero bits
Provide a more efficient ARMv7 implementation to determine the first set bit in the supplied value. Signed-off-by: Russell King (Oracle) <rmk@armlinux.org.uk> --- arch/arm/lib/findbit.S | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)