flang/runtime/exceptions.cpp

   1 //===-- runtime/exceptions.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 // Runtime exception support.
  10
  11 #include "flang/Runtime/exceptions.h"
  12 #include "terminator.h"
  13 #include <cfenv>
  14
  15 // When not supported, these macro are undefined in cfenv.h,
  16 // set them to zero in that case.
  17 #ifndef FE_INVALID
  18 #define FE_INVALID 0
  19 #endif
  20 #ifndef __FE_DENORM
  21 #define __FE_DENORM 0 // denorm is nonstandard
  22 #endif
  23 #ifndef FE_DIVBYZERO
  24 #define FE_DIVBYZERO 0
  25 #endif
  26 #ifndef FE_OVERFLOW
  27 #define FE_OVERFLOW 0
  28 #endif
  29 #ifndef FE_UNDERFLOW
  30 #define FE_UNDERFLOW 0
  31 #endif
  32 #ifndef FE_INEXACT
  33 #define FE_INEXACT 0
  34 #endif
  35
  36 namespace Fortran::runtime {
  37
  38 extern "C" {
  39
  40 // Map a set of Fortran ieee_arithmetic module exceptions to a libm fenv.h
  41 // excepts value.
  42 uint32_t RTNAME(MapException)(uint32_t excepts) {
  43   Terminator terminator{__FILE__, __LINE__};
  44
  45   static constexpr uint32_t v{FE_INVALID};
  46   static constexpr uint32_t s{__FE_DENORM}; // subnormal
  47   static constexpr uint32_t z{FE_DIVBYZERO};
  48   static constexpr uint32_t o{FE_OVERFLOW};
  49   static constexpr uint32_t u{FE_UNDERFLOW};
  50   static constexpr uint32_t x{FE_INEXACT};
  51
  52 #define vm(p) p, p | v
  53 #define sm(p) vm(p), vm(p | s)
  54 #define zm(p) sm(p), sm(p | z)
  55 #define om(p) zm(p), zm(p | o)
  56 #define um(p) om(p), om(p | u)
  57 #define xm um(0), um(x)
  58
  59   static constexpr uint32_t map[]{xm};
  60   static constexpr uint32_t mapSize{sizeof(map) / sizeof(uint32_t)};
  61   static_assert(mapSize == 64);
  62   if (excepts == 0 || excepts >= mapSize) {
  63     terminator.Crash("Invalid excepts value: %d", excepts);
  64   }
  65   uint32_t except_value = map[excepts];
  66   if (except_value == 0) {
  67     terminator.Crash(
  68         "Excepts value %d not supported by flang runtime", excepts);
  69   }
  70   return except_value;
  71 }
  72
  73 // Verify that the size of ieee_modes_type and ieee_status_type objects from
  74 // intrinsic module file __fortran_ieee_exceptions.f90 are large enough to
  75 // hold fenv_t object.
  76 // TODO: fenv_t can be way larger than
  77 //      sizeof(int) * _FORTRAN_RUNTIME_IEEE_FENV_T_EXTENT
  78 // on some systems, e.g. Solaris, so omit object size comparison for now.
  79 // TODO: consider femode_t object size comparison once its more mature.
  80
  81 } // extern "C"
  82 } // namespace Fortran::runtime