VPR Context

class VprContext : public Context

This object encapsulates VPR’s state.

There is typically a single instance which is accessed via the global variable g_vpr_ctx (see globals.h/.cpp).

It is divided up into separate sub-contexts of logically related data structures.

Each sub-context can be accessed via member functions which return a reference to the sub-context:

• The default the member function (e.g. device()) return an const (immutable) reference providing read-only access to the context. This should be the preferred form, as the compiler will detect unintentional state changes.

• The ‘mutable’ member function (e.g. mutable_device()) will return a non-const (mutable) reference allowing modification of the context. This should only be used on an as-needed basis.

Typical usage in VPR would be to call the appropriate accessor to get a reference to the context of interest, and then operate on it.

For example if we were performing an action which required access to the current placement, we would do:

void my_analysis_algorithm() {
    //Get read-only access to the placement
    auto& place_ctx = g_vpr_ctx.placement();

    //Do something that depends on (but does not change)
    //the current placement...

}

If we needed to modify the placement (e.g. we were implementing another placement algorithm) we would do:

void my_placement_algorithm() {
    //Get read-write access to the placement
    auto& place_ctx = g_vpr_ctx.mutable_placement();

    //Do something that modifies the placement
    //...
}

Note

The returned contexts are not copyable, so they must be taken by reference.

Public Functions

const AtomContext &atom() const

AtomContext &mutable_atom()

const DeviceContext &device() const

DeviceContext &mutable_device()

const TimingContext &timing() const

TimingContext &mutable_timing()

const PowerContext &power() const

PowerContext &mutable_power()

const ClusteringContext &clustering() const

ClusteringContext &mutable_clustering()

const PlacementContext &placement() const

PlacementContext &mutable_placement()

const RoutingContext &routing() const

RoutingContext &mutable_routing()

Private Members

DeviceContext device_

AtomContext atom_

TimingContext timing_

PowerContext power_

ClusteringContext clustering_

PlacementContext placement_

RoutingContext routing_