1*c6d03b58SMichael Jones //===-- Implementation of strncmp -----------------------------------------===// 2*c6d03b58SMichael Jones // 3*c6d03b58SMichael Jones // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*c6d03b58SMichael Jones // See https://llvm.org/LICENSE.txt for license information. 5*c6d03b58SMichael Jones // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*c6d03b58SMichael Jones // 7*c6d03b58SMichael Jones //===----------------------------------------------------------------------===// 8*c6d03b58SMichael Jones 9*c6d03b58SMichael Jones #include "src/string/strncmp.h" 10*c6d03b58SMichael Jones 11*c6d03b58SMichael Jones #include "src/__support/common.h" 12*c6d03b58SMichael Jones #include <stddef.h> 13*c6d03b58SMichael Jones 14*c6d03b58SMichael Jones namespace __llvm_libc { 15*c6d03b58SMichael Jones 16*c6d03b58SMichael Jones // TODO: Look at benefits for comparing words at a time. 17*c6d03b58SMichael Jones LLVM_LIBC_FUNCTION(int, strncmp, 18*c6d03b58SMichael Jones (const char *left, const char *right, size_t n)) { 19*c6d03b58SMichael Jones 20*c6d03b58SMichael Jones if (n == 0) 21*c6d03b58SMichael Jones return 0; 22*c6d03b58SMichael Jones 23*c6d03b58SMichael Jones for (; n > 1; --n, ++left, ++right) { 24*c6d03b58SMichael Jones char lc = *left; 25*c6d03b58SMichael Jones if (lc == '\0' || lc != *right) 26*c6d03b58SMichael Jones break; 27*c6d03b58SMichael Jones } 28*c6d03b58SMichael Jones return *reinterpret_cast<const unsigned char *>(left) - 29*c6d03b58SMichael Jones *reinterpret_cast<const unsigned char *>(right); 30*c6d03b58SMichael Jones } 31*c6d03b58SMichael Jones 32*c6d03b58SMichael Jones } // namespace __llvm_libc 33