1 //===-- Elementary operations for aarch64 --------------------------------===// 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 9 #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_ELEMENTS_AARCH64_H 10 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_ELEMENTS_AARCH64_H 11 12 #include <src/string/memory_utils/elements.h> 13 #include <stddef.h> // size_t 14 #include <stdint.h> // uint8_t, uint16_t, uint32_t, uint64_t 15 16 #ifdef __ARM_NEON 17 #include <arm_neon.h> 18 #endif 19 20 namespace __llvm_libc { 21 namespace aarch64_memset { 22 #ifdef __ARM_NEON 23 struct Splat8 { 24 static constexpr size_t kSize = 8; 25 static void SplatSet(char *dst, const unsigned char value) { 26 vst1_u8((uint8_t *)dst, vdup_n_u8(value)); 27 } 28 }; 29 30 struct Splat16 { 31 static constexpr size_t kSize = 16; 32 static void SplatSet(char *dst, const unsigned char value) { 33 vst1q_u8((uint8_t *)dst, vdupq_n_u8(value)); 34 } 35 }; 36 37 using _8 = Splat8; 38 using _16 = Splat16; 39 #else 40 using _8 = __llvm_libc::scalar::_8; 41 using _16 = Repeated<_8, 2>; 42 #endif // __ARM_NEON 43 44 using _1 = __llvm_libc::scalar::_1; 45 using _2 = __llvm_libc::scalar::_2; 46 using _3 = __llvm_libc::scalar::_3; 47 using _4 = __llvm_libc::scalar::_4; 48 using _32 = Chained<_16, _16>; 49 using _64 = Chained<_32, _32>; 50 51 struct ZVA { 52 static constexpr size_t kSize = 64; 53 static void SplatSet(char *dst, const unsigned char value) { 54 asm("dc zva, %[dst]" : : [dst] "r"(dst) : "memory"); 55 } 56 }; 57 58 inline static bool AArch64ZVA(char *dst, size_t count) { 59 uint64_t zva_val; 60 asm("mrs %[zva_val], dczid_el0" : [zva_val] "=r"(zva_val)); 61 if ((zva_val & 31) != 4) 62 return false; 63 SplatSet<Align<_64, Arg::_1>::Then<Loop<ZVA, _64>>>(dst, 0, count); 64 return true; 65 } 66 67 } // namespace aarch64_memset 68 69 namespace aarch64 { 70 71 using _1 = __llvm_libc::scalar::_1; 72 using _2 = __llvm_libc::scalar::_2; 73 using _3 = __llvm_libc::scalar::_3; 74 using _4 = __llvm_libc::scalar::_4; 75 using _8 = __llvm_libc::scalar::_8; 76 using _16 = __llvm_libc::scalar::_16; 77 78 #ifdef __ARM_NEON 79 struct N32 { 80 static constexpr size_t kSize = 32; 81 static bool Equals(const char *lhs, const char *rhs) { 82 uint8x16_t l_0 = vld1q_u8((const uint8_t *)lhs); 83 uint8x16_t r_0 = vld1q_u8((const uint8_t *)rhs); 84 uint8x16_t l_1 = vld1q_u8((const uint8_t *)(lhs + 16)); 85 uint8x16_t r_1 = vld1q_u8((const uint8_t *)(rhs + 16)); 86 uint8x16_t temp = vpmaxq_u8(veorq_u8(l_0, r_0), veorq_u8(l_1, r_1)); 87 uint64_t res = 88 vgetq_lane_u64(vreinterpretq_u64_u8(vpmaxq_u8(temp, temp)), 0); 89 return res == 0; 90 } 91 static int ThreeWayCompare(const char *lhs, const char *rhs) { 92 uint8x16_t l_0 = vld1q_u8((const uint8_t *)lhs); 93 uint8x16_t r_0 = vld1q_u8((const uint8_t *)rhs); 94 uint8x16_t l_1 = vld1q_u8((const uint8_t *)(lhs + 16)); 95 uint8x16_t r_1 = vld1q_u8((const uint8_t *)(rhs + 16)); 96 uint8x16_t temp = vpmaxq_u8(veorq_u8(l_0, r_0), veorq_u8(l_1, r_1)); 97 uint64_t res = 98 vgetq_lane_u64(vreinterpretq_u64_u8(vpmaxq_u8(temp, temp)), 0); 99 if (res == 0) 100 return 0; 101 size_t index = (__builtin_ctzl(res) >> 3) << 2; 102 uint32_t l = *((const uint32_t *)(lhs + index)); 103 uint32_t r = *((const uint32_t *)(rhs + index)); 104 return __llvm_libc::scalar::_4::ScalarThreeWayCompare(l, r); 105 } 106 }; 107 108 using _32 = N32; 109 #else 110 using _32 = __llvm_libc::scalar::_32; 111 #endif // __ARM_NEON 112 113 } // namespace aarch64 114 } // namespace __llvm_libc 115 116 #endif // LLVM_LIBC_SRC_STRING_MEMORY_UTILS_ELEMENTS_AARCH64_H 117