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crc32: add-pointer-to-tab.diff

PATCH In review Bob Pearson 1 participant 1 message Aug 11, 2011 Library code

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PATCH v5 1/8 crc32: add-pointer-to-tab.diff

replace 2D array references by pointer references in loops

Signed-off-by Bob Pearson <[email protected]>
---
 lib/crc32.c |   21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)
lib/crc32.c +11 -10
Index: infiniband/lib/crc32.c
===================================================================
@@ -51,20 +51,21 @@ static inline u32
 crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 (*tab)[256])
 {
 # ifdef __LITTLE_ENDIAN
-#  define DO_CRC(x) crc = tab[0][(crc ^ (x)) & 255] ^ (crc >> 8)
-#  define DO_CRC4 crc = tab[3][(crc) & 255] ^ \
-		tab[2][(crc >> 8) & 255] ^ \
-		tab[1][(crc >> 16) & 255] ^ \
-		tab[0][(crc >> 24) & 255]
+#  define DO_CRC(x) (crc = t0[(crc ^ (x)) & 255] ^ (crc >> 8))
+#  define DO_CRC4 crc = t3[(crc) & 255] ^ \
+			t2[(crc >> 8) & 255] ^ \
+			t1[(crc >> 16) & 255] ^ \
+			t0[(crc >> 24) & 255]
 # else
-#  define DO_CRC(x) crc = tab[0][((crc >> 24) ^ (x)) & 255] ^ (crc << 8)
-#  define DO_CRC4 crc = tab[0][(crc) & 255] ^ \
-		tab[1][(crc >> 8) & 255] ^ \
-		tab[2][(crc >> 16) & 255] ^ \
-		tab[3][(crc >> 24) & 255]
+#  define DO_CRC(x) (crc = t0[((crc >> 24) ^ (x)) & 255] ^ (crc << 8))
+#  define DO_CRC4 crc = t0[(crc) & 255] ^ \
+			t1[(crc >> 8) & 255] ^ \
+			t2[(crc >> 16) & 255] ^ \
+			t3[(crc >> 24) & 255]
 # endif
 	const u32 *b;
 	size_t    rem_len;
+	const u32 *t0 = tab[0], *t1 = tab[1], *t2 = tab[2], *t3 = tab[3];
 
 	/* Align it */
 	if (unlikely((long)buf & 3 && len)) {