V3Simulate/V3Table: change deques to vectors for performance

We can get away with only push_back and back on sequence containers, in
which case std::vector is significantly faster than std::deque.

src/V3Simulate.h

@@ -42,6 +42,7 @@
 
 #include <deque>
 #include <sstream>
+#include <vector>
 
 //============================================================================
 
@@ -104,12 +105,12 @@ private:
     // Simulating:
     ConstPile m_constFreeps;  ///< List of all AstConst* free and not in use
     ConstPile m_constAllps;  ///< List of all AstConst* free and in use
-    std::deque<SimStackNode*> m_callStack;  ///< Call stack for verbose error messages
+    std::vector<SimStackNode*> m_callStack;  ///< Call stack for verbose error messages
 
     // Cleanup
     // V3Numbers that represents strings are a bit special and the API for
     // V3Number does not allow changing them.
-    std::deque<AstNode*> m_reclaimValuesp;  // List of allocated string numbers
+    std::vector<AstNode*> m_reclaimValuesp;  // List of allocated string numbers
 
     // Note level 8&9 include debugging each simulation value
     VL_DEBUG_FUNC;  // Declare debug()
@@ -180,8 +181,7 @@ public:
             }
             m_whyNotOptimizable = why;
             std::ostringstream stack;
-            for (std::deque<SimStackNode*>::iterator it = m_callStack.begin();
+            for (auto it = m_callStack.rbegin(); it != m_callStack.rend(); ++it) {
-                 it != m_callStack.end(); ++it) {
                 AstFuncRef* funcp = (*it)->m_funcp;
                 stack << "\n        " << funcp->fileline() << "... Called from "
                       << funcp->prettyName() << "() with parameters:";
@@ -978,7 +978,7 @@ private:
             }
         }
         SimStackNode stackNode(nodep, &tconnects);
-        m_callStack.push_front(&stackNode);
+        m_callStack.push_back(&stackNode);
         // Clear output variable
         if (auto* const basicp = VN_CAST(funcp->fvarp(), Var)->basicp()) {
             AstConst cnst(funcp->fvarp()->fileline(), AstConst::WidthedValue(), basicp->widthMin(),
@@ -992,7 +992,7 @@ private:
         }
         // Evaluate the function
         iterate(funcp);
-        m_callStack.pop_front();
+        m_callStack.pop_back();
         if (!m_checkOnly && optimizable()) {
             // Grab return value from output variable (if it's a function)
             UASSERT_OBJ(funcp->fvarp(), nodep, "Function reference points at non-function");

src/V3Table.cpp

@@ -31,7 +31,7 @@
 #include "V3Ast.h"
 
 #include <cmath>
-#include <deque>
+#include <vector>
 
 //######################################################################
 // Table class functions
@@ -156,7 +156,6 @@ private:
     //  State cleared on each module
     AstNodeModule* m_modp = nullptr;  // Current MODULE
     int m_modTables = 0;  // Number of tables created in this module
-    std::deque<AstVarScope*> m_modTableVscs;  // All tables created
 
     //  State cleared on each scope
     AstScope* m_scopep = nullptr;  // Current SCOPE
@@ -165,7 +164,7 @@ private:
     bool m_assignDly = false;  // Consists of delayed assignments instead of normal assignments
     unsigned m_inWidthBits = 0;  // Input table width - in bits
     unsigned m_outWidthBytes = 0;  // Output table width - in bytes
-    std::deque<AstVarScope*> m_inVarps;  // Input variable list
+    std::vector<AstVarScope*> m_inVarps;  // Input variable list
     std::vector<TableOutputVar> m_outVarps;  // Output variable list
 
     // METHODS
@@ -380,11 +379,9 @@ private:
     virtual void visit(AstNodeModule* nodep) override {
         VL_RESTORER(m_modp);
         VL_RESTORER(m_modTables);
-        VL_RESTORER(m_modTableVscs);
         {
             m_modp = nodep;
             m_modTables = 0;
-            m_modTableVscs.clear();
             iterateChildren(nodep);
         }
     }