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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_BKEY_CMP_H
#define _BCACHEFS_BKEY_CMP_H
#include "bkey.h"
#ifdef CONFIG_X86_64
static inline int __bkey_cmp_bits(const u64 *l, const u64 *r,
unsigned nr_key_bits)
{
long d0, d1, d2, d3;
int cmp;
/* we shouldn't need asm for this, but gcc is being retarded: */
asm(".intel_syntax noprefix;"
"xor eax, eax;"
"xor edx, edx;"
"1:;"
"mov r8, [rdi];"
"mov r9, [rsi];"
"sub ecx, 64;"
"jl 2f;"
"cmp r8, r9;"
"jnz 3f;"
"lea rdi, [rdi - 8];"
"lea rsi, [rsi - 8];"
"jmp 1b;"
"2:;"
"not ecx;"
"shr r8, 1;"
"shr r9, 1;"
"shr r8, cl;"
"shr r9, cl;"
"cmp r8, r9;"
"3:\n"
"seta al;"
"setb dl;"
"sub eax, edx;"
".att_syntax prefix;"
: "=&D" (d0), "=&S" (d1), "=&d" (d2), "=&c" (d3), "=&a" (cmp)
: "0" (l), "1" (r), "3" (nr_key_bits)
: "r8", "r9", "cc", "memory");
return cmp;
}
#else
static inline int __bkey_cmp_bits(const u64 *l, const u64 *r,
unsigned nr_key_bits)
{
u64 l_v, r_v;
if (!nr_key_bits)
return 0;
/* for big endian, skip past header */
nr_key_bits += high_bit_offset;
l_v = *l & (~0ULL >> high_bit_offset);
r_v = *r & (~0ULL >> high_bit_offset);
while (1) {
if (nr_key_bits < 64) {
l_v >>= 64 - nr_key_bits;
r_v >>= 64 - nr_key_bits;
nr_key_bits = 0;
} else {
nr_key_bits -= 64;
}
if (!nr_key_bits || l_v != r_v)
break;
l = next_word(l);
r = next_word(r);
l_v = *l;
r_v = *r;
}
return cmp_int(l_v, r_v);
}
#endif
static inline __pure __flatten
int __bch2_bkey_cmp_packed_format_checked_inlined(const struct bkey_packed *l,
const struct bkey_packed *r,
const struct btree *b)
{
const struct bkey_format *f = &b->format;
int ret;
EBUG_ON(!bkey_packed(l) || !bkey_packed(r));
EBUG_ON(b->nr_key_bits != bkey_format_key_bits(f));
ret = __bkey_cmp_bits(high_word(f, l),
high_word(f, r),
b->nr_key_bits);
EBUG_ON(ret != bpos_cmp(bkey_unpack_pos(b, l),
bkey_unpack_pos(b, r)));
return ret;
}
static inline __pure __flatten
int bch2_bkey_cmp_packed_inlined(const struct btree *b,
const struct bkey_packed *l,
const struct bkey_packed *r)
{
struct bkey unpacked;
if (likely(bkey_packed(l) && bkey_packed(r)))
return __bch2_bkey_cmp_packed_format_checked_inlined(l, r, b);
if (bkey_packed(l)) {
__bkey_unpack_key_format_checked(b, &unpacked, l);
l = (void *) &unpacked;
} else if (bkey_packed(r)) {
__bkey_unpack_key_format_checked(b, &unpacked, r);
r = (void *) &unpacked;
}
return bpos_cmp(((struct bkey *) l)->p, ((struct bkey *) r)->p);
}
#endif /* _BCACHEFS_BKEY_CMP_H */