| //===-- Implementation of bcmp --------------------------------------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_BCMP_IMPLEMENTATIONS_H |
| #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_BCMP_IMPLEMENTATIONS_H |
| |
| #include "src/__support/common.h" |
| #include "src/__support/macros/optimization.h" // LIBC_UNLIKELY LIBC_LOOP_NOUNROLL |
| #include "src/__support/macros/properties/architectures.h" |
| #include "src/string/memory_utils/op_aarch64.h" |
| #include "src/string/memory_utils/op_builtin.h" |
| #include "src/string/memory_utils/op_generic.h" |
| #include "src/string/memory_utils/op_x86.h" |
| |
| #include <stddef.h> // size_t |
| |
| namespace __llvm_libc { |
| |
| [[maybe_unused]] LIBC_INLINE BcmpReturnType |
| inline_bcmp_byte_per_byte(CPtr p1, CPtr p2, size_t offset, size_t count) { |
| LIBC_LOOP_NOUNROLL |
| for (; offset < count; ++offset) |
| if (p1[offset] != p2[offset]) |
| return BcmpReturnType::NONZERO(); |
| return BcmpReturnType::ZERO(); |
| } |
| |
| [[maybe_unused]] LIBC_INLINE BcmpReturnType |
| inline_bcmp_aligned_access_64bit(CPtr p1, CPtr p2, size_t count) { |
| constexpr size_t kAlign = sizeof(uint64_t); |
| if (count <= 2 * kAlign) |
| return inline_bcmp_byte_per_byte(p1, p2, 0, count); |
| size_t bytes_to_p1_align = distance_to_align_up<kAlign>(p1); |
| if (auto value = inline_bcmp_byte_per_byte(p1, p2, 0, bytes_to_p1_align)) |
| return value; |
| size_t offset = bytes_to_p1_align; |
| size_t p2_alignment = distance_to_align_down<kAlign>(p2 + offset); |
| for (; offset < count - kAlign; offset += kAlign) { |
| uint64_t a; |
| if (p2_alignment == 0) |
| a = load64_aligned<uint64_t>(p2, offset); |
| else if (p2_alignment == 4) |
| a = load64_aligned<uint32_t, uint32_t>(p2, offset); |
| else if (p2_alignment == 2) |
| a = load64_aligned<uint16_t, uint16_t, uint16_t, uint16_t>(p2, offset); |
| else |
| a = load64_aligned<uint8_t, uint16_t, uint16_t, uint16_t, uint8_t>( |
| p2, offset); |
| uint64_t b = load64_aligned<uint64_t>(p1, offset); |
| if (a != b) |
| return BcmpReturnType::NONZERO(); |
| } |
| return inline_bcmp_byte_per_byte(p1, p2, offset, count); |
| } |
| |
| [[maybe_unused]] LIBC_INLINE BcmpReturnType |
| inline_bcmp_aligned_access_32bit(CPtr p1, CPtr p2, size_t count) { |
| constexpr size_t kAlign = sizeof(uint32_t); |
| if (count <= 2 * kAlign) |
| return inline_bcmp_byte_per_byte(p1, p2, 0, count); |
| size_t bytes_to_p1_align = distance_to_align_up<kAlign>(p1); |
| if (auto value = inline_bcmp_byte_per_byte(p1, p2, 0, bytes_to_p1_align)) |
| return value; |
| size_t offset = bytes_to_p1_align; |
| size_t p2_alignment = distance_to_align_down<kAlign>(p2 + offset); |
| for (; offset < count - kAlign; offset += kAlign) { |
| uint32_t a; |
| if (p2_alignment == 0) |
| a = load32_aligned<uint32_t>(p2, offset); |
| else if (p2_alignment == 2) |
| a = load32_aligned<uint16_t, uint16_t>(p2, offset); |
| else |
| a = load32_aligned<uint8_t, uint16_t, uint8_t>(p2, offset); |
| uint32_t b = load32_aligned<uint32_t>(p1, offset); |
| if (a != b) |
| return BcmpReturnType::NONZERO(); |
| } |
| return inline_bcmp_byte_per_byte(p1, p2, offset, count); |
| } |
| |
| #if defined(LIBC_TARGET_ARCH_IS_X86) || defined(LIBC_TARGET_ARCH_IS_AARCH64) |
| [[maybe_unused]] LIBC_INLINE BcmpReturnType |
| inline_bcmp_generic_gt16(CPtr p1, CPtr p2, size_t count) { |
| if (count < 256) |
| return generic::Bcmp<16>::loop_and_tail(p1, p2, count); |
| if (auto value = generic::Bcmp<64>::block(p1, p2)) |
| return value; |
| align_to_next_boundary<64, Arg::P1>(p1, p2, count); |
| return generic::Bcmp<64>::loop_and_tail(p1, p2, count); |
| } |
| #endif // defined(LIBC_TARGET_ARCH_IS_X86) || |
| // defined(LIBC_TARGET_ARCH_IS_AARCH64) |
| |
| #if defined(LIBC_TARGET_ARCH_IS_X86) |
| [[maybe_unused]] LIBC_INLINE BcmpReturnType |
| inline_bcmp_x86_sse2_gt16(CPtr p1, CPtr p2, size_t count) { |
| if (count <= 32) |
| return x86::sse2::Bcmp<16>::head_tail(p1, p2, count); |
| if (count < 256) |
| return x86::sse2::Bcmp<16>::loop_and_tail(p1, p2, count); |
| if (auto value = x86::sse2::Bcmp<16>::block(p1, p2)) |
| return value; |
| align_to_next_boundary<16, Arg::P1>(p1, p2, count); |
| return x86::sse2::Bcmp<64>::loop_and_tail(p1, p2, count); |
| } |
| |
| [[maybe_unused]] LIBC_INLINE BcmpReturnType |
| inline_bcmp_x86_avx2_gt16(CPtr p1, CPtr p2, size_t count) { |
| if (count <= 32) |
| return x86::sse2::Bcmp<16>::head_tail(p1, p2, count); |
| if (count <= 64) |
| return x86::avx2::Bcmp<32>::head_tail(p1, p2, count); |
| if (count <= 128) |
| return x86::avx2::Bcmp<64>::head_tail(p1, p2, count); |
| if (LIBC_UNLIKELY(count >= 256)) { |
| if (auto value = x86::avx2::Bcmp<64>::block(p1, p2)) |
| return value; |
| align_to_next_boundary<64, Arg::P1>(p1, p2, count); |
| } |
| return x86::avx2::Bcmp<64>::loop_and_tail(p1, p2, count); |
| } |
| |
| [[maybe_unused]] LIBC_INLINE BcmpReturnType |
| inline_bcmp_x86_avx512bw_gt16(CPtr p1, CPtr p2, size_t count) { |
| if (count <= 32) |
| return x86::sse2::Bcmp<16>::head_tail(p1, p2, count); |
| if (count <= 64) |
| return x86::avx2::Bcmp<32>::head_tail(p1, p2, count); |
| if (count <= 128) |
| return x86::avx512bw::Bcmp<64>::head_tail(p1, p2, count); |
| if (LIBC_UNLIKELY(count >= 256)) { |
| if (auto value = x86::avx512bw::Bcmp<64>::block(p1, p2)) |
| return value; |
| align_to_next_boundary<64, Arg::P1>(p1, p2, count); |
| } |
| return x86::avx512bw::Bcmp<64>::loop_and_tail(p1, p2, count); |
| } |
| |
| [[maybe_unused]] LIBC_INLINE BcmpReturnType inline_bcmp_x86(CPtr p1, CPtr p2, |
| size_t count) { |
| if (count == 0) |
| return BcmpReturnType::ZERO(); |
| if (count == 1) |
| return generic::Bcmp<1>::block(p1, p2); |
| if (count == 2) |
| return generic::Bcmp<2>::block(p1, p2); |
| if (count <= 4) |
| return generic::Bcmp<2>::head_tail(p1, p2, count); |
| if (count <= 8) |
| return generic::Bcmp<4>::head_tail(p1, p2, count); |
| if (count <= 16) |
| return generic::Bcmp<8>::head_tail(p1, p2, count); |
| if constexpr (x86::kAvx512BW) |
| return inline_bcmp_x86_avx512bw_gt16(p1, p2, count); |
| else if constexpr (x86::kAvx2) |
| return inline_bcmp_x86_avx2_gt16(p1, p2, count); |
| else if constexpr (x86::kSse2) |
| return inline_bcmp_x86_sse2_gt16(p1, p2, count); |
| else |
| return inline_bcmp_generic_gt16(p1, p2, count); |
| } |
| #endif // defined(LIBC_TARGET_ARCH_IS_X86) |
| |
| #if defined(LIBC_TARGET_ARCH_IS_AARCH64) |
| [[maybe_unused]] LIBC_INLINE BcmpReturnType inline_bcmp_aarch64(CPtr p1, |
| CPtr p2, |
| size_t count) { |
| if (LIBC_LIKELY(count <= 32)) { |
| if (LIBC_UNLIKELY(count >= 16)) { |
| return aarch64::Bcmp<16>::head_tail(p1, p2, count); |
| } |
| switch (count) { |
| case 0: |
| return BcmpReturnType::ZERO(); |
| case 1: |
| return generic::Bcmp<1>::block(p1, p2); |
| case 2: |
| return generic::Bcmp<2>::block(p1, p2); |
| case 3: |
| return generic::Bcmp<2>::head_tail(p1, p2, count); |
| case 4: |
| return generic::Bcmp<4>::block(p1, p2); |
| case 5: |
| case 6: |
| case 7: |
| return generic::Bcmp<4>::head_tail(p1, p2, count); |
| case 8: |
| return generic::Bcmp<8>::block(p1, p2); |
| case 9: |
| case 10: |
| case 11: |
| case 12: |
| case 13: |
| case 14: |
| case 15: |
| return generic::Bcmp<8>::head_tail(p1, p2, count); |
| } |
| } |
| |
| if (count <= 64) |
| return aarch64::Bcmp<32>::head_tail(p1, p2, count); |
| |
| // Aligned loop if > 256, otherwise normal loop |
| if (LIBC_UNLIKELY(count > 256)) { |
| if (auto value = aarch64::Bcmp<32>::block(p1, p2)) |
| return value; |
| align_to_next_boundary<16, Arg::P1>(p1, p2, count); |
| } |
| return aarch64::Bcmp<32>::loop_and_tail(p1, p2, count); |
| } |
| #endif // defined(LIBC_TARGET_ARCH_IS_AARCH64) |
| |
| LIBC_INLINE BcmpReturnType inline_bcmp(CPtr p1, CPtr p2, size_t count) { |
| #if defined(LIBC_TARGET_ARCH_IS_X86) |
| return inline_bcmp_x86(p1, p2, count); |
| #elif defined(LIBC_TARGET_ARCH_IS_AARCH64) |
| return inline_bcmp_aarch64(p1, p2, count); |
| #elif defined(LIBC_TARGET_ARCH_IS_RISCV64) |
| return inline_bcmp_aligned_access_64bit(p1, p2, count); |
| #elif defined(LIBC_TARGET_ARCH_IS_RISCV32) |
| return inline_bcmp_aligned_access_32bit(p1, p2, count); |
| #else |
| return inline_bcmp_byte_per_byte(p1, p2, 0, count); |
| #endif |
| } |
| |
| LIBC_INLINE int inline_bcmp(const void *p1, const void *p2, size_t count) { |
| return static_cast<int>(inline_bcmp(reinterpret_cast<CPtr>(p1), |
| reinterpret_cast<CPtr>(p2), count)); |
| } |
| |
| } // namespace __llvm_libc |
| |
| #endif // LLVM_LIBC_SRC_STRING_MEMORY_UTILS_BCMP_IMPLEMENTATIONS_H |
