llvm-project/flang/runtime/misc-intrinsic.cpp

70 lines
2.4 KiB
C++

//===-- runtime/misc-intrinsic.cpp ----------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "flang/Runtime/misc-intrinsic.h"
#include "terminator.h"
#include "flang/Runtime/descriptor.h"
#include <algorithm>
#include <cstring>
namespace Fortran::runtime {
extern "C" {
void RTNAME(Transfer)(Descriptor &result, const Descriptor &source,
const Descriptor &mold, const char *sourceFile, int line) {
if (mold.rank() > 0) {
std::size_t moldElementBytes{mold.ElementBytes()};
std::size_t elements{
(source.Elements() * source.ElementBytes() + moldElementBytes - 1) /
moldElementBytes};
return RTNAME(TransferSize)(result, source, mold, sourceFile, line,
static_cast<std::int64_t>(elements));
} else {
return RTNAME(TransferSize)(result, source, mold, sourceFile, line, 1);
}
}
void RTNAME(TransferSize)(Descriptor &result, const Descriptor &source,
const Descriptor &mold, const char *sourceFile, int line,
std::int64_t size) {
int rank{mold.rank() > 0 ? 1 : 0};
std::size_t elementBytes{mold.ElementBytes()};
result.Establish(mold.type(), elementBytes, nullptr, rank, nullptr,
CFI_attribute_allocatable, mold.Addendum() != nullptr);
if (rank > 0) {
result.GetDimension(0).SetBounds(1, size);
}
if (const DescriptorAddendum * addendum{mold.Addendum()}) {
*result.Addendum() = *addendum;
}
if (int stat{result.Allocate()}) {
Terminator{sourceFile, line}.Crash(
"TRANSFER: could not allocate memory for result; STAT=%d", stat);
}
char *to{result.OffsetElement<char>()};
std::size_t resultBytes{size * elementBytes};
const std::size_t sourceElementBytes{source.ElementBytes()};
std::size_t sourceElements{source.Elements()};
SubscriptValue sourceAt[maxRank];
source.GetLowerBounds(sourceAt);
while (resultBytes > 0 && sourceElements > 0) {
std::size_t toMove{std::min(resultBytes, sourceElementBytes)};
std::memcpy(to, source.Element<char>(sourceAt), toMove);
to += toMove;
resultBytes -= toMove;
--sourceElements;
source.IncrementSubscripts(sourceAt);
}
if (resultBytes > 0) {
std::memset(to, 0, resultBytes);
}
}
} // extern "C"
} // namespace Fortran::runtime