1 // Copyright 2015, VIXL authors 2 // All rights reserved. 3 // 4 // Redistribution and use in source and binary forms, with or without 5 // modification, are permitted provided that the following conditions are met: 6 // 7 // * Redistributions of source code must retain the above copyright notice, 8 // this list of conditions and the following disclaimer. 9 // * Redistributions in binary form must reproduce the above copyright notice, 10 // this list of conditions and the following disclaimer in the documentation 11 // and/or other materials provided with the distribution. 12 // * Neither the name of ARM Limited nor the names of its contributors may be 13 // used to endorse or promote products derived from this software without 14 // specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND 17 // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 18 // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 19 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 20 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 22 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 23 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 25 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 27 #include "examples.h" 28 29 // Macro to compute the number of elements in a vector. 30 #define ARRAY_SIZE(Array) (sizeof(Array) / sizeof((Array)[0])) 31 #define __ masm-> 32 33 /* 34 * This example adds two vectors with 1-byte elements using NEON instructions, 35 * and returns the results in the first vector. 36 */ 37 void GenerateAdd2Vectors(MacroAssembler* masm) { 38 // void add2_vectors(uint8_t *vec*, const uint8_t *vecB, unsigned size) 39 // Argument locations: 40 // vecA (pointer) -> x0 41 // vecB (pointer) -> x1 42 // size (integer) -> w2 43 // Result returned in vecA. 44 45 Label loop16, loopr, end; 46 47 // Loop to add vector elements in 16-byte chunks. 48 __ Bind(&loop16); 49 50 // Handle vectors smaller than 16-bytes in the remainder loop. 51 __ Cmp(w2, 16); 52 __ B(lo, &loopr); 53 __ Sub(w2, w2, 16); 54 55 // Add vectors in 16-byte chunks. 56 __ Ld1(v0.V16B(), MemOperand(x0)); 57 __ Ld1(v1.V16B(), MemOperand(x1, 16, PostIndex)); 58 __ Add(v0.V16B(), v0.V16B(), v1.V16B()); 59 __ St1(v0.V16B(), MemOperand(x0, 16, PostIndex)); 60 61 __ B(&loop16); 62 63 // Loop to add the remaining vector elements. 64 __ Bind(&loopr); 65 66 // If there are no more vector elements to process, then exit. 67 __ Cbz(w2, &end); 68 __ Sub(w2, w2, 1); 69 70 // Add remaining vector elements in 1-byte chunks. 71 __ Ldrb(w5, MemOperand(x0)); 72 __ Ldrb(w6, MemOperand(x1, 1, PostIndex)); 73 __ Add(w5, w5, w6); 74 __ Strb(w5, MemOperand(x0, 1, PostIndex)); 75 76 __ B(&loopr); 77 78 __ Bind(&end); 79 80 __ Ret(); 81 } 82 83 84 void PrintVector(const uint8_t* vec, unsigned num) { 85 unsigned i; 86 printf("( "); 87 if (num > 0) { 88 for (i = 0; i < num - 1; ++i) { 89 printf("%d, ", vec[i]); 90 } 91 printf("%d", vec[i]); 92 } 93 printf(" )\n"); 94 } 95 96 97 #ifndef TEST_EXAMPLES 98 int main(void) { 99 MacroAssembler masm; 100 101 // Generate native code for the example function. 102 Label add2_vectors; 103 masm.Bind(&add2_vectors); 104 GenerateAdd2Vectors(&masm); 105 masm.FinalizeCode(); 106 107 // Initialize input data for the example function. 108 // clang-format: off 109 uint8_t vecA[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 110 13, 14, 15, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 111 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20}; 112 uint8_t vecB[] = {16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 113 29, 30, 31, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 114 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36}; 115 // clang-format on 116 uint8_t vecC[ARRAY_SIZE(vecA)]; 117 118 // Check whether the number of elements in both vectors match. 119 VIXL_CHECK(ARRAY_SIZE(vecA) == ARRAY_SIZE(vecB)); 120 121 // Compute the result in C. 122 for (unsigned i = 0; i < ARRAY_SIZE(vecA); i++) { 123 vecC[i] = vecA[i] + vecB[i]; 124 } 125 126 #ifdef VIXL_INCLUDE_SIMULATOR_AARCH64 127 uintptr_t vecA_addr = reinterpret_cast<uintptr_t>(vecA); 128 uintptr_t vecB_addr = reinterpret_cast<uintptr_t>(vecB); 129 130 // Configure register environment in the simulator. 131 Decoder decoder; 132 Simulator simulator(&decoder); 133 simulator.WriteXRegister(0, vecA_addr); 134 simulator.WriteXRegister(1, vecB_addr); 135 simulator.WriteXRegister(2, ARRAY_SIZE(vecA)); 136 PrintVector(vecA, ARRAY_SIZE(vecA)); 137 printf(" +\n"); 138 PrintVector(vecB, ARRAY_SIZE(vecB)); 139 140 // Run the example function in the simulator. 141 simulator.RunFrom(masm.GetLabelAddress<Instruction*>(&add2_vectors)); 142 printf(" =\n"); 143 PrintVector(vecA, ARRAY_SIZE(vecA)); 144 145 // Check that the computed value in NEON matches the C version. 146 for (unsigned i = 0; i < ARRAY_SIZE(vecA); i++) { 147 VIXL_CHECK(vecC[i] == vecA[i]); 148 } 149 #else 150 USE(vecC); 151 152 // Placeholder to run test natively. 153 printf("Running tests natively is not supported yet.\n"); 154 #endif // VIXL_INCLUDE_SIMULATOR_AARCH64 155 156 return 0; 157 } 158 #endif // TEST_EXAMPLES 159
