Coverage Report

Created: 2020-11-24 06:42

/Users/buildslave/jenkins/workspace/coverage/llvm-project/libcxx/src/filesystem/int128_builtins.cpp
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/*===-- int128_builtins.cpp - Implement __muloti4 --------------------------===
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 *
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 * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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 * See https://llvm.org/LICENSE.txt for license information.
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 * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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 *
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 * ===----------------------------------------------------------------------===
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 *
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 * This file implements __muloti4, and is stolen from the compiler_rt library.
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 *
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 * FIXME: we steal and re-compile it into filesystem, which uses __int128_t,
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 * and requires this builtin when sanitized. See llvm.org/PR30643
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 *
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 * ===----------------------------------------------------------------------===
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 */
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#include "__config"
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#include "climits"
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#if !defined(_LIBCPP_HAS_NO_INT128)
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extern "C" __attribute__((no_sanitize("undefined"))) _LIBCPP_FUNC_VIS
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__int128_t __muloti4(__int128_t a, __int128_t b, int* overflow) {
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  const int N = (int)(sizeof(__int128_t) * CHAR_BIT);
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  const __int128_t MIN = (__int128_t)1 << (N - 1);
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  const __int128_t MAX = ~MIN;
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  *overflow = 0;
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  __int128_t result = a * b;
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  if (a == MIN) {
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    if (b != 0 && b != 1)
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      *overflow = 1;
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    return result;
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  }
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  if (b == MIN) {
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    if (a != 0 && a != 1)
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      *overflow = 1;
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    return result;
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  }
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  __int128_t sa = a >> (N - 1);
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  __int128_t abs_a = (a ^ sa) - sa;
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  __int128_t sb = b >> (N - 1);
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  __int128_t abs_b = (b ^ sb) - sb;
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  if (abs_a < 2 || abs_b < 2)
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    return result;
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  if (sa == sb) {
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    if (abs_a > MAX / abs_b)
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      *overflow = 1;
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  } else {
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    if (abs_a > MIN / -abs_b)
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      *overflow = 1;
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  }
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  return result;
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}
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#endif