| //===-- Implementation of memcmp ------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "src/string/memcmp.h" |
| #include "src/__support/common.h" |
| #include "src/string/memory_utils/elements.h" |
| |
| #include <stddef.h> // size_t |
| |
| namespace __llvm_libc { |
| |
| static int memcmp_impl(const char *lhs, const char *rhs, size_t count) { |
| #if defined(__i386__) || defined(__x86_64__) |
| using namespace ::__llvm_libc::x86; |
| #else |
| using namespace ::__llvm_libc::scalar; |
| #endif |
| |
| if (count == 0) |
| return 0; |
| if (count == 1) |
| return ThreeWayCompare<_1>(lhs, rhs); |
| if (count == 2) |
| return ThreeWayCompare<_2>(lhs, rhs); |
| if (count == 3) |
| return ThreeWayCompare<_3>(lhs, rhs); |
| if (count <= 8) |
| return ThreeWayCompare<HeadTail<_4>>(lhs, rhs, count); |
| if (count <= 16) |
| return ThreeWayCompare<HeadTail<_8>>(lhs, rhs, count); |
| if (count <= 32) |
| return ThreeWayCompare<HeadTail<_16>>(lhs, rhs, count); |
| if (count <= 64) |
| return ThreeWayCompare<HeadTail<_32>>(lhs, rhs, count); |
| if (count <= 128) |
| return ThreeWayCompare<HeadTail<_64>>(lhs, rhs, count); |
| return ThreeWayCompare<Align<_32>::Then<Loop<_32>>>(lhs, rhs, count); |
| } |
| |
| LLVM_LIBC_FUNCTION(int, memcmp, |
| (const void *lhs, const void *rhs, size_t count)) { |
| return memcmp_impl(static_cast<const char *>(lhs), |
| static_cast<const char *>(rhs), count); |
| } |
| |
| } // namespace __llvm_libc |