Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/fs/bcachefs/bkey_cmp.h
26285 views
1
/* SPDX-License-Identifier: GPL-2.0 */

2
#ifndef _BCACHEFS_BKEY_CMP_H

3
#define _BCACHEFS_BKEY_CMP_H

4


5
#include "bkey.h"

6


7
#ifdef CONFIG_X86_64

8
static inline int __bkey_cmp_bits(const u64 *l, const u64 *r,

9
				  unsigned nr_key_bits)

10
{

11
	long d0, d1, d2, d3;

12
	int cmp;

13


14
	/* we shouldn't need asm for this, but gcc is being retarded: */

15


16
	asm(".intel_syntax noprefix;"

17
	    "xor eax, eax;"

18
	    "xor edx, edx;"

19
	    "1:;"

20
	    "mov r8, [rdi];"

21
	    "mov r9, [rsi];"

22
	    "sub ecx, 64;"

23
	    "jl 2f;"

24


25
	    "cmp r8, r9;"

26
	    "jnz 3f;"

27


28
	    "lea rdi, [rdi - 8];"

29
	    "lea rsi, [rsi - 8];"

30
	    "jmp 1b;"

31


32
	    "2:;"

33
	    "not ecx;"

34
	    "shr r8, 1;"

35
	    "shr r9, 1;"

36
	    "shr r8, cl;"

37
	    "shr r9, cl;"

38
	    "cmp r8, r9;"

39


40
	    "3:\n"

41
	    "seta al;"

42
	    "setb dl;"

43
	    "sub eax, edx;"

44
	    ".att_syntax prefix;"

45
	    : "=&D" (d0), "=&S" (d1), "=&d" (d2), "=&c" (d3), "=&a" (cmp)

46
	    : "0" (l), "1" (r), "3" (nr_key_bits)

47
	    : "r8", "r9", "cc", "memory");

48


49
	return cmp;

50
}

51
#else

52
static inline int __bkey_cmp_bits(const u64 *l, const u64 *r,

53
				  unsigned nr_key_bits)

54
{

55
	u64 l_v, r_v;

56


57
	if (!nr_key_bits)

58
		return 0;

59


60
	/* for big endian, skip past header */

61
	nr_key_bits += high_bit_offset;

62
	l_v = *l & (~0ULL >> high_bit_offset);

63
	r_v = *r & (~0ULL >> high_bit_offset);

64


65
	while (1) {

66
		if (nr_key_bits < 64) {

67
			l_v >>= 64 - nr_key_bits;

68
			r_v >>= 64 - nr_key_bits;

69
			nr_key_bits = 0;

70
		} else {

71
			nr_key_bits -= 64;

72
		}

73


74
		if (!nr_key_bits || l_v != r_v)

75
			break;

76


77
		l = next_word(l);

78
		r = next_word(r);

79


80
		l_v = *l;

81
		r_v = *r;

82
	}

83


84
	return cmp_int(l_v, r_v);

85
}

86
#endif

87


88
static inline __pure __flatten

89
int __bch2_bkey_cmp_packed_format_checked_inlined(const struct bkey_packed *l,

90
					  const struct bkey_packed *r,

91
					  const struct btree *b)

92
{

93
	const struct bkey_format *f = &b->format;

94
	int ret;

95


96
	EBUG_ON(!bkey_packed(l) || !bkey_packed(r));

97
	EBUG_ON(b->nr_key_bits != bkey_format_key_bits(f));

98


99
	ret = __bkey_cmp_bits(high_word(f, l),

100
			      high_word(f, r),

101
			      b->nr_key_bits);

102


103
	EBUG_ON(ret != bpos_cmp(bkey_unpack_pos(b, l),

104
				bkey_unpack_pos(b, r)));

105
	return ret;

106
}

107


108
static inline __pure __flatten

109
int bch2_bkey_cmp_packed_inlined(const struct btree *b,

110
			 const struct bkey_packed *l,

111
			 const struct bkey_packed *r)

112
{

113
	struct bkey unpacked;

114


115
	if (likely(bkey_packed(l) && bkey_packed(r)))

116
		return __bch2_bkey_cmp_packed_format_checked_inlined(l, r, b);

117


118
	if (bkey_packed(l)) {

119
		__bkey_unpack_key_format_checked(b, &unpacked, l);

120
		l = (void *) &unpacked;

121
	} else if (bkey_packed(r)) {

122
		__bkey_unpack_key_format_checked(b, &unpacked, r);

123
		r = (void *) &unpacked;

124
	}

125


126
	return bpos_cmp(((struct bkey *) l)->p, ((struct bkey *) r)->p);

127
}

128


129
#endif /* _BCACHEFS_BKEY_CMP_H */

130


131