Don't compile crc32c-intel on non-x86 platforms
[fio.git] / crc / crc32c-intel.c
CommitLineData
3845591f 1#include <inttypes.h>
419484b9 2#include "crc32c.h"
3845591f
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3
4/*
5 * Based on a posting to lkml by Austin Zhang <austin.zhang@intel.com>
6 *
7 * Using hardware provided CRC32 instruction to accelerate the CRC32 disposal.
8 * CRC32C polynomial:0x1EDC6F41(BE)/0x82F63B78(LE)
9 * CRC32 is a new instruction in Intel SSE4.2, the reference can be found at:
10 * http://www.intel.com/products/processor/manuals/
11 * Intel(R) 64 and IA-32 Architectures Software Developer's Manual
12 * Volume 2A: Instruction Set Reference, A-M
13 */
14
419484b9
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15#ifdef ARCH_HAVE_SSE
16
3845591f
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17#if BITS_PER_LONG == 64
18#define REX_PRE "0x48, "
19#define SCALE_F 8
20#else
21#define REX_PRE
22#define SCALE_F 4
23#endif
24
25uint32_t crc32c_intel_le_hw_byte(uint32_t crc, unsigned char const *data,
26 unsigned long length)
27{
28 while (length--) {
29 __asm__ __volatile__(
30 ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1"
31 :"=S"(crc)
32 :"0"(crc), "c"(*data)
33 );
34 data++;
35 }
36
37 return crc;
38}
39
40/*
41 * Steps through buffer one byte at at time, calculates reflected
42 * crc using table.
43 */
44uint32_t crc32c_intel(unsigned char const *data, unsigned long length)
45{
46 unsigned int iquotient = length / SCALE_F;
47 unsigned int iremainder = length % SCALE_F;
48#if BITS_PER_LONG == 64
49 uint64_t *ptmp = (uint64_t *) data;
50#else
51 uint32_t *ptmp = (uint32_t *) data;
52#endif
53 uint32_t crc = ~0;
54
55 while (iquotient--) {
56 __asm__ __volatile__(
57 ".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;"
58 :"=S"(crc)
59 :"0"(crc), "c"(*ptmp)
60 );
61 ptmp++;
62 }
63
64 if (iremainder)
65 crc = crc32c_intel_le_hw_byte(crc, (unsigned char *)ptmp,
66 iremainder);
67
68 return crc;
69}
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70
71#endif /* ARCH_HAVE_SSE */
72