[PATCH 2/2] powerpc: Use CONFIG_ARCH_HAS_FAST_MULTIPLIER
From: Anton Blanchard <hidden>
Date: 2014-09-16 00:49:15
Also in:
lkml
I ran some tests to compare hash_64 using shifts and multiplies. The results: POWER6: ~2x slower POWER7: ~2x faster POWER8: ~2x faster Now we have a proper config option, select CONFIG_ARCH_HAS_FAST_MULTIPLIER on POWER7 and POWER8. Signed-off-by: Anton Blanchard <redacted> --- Index: b/arch/powerpc/platforms/Kconfig.cputype ===================================================================
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype@@ -116,10 +116,12 @@ config POWER6_CPU config POWER7_CPU bool "POWER7" depends on PPC_BOOK3S_64 + select ARCH_HAS_FAST_MULTIPLIER config POWER8_CPU bool "POWER8" depends on PPC_BOOK3S_64 + select ARCH_HAS_FAST_MULTIPLIER config E5500_CPU bool "Freescale e5500"