1 //===-- Bcmp implementation for aarch64 -------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 #ifndef LIBC_SRC_STRING_MEMORY_UTILS_AARCH64_INLINE_BCMP_H
9 #define LIBC_SRC_STRING_MEMORY_UTILS_AARCH64_INLINE_BCMP_H
10
11 #include "src/__support/macros/attributes.h" // LIBC_INLINE
12 #include "src/__support/macros/optimization.h" // LIBC_UNLIKELY
13 #include "src/string/memory_utils/op_aarch64.h"
14 #include "src/string/memory_utils/op_generic.h"
15 #include "src/string/memory_utils/utils.h" // Ptr, CPtr
16
17 #include <stddef.h> // size_t
18
19 namespace LIBC_NAMESPACE {
20
inline_bcmp_aarch64(CPtr p1,CPtr p2,size_t count)21 [[maybe_unused]] LIBC_INLINE BcmpReturnType inline_bcmp_aarch64(CPtr p1,
22 CPtr p2,
23 size_t count) {
24 if (LIBC_LIKELY(count <= 32)) {
25 if (LIBC_UNLIKELY(count >= 16)) {
26 return aarch64::Bcmp<16>::head_tail(p1, p2, count);
27 }
28 switch (count) {
29 case 0:
30 return BcmpReturnType::zero();
31 case 1:
32 return generic::Bcmp<uint8_t>::block(p1, p2);
33 case 2:
34 return generic::Bcmp<uint16_t>::block(p1, p2);
35 case 3:
36 return generic::Bcmp<uint16_t>::head_tail(p1, p2, count);
37 case 4:
38 return generic::Bcmp<uint32_t>::block(p1, p2);
39 case 5:
40 case 6:
41 case 7:
42 return generic::Bcmp<uint32_t>::head_tail(p1, p2, count);
43 case 8:
44 return generic::Bcmp<uint64_t>::block(p1, p2);
45 case 9:
46 case 10:
47 case 11:
48 case 12:
49 case 13:
50 case 14:
51 case 15:
52 return generic::Bcmp<uint64_t>::head_tail(p1, p2, count);
53 }
54 }
55
56 if (count <= 64)
57 return aarch64::Bcmp<32>::head_tail(p1, p2, count);
58
59 // Aligned loop if > 256, otherwise normal loop
60 if (LIBC_UNLIKELY(count > 256)) {
61 if (auto value = aarch64::Bcmp<32>::block(p1, p2))
62 return value;
63 align_to_next_boundary<16, Arg::P1>(p1, p2, count);
64 }
65 return aarch64::Bcmp<32>::loop_and_tail(p1, p2, count);
66 }
67
68 } // namespace LIBC_NAMESPACE
69
70 #endif // LIBC_SRC_STRING_MEMORY_UTILS_AARCH64_INLINE_BCMP_H
71