b6d3ae3d3d
This patch seems to introduce bugs on aarch64.
Reverting while we investigate the root cause.
This reverts commit 0284148813.
106 lines
4.0 KiB
C++
106 lines
4.0 KiB
C++
//===-- Implementation of memcmp ------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_MEMCMP_IMPLEMENTATIONS_H
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#define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_MEMCMP_IMPLEMENTATIONS_H
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#include "src/__support/architectures.h"
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#include "src/__support/common.h"
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#include "src/string/memory_utils/elements.h"
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#include <stddef.h> // size_t
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namespace __llvm_libc {
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static inline int inline_memcmp(const char *lhs, const char *rhs,
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size_t count) {
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#if defined(LLVM_LIBC_ARCH_X86)
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/////////////////////////////////////////////////////////////////////////////
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// LLVM_LIBC_ARCH_X86
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/////////////////////////////////////////////////////////////////////////////
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using namespace __llvm_libc::x86;
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if (count == 0)
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return 0;
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if (count == 1)
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return three_way_compare<_1>(lhs, rhs);
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if (count == 2)
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return three_way_compare<_2>(lhs, rhs);
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if (count == 3)
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return three_way_compare<_3>(lhs, rhs);
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if (count <= 8)
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return three_way_compare<HeadTail<_4>>(lhs, rhs, count);
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if (count <= 16)
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return three_way_compare<HeadTail<_8>>(lhs, rhs, count);
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if (count <= 32)
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return three_way_compare<HeadTail<_16>>(lhs, rhs, count);
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if (count <= 64)
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return three_way_compare<HeadTail<_32>>(lhs, rhs, count);
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if (count <= 128)
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return three_way_compare<HeadTail<_64>>(lhs, rhs, count);
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return three_way_compare<Align<_32>::Then<Loop<_32>>>(lhs, rhs, count);
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#elif defined(LLVM_LIBC_ARCH_AARCH64)
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/////////////////////////////////////////////////////////////////////////////
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// LLVM_LIBC_ARCH_AARCH64
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/////////////////////////////////////////////////////////////////////////////
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using namespace ::__llvm_libc::aarch64;
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if (count == 0) // [0, 0]
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return 0;
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if (count == 1) // [1, 1]
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return three_way_compare<_1>(lhs, rhs);
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if (count == 2) // [2, 2]
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return three_way_compare<_2>(lhs, rhs);
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if (count == 3) // [3, 3]
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return three_way_compare<_3>(lhs, rhs);
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if (count < 8) // [4, 7]
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return three_way_compare<HeadTail<_4>>(lhs, rhs, count);
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if (count < 16) // [8, 15]
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return three_way_compare<HeadTail<_8>>(lhs, rhs, count);
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if (unlikely(count >= 128)) // [128, ∞]
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return three_way_compare<Align<_16>::Then<Loop<_32>>>(lhs, rhs, count);
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if (!equals<_16>(lhs, rhs)) // [16, 16]
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return three_way_compare<_16>(lhs, rhs);
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if (count < 32) // [17, 31]
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return three_way_compare<Tail<_16>>(lhs, rhs, count);
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if (!equals<Skip<16>::Then<_16>>(lhs, rhs)) // [32, 32]
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return three_way_compare<Skip<16>::Then<_16>>(lhs, rhs);
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if (count < 64) // [33, 63]
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return three_way_compare<Tail<_32>>(lhs, rhs, count);
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// [64, 127]
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return three_way_compare<Skip<32>::Then<Loop<_16>>>(lhs, rhs, count);
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#else
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/////////////////////////////////////////////////////////////////////////////
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// Default
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/////////////////////////////////////////////////////////////////////////////
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using namespace ::__llvm_libc::scalar;
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if (count == 0)
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return 0;
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if (count == 1)
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return three_way_compare<_1>(lhs, rhs);
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if (count == 2)
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return three_way_compare<_2>(lhs, rhs);
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if (count == 3)
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return three_way_compare<_3>(lhs, rhs);
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if (count <= 8)
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return three_way_compare<HeadTail<_4>>(lhs, rhs, count);
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if (count <= 16)
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return three_way_compare<HeadTail<_8>>(lhs, rhs, count);
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if (count <= 32)
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return three_way_compare<HeadTail<_16>>(lhs, rhs, count);
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if (count <= 64)
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return three_way_compare<HeadTail<_32>>(lhs, rhs, count);
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if (count <= 128)
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return three_way_compare<HeadTail<_64>>(lhs, rhs, count);
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return three_way_compare<Align<_32>::Then<Loop<_32>>>(lhs, rhs, count);
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#endif
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}
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} // namespace __llvm_libc
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#endif // LLVM_LIBC_SRC_STRING_MEMORY_UTILS_MEMCMP_IMPLEMENTATIONS_H
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