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Document and ensure OrderGraph is bipartite

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Minor refactoring and documentation. No functional change.
This commit is contained in:
Geza Lore
2022-08-31 16:52:05 +01:00
parent 2ecda74471
commit 8de21e9bb7
5 changed files with 265 additions and 226 deletions
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src/V3Order.cpp
+16 -44
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@@ -86,6 +86,7 @@
#include "V3GraphStream.h"
#include "V3List.h"
#include "V3OrderGraph.h"
#include "V3OrderMoveGraph.h"
#include "V3Partition.h"
#include "V3PartitionGraph.h"
#include "V3Sched.h"
@@ -102,21 +103,6 @@
#include <unordered_map>
#include <vector>
//######################################################################
// Functions for above graph classes
void OrderGraph::loopsVertexCb(V3GraphVertex* vertexp) {
if (debug()) cout << "-Info-Loop: " << vertexp << "\n";
if (OrderLogicVertex* const vvertexp = dynamic_cast<OrderLogicVertex*>(vertexp)) {
std::cerr << vvertexp->nodep()->fileline()->warnOther()
<< " Example path: " << vvertexp->nodep()->typeName() << endl;
}
if (OrderVarVertex* const vvertexp = dynamic_cast<OrderVarVertex*>(vertexp)) {
std::cerr << vvertexp->vscp()->fileline()->warnOther()
<< " Example path: " << vvertexp->vscp()->prettyName() << endl;
}
}
//######################################################################
// Order information stored under each AstNode::user1p()...
@@ -138,7 +124,7 @@ private:
public:
// METHODS
OrderVarVertex* getVarVertex(V3Graph* graphp, AstVarScope* varscp, VarVertexType type) {
OrderVarVertex* getVarVertex(OrderGraph* graphp, AstVarScope* varscp, VarVertexType type) {
const unsigned idx = static_cast<unsigned>(type);
OrderVarVertex* vertexp = m_vertexps[idx];
if (!vertexp) {
@@ -312,21 +298,7 @@ class OrderBuildVisitor final : public VNVisitor {
}
}
// Roles of vertices:
// VarVertexType::STD: Data dependencies for combinational logic and delayed
// assignment updates (AssignPost).
// VarVertexType::POST: Ensures all sequential blocks reading a signal do so before
// any combinational or delayed assignments update that signal.
// VarVertexType::PORD: Ensures a _d = _q AssignPre is the first write of a _d,
// before any sequential blocks write to that _d.
// VarVertexType::PRE: This is an optimization. Try to ensure that a _d = _q
// AssignPre is the last read of a _q, after all reads of that
// _q by sequential logic. Note: The model is still correct if we
// cannot satisfy this due to other constraints. If this ordering
// is possible, then combined with the PORD constraint we get
// that all writes to _d are after all reads of a _q, which then
// allows us to eliminate the _d completely and assign to the _q
// directly (this is what V3LifePost does).
// Note: See V3OrderGraph.h about the roles of the various vertex types
// Variable is produced
if (gen) {
@@ -338,9 +310,9 @@ class OrderBuildVisitor final : public VNVisitor {
OrderVarVertex* const varVxp = getVarVertex(varscp, VarVertexType::STD);
// Add edge from producing LogicVertex -> produced VarStdVertex
if (m_inPost) {
new OrderPostCutEdge(m_graphp, m_logicVxp, varVxp);
m_graphp->addSoftEdge(m_logicVxp, varVxp, WEIGHT_COMBO);
} else {
new OrderEdge(m_graphp, m_logicVxp, varVxp, WEIGHT_NORMAL);
m_graphp->addHardEdge(m_logicVxp, varVxp, WEIGHT_NORMAL);
}
// Add edge from produced VarPostVertex -> to producing LogicVertex
@@ -352,22 +324,22 @@ class OrderBuildVisitor final : public VNVisitor {
// ALWAYS do it:
// There maybe a wire a=b; between the two blocks
OrderVarVertex* const postVxp = getVarVertex(varscp, VarVertexType::POST);
new OrderEdge(m_graphp, postVxp, m_logicVxp, WEIGHT_POST);
m_graphp->addHardEdge(postVxp, m_logicVxp, WEIGHT_POST);
} else if (m_inPre) { // AstAssignPre
// Add edge from producing LogicVertex -> produced VarPordVertex
OrderVarVertex* const ordVxp = getVarVertex(varscp, VarVertexType::PORD);
new OrderEdge(m_graphp, m_logicVxp, ordVxp, WEIGHT_NORMAL);
m_graphp->addHardEdge(m_logicVxp, ordVxp, WEIGHT_NORMAL);
// Add edge from producing LogicVertex -> produced VarStdVertex
OrderVarVertex* const varVxp = getVarVertex(varscp, VarVertexType::STD);
new OrderEdge(m_graphp, m_logicVxp, varVxp, WEIGHT_NORMAL);
m_graphp->addHardEdge(m_logicVxp, varVxp, WEIGHT_NORMAL);
} else {
// Sequential (clocked) logic
// Add edge from produced VarPordVertex -> to producing LogicVertex
OrderVarVertex* const ordVxp = getVarVertex(varscp, VarVertexType::PORD);
new OrderEdge(m_graphp, ordVxp, m_logicVxp, WEIGHT_NORMAL);
m_graphp->addHardEdge(ordVxp, m_logicVxp, WEIGHT_NORMAL);
// Add edge from producing LogicVertex-> to produced VarStdVertex
OrderVarVertex* const varVxp = getVarVertex(varscp, VarVertexType::STD);
new OrderEdge(m_graphp, m_logicVxp, varVxp, WEIGHT_NORMAL);
m_graphp->addHardEdge(m_logicVxp, varVxp, WEIGHT_NORMAL);
}
}
@@ -382,7 +354,7 @@ class OrderBuildVisitor final : public VNVisitor {
// Ignore explicit sensitivities
OrderVarVertex* const varVxp = getVarVertex(varscp, VarVertexType::STD);
// Add edge from consumed VarStdVertex -> to consuming LogicVertex
new OrderEdge(m_graphp, varVxp, m_logicVxp, WEIGHT_MEDIUM);
m_graphp->addHardEdge(varVxp, m_logicVxp, WEIGHT_MEDIUM);
}
} else if (m_inPre) {
// AstAssignPre logic
@@ -390,17 +362,17 @@ class OrderBuildVisitor final : public VNVisitor {
// This one is cutable (vs the producer) as there's only one such consumer,
// but may be many producers
OrderVarVertex* const preVxp = getVarVertex(varscp, VarVertexType::PRE);
new OrderPreCutEdge(m_graphp, preVxp, m_logicVxp);
m_graphp->addSoftEdge(preVxp, m_logicVxp, WEIGHT_PRE);
} else {
// Sequential (clocked) logic
// Add edge from consuming LogicVertex -> to consumed VarPreVertex
// Generation of 'pre' because we want to indicate it should be before
// AstAssignPre
OrderVarVertex* const preVxp = getVarVertex(varscp, VarVertexType::PRE);
new OrderEdge(m_graphp, m_logicVxp, preVxp, WEIGHT_NORMAL);
m_graphp->addHardEdge(m_logicVxp, preVxp, WEIGHT_NORMAL);
// Add edge from consuming LogicVertex -> to consumed VarPostVertex
OrderVarVertex* const postVxp = getVarVertex(varscp, VarVertexType::POST);
new OrderEdge(m_graphp, m_logicVxp, postVxp, WEIGHT_POST);
m_graphp->addHardEdge(m_logicVxp, postVxp, WEIGHT_POST);
}
}
}
@@ -742,7 +714,7 @@ private:
// Path from vertexp to a logic vertex; new edge.
// Note we use the last edge's weight, not some function of
// multiple edges
new OrderEdge(m_outGraphp, moveVxp, m_logic2move[toLVertexp], weight);
new V3GraphEdge(m_outGraphp, moveVxp, m_logic2move[toLVertexp], weight);
madeDeps = true;
} else {
// This is an OrderVarVertex.
@@ -767,7 +739,7 @@ private:
// Create incoming edge, from previous logic that writes
// this var, to the Vertex representing the (var,domain)
new OrderEdge(m_outGraphp, moveVxp, m_var2move[key], weight);
new V3GraphEdge(m_outGraphp, moveVxp, m_var2move[key], weight);
madeDeps = true;
}
}