verilator/src/V3Inline.cpp
2014-01-20 21:59:53 -05:00

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// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Add temporaries, such as for inline nodes
//
// Code available from: http://www.veripool.org/verilator
//
//*************************************************************************
//
// Copyright 2003-2014 by Wilson Snyder. This program is free software; you can
// redistribute it and/or modify it under the terms of either the GNU
// Lesser General Public License Version 3 or the Perl Artistic License
// Version 2.0.
//
// Verilator is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
//*************************************************************************
// V3Inline's Transformations:
//
// Each module:
// Look for CELL... PRAGMA INLINE_MODULE
// Replicate the cell's module
// Convert pins to wires that make assignments
// Rename vars to include cell name
// Insert cell's module statements into the upper module
//
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include <cstdio>
#include <cstdarg>
#include <unistd.h>
#include <algorithm>
#include <vector>
#include "V3Global.h"
#include "V3Inline.h"
#include "V3Inst.h"
#include "V3Stats.h"
#include "V3Ast.h"
// CONFIG
static const int INLINE_MODS_SMALLER = 100; // If a mod is < this # nodes, can always inline it
//######################################################################
// Inline state, as a visitor of each AstNode
class InlineMarkVisitor : public AstNVisitor {
private:
// NODE STATE
// Output
// AstNodeModule::user1() // OUTPUT: bool. User request to inline this module
// Entire netlist (can be cleared after this visit completes)
// AstNodeModule::user2() // CIL_*. Allowed to automatically inline module
// AstNodeModule::user3() // int. Number of cells referencing this module
AstUser1InUse m_inuser1;
AstUser2InUse m_inuser2;
AstUser3InUse m_inuser3;
enum {CIL_NOTHARD=0, // For user2, inline not supported
CIL_NOTSOFT, // For user2, don't inline unless user overrides
CIL_MAYBE}; // For user2, might inline
// STATE
AstNodeModule* m_modp; // Flattened cell's containing module
int m_stmtCnt; // Statements in module
V3Double0 m_statUnsup; // Statistic tracking
// METHODS
static int debug() {
static int level = -1;
if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__);
return level;
}
void cantInline(const char* reason, bool hard) {
if (hard) {
if (m_modp->user2() != CIL_NOTHARD) {
UINFO(4," No inline hard: "<<reason<<" "<<m_modp<<endl);
m_modp->user2(CIL_NOTHARD);
m_statUnsup++;
}
} else {
if (m_modp->user2() == CIL_MAYBE) {
UINFO(4," No inline soft: "<<reason<<" "<<m_modp<<endl);
m_modp->user2(CIL_NOTSOFT);
}
}
}
// VISITORS
virtual void visit(AstNodeModule* nodep, AstNUser*) {
m_stmtCnt = 0;
m_modp = nodep;
m_modp->user2(CIL_MAYBE);
if (m_modp->castIface()) {
// Inlining an interface means we no longer have a cell handle to resolve to.
// If inlining moves post-scope this can perhaps be relaxed.
cantInline("modIface",true);
}
if (m_modp->modPublic()) cantInline("modPublic",false);
//
nodep->iterateChildren(*this);
//
bool userinline = nodep->user1();
int allowed = nodep->user2();
int refs = nodep->user3();
// Should we automatically inline this module?
// inlineMult = 2000 by default. If a mod*#instances is < this # nodes, can inline it
bool doit = ((allowed == CIL_NOTSOFT || allowed == CIL_MAYBE)
&& (userinline
|| ((allowed == CIL_MAYBE)
&& (refs==1
|| m_stmtCnt < INLINE_MODS_SMALLER
|| v3Global.opt.inlineMult() < 1
|| refs*m_stmtCnt < v3Global.opt.inlineMult()))));
// Packages aren't really "under" anything so they confuse this algorithm
if (nodep->castPackage()) doit = false;
UINFO(4, " Inline="<<doit<<" Possible="<<allowed<<" Usr="<<userinline<<" Refs="<<refs<<" Stmts="<<m_stmtCnt
<<" "<<nodep<<endl);
nodep->user1(doit);
m_modp = NULL;
}
virtual void visit(AstCell* nodep, AstNUser*) {
nodep->modp()->user3Inc();
nodep->iterateChildren(*this);
}
virtual void visit(AstPragma* nodep, AstNUser*) {
if (nodep->pragType() == AstPragmaType::INLINE_MODULE) {
//UINFO(0,"PRAG MARK "<<m_modp<<endl);
if (!m_modp) {
nodep->v3error("Inline pragma not under a module");
} else {
m_modp->user1(1);
}
nodep->unlinkFrBack()->deleteTree(); nodep=NULL; // Remove so don't propagate to upper cell...
} else if (nodep->pragType() == AstPragmaType::NO_INLINE_MODULE) {
if (!m_modp) {
nodep->v3error("Inline pragma not under a module");
} else {
cantInline("Pragma NO_INLINE_MODULE",false);
}
nodep->unlinkFrBack()->deleteTree(); nodep=NULL; // Remove so don't propagate to upper cell...
} else {
nodep->iterateChildren(*this);
}
}
virtual void visit(AstVarXRef* nodep, AstNUser*) {
// Cleanup link until V3LinkDot can correct it
nodep->varp(NULL);
}
virtual void visit(AstVar* nodep, AstNUser*) {
// Can't look at AstIfaceRefDType directly as it is no longer underneath the module
if (nodep->isIfaceRef()) {
// Unsupported: Inlining of modules with ifaces (see AstIface comment above)
if (m_modp) cantInline("Interfaced",true);
}
nodep->iterateChildren(*this);
}
virtual void visit(AstNodeFTaskRef* nodep, AstNUser*) {
// Cleanup link until V3LinkDot can correct it
if (!nodep->packagep()) nodep->taskp(NULL);
nodep->iterateChildren(*this);
}
// Nop's to speed up the loop
virtual void visit(AstAlways* nodep, AstNUser*) {
nodep->iterateChildren(*this);
m_stmtCnt++;
}
virtual void visit(AstNodeAssign* nodep, AstNUser*) {
// Don't count assignments, as they'll likely flatten out
// Still need to iterate though to nullify VarXRefs
int oldcnt = m_stmtCnt;
nodep->iterateChildren(*this);
m_stmtCnt = oldcnt;
}
//--------------------
// Default: Just iterate
virtual void visit(AstNode* nodep, AstNUser*) {
nodep->iterateChildren(*this);
m_stmtCnt++;
}
public:
// CONSTUCTORS
InlineMarkVisitor(AstNode* nodep) {
m_modp = NULL;
m_stmtCnt = 0;
nodep->accept(*this);
}
virtual ~InlineMarkVisitor() {
V3Stats::addStat("Optimizations, Inline unsupported", m_statUnsup);
// Done with these, are not outputs
AstNode::user2ClearTree();
AstNode::user3ClearTree();
}
};
//######################################################################
// Using clonep(), find cell cross references.
// clone() must not be called inside this visitor
class InlineCollectVisitor : public AstNVisitor {
private:
// NODE STATE
// Output:
// AstCell::user4p() // AstCell* of the created clone
static int debug() {
static int level = -1;
if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__);
return level;
}
// VISITORS
virtual void visit(AstCell* nodep, AstNUser*) {
nodep->user4p(nodep->clonep());
}
// Accelerate
virtual void visit(AstNodeStmt* nodep, AstNUser*) {}
virtual void visit(AstNodeMath* nodep, AstNUser*) {}
virtual void visit(AstNode* nodep, AstNUser*) {
nodep->iterateChildren(*this);
}
public:
// CONSTUCTORS
InlineCollectVisitor(AstNodeModule* nodep) { // passed OLD module, not new one
nodep->accept(*this);
}
virtual ~InlineCollectVisitor() {}
};
//######################################################################
// After cell is cloned, relink the new module's contents
class InlineRelinkVisitor : public AstNVisitor {
private:
// NODE STATE
// Input:
// See InlineVisitor
// STATE
AstNodeModule* m_modp; // Current module
AstCell* m_cellp; // Cell being cloned
static int debug() {
static int level = -1;
if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__);
return level;
}
// VISITORS
virtual void visit(AstCellInline* nodep, AstNUser*) {
// Inlined cell under the inline cell, need to move to avoid conflicts
nodep->unlinkFrBack();
m_modp->addInlinesp(nodep);
// Rename
string name = m_cellp->name() + "__DOT__" + nodep->name();
nodep->name(name);
UINFO(6, " Inline "<<nodep<<endl);
// Do CellInlines under this, but don't move them
nodep->iterateChildren(*this);
}
virtual void visit(AstCell* nodep, AstNUser*) {
// Cell under the inline cell, need to rename to avoid conflicts
string name = m_cellp->name() + "__DOT__" + nodep->name();
nodep->name(name);
nodep->iterateChildren(*this);
}
virtual void visit(AstVar* nodep, AstNUser*) {
if (nodep->user2p()) {
// Make an assignment, so we'll trace it properly
// user2p is either a const or a var.
AstConst* exprconstp = nodep->user2p()->castNode()->castConst();
AstVarRef* exprvarrefp = nodep->user2p()->castNode()->castVarRef();
UINFO(8,"connectto: "<<nodep->user2p()->castNode()<<endl);
if (!exprconstp && !exprvarrefp) {
nodep->v3fatalSrc("Unknown interconnect type; pinReconnectSimple should have cleared up\n");
}
if (exprconstp) {
m_modp->addStmtp(new AstAssignW(nodep->fileline(),
new AstVarRef(nodep->fileline(), nodep, true),
exprconstp->cloneTree(true)));
} else if (nodep->user3()) {
// Public variable at the lower module end - we need to make sure we propagate
// the logic changes up and down; if we aliased, we might remove the change detection
// on the output variable.
UINFO(9,"public pin assign: "<<exprvarrefp<<endl);
if (nodep->isInput()) nodep->v3fatalSrc("Outputs only - inputs use AssignAlias");
m_modp->addStmtp(new AstAssignW(nodep->fileline(),
new AstVarRef(nodep->fileline(), exprvarrefp->varp(), true),
new AstVarRef(nodep->fileline(), nodep, false)));
} else if (nodep->isIfaceRef()) {
m_modp->addStmtp(new AstAssignVarScope(nodep->fileline(),
new AstVarRef(nodep->fileline(), nodep, true),
new AstVarRef(nodep->fileline(), exprvarrefp->varp(), false)));
AstNode* nodebp=exprvarrefp->varp();
nodep ->fileline()->modifyStateInherit(nodebp->fileline());
nodebp->fileline()->modifyStateInherit(nodep ->fileline());
} else {
// Do to inlining child's variable now within the same module, so a AstVarRef not AstVarXRef below
m_modp->addStmtp(new AstAssignAlias(nodep->fileline(),
new AstVarRef(nodep->fileline(), nodep, true),
new AstVarRef(nodep->fileline(), exprvarrefp->varp(), false)));
AstNode* nodebp=exprvarrefp->varp();
nodep ->fileline()->modifyStateInherit(nodebp->fileline());
nodebp->fileline()->modifyStateInherit(nodep ->fileline());
}
}
// Variable under the inline cell, need to rename to avoid conflicts
// Also clear I/O bits, as it is now local.
string name = m_cellp->name() + "__DOT__" + nodep->name();
if (!nodep->isFuncLocal()) nodep->inlineAttrReset(name);
if (debug()>=9) { nodep->dumpTree(cout,"varchanged:"); }
if (debug()>=9) { nodep->valuep()->dumpTree(cout,"varchangei:"); }
// Iterate won't hit AstIfaceRefDType directly as it is no longer underneath the module
if (AstIfaceRefDType* ifacerefp = nodep->dtypep()->castIfaceRefDType()) {
// Relink to point to newly cloned cell
if (ifacerefp->cellp()) {
if (AstCell* newcellp = ifacerefp->cellp()->user4p()->castNode()->castCell()) {
ifacerefp->cellp(newcellp);
ifacerefp->cellName(newcellp->name());
}
}
}
nodep->iterateChildren(*this);
}
virtual void visit(AstNodeFTask* nodep, AstNUser*) {
// Function under the inline cell, need to rename to avoid conflicts
nodep->name(m_cellp->name() + "__DOT__" + nodep->name());
nodep->iterateChildren(*this);
}
virtual void visit(AstTypedef* nodep, AstNUser*) {
// Typedef under the inline cell, need to rename to avoid conflicts
nodep->name(m_cellp->name() + "__DOT__" + nodep->name());
nodep->iterateChildren(*this);
}
virtual void visit(AstVarRef* nodep, AstNUser*) {
if (nodep->varp()->user2p() // It's being converted to an alias.
&& !nodep->varp()->user3()
&& !nodep->backp()->castAssignAlias()) { // Don't constant propagate aliases (we just made)
AstConst* exprconstp = nodep->varp()->user2p()->castNode()->castConst();
AstVarRef* exprvarrefp = nodep->varp()->user2p()->castNode()->castVarRef();
if (exprconstp) {
nodep->replaceWith(exprconstp->cloneTree(true));
nodep->deleteTree(); nodep=NULL;
return;
}
else if (exprvarrefp) {
nodep->varp( exprvarrefp->varp() );
}
else {
nodep->v3fatalSrc("Null connection?\n");
}
}
nodep->name(nodep->varp()->name());
nodep->iterateChildren(*this);
}
virtual void visit(AstVarXRef* nodep, AstNUser*) {
// Track what scope it was originally under so V3LinkDot can resolve it
string newname = m_cellp->name();
if (nodep->inlinedDots() != "") { newname += "." + nodep->inlinedDots(); }
nodep->inlinedDots(newname);
UINFO(8," "<<nodep<<endl);
nodep->iterateChildren(*this);
}
virtual void visit(AstNodeFTaskRef* nodep, AstNUser*) {
// Track what scope it was originally under so V3LinkDot can resolve it
string newname = m_cellp->name();
if (nodep->inlinedDots() != "") { newname += "." + nodep->inlinedDots(); }
nodep->inlinedDots(newname);
UINFO(8," "<<nodep<<endl);
nodep->iterateChildren(*this);
}
// Not needed, as V3LinkDot doesn't care about typedefs
//virtual void visit(AstRefDType* nodep, AstNUser*) {}
virtual void visit(AstScopeName* nodep, AstNUser*) {
// If there's a %m in the display text, we add a special node that will contain the name()
// Similar code in V3Begin
// To keep correct visual order, must add before other Text's
AstNode* afterp = nodep->scopeAttrp();
if (afterp) afterp->unlinkFrBackWithNext();
nodep->scopeAttrp(new AstText(nodep->fileline(), (string)"__DOT__"+m_cellp->name()));
if (afterp) nodep->scopeAttrp(afterp);
nodep->iterateChildren(*this);
}
virtual void visit(AstCoverDecl* nodep, AstNUser*) {
// Fix path in coverage statements
nodep->hier(m_cellp->prettyName()
+ (nodep->hier()!="" ? ".":"")
+ nodep->hier());
nodep->iterateChildren(*this);
}
virtual void visit(AstNode* nodep, AstNUser*) {
nodep->iterateChildren(*this);
}
public:
// CONSTUCTORS
InlineRelinkVisitor(AstNodeModule* cloneModp, AstNodeModule* oldModp, AstCell* cellp) {
m_modp = oldModp;
m_cellp = cellp;
cloneModp->accept(*this);
}
virtual ~InlineRelinkVisitor() {}
};
//######################################################################
// Inline state, as a visitor of each AstNode
class InlineVisitor : public AstNVisitor {
private:
// NODE STATE
// Cleared entire netlist
// Input:
// AstNodeModule::user1p() // bool. True to inline this module (from InlineMarkVisitor)
// Cleared each cell
// AstVar::user2p() // AstVarRef*/AstConst* Points to signal this is a direct connect to
// AstVar::user3() // bool Don't alias the user2, keep it as signal
// AstCell::user4 // AstCell* of the created clone
AstUser4InUse m_inuser4;
// STATE
AstNodeModule* m_modp; // Current module
V3Double0 m_statCells; // Statistic tracking
static int debug() {
static int level = -1;
if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__);
return level;
}
// VISITORS
virtual void visit(AstNetlist* nodep, AstNUser*) {
// Iterate modules backwards, in bottom-up order. Required!
nodep->iterateChildrenBackwards(*this);
}
virtual void visit(AstNodeModule* nodep, AstNUser*) {
m_modp = nodep;
nodep->iterateChildren(*this);
}
virtual void visit(AstCell* nodep, AstNUser*) {
if (nodep->modp()->user1()) { // Marked with inline request
UINFO(5," Inline CELL "<<nodep<<endl);
UINFO(5," To MOD "<<m_modp<<endl);
++m_statCells;
// Before cloning simplify pin assignments
// Better off before, as if module has multiple instantiations
// we'll save work, and we can't call pinReconnectSimple in
// this loop as it clone()s itself.
for (AstPin* pinp = nodep->pinsp(); pinp; pinp=pinp->nextp()->castPin()) {
if (!pinp->exprp()) continue;
V3Inst::pinReconnectSimple(pinp, nodep, m_modp, false);
}
// Clone original module
if (debug()>=9) { nodep->dumpTree(cout,"inlcell:"); }
//if (debug()>=9) { nodep->modp()->dumpTree(cout,"oldmod:"); }
AstNodeModule* newmodp = nodep->modp()->cloneTree(false);
if (debug()>=9) { newmodp->dumpTree(cout,"newmod:"); }
// Clear var markings and find cell cross references
AstNode::user2ClearTree();
AstNode::user4ClearTree();
{ InlineCollectVisitor(nodep->modp()); } // {} to destroy visitor immediately
// Create data for dotted variable resolution
AstCellInline* inlinep = new AstCellInline(nodep->fileline(),
nodep->name(), nodep->modp()->origName());
m_modp->addInlinesp(inlinep); // Must be parsed before any AstCells
// Create assignments to the pins
for (AstPin* pinp = nodep->pinsp(); pinp; pinp=pinp->nextp()->castPin()) {
if (!pinp->exprp()) continue;
UINFO(6," Pin change from "<<pinp->modVarp()<<endl);
// Make new signal; even though we'll optimize the interconnect, we
// need an alias to trace correctly. If tracing is disabled, we'll
// delete it in later optimizations.
AstVar* pinOldVarp = pinp->modVarp();
AstVar* pinNewVarp = pinOldVarp->clonep()->castVar();
AstNode* connectRefp = pinp->exprp();
if (!connectRefp->castConst() && !connectRefp->castVarRef()) {
pinp->v3fatalSrc("Unknown interconnect type; pinReconnectSimple should have cleared up\n");
}
if (pinNewVarp->isOutOnly() && connectRefp->castConst()) {
pinp->v3error("Output port is connected to a constant pin, electrical short");
}
// Propagate any attributes across the interconnect
pinNewVarp->propagateAttrFrom(pinOldVarp);
if (connectRefp->castVarRef()) {
connectRefp->castVarRef()->varp()->propagateAttrFrom(pinOldVarp);
}
// One to one interconnect won't make a temporary variable.
// This prevents creating a lot of extra wires for clock signals.
// It will become a tracing alias.
UINFO(6,"One-to-one "<<connectRefp<<endl);
UINFO(6," -to "<<pinNewVarp<<endl);
pinNewVarp->user2p(connectRefp);
// Public output inside the cell must go via an assign rather than alias
// Else the public logic will set the alias, losing the value to be propagated up
// (InOnly isn't a problem as the AssignAlias will create the assignment for us)
pinNewVarp->user3(pinNewVarp->isSigUserRWPublic() && pinNewVarp->isOutOnly());
}
// Cleanup var names, etc, to not conflict
{ InlineRelinkVisitor(newmodp, m_modp, nodep); }
// Move statements to top module
if (debug()>=9) { newmodp->dumpTree(cout,"fixmod:"); }
AstNode* stmtsp = newmodp->stmtsp();
if (stmtsp) stmtsp->unlinkFrBackWithNext();
if (stmtsp) m_modp->addStmtp(stmtsp);
// Remove the cell
newmodp->deleteTree(); newmodp=NULL; // Clear any leftover ports, etc
nodep->unlinkFrBack();
pushDeletep(nodep); nodep = NULL;
if (debug()>=9) { m_modp->dumpTree(cout,"donemod:"); }
}
}
//--------------------
virtual void visit(AstNodeMath* nodep, AstNUser*) {} // Accelerate
virtual void visit(AstNodeStmt* nodep, AstNUser*) {} // Accelerate
virtual void visit(AstNode* nodep, AstNUser*) {
nodep->iterateChildren(*this);
}
public:
// CONSTUCTORS
InlineVisitor(AstNode* nodep) {
m_modp = NULL;
nodep->accept(*this);
}
virtual ~InlineVisitor() {
V3Stats::addStat("Optimizations, Inlined cells", m_statCells);
}
};
//######################################################################
// Inline class functions
void V3Inline::inlineAll(AstNetlist* nodep) {
UINFO(2,__FUNCTION__<<": "<<endl);
InlineMarkVisitor mvisitor (nodep);
InlineVisitor visitor (nodep);
// Remove all modules that were inlined
// V3Dead will also clean them up, but if we have debug on, it's a good
// idea to avoid dumping the hugely exploded tree.
AstNodeModule* nextmodp;
for (AstNodeModule* modp = v3Global.rootp()->modulesp(); modp; modp=nextmodp) {
nextmodp = modp->nextp()->castNodeModule();
if (modp->user1()) { // Was inlined
modp->unlinkFrBack()->deleteTree(); modp=NULL;
}
}
}