libc/utils/testutils/RoundingModeUtils.cpp

   1 //===-- RoundingModeUtils.cpp ---------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "RoundingModeUtils.h"
  10
  11 #include <fenv.h>
  12
  13 namespace __llvm_libc {
  14 namespace testutils {
  15
  16 int get_fe_rounding(RoundingMode mode) {
  17   switch (mode) {
  18   case RoundingMode::Upward:
  19     return FE_UPWARD;
  20     break;
  21   case RoundingMode::Downward:
  22     return FE_DOWNWARD;
  23     break;
  24   case RoundingMode::TowardZero:
  25     return FE_TOWARDZERO;
  26     break;
  27   case RoundingMode::Nearest:
  28     return FE_TONEAREST;
  29     break;
  30   default:
  31     __builtin_unreachable();
  32   }
  33 }
  34
  35 ForceRoundingMode::ForceRoundingMode(RoundingMode mode) {
  36   old_rounding_mode = fegetround();
  37   rounding_mode = get_fe_rounding(mode);
  38   if (old_rounding_mode != rounding_mode)
  39     fesetround(rounding_mode);
  40 }
  41
  42 ForceRoundingMode::~ForceRoundingMode() {
  43   if (old_rounding_mode != rounding_mode)
  44     fesetround(old_rounding_mode);
  45 }
  46
  47 } // namespace testutils
  48 } // namespace __llvm_libc