SLP Vectorize

src/CMakeLists.txt

@@ -222,6 +222,7 @@ set(COMMON_SOURCES
     V3DfgPasses.cpp
     V3DfgPeephole.cpp
     V3DfgRegularize.cpp
+    V3DfgVectorize.cpp
     V3DupFinder.cpp
     V3Timing.cpp
     V3EmitCBase.cpp

src/Makefile_obj.in

@@ -235,6 +235,7 @@ RAW_OBJS_PCH_ASTNOMT = \
 	V3DfgPasses.o \
 	V3DfgPeephole.o \
 	V3DfgRegularize.o \
+	V3DfgVectorize.o \
 	V3DupFinder.o \
 	V3EmitCMain.o \
 	V3EmitCMake.o \

src/V3Dfg.cpp

@@ -55,14 +55,14 @@ void DfgGraph::addGraph(DfgGraph& other) {
     m_opVertices.splice(m_opVertices.end(), other.m_opVertices);
 }
 
-static const string toDotId(const DfgVertex& vtx) { return '"' + cvtToHex(&vtx) + '"'; }
+const std::string DfgVertex::toDotId() const { return '"' + cvtToHex(this) + '"'; }
 
 // Dump one DfgVertex in Graphviz format
 static void dumpDotVertex(std::ostream& os, const DfgVertex& vtx) {
 
     if (const DfgVarPacked* const varVtxp = vtx.cast<DfgVarPacked>()) {
         AstVar* const varp = varVtxp->varp();
-        os << toDotId(vtx);
+        os << vtx.toDotId();
         os << " [label=\"" << varp->name() << "\nW" << varVtxp->width() << " / F"
            << varVtxp->fanout() << '"';
 
@@ -90,7 +90,7 @@ static void dumpDotVertex(std::ostream& os, const DfgVertex& vtx) {
     if (const DfgVarArray* const arrVtxp = vtx.cast<DfgVarArray>()) {
         AstVar* const varp = arrVtxp->varp();
         const int elements = VN_AS(arrVtxp->dtypep(), UnpackArrayDType)->elementsConst();
-        os << toDotId(vtx);
+        os << vtx.toDotId();
         os << " [label=\"" << varp->name() << "[" << elements << "]\"";
         if (varp->direction() == VDirection::INPUT) {
             os << ", shape=box3d, style=filled, fillcolor=chartreuse2";  // Green
@@ -116,7 +116,7 @@ static void dumpDotVertex(std::ostream& os, const DfgVertex& vtx) {
     if (const DfgConst* const constVtxp = vtx.cast<DfgConst>()) {
         const V3Number& num = constVtxp->num();
 
-        os << toDotId(vtx);
+        os << vtx.toDotId();
         os << " [label=\"";
         if (num.width() <= 32 && !num.isSigned()) {
             os << constVtxp->width() << "'d" << num.toUInt() << "\n";
@@ -133,7 +133,7 @@ static void dumpDotVertex(std::ostream& os, const DfgVertex& vtx) {
     if (const DfgSel* const selVtxp = vtx.cast<DfgSel>()) {
         const uint32_t lsb = selVtxp->lsb();
         const uint32_t msb = lsb + selVtxp->width() - 1;
-        os << toDotId(vtx);
+        os << vtx.toDotId();
         os << " [label=\"SEL\n_[" << msb << ":" << lsb << "]\nW" << vtx.width() << " / F"
            << vtx.fanout() << '"';
         if (vtx.hasMultipleSinks()) {
@@ -145,7 +145,7 @@ static void dumpDotVertex(std::ostream& os, const DfgVertex& vtx) {
         return;
     }
 
-    os << toDotId(vtx);
+    os << vtx.toDotId();
     os << " [label=\"" << vtx.typeName() << "\nW" << vtx.width() << " / F" << vtx.fanout() << '"';
     if (vtx.hasMultipleSinks()) {
         os << ", shape=doublecircle";
@@ -157,18 +157,18 @@ static void dumpDotVertex(std::ostream& os, const DfgVertex& vtx) {
 
 // Dump one DfgEdge in Graphviz format
 static void dumpDotEdge(std::ostream& os, const DfgEdge& edge, const string& headlabel) {
-    os << toDotId(*edge.sourcep()) << " -> " << toDotId(*edge.sinkp());
+    os << edge.sourcep()->toDotId() << " -> " << edge.sinkp()->toDotId();
     if (!headlabel.empty()) os << " [headlabel=\"" << headlabel << "\"]";
     os << "\n";
 }
 
 // Dump one DfgVertex and all of its source DfgEdges in Graphviz format
-static void dumpDotVertexAndSourceEdges(std::ostream& os, const DfgVertex& vtx) {
-    dumpDotVertex(os, vtx);
-    vtx.forEachSourceEdge([&](const DfgEdge& edge, size_t idx) {  //
+void DfgVertex::dumpDotVertexAndSourceEdges(std::ostream& os) const {
+    dumpDotVertex(os, *this);
+    forEachSourceEdge([&](const DfgEdge& edge, size_t idx) {
         if (edge.sourcep()) {
             string headLabel;
-            if (vtx.arity() > 1 || vtx.is<DfgVertexVar>()) headLabel = vtx.srcName(idx);
+            if (arity() > 1 || is<DfgVertexVar>()) headLabel = srcName(idx);
             dumpDotEdge(os, edge, headLabel);
         }
     });
@@ -183,7 +183,7 @@ void DfgGraph::dumpDot(std::ostream& os, const string& label) const {
     os << "graph [rankdir=LR]\n";
 
     // Emit all vertices
-    forEachVertex([&](const DfgVertex& vtx) { dumpDotVertexAndSourceEdges(os, vtx); });
+    forEachVertex([&](const DfgVertex& vtx) { vtx.dumpDotVertexAndSourceEdges(os); });
 
     // Footer
     os << "}\n";
@@ -228,13 +228,13 @@ static void dumpDotUpstreamConeFromVertex(std::ostream& os, const DfgVertex& vtx
         itemp->forEachSource([&](const DfgVertex& src) { queue.push_back(&src); });
 
         // Emit this vertex and all of its source edges
-        dumpDotVertexAndSourceEdges(os, *itemp);
+        itemp->dumpDotVertexAndSourceEdges(os);
     }
 
     // Emit all DfgVarPacked vertices that have external references driven by this vertex
     vtx.forEachSink([&](const DfgVertex& dst) {
         if (const DfgVarPacked* const varVtxp = dst.cast<DfgVarPacked>()) {
-            if (varVtxp->hasNonLocalRefs()) dumpDotVertexAndSourceEdges(os, dst);
+            if (varVtxp->hasNonLocalRefs()) dst.dumpDotVertexAndSourceEdges(os);
         }
     });
 }

src/V3Dfg.h

@@ -281,6 +281,11 @@ class DfgVertex VL_NOT_FINAL {
     // Fanout (number of sinks) of this vertex (expensive to compute)
     uint32_t fanout() const VL_MT_DISABLED;
 
+    // If this vertex has a single sink, return it, otherwise return nullptr
+    DfgVertex* singleSink() {
+        return m_sinksp && !m_sinksp->m_nextp ? m_sinksp->sinkp() : nullptr;
+    }
+
     // Unlink from container (graph or builder), then delete this vertex
     void unlinkDelete(DfgGraph& dfg) VL_MT_DISABLED;
 
@@ -399,6 +404,11 @@ class DfgVertex VL_NOT_FINAL {
 
     // Human-readable name for source operand with given index for debugging
     virtual const string srcName(size_t idx) const = 0;
+
+    // Returns Graphviz id of this vertex.
+    const std::string toDotId() const;
+    // Dump this vertex and all it's source edges in Graphviz format to given stream 'os'.
+    void dumpDotVertexAndSourceEdges(std::ostream& os) const;
 };
 
 //------------------------------------------------------------------------------

src/V3DfgPasses.cpp

@@ -363,6 +363,10 @@ void V3DfgPasses::optimize(DfgGraph& dfg, V3DfgOptimizationContext& ctx) {
     }
     // Accumulate patterns for reporting
     if (v3Global.opt.stats()) ctx.m_patternStats.accumulate(dfg);
+    apply(4, "vectorize", [&]() {
+        vectorize(dfg);
+        removeUnused(dfg);
+    });
     apply(4, "regularize", [&]() { regularize(dfg, ctx.m_regularizeContext); });
     if (dumpDfgLevel() >= 8) dfg.dumpDotAllVarConesPrefixed(ctx.prefix() + "optimized");
 }

src/V3DfgPasses.h

@@ -130,11 +130,12 @@ void inlineVars(DfgGraph&) VL_MT_DISABLED;
 void peephole(DfgGraph&, V3DfgPeepholeContext&) VL_MT_DISABLED;
 // Regularize graph. This must be run before converting back to Ast.
 void regularize(DfgGraph&, V3DfgRegularizeContext&) VL_MT_DISABLED;
+// Vectorize compatible vertices
+void vectorize(DfgGraph&);
 // Remove unused nodes
 void removeUnused(DfgGraph&) VL_MT_DISABLED;
 // Eliminate (remove or replace) redundant variables. Also removes resulting unused logic.
 void eliminateVars(DfgGraph&, V3DfgEliminateVarsContext&) VL_MT_DISABLED;
-
 }  // namespace V3DfgPasses
 
 #endif