diff options
| -rw-r--r-- | drivers/md/bcache/bkey.c | 53 |
1 files changed, 49 insertions, 4 deletions
diff --git a/drivers/md/bcache/bkey.c b/drivers/md/bcache/bkey.c index cf46ef55e0ed..484cd4956ae2 100644 --- a/drivers/md/bcache/bkey.c +++ b/drivers/md/bcache/bkey.c @@ -749,7 +749,51 @@ unsigned bkey_ffs(const struct bkey_format *format, return 0; } -static int __bkey_cmp_bits(unsigned nr_key_bits, const u64 *l, const u64 *r) +#ifdef CONFIG_X86_64 +static 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 int __bkey_cmp_bits(const u64 *l, const u64 *r, unsigned nr_key_bits) { u64 l_v, r_v; @@ -783,6 +827,7 @@ static int __bkey_cmp_bits(unsigned nr_key_bits, const u64 *l, const u64 *r) r_v = *r; } } +#endif /* * Would like to use this if we can make __bkey_cmp_bits() fast enough, it'll be @@ -829,9 +874,9 @@ int __bkey_cmp_packed(const struct bkey_format *f, EBUG_ON(!bkey_packed(l) || !bkey_packed(r)); - ret = __bkey_cmp_bits(bkey_format_key_bits(f), - high_word(f, l), - high_word(f, r)); + ret = __bkey_cmp_bits(high_word(f, l), + high_word(f, r), + bkey_format_key_bits(f)); EBUG_ON(ret != bkey_cmp(bkey_unpack_key(f, l).p, bkey_unpack_key(f, r).p)); |