Implement a (poor?) 64-bit CRC.

ccan/crc/_info

 #include <string.h>
+#include <stdio.h>
 
 /**
  * crc - routines for crc of bytes
@@ -35,6 +36,7 @@ int main(int argc, char *argv[])
 		return 1;
 
 	if (strcmp(argv[1], "depends") == 0) {
+		printf("ccan/array_size\n");
 		return 0;
 	}
 

ccan/crc/crc.c

@@ -24,6 +24,7 @@
  */
 
 #include "crc.h"
+#include <ccan/array_size/array_size.h>
 #include <stdbool.h>
 #include <stdlib.h>
 
@@ -185,106 +186,122 @@ const uint32_t *crc32_ieee_table(void)
 	return crc32_ieee_tab;
 }
 
-static uint64_t crc64_tab[] = {
-    0x0000000000000000ULL, 0x01b0000000000000ULL, 0x0360000000000000ULL,
-    0x02d0000000000000ULL, 0x06c0000000000000ULL, 0x0770000000000000ULL,
-    0x05a0000000000000ULL, 0x0410000000000000ULL, 0x0d80000000000000ULL,
-    0x0c30000000000000ULL, 0x0ee0000000000000ULL, 0x0f50000000000000ULL,
-    0x0b40000000000000ULL, 0x0af0000000000000ULL, 0x0820000000000000ULL,
-    0x0990000000000000ULL, 0x1b00000000000000ULL, 0x1ab0000000000000ULL,
-    0x1860000000000000ULL, 0x19d0000000000000ULL, 0x1dc0000000000000ULL,
-    0x1c70000000000000ULL, 0x1ea0000000000000ULL, 0x1f10000000000000ULL,
-    0x1680000000000000ULL, 0x1730000000000000ULL, 0x15e0000000000000ULL,
-    0x1450000000000000ULL, 0x1040000000000000ULL, 0x11f0000000000000ULL,
-    0x1320000000000000ULL, 0x1290000000000000ULL, 0x3600000000000000ULL,
-    0x37b0000000000000ULL, 0x3560000000000000ULL, 0x34d0000000000000ULL,
-    0x30c0000000000000ULL, 0x3170000000000000ULL, 0x33a0000000000000ULL,
-    0x3210000000000000ULL, 0x3b80000000000000ULL, 0x3a30000000000000ULL,
-    0x38e0000000000000ULL, 0x3950000000000000ULL, 0x3d40000000000000ULL,
-    0x3cf0000000000000ULL, 0x3e20000000000000ULL, 0x3f90000000000000ULL,
-    0x2d00000000000000ULL, 0x2cb0000000000000ULL, 0x2e60000000000000ULL,
-    0x2fd0000000000000ULL, 0x2bc0000000000000ULL, 0x2a70000000000000ULL,
-    0x28a0000000000000ULL, 0x2910000000000000ULL, 0x2080000000000000ULL,
-    0x2130000000000000ULL, 0x23e0000000000000ULL, 0x2250000000000000ULL,
-    0x2640000000000000ULL, 0x27f0000000000000ULL, 0x2520000000000000ULL,
-    0x2490000000000000ULL, 0x6c00000000000000ULL, 0x6db0000000000000ULL,
-    0x6f60000000000000ULL, 0x6ed0000000000000ULL, 0x6ac0000000000000ULL,
-    0x6b70000000000000ULL, 0x69a0000000000000ULL, 0x6810000000000000ULL,
-    0x6180000000000000ULL, 0x6030000000000000ULL, 0x62e0000000000000ULL,
-    0x6350000000000000ULL, 0x6740000000000000ULL, 0x66f0000000000000ULL,
-    0x6420000000000000ULL, 0x6590000000000000ULL, 0x7700000000000000ULL,
-    0x76b0000000000000ULL, 0x7460000000000000ULL, 0x75d0000000000000ULL,
-    0x71c0000000000000ULL, 0x7070000000000000ULL, 0x72a0000000000000ULL,
-    0x7310000000000000ULL, 0x7a80000000000000ULL, 0x7b30000000000000ULL,
-    0x79e0000000000000ULL, 0x7850000000000000ULL, 0x7c40000000000000ULL,
-    0x7df0000000000000ULL, 0x7f20000000000000ULL, 0x7e90000000000000ULL,
-    0x5a00000000000000ULL, 0x5bb0000000000000ULL, 0x5960000000000000ULL,
-    0x58d0000000000000ULL, 0x5cc0000000000000ULL, 0x5d70000000000000ULL,
-    0x5fa0000000000000ULL, 0x5e10000000000000ULL, 0x5780000000000000ULL,
-    0x5630000000000000ULL, 0x54e0000000000000ULL, 0x5550000000000000ULL,
-    0x5140000000000000ULL, 0x50f0000000000000ULL, 0x5220000000000000ULL,
-    0x5390000000000000ULL, 0x4100000000000000ULL, 0x40b0000000000000ULL,
-    0x4260000000000000ULL, 0x43d0000000000000ULL, 0x47c0000000000000ULL,
-    0x4670000000000000ULL, 0x44a0000000000000ULL, 0x4510000000000000ULL,
-    0x4c80000000000000ULL, 0x4d30000000000000ULL, 0x4fe0000000000000ULL,
-    0x4e50000000000000ULL, 0x4a40000000000000ULL, 0x4bf0000000000000ULL,
-    0x4920000000000000ULL, 0x4890000000000000ULL, 0xd800000000000000ULL,
-    0xd9b0000000000000ULL, 0xdb60000000000000ULL, 0xdad0000000000000ULL,
-    0xdec0000000000000ULL, 0xdf70000000000000ULL, 0xdda0000000000000ULL,
-    0xdc10000000000000ULL, 0xd580000000000000ULL, 0xd430000000000000ULL,
-    0xd6e0000000000000ULL, 0xd750000000000000ULL, 0xd340000000000000ULL,
-    0xd2f0000000000000ULL, 0xd020000000000000ULL, 0xd190000000000000ULL,
-    0xc300000000000000ULL, 0xc2b0000000000000ULL, 0xc060000000000000ULL,
-    0xc1d0000000000000ULL, 0xc5c0000000000000ULL, 0xc470000000000000ULL,
-    0xc6a0000000000000ULL, 0xc710000000000000ULL, 0xce80000000000000ULL,
-    0xcf30000000000000ULL, 0xcde0000000000000ULL, 0xcc50000000000000ULL,
-    0xc840000000000000ULL, 0xc9f0000000000000ULL, 0xcb20000000000000ULL,
-    0xca90000000000000ULL, 0xee00000000000000ULL, 0xefb0000000000000ULL,
-    0xed60000000000000ULL, 0xecd0000000000000ULL, 0xe8c0000000000000ULL,
-    0xe970000000000000ULL, 0xeba0000000000000ULL, 0xea10000000000000ULL,
-    0xe380000000000000ULL, 0xe230000000000000ULL, 0xe0e0000000000000ULL,
-    0xe150000000000000ULL, 0xe540000000000000ULL, 0xe4f0000000000000ULL,
-    0xe620000000000000ULL, 0xe790000000000000ULL, 0xf500000000000000ULL,
-    0xf4b0000000000000ULL, 0xf660000000000000ULL, 0xf7d0000000000000ULL,
-    0xf3c0000000000000ULL, 0xf270000000000000ULL, 0xf0a0000000000000ULL,
-    0xf110000000000000ULL, 0xf880000000000000ULL, 0xf930000000000000ULL,
-    0xfbe0000000000000ULL, 0xfa50000000000000ULL, 0xfe40000000000000ULL,
-    0xfff0000000000000ULL, 0xfd20000000000000ULL, 0xfc90000000000000ULL,
-    0xb400000000000000ULL, 0xb5b0000000000000ULL, 0xb760000000000000ULL,
-    0xb6d0000000000000ULL, 0xb2c0000000000000ULL, 0xb370000000000000ULL,
-    0xb1a0000000000000ULL, 0xb010000000000000ULL, 0xb980000000000000ULL,
-    0xb830000000000000ULL, 0xbae0000000000000ULL, 0xbb50000000000000ULL,
-    0xbf40000000000000ULL, 0xbef0000000000000ULL, 0xbc20000000000000ULL,
-    0xbd90000000000000ULL, 0xaf00000000000000ULL, 0xaeb0000000000000ULL,
-    0xac60000000000000ULL, 0xadd0000000000000ULL, 0xa9c0000000000000ULL,
-    0xa870000000000000ULL, 0xaaa0000000000000ULL, 0xab10000000000000ULL,
-    0xa280000000000000ULL, 0xa330000000000000ULL, 0xa1e0000000000000ULL,
-    0xa050000000000000ULL, 0xa440000000000000ULL, 0xa5f0000000000000ULL,
-    0xa720000000000000ULL, 0xa690000000000000ULL, 0x8200000000000000ULL,
-    0x83b0000000000000ULL, 0x8160000000000000ULL, 0x80d0000000000000ULL,
-    0x84c0000000000000ULL, 0x8570000000000000ULL, 0x87a0000000000000ULL,
-    0x8610000000000000ULL, 0x8f80000000000000ULL, 0x8e30000000000000ULL,
-    0x8ce0000000000000ULL, 0x8d50000000000000ULL, 0x8940000000000000ULL,
-    0x88f0000000000000ULL, 0x8a20000000000000ULL, 0x8b90000000000000ULL,
-    0x9900000000000000ULL, 0x98b0000000000000ULL, 0x9a60000000000000ULL,
-    0x9bd0000000000000ULL, 0x9fc0000000000000ULL, 0x9e70000000000000ULL,
-    0x9ca0000000000000ULL, 0x9d10000000000000ULL, 0x9480000000000000ULL,
-    0x9530000000000000ULL, 0x97e0000000000000ULL, 0x9650000000000000ULL,
-    0x9240000000000000ULL, 0x93f0000000000000ULL, 0x9120000000000000ULL,
-    0x9090000000000000ULL
+/* We only keep the upper 16 bits of the table: the lower 48 are always 0 */
+static uint16_t crc64_tab[] = {
+    0x0000, 0x01b0, 0x0360,
+    0x02d0, 0x06c0, 0x0770,
+    0x05a0, 0x0410, 0x0d80,
+    0x0c30, 0x0ee0, 0x0f50,
+    0x0b40, 0x0af0, 0x0820,
+    0x0990, 0x1b00, 0x1ab0,
+    0x1860, 0x19d0, 0x1dc0,
+    0x1c70, 0x1ea0, 0x1f10,
+    0x1680, 0x1730, 0x15e0,
+    0x1450, 0x1040, 0x11f0,
+    0x1320, 0x1290, 0x3600,
+    0x37b0, 0x3560, 0x34d0,
+    0x30c0, 0x3170, 0x33a0,
+    0x3210, 0x3b80, 0x3a30,
+    0x38e0, 0x3950, 0x3d40,
+    0x3cf0, 0x3e20, 0x3f90,
+    0x2d00, 0x2cb0, 0x2e60,
+    0x2fd0, 0x2bc0, 0x2a70,
+    0x28a0, 0x2910, 0x2080,
+    0x2130, 0x23e0, 0x2250,
+    0x2640, 0x27f0, 0x2520,
+    0x2490, 0x6c00, 0x6db0,
+    0x6f60, 0x6ed0, 0x6ac0,
+    0x6b70, 0x69a0, 0x6810,
+    0x6180, 0x6030, 0x62e0,
+    0x6350, 0x6740, 0x66f0,
+    0x6420, 0x6590, 0x7700,
+    0x76b0, 0x7460, 0x75d0,
+    0x71c0, 0x7070, 0x72a0,
+    0x7310, 0x7a80, 0x7b30,
+    0x79e0, 0x7850, 0x7c40,
+    0x7df0, 0x7f20, 0x7e90,
+    0x5a00, 0x5bb0, 0x5960,
+    0x58d0, 0x5cc0, 0x5d70,
+    0x5fa0, 0x5e10, 0x5780,
+    0x5630, 0x54e0, 0x5550,
+    0x5140, 0x50f0, 0x5220,
+    0x5390, 0x4100, 0x40b0,
+    0x4260, 0x43d0, 0x47c0,
+    0x4670, 0x44a0, 0x4510,
+    0x4c80, 0x4d30, 0x4fe0,
+    0x4e50, 0x4a40, 0x4bf0,
+    0x4920, 0x4890, 0xd800,
+    0xd9b0, 0xdb60, 0xdad0,
+    0xdec0, 0xdf70, 0xdda0,
+    0xdc10, 0xd580, 0xd430,
+    0xd6e0, 0xd750, 0xd340,
+    0xd2f0, 0xd020, 0xd190,
+    0xc300, 0xc2b0, 0xc060,
+    0xc1d0, 0xc5c0, 0xc470,
+    0xc6a0, 0xc710, 0xce80,
+    0xcf30, 0xcde0, 0xcc50,
+    0xc840, 0xc9f0, 0xcb20,
+    0xca90, 0xee00, 0xefb0,
+    0xed60, 0xecd0, 0xe8c0,
+    0xe970, 0xeba0, 0xea10,
+    0xe380, 0xe230, 0xe0e0,
+    0xe150, 0xe540, 0xe4f0,
+    0xe620, 0xe790, 0xf500,
+    0xf4b0, 0xf660, 0xf7d0,
+    0xf3c0, 0xf270, 0xf0a0,
+    0xf110, 0xf880, 0xf930,
+    0xfbe0, 0xfa50, 0xfe40,
+    0xfff0, 0xfd20, 0xfc90,
+    0xb400, 0xb5b0, 0xb760,
+    0xb6d0, 0xb2c0, 0xb370,
+    0xb1a0, 0xb010, 0xb980,
+    0xb830, 0xbae0, 0xbb50,
+    0xbf40, 0xbef0, 0xbc20,
+    0xbd90, 0xaf00, 0xaeb0,
+    0xac60, 0xadd0, 0xa9c0,
+    0xa870, 0xaaa0, 0xab10,
+    0xa280, 0xa330, 0xa1e0,
+    0xa050, 0xa440, 0xa5f0,
+    0xa720, 0xa690, 0x8200,
+    0x83b0, 0x8160, 0x80d0,
+    0x84c0, 0x8570, 0x87a0,
+    0x8610, 0x8f80, 0x8e30,
+    0x8ce0, 0x8d50, 0x8940,
+    0x88f0, 0x8a20, 0x8b90,
+    0x9900, 0x98b0, 0x9a60,
+    0x9bd0, 0x9fc0, 0x9e70,
+    0x9ca0, 0x9d10, 0x9480,
+    0x9530, 0x97e0, 0x9650,
+    0x9240, 0x93f0, 0x9120,
+    0x9090
 };
 
 uint64_t crc64_iso(uint64_t crc, const void *buf, size_t size)
 {
 	const uint8_t *p = buf;
 
-	while (size--)
-		crc = crc64_tab[(crc ^ *p++) & 0xFFL] ^ (crc >> 8);
-
+	while (size--) {
+		uint64_t tabval = crc64_tab[(crc ^ *p++) & 0xFFL];
+		tabval <<= 48;
+		crc = tabval ^ (crc >> 8);
+	}
 	return crc;
 }
 
 const uint64_t *crc64_iso_table(void)
 {
-	return crc64_tab;
+	static uint64_t *fulltab = NULL;
+	unsigned int i;
+
+	if (fulltab)
+		return fulltab;
+
+	fulltab = malloc(sizeof(uint64_t)*ARRAY_SIZE(crc64_tab));
+	if (!fulltab)
+		return NULL;
+
+	for (i = 0; i < ARRAY_SIZE(crc64_tab); i++)
+		fulltab[i] = (uint64_t)crc64_tab[i] << 48;
+
+	return fulltab;
 }