@@ -31,7 +31,7 @@ The pair ```(Dst, ic)``` must be unique, i.e. no two input binds in the same gra
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@@ -31,7 +31,7 @@ The pair ```(Dst, ic)``` must be unique, i.e. no two input binds in the same gra
Conversely, an internal node binds output ```oc``` of its child node ```Src``` to its output ```op``` using an *output bind*. The pair ```(Src, oc)``` and destination ```op``` must be unique, i.e. no two output binds in the same graph can have the same source destination, as that would create a conflict.
Conversely, an internal node binds output ```oc``` of its child node ```Src``` to its output ```op``` using an *output bind*. The pair ```(Src, oc)``` and destination ```op``` must be unique, i.e. no two output binds in the same graph can have the same source destination, as that would create a conflict.
A bind is always all-to-all.
A bind is always ***all-to-all***.
## Host Code
## Host Code
In an HPVM program, the host code is responsible for setting up, initiating the execution and blocking for completion of a DFG. The host can interact with the DFG to sustain a streaming computation by sending all data required for, and receiving all data produced by, one execution of the DFG. The list of actions that can be performed by the host is described below:
In an HPVM program, the host code is responsible for setting up, initiating the execution and blocking for completion of a DFG. The host can interact with the DFG to sustain a streaming computation by sending all data required for, and receiving all data produced by, one execution of the DFG. The list of actions that can be performed by the host is described below:
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@@ -63,6 +63,8 @@ The code for each dataflow node is given as a separate LLVM function, called the
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@@ -63,6 +63,8 @@ The code for each dataflow node is given as a separate LLVM function, called the
The incoming dataflow edges and their data types are denoted by the parameters to the node function. The outgoing dataflow edges are represented by the return type of the node function, which must be an LLVM struct type with zero or more fields (one per outgoing edge).
The incoming dataflow edges and their data types are denoted by the parameters to the node function. The outgoing dataflow edges are represented by the return type of the node function, which must be an LLVM struct type with zero or more fields (one per outgoing edge).
Each top-level DFG in an HPVM program is defined by its own *root node function* which creates the underlying DFG structure. The DFG is the (internal) root node's child graph. Unlike regular internal nodes, the root node only has one dynamic instance because it instantiates the top-level DFG. The DFG is launched by the host code using the root node function, as described below.
We represent nodes with opaque handles (pointers of LLVM type i8\*). We represent input edges of a node as integer indices into the list of function arguments, and output edges of a node as integer indices into the return struct type.
We represent nodes with opaque handles (pointers of LLVM type i8\*). We represent input edges of a node as integer indices into the list of function arguments, and output edges of a node as integer indices into the return struct type.
Pointer arguments of node functions are required to be annotated with attributes in, and/or out, depending on their expected use (read only, write only, read write).
Pointer arguments of node functions are required to be annotated with attributes in, and/or out, depending on their expected use (read only, write only, read write).
