[PATCH v6 2/5] lib: implement __arch_bitrev8x4()
From: Joshua Clayton <hidden>
Date: 2016-12-16 23:18:52
Also in:
linux-arm-kernel, lkml
Subsystem:
arm port, arm64 port (aarch64 architecture), bitops api, mips, the rest · Maintainers:
Russell King, Catalin Marinas, Will Deacon, Yury Norov, Thomas Bogendoerfer, Linus Torvalds
Implement faster bitrev8x4() for arm, arm64 and mips, all the platforms with CONFIG_HAVE_ARCH_BITREVERSE. ARM platforms just need a byteswap added to the existing __arch_bitrev32() Amusingly, the mips implementation is exactly the opposite, requiring removal of the byteswap from its __arch_bitrev32() Signed-off-by: Joshua Clayton <redacted> --- arch/arm/include/asm/bitrev.h | 6 ++++++ arch/arm64/include/asm/bitrev.h | 6 ++++++ arch/mips/include/asm/bitrev.h | 6 ++++++ include/linux/bitrev.h | 1 + 4 files changed, 19 insertions(+)
diff --git a/arch/arm/include/asm/bitrev.h b/arch/arm/include/asm/bitrev.h
index ec291c3..9482f78 100644
--- a/arch/arm/include/asm/bitrev.h
+++ b/arch/arm/include/asm/bitrev.h@@ -17,4 +17,10 @@ static __always_inline __attribute_const__ u8 __arch_bitrev8(u8 x) return __arch_bitrev32((u32)x) >> 24; } +static __always_inline __attribute_const__ u32 __arch_bitrev8x4(u32 x) +{ + __asm__ ("rbit %0, %1; rev %0, %0" : "=r" (x) : "r" (x)); + return x; +} + #endif
diff --git a/arch/arm64/include/asm/bitrev.h b/arch/arm64/include/asm/bitrev.h
index a5a0c36..1801078 100644
--- a/arch/arm64/include/asm/bitrev.h
+++ b/arch/arm64/include/asm/bitrev.h@@ -16,4 +16,10 @@ static __always_inline __attribute_const__ u8 __arch_bitrev8(u8 x) return __arch_bitrev32((u32)x) >> 24; } +static __always_inline __attribute_const__ u32 __arch_bitrev8x4(u32 x) +{ + __asm__ ("rbit %0, %1; rev %0, %0" : "=r" (x) : "r" (x)); + return x; +} + #endif
diff --git a/arch/mips/include/asm/bitrev.h b/arch/mips/include/asm/bitrev.h
index bc739a4..9ac6439 100644
--- a/arch/mips/include/asm/bitrev.h
+++ b/arch/mips/include/asm/bitrev.h@@ -27,4 +27,10 @@ static __always_inline __attribute_const__ u8 __arch_bitrev8(u8 x) return ret; } +static __always_inline __attribute_const__ u32 __arch_bitrev8x4(u32 x) +{ + u32 ret; + asm("bitswap %0, %1" : "=r"(ret) : "r"(x)); + return ret; +} #endif /* __MIPS_ASM_BITREV_H__ */
diff --git a/include/linux/bitrev.h b/include/linux/bitrev.h
index 868dcb6..b1cfa1a 100644
--- a/include/linux/bitrev.h
+++ b/include/linux/bitrev.h@@ -9,6 +9,7 @@ #define __bitrev32 __arch_bitrev32 #define __bitrev16 __arch_bitrev16 #define __bitrev8 __arch_bitrev8 +#define __bitrev8x4 __arch_bitrev8x4 #else extern u8 const byte_rev_table[256];
--
2.9.3
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html