/* * Copyright (C) 2025 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include #include #include // For usleep function typedef uint32_t UInt32; typedef uint16_t UInt16; void cond_branch_example_function(uint16_t* prob, uint8_t* buf) { UInt32 range = 0xFFFFFFFF; UInt32 code = 0; UInt32 bound; UInt16 ttt; UInt32 symbol = 0; do { ttt = *(prob + symbol); if (range < ((UInt32)1 << 24)) { range <<= 8; code = (code << 8) | (*buf++); } bound = (range >> 11) * ttt; if (code < bound) { // <== This is mispredicted branch (conditional branch) range = bound; *(prob + symbol) = (UInt16)(ttt + (((1 << 11) - ttt) >> 5)); symbol = (symbol + symbol); } else { range -= bound; code -= bound; *(prob + symbol) = (UInt16)(ttt - (ttt >> 5)); symbol = (symbol + symbol) + 1; } } while (symbol < 0x100); // conditional branch } int main() { uint16_t prob[256] = {0}; uint8_t buf[256] = {0}; usleep(15000000); // Call the conditional branch example function cond_branch_example_function(prob, buf); return 0; }