1 // Copyright 2015, ARM Limited 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 BUF_SIZE (4096) 32 #define __ masm-> 33 34 /* 35 * This example adds two vectors with 1-byte elements using NEON instructions, 36 * and returns the results in the first vector. 37 */ 38 void GenerateAdd2Vectors(MacroAssembler* masm) { 39 // void add2_vectors(uint8_t *vec*, const uint8_t *vecB, unsigned size) 40 // Argument locations: 41 // vecA (pointer) -> x0 42 // vecB (pointer) -> x1 43 // size (integer) -> w2 44 // Result returned in vecA. 45 46 Label loop16, loopr, end; 47 48 // Loop to add vector elements in 16-byte chunks. 49 __ Bind(&loop16); 50 51 // Handle vectors smaller than 16-bytes in the remainder loop. 52 __ Cmp(w2, 16); 53 __ B(lo, &loopr); 54 __ Sub(w2, w2, 16); 55 56 // Add vectors in 16-byte chunks. 57 __ Ld1(v0.V16B(), MemOperand(x0)); 58 __ Ld1(v1.V16B(), MemOperand(x1, 16, PostIndex)); 59 __ Add(v0.V16B(), v0.V16B(), v1.V16B()); 60 __ St1(v0.V16B(), MemOperand(x0, 16, PostIndex)); 61 62 __ B(&loop16); 63 64 // Loop to add the remaining vector elements. 65 __ Bind(&loopr); 66 67 // If there are no more vector elements to process, then exit. 68 __ Cbz(w2, &end); 69 __ Sub(w2, w2, 1); 70 71 // Add remaining vector elements in 1-byte chunks. 72 __ Ldrb(w5, MemOperand(x0)); 73 __ Ldrb(w6, MemOperand(x1, 1, PostIndex)); 74 __ Add(w5, w5, w6); 75 __ Strb(w5, MemOperand(x0, 1, PostIndex)); 76 77 __ B(&loopr); 78 79 __ Bind(&end); 80 81 __ Ret(); 82 } 83 84 85 void PrintVector(const uint8_t *vec, unsigned num) { 86 unsigned i; 87 printf("( "); 88 if (num > 0) { 89 for (i = 0; i < num - 1; ++i) { 90 printf("%d, ", vec[i]); 91 } 92 printf("%d", vec[i]); 93 } 94 printf(" )\n"); 95 } 96 97 98 #ifndef TEST_EXAMPLES 99 int main(void) { 100 // Create and initialize the assembler. 101 byte assm_buf[BUF_SIZE]; 102 MacroAssembler masm(assm_buf, BUF_SIZE); 103 104 // Generate native code for the example function. 105 Label add2_vectors; 106 masm.Bind(&add2_vectors); 107 GenerateAdd2Vectors(&masm); 108 masm.FinalizeCode(); 109 110 // Initialize input data for the example function. 111 uint8_t vecA[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 112 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 113 16, 17, 18, 19, 20}; 114 uint8_t vecB[] = {16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 115 30, 31, 116 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 117 30, 31, 118 32, 33, 34, 35, 36}; 119 uint8_t vecC[ARRAY_SIZE(vecA)]; 120 121 // Check whether the number of elements in both vectors match. 122 assert(ARRAY_SIZE(vecA) == ARRAY_SIZE(vecB)); 123 124 // Compute the result in C. 125 for (unsigned i = 0; i < ARRAY_SIZE(vecA); i++) { 126 vecC[i] = vecA[i] + vecB[i]; 127 } 128 129 #ifdef VIXL_INCLUDE_SIMULATOR 130 uintptr_t vecA_addr = reinterpret_cast<uintptr_t>(vecA); 131 uintptr_t vecB_addr = reinterpret_cast<uintptr_t>(vecB); 132 133 // Configure register environment in the simulator. 134 Decoder decoder; 135 Simulator simulator(&decoder); 136 simulator.set_xreg(0, vecA_addr); 137 simulator.set_xreg(1, vecB_addr); 138 simulator.set_xreg(2, ARRAY_SIZE(vecA)); 139 PrintVector(vecA, ARRAY_SIZE(vecA)); 140 printf(" +\n"); 141 PrintVector(vecB, ARRAY_SIZE(vecB)); 142 143 // Run the example function in the simulator. 144 simulator.RunFrom(masm.GetLabelAddress<Instruction*>(&add2_vectors)); 145 printf(" =\n"); 146 PrintVector(vecA, ARRAY_SIZE(vecA)); 147 #else 148 // Placeholder to run test natively. 149 printf("Running tests natively is not supported yet.\n"); 150 return 0; 151 #endif // VIXL_INCLUDE_SIMULATOR 152 // Check that the computed value in NEON matches the C version. 153 for (unsigned i = 0; i < ARRAY_SIZE(vecA); i++) { 154 assert(vecC[i] == vecA[i]); 155 } 156 157 return 0; 158 } 159 #endif // TEST_EXAMPLES 160
