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