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 <stillcompiling@xxxxxxxxx>
---
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
--
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