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#include "src/tint/lang/core/ir/var.h"

#include "src/tint/lang/core/ir/clone_context.h"
#include "src/tint/lang/core/ir/module.h"
#include "src/tint/lang/core/ir/store.h"
#include "src/tint/lang/core/type/pointer.h"
#include "src/tint/utils/ice/ice.h"

TINT_INSTANTIATE_TYPEINFO(tint::core::ir::Var);

namespace tint::core::ir {

Var::Var(Id id) : Base(id) {}

Var::Var(Id id, InstructionResult* result) : Base(id) {
    if (result && result->Type()) {
        TINT_ASSERT(result->Type()->Is<core::type::MemoryView>());
    }

    // Default to no initializer.
    AddOperand(Var::kInitializerOperandOffset, nullptr);
    AddResult(result);
}

Var::~Var() = default;

Var* Var::Clone(CloneContext& ctx) {
    auto* new_result = ctx.Clone(Result());
    auto* new_var = ctx.ir.CreateInstruction<Var>(new_result);

    new_var->attributes_ = attributes_;

    if (auto* init = Initializer()) {
        new_var->SetInitializer(ctx.Clone(init));
    }

    auto name = ctx.ir.NameOf(this);
    if (name.IsValid()) {
        ctx.ir.SetName(new_var, name.Name());
    }
    return new_var;
}

void Var::SetInitializer(Value* initializer) {
    SetOperand(Var::kInitializerOperandOffset, initializer);
}

void Var::DestroyIfOnlyAssigned() {
    auto* result = Result();
    if (result->UsagesUnsorted().All(
            [](const Usage& u) { return u.instruction->Is<ir::Store>(); })) {
        while (result->IsUsed()) {
            auto& usage = *result->UsagesUnsorted().begin();
            usage->instruction->Destroy();
        }
        Destroy();
    }
}

}  // namespace tint::core::ir
