PTO-TILE-MODEL-MEMORY-ATOMICS

1// PTO-UNIT: {"id":"PTO-TILE-MODEL-MEMORY-ATOMICS","surface":"tile","classification":["model","memory","atomics"],"depends_on":["PTO-TILE-MODEL-MEMORY-GATHER-SCATTER","PTO-ARCH-MEMORY-MODEL-ATOMICITY"]}2func MGATHER_CAS(destination: TileIndex, base_address: Word, indices: TileIndex,3                 expected: TileIndex, replacement: TileIndex,4                 pad_value: TilePadValue)5begin6    let destination_tile = _Tiles[[destination]];7    let index_tile = _Tiles[[indices]];8    let expected_payload = _Tiles[[expected]].payload;9    let replacement_payload = _Tiles[[replacement]].payload;10    assert destination_tile.allocated;11    assert index_tile.allocated && index_tile.contents_defined;12    assert _Tiles[[expected]].allocated && _Tiles[[expected]].contents_defined;13    assert _Tiles[[replacement]].allocated &&14        _Tiles[[replacement]].contents_defined;15    assert destination_tile.valid_rows == index_tile.valid_rows;16    assert destination_tile.valid_columns == index_tile.valid_columns;17    assert IndexedTLSUIndexDataTypeLegal(index_tile.data_type);18    assert IndexedTLSUTransferDataTypeLegal(destination_tile.data_type);19    let index_payload = index_tile.payload;20    var original_addresses: TilePayload;21    var translated_addresses: TilePayload;22    var write_translated_addresses: TilePayload;23    var expected_values: TilePayload;24    var replacement_values: TilePayload;25    var lane_order: ScatterLaneOrder;26    var lane_count: integer {0..PTO_MODEL_TILE_ELEMENTS} = 0;27    var result_payload = destination_tile.payload;28    for row = 0 to destination_tile.valid_rows - 1 looplimit 65536 do29        for column = 0 to destination_tile.valid_columns - 1 looplimit 65536 do30            let destination_element = TileLinearIndex(destination_tile,31                row as integer {0..65535}, column as integer {0..65535});32            let index_element = TileLinearIndex(index_tile,33                row as integer {0..65535}, column as integer {0..65535});34            let expected_element = TileLinearIndex(_Tiles[[expected]],35                row as integer {0..65535}, column as integer {0..65535});36            let replacement_element = TileLinearIndex(_Tiles[[replacement]],37                row as integer {0..65535}, column as integer {0..65535});38            let address = TileMemoryByteDisplacementAddress(base_address,39                index_payload[[index_element]], index_tile.data_type);40            let read_probe = ProbeTileMemoryAccess(address,41                destination_tile.data_type, FALSE);42            if RaiseDataAccessFault(read_probe, address) then return; end;43            let write_probe = ProbeTileMemoryAccess(address,44                destination_tile.data_type, TRUE);45            if RaiseDataAccessFault(write_probe, address) then return; end;46            if read_probe.translated_address != write_probe.translated_address then47                SetFault(Fault_DataPage, address);48                return;49            end;50            original_addresses[[destination_element]] = address;51            translated_addresses[[destination_element]] =52                read_probe.translated_address;53            write_translated_addresses[[destination_element]] =54                write_probe.translated_address;55            expected_values[[destination_element]] =56                expected_payload[[expected_element]];57            replacement_values[[destination_element]] =58                replacement_payload[[replacement_element]];59            lane_order[[lane_count]] = NaturalToWord(destination_element);60            lane_count = (lane_count + 1) as61                integer {0..PTO_MODEL_TILE_ELEMENTS};62        end;63    end;64    for row = 0 to destination_tile.rows - 1 looplimit 65536 do65        for column = 0 to destination_tile.columns - 1 looplimit 65536 do66            let element = TileLinearIndex(destination_tile,67                row as integer {0..65535}, column as integer {0..65535});68            result_payload[[element]] = TilePadValueForDataType(69                pad_value, destination_tile.data_type);70        end;71    end;72    // Duplicate addresses are serialized in an implementation-defined order.73    // Each selected lane remains one atomic read-modify-write, but neither74    // row-major order nor another fixed order becomes architectural.75    for position = 0 to lane_count - 1 looplimit PTO_MODEL_TILE_ELEMENTS do76            var selected_position:77                integer {0..PTO_MODEL_TILE_ELEMENTS-1} =78                    position as integer {0..PTO_MODEL_TILE_ELEMENTS-1};79            var selected = FALSE;80            for candidate_position = position to lane_count - 181                looplimit PTO_MODEL_TILE_ELEMENTS do82                if !selected && ARBITRARY: boolean then83                    selected_position = candidate_position as84                        integer {0..PTO_MODEL_TILE_ELEMENTS-1};85                    selected = TRUE;86                end;87            end;88            let selected_element = lane_order[[selected_position]];89            lane_order[[selected_position]] = lane_order[[position]];90            lane_order[[position]] = selected_element;91            let element = UInt(lane_order[[position]]) as92                ModelTileElementIndex;93            let old_raw = LoadTranslatedUnsigned(94                translated_addresses[[element]],95                TileMemoryElementBytes(destination_tile.data_type));96            let old_value = DecodeTileMemoryElementRaw(97                old_raw, destination_tile.data_type, FALSE);98            result_payload[[element]] = old_value;99            let succeeds = NormalizeMemoryAccessValue(old_value,100                TileMemoryElementBytes(destination_tile.data_type)) ==101                NormalizeMemoryAccessValue(expected_values[[element]],102                    TileMemoryElementBytes(destination_tile.data_type));103            let write_value = NormalizeMemoryAccessValue(104                replacement_values[[element]],105                TileMemoryElementBytes(destination_tile.data_type));106            if succeeds then107                - = StoreTileMemoryElement(original_addresses[[element]],108                    write_translated_addresses[[element]],109                    destination_tile.data_type, FALSE,110                    replacement_values[[element]]);111            end;112            RecordAtomicEvent(write_translated_addresses[[element]],113                TileMemoryElementBytes(destination_tile.data_type), old_raw,114                write_value, CurrentBundleMemoryOrder(), succeeds);115    end;116    _Tiles[[destination]].payload = result_payload;117    MarkTilePhysicalRegionDefined(destination);118end;119
120func MGATHER_CAS(destination: TileIndex, base_address: Word,121                 indices: TileIndex, expected: TileIndex,122                 replacement: TileIndex)123begin124    MGATHER_CAS(destination, base_address, indices, expected, replacement,125        TilePad_Null);126end;127