[PATCH 2/2] MIPS: enable GENERIC_FIND_FIRST_BIT

Yury Norov yury.norov at gmail.com
Thu Feb 25 08:57:00 EST 2021


From: Alexander Lobakin <alobakin at pm.me>

MIPS doesn't have architecture-optimized bitsearching functions,
like find_{first,next}_bit() etc.
It's absolutely harmless to enable GENERIC_FIND_FIRST_BIT as this
functionality is not new at all and well-tested. It provides more
optimized code and saves some .text memory (32 R2):

add/remove: 4/1 grow/shrink: 1/53 up/down: 216/-372 (-156)

Users of for_each_set_bit() like hotpath gic_handle_shared_int()
will also benefit from this.

Suggested-by: Yury Norov <yury.norov at gmail.com>
Signed-off-by: Alexander Lobakin <alobakin at pm.me>
Signed-off-by: Yury Norov <yury.norov at gmail.com>
---
 arch/mips/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index d89efba3d8a4..164bdd715d4b 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -26,6 +26,7 @@ config MIPS
 	select GENERIC_ATOMIC64 if !64BIT
 	select GENERIC_CMOS_UPDATE
 	select GENERIC_CPU_AUTOPROBE
+	select GENERIC_FIND_FIRST_BIT
 	select GENERIC_GETTIMEOFDAY
 	select GENERIC_IOMAP
 	select GENERIC_IRQ_PROBE
-- 
2.25.1




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