summaryrefslogtreecommitdiff
path: root/source/slang/slang-ir-lower-existential.cpp
blob: 4078ad88471d59b943ddf40a7c697e770f94c92c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
// slang-ir-lower-generic-existential.cpp

#include "slang-ir-lower-existential.h"
#include "slang-ir-generics-lowering-context.h"
#include "slang-ir.h"
#include "slang-ir-insts.h"

namespace Slang
{
    struct ExistentialLoweringContext
    {
        SharedGenericsLoweringContext* sharedContext;

        void processMakeExistential(IRMakeExistentialWithRTTI* inst)
        {
            IRBuilder builderStorage;
            auto builder = &builderStorage;
            builder->sharedBuilder = &sharedContext->sharedBuilderStorage;
            builder->setInsertBefore(inst);

            auto value = inst->getWrappedValue();
            auto valueType = sharedContext->lowerType(builder, value->getDataType());
            auto witnessTableType = cast<IRWitnessTableType>(inst->getWitnessTable()->getDataType());
            auto interfaceType = witnessTableType->getConformanceType();
            auto anyValueSize = sharedContext->getInterfaceAnyValueSize(interfaceType, inst->sourceLoc);
            auto anyValueType = builder->getAnyValueType(anyValueSize);
            auto rttiType = builder->getPtrType(builder->getRTTIType());
            auto tupleType = builder->getTupleType(anyValueType, witnessTableType, rttiType);

            IRInst* rttiObject = inst->getRTTI();
            if (auto type = as<IRType>(rttiObject))
            {
                rttiObject = sharedContext->maybeEmitRTTIObject(type);
                rttiObject = builder->emitGetAddress(rttiType, rttiObject);
            }
            IRInst* packedValue = value;
            if (valueType->op != kIROp_AnyValueType)
                packedValue = builder->emitPackAnyValue(anyValueType, value);
            IRInst* tupleArgs[] = { packedValue, inst->getWitnessTable(), rttiObject };
            auto tuple = builder->emitMakeTuple(tupleType, 3, tupleArgs);
            inst->replaceUsesWith(tuple);
            inst->removeAndDeallocate();
        }

        IRInst* extractTupleElement(IRBuilder* builder, IRInst* value, UInt index)
        {
            auto tupleType = cast<IRTupleType>(sharedContext->lowerType(builder, value->getDataType()));
            auto getElement = builder->emitGetTupleElement(
                (IRType*)tupleType->getOperand(index),
                value,
                index);
            return getElement;
        }

        void processExtractExistentialElement(IRInst* extractInst, UInt elementId)
        {
            IRBuilder builderStorage;
            auto builder = &builderStorage;
            builder->sharedBuilder = &sharedContext->sharedBuilderStorage;
            builder->setInsertBefore(extractInst);

            auto element = extractTupleElement(builder, extractInst->getOperand(0), elementId);
            extractInst->replaceUsesWith(element);
            extractInst->removeAndDeallocate();
        }

        void processExtractExistentialValue(IRExtractExistentialValue* inst)
        {
            processExtractExistentialElement(inst, 0);
        }

        void processExtractExistentialWitnessTable(IRExtractExistentialWitnessTable* inst)
        {
            processExtractExistentialElement(inst, 1);
        }

        void processExtractExistentialType(IRExtractExistentialType* inst)
        {
            processExtractExistentialElement(inst, 2);
        }

        void processInst(IRInst* inst)
        {
            if (auto makeExistential = as<IRMakeExistentialWithRTTI>(inst))
            {
                processMakeExistential(makeExistential);
            }
            else if (auto extractExistentialVal = as<IRExtractExistentialValue>(inst))
            {
                processExtractExistentialValue(extractExistentialVal);
            }
            else if (auto extractExistentialType = as<IRExtractExistentialType>(inst))
            {
                processExtractExistentialType(extractExistentialType);
            }
            else if (auto extractExistentialWitnessTable = as<IRExtractExistentialWitnessTable>(inst))
            {
                processExtractExistentialWitnessTable(extractExistentialWitnessTable);
            }
        }

        void processModule()
        {
            // We start by initializing our shared IR building state,
            // since we will re-use that state for any code we
            // generate along the way.
            //
            SharedIRBuilder* sharedBuilder = &sharedContext->sharedBuilderStorage;
            sharedBuilder->module = sharedContext->module;
            sharedBuilder->session = sharedContext->module->session;

            sharedContext->addToWorkList(sharedContext->module->getModuleInst());

            while (sharedContext->workList.getCount() != 0)
            {
                IRInst* inst = sharedContext->workList.getLast();

                sharedContext->workList.removeLast();
                sharedContext->workListSet.Remove(inst);

                processInst(inst);

                for (auto child = inst->getLastChild(); child; child = child->getPrevInst())
                {
                    sharedContext->addToWorkList(child);
                }
            }
        }
    };


    void lowerExistentials(SharedGenericsLoweringContext* sharedContext)
    {
        ExistentialLoweringContext context;
        context.sharedContext = sharedContext;
        context.processModule();
    }
}