[PATCH v2 2/3] word-at-a-time.h: support zero_bytemask() on alpha and tile

From: Chris Metcalf
Date: Tue Oct 06 2015 - 15:24:18 EST


Both alpha and tile needed implementations of zero_bytemask.

The alpha version is untested.

Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
---
arch/alpha/include/asm/word-at-a-time.h | 2 ++
arch/tile/include/asm/word-at-a-time.h | 8 +++++++-
2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/alpha/include/asm/word-at-a-time.h b/arch/alpha/include/asm/word-at-a-time.h
index 6b340d0f1521..902e6ab00a06 100644
--- a/arch/alpha/include/asm/word-at-a-time.h
+++ b/arch/alpha/include/asm/word-at-a-time.h
@@ -52,4 +52,6 @@ static inline unsigned long find_zero(unsigned long bits)
#endif
}

+#define zero_bytemask(mask) ((2ul << (find_zero(mask) * 8)) - 1)
+
#endif /* _ASM_WORD_AT_A_TIME_H */
diff --git a/arch/tile/include/asm/word-at-a-time.h b/arch/tile/include/asm/word-at-a-time.h
index 9e5ce0d7b292..b66a693c2c34 100644
--- a/arch/tile/include/asm/word-at-a-time.h
+++ b/arch/tile/include/asm/word-at-a-time.h
@@ -6,7 +6,7 @@
struct word_at_a_time { /* unused */ };
#define WORD_AT_A_TIME_CONSTANTS {}

-/* Generate 0x01 byte values for non-zero bytes using a SIMD instruction. */
+/* Generate 0x01 byte values for zero bytes using a SIMD instruction. */
static inline unsigned long has_zero(unsigned long val, unsigned long *data,
const struct word_at_a_time *c)
{
@@ -33,4 +33,10 @@ static inline long find_zero(unsigned long mask)
#endif
}

+#ifdef __BIG_ENDIAN
+#define zero_bytemask(mask) (~1ul << (63 - __builtin_clzl(mask)))
+#else
+#define zero_bytemask(mask) ((2ul << __builtin_ctzl(mask)) - 1)
+#endif
+
#endif /* _ASM_WORD_AT_A_TIME_H */
--
2.1.2

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