flang/runtime/misc-intrinsic.cpp

   1 //===-- runtime/misc-intrinsic.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 "flang/Runtime/misc-intrinsic.h"
  10 #include "terminator.h"
  11 #include "tools.h"
  12 #include "flang/Runtime/descriptor.h"
  13 #include <algorithm>
  14 #include <cstring>
  15 #include <optional>
  16
  17 namespace Fortran::runtime {
  18
  19 static RT_API_ATTRS void TransferImpl(Descriptor &result,
  20     const Descriptor &source, const Descriptor &mold, const char *sourceFile,
  21     int line, std::optional<std::int64_t> resultExtent) {
  22   int rank{resultExtent.has_value() ? 1 : 0};
  23   std::size_t elementBytes{mold.ElementBytes()};
  24   result.Establish(mold.type(), elementBytes, nullptr, rank, nullptr,
  25       CFI_attribute_allocatable, mold.Addendum() != nullptr);
  26   if (resultExtent) {
  27     result.GetDimension(0).SetBounds(1, *resultExtent);
  28   }
  29   if (const DescriptorAddendum * addendum{mold.Addendum()}) {
  30     *result.Addendum() = *addendum;
  31   }
  32   if (int stat{result.Allocate()}) {
  33     Terminator{sourceFile, line}.Crash(
  34         "TRANSFER: could not allocate memory for result; STAT=%d", stat);
  35   }
  36   char *to{result.OffsetElement<char>()};
  37   std::size_t resultBytes{result.Elements() * result.ElementBytes()};
  38   const std::size_t sourceElementBytes{source.ElementBytes()};
  39   std::size_t sourceElements{source.Elements()};
  40   SubscriptValue sourceAt[maxRank];
  41   source.GetLowerBounds(sourceAt);
  42   while (resultBytes > 0 && sourceElements > 0) {
  43     std::size_t toMove{std::min(resultBytes, sourceElementBytes)};
  44     std::memcpy(to, source.Element<char>(sourceAt), toMove);
  45     to += toMove;
  46     resultBytes -= toMove;
  47     --sourceElements;
  48     source.IncrementSubscripts(sourceAt);
  49   }
  50   if (resultBytes > 0) {
  51     std::memset(to, 0, resultBytes);
  52   }
  53 }
  54
  55 extern "C" {
  56 RT_EXT_API_GROUP_BEGIN
  57
  58 void RTDEF(Transfer)(Descriptor &result, const Descriptor &source,
  59     const Descriptor &mold, const char *sourceFile, int line) {
  60   std::optional<std::int64_t> elements;
  61   if (mold.rank() > 0) {
  62     if (std::size_t sourceElementBytes{
  63             source.Elements() * source.ElementBytes()}) {
  64       if (std::size_t moldElementBytes{mold.ElementBytes()}) {
  65         elements = static_cast<std::int64_t>(
  66             (sourceElementBytes + moldElementBytes - 1) / moldElementBytes);
  67       } else {
  68         Terminator{sourceFile, line}.Crash("TRANSFER: zero-sized type of MOLD= "
  69                                            "when SOURCE= is not zero-sized");
  70       }
  71     } else {
  72       elements = std::int64_t{0};
  73     }
  74   }
  75   return TransferImpl(
  76       result, source, mold, sourceFile, line, std::move(elements));
  77 }
  78
  79 void RTDEF(TransferSize)(Descriptor &result, const Descriptor &source,
  80     const Descriptor &mold, const char *sourceFile, int line,
  81     std::int64_t size) {
  82   return TransferImpl(result, source, mold, sourceFile, line, size);
  83 }
  84
  85 RT_EXT_API_GROUP_END
  86 } // extern "C"
  87 } // namespace Fortran::runtime