move Rust sources to top level, C sources into c_src

[bcachefs-tools-debian] / c_src / libbcachefs / bkey_cmp.h

diff --git a/c_src/libbcachefs/bkey_cmp.h b/c_src/libbcachefs/bkey_cmp.h
new file mode 100644 (file)
index 0000000..5f42a6e
--- /dev/null
+++ b/c_src/libbcachefs/bkey_cmp.h
@@ -0,0 +1,129 @@
+/* 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 */