llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-flang-runtime Author: Slava Zakharin (vzakhari) <details> <summary>Changes</summary> An InternalUnit might be constructed to allocate its own "output" buffer of a predefined size. The buffer is then used for collecting all the output, and it printed by std::printf at the end of the statement. This is a suggested way for supporting 'PRINT *, ...' in the device code. It might be not ideal, because the output is not formatted the same way as the UNIT=5 output is formatted by default. --- Full diff: https://github.com/llvm/llvm-project/pull/85181.diff 3 Files Affected: - (modified) flang/runtime/internal-unit.cpp (+34-3) - (modified) flang/runtime/internal-unit.h (+12-1) - (modified) flang/runtime/io-stmt.cpp (+5-1) ``````````diff diff --git a/flang/runtime/internal-unit.cpp b/flang/runtime/internal-unit.cpp index 66140e00588723..39fefd8c58cafb 100644 --- a/flang/runtime/internal-unit.cpp +++ b/flang/runtime/internal-unit.cpp @@ -15,13 +15,24 @@ namespace Fortran::runtime::io { template <Direction DIR> -InternalDescriptorUnit<DIR>::InternalDescriptorUnit( - Scalar scalar, std::size_t length, int kind) { +InternalDescriptorUnit<DIR>::InternalDescriptorUnit(Scalar scalar, + std::size_t length, int kind, const Terminator &terminator, + bool allocateOwnOutput) { internalIoCharKind = kind; recordLength = length; endfileRecordNumber = 2; void *pointer{reinterpret_cast<void *>(const_cast<char *>(scalar))}; - descriptor().Establish(TypeCode{TypeCategory::Character, kind}, length * kind, + std::size_t bufferSize{length * kind}; + if (allocateOwnOutput) { + RUNTIME_CHECK(terminator, DIR == Direction::Output); + pointer = AllocateMemoryOrCrash(terminator, ownBufferSizeInBytes); + usesOwnBuffer = true; + + // Reserve one character of the kind for '\0' at the end. + bufferSize = (ownBufferSizeInBytes / kind) * kind - kind; + recordLength = bufferSize / kind; + } + descriptor().Establish(TypeCode{TypeCategory::Character, kind}, bufferSize, pointer, 0, nullptr, CFI_attribute_pointer); } @@ -41,6 +52,26 @@ InternalDescriptorUnit<DIR>::InternalDescriptorUnit( endfileRecordNumber = d.Elements() + 1; } +template <Direction DIR> void InternalDescriptorUnit<DIR>::EndIoStatement() { + if constexpr (DIR == Direction::Output) { + if (usesOwnBuffer) { + // Null terminate the buffer that contains just a single record. + Terminator terminator{__FILE__, __LINE__}; + RUNTIME_CHECK(terminator, + furthestPositionInRecord < + static_cast<std::int64_t>(ownBufferSizeInBytes)); + *reinterpret_cast<char *>(CurrentRecord() + furthestPositionInRecord) = + '\0'; + + // Print the buffer and deallocate memory. + // FIXME: this output does not match the regular unit 5 output. + std::printf("%s\n", descriptor().OffsetElement()); + FreeMemory(descriptor().OffsetElement()); + descriptor().set_base_addr(nullptr); + } + } +} + template <Direction DIR> bool InternalDescriptorUnit<DIR>::Emit( const char *data, std::size_t bytes, IoErrorHandler &handler) { diff --git a/flang/runtime/internal-unit.h b/flang/runtime/internal-unit.h index b536ffb831d550..fdf6e498eabf7e 100644 --- a/flang/runtime/internal-unit.h +++ b/flang/runtime/internal-unit.h @@ -12,6 +12,7 @@ #define FORTRAN_RUNTIME_IO_INTERNAL_UNIT_H_ #include "connection.h" +#include "flang/Runtime/api-attrs.h" #include "flang/Runtime/descriptor.h" #include <cinttypes> #include <type_traits> @@ -21,13 +22,19 @@ namespace Fortran::runtime::io { class IoErrorHandler; // Points to (but does not own) a CHARACTER scalar or array for internal I/O. +// The internal unit does not own the scalar buffer unless it is constructed +// with allocateOwnOutput set to true: in this case, it owns the buffer +// and also prints it to stdout at the end of the statement. +// This is used to support output on offload devices. // Does not buffer. template <Direction DIR> class InternalDescriptorUnit : public ConnectionState { public: using Scalar = std::conditional_t<DIR == Direction::Input, const char *, char *>; - InternalDescriptorUnit(Scalar, std::size_t chars, int kind); + InternalDescriptorUnit(Scalar, std::size_t chars, int kind, + const Terminator &terminator, bool allocateOwnOutput = false); InternalDescriptorUnit(const Descriptor &, const Terminator &); + void EndIoStatement(); bool Emit(const char *, std::size_t, IoErrorHandler &); std::size_t GetNextInputBytes(const char *&, IoErrorHandler &); @@ -48,6 +55,10 @@ template <Direction DIR> class InternalDescriptorUnit : public ConnectionState { void BlankFillOutputRecord(); StaticDescriptor<maxRank, true /*addendum*/> staticDescriptor_; + RT_OFFLOAD_VAR_GROUP_BEGIN + static constexpr std::size_t ownBufferSizeInBytes{1024}; + RT_OFFLOAD_VAR_GROUP_END + bool usesOwnBuffer{false}; }; extern template class InternalDescriptorUnit<Direction::Output>; diff --git a/flang/runtime/io-stmt.cpp b/flang/runtime/io-stmt.cpp index efefbc5e1a1c08..417225f79006ff 100644 --- a/flang/runtime/io-stmt.cpp +++ b/flang/runtime/io-stmt.cpp @@ -82,7 +82,8 @@ void IoStatementBase::BadInquiryKeywordHashCrash(InquiryKeywordHash inquiry) { template <Direction DIR> InternalIoStatementState<DIR>::InternalIoStatementState( Buffer scalar, std::size_t length, const char *sourceFile, int sourceLine) - : IoStatementBase{sourceFile, sourceLine}, unit_{scalar, length, 1} {} + : IoStatementBase{sourceFile, sourceLine}, + unit_{scalar, length, /*kind=*/1, *this} {} template <Direction DIR> InternalIoStatementState<DIR>::InternalIoStatementState( @@ -119,6 +120,9 @@ template <Direction DIR> void InternalIoStatementState<DIR>::BackspaceRecord() { } template <Direction DIR> int InternalIoStatementState<DIR>::EndIoStatement() { + if constexpr (DIR == Direction::Output) { + unit_.EndIoStatement(); + } auto result{IoStatementBase::EndIoStatement()}; if (free_) { FreeMemory(this); `````````` </details> https://github.com/llvm/llvm-project/pull/85181 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
