verilator/src/V3Param.cpp
2011-01-18 21:19:12 -05:00

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//*************************************************************************
// DESCRIPTION: Verilator: Replicate modules for parameterization
//
// Code available from: http://www.veripool.org/verilator
//
// AUTHORS: Wilson Snyder with Paul Wasson, Duane Gabli
//
//*************************************************************************
//
// Copyright 2003-2011 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.
//
//*************************************************************************
// PARAM TRANSFORMATIONS:
// Top down traversal:
// For each cell:
// If parameterized,
// Determine all parameter widths, constant values
// Clone module cell calls, renaming with __{par1}_{par2}_...
// Substitute constants for cell's module's parameters
// Relink pins and cell to point to new module
//
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include <cstdio>
#include <cstdarg>
#include <unistd.h>
#include <map>
#include <vector>
#include "V3Global.h"
#include "V3Param.h"
#include "V3Ast.h"
#include "V3Case.h"
#include "V3Const.h"
#include "V3Width.h"
#include "V3Signed.h"
#include "V3Unroll.h"
//######################################################################
// Param state, as a visitor of each AstNode
class ParamVisitor : public AstNVisitor {
private:
// NODE STATE
// AstNodeModule::user5() // bool True if parameters numbered
// AstVar::user4() // int Global parameter number (for naming new module)
// // (0=not processed, 1=iterated, but no number, 65+ parameter numbered)
AstUser4InUse m_inuser4;
AstUser5InUse m_inuser5;
// User1/2/3 used by constant function simulations
// STATE
typedef std::map<AstVar*,AstVar*> VarCloneMap;
struct ModInfo {
AstNodeModule* m_modp; // Module with specified name
VarCloneMap m_cloneMap; // Map of old-varp -> new cloned varp
ModInfo(AstNodeModule* modp) { m_modp=modp; }
};
typedef std::map<string,ModInfo> ModNameMap;
ModNameMap m_modNameMap; // Hash of created module flavors by name
typedef std::map<string,string> LongMap;
LongMap m_longMap; // Hash of very long names to unique identity number
int m_longId;
// METHODS
static int debug() {
static int level = -1;
if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__);
return level;
}
void makeSmallNames(AstNodeModule* modp) {
vector<int> usedLetter; usedLetter.resize(256);
// Pass 1, assign first letter to each gparam's name
for (AstNode* stmtp = modp->stmtsp(); stmtp; stmtp=stmtp->nextp()) {
if (AstVar* varp = stmtp->castVar()) {
if (varp->isGParam()) {
char ch = varp->name()[0];
ch = toupper(ch); if (ch<'A' || ch>'Z') ch='Z';
varp->user4(usedLetter[ch]*256 + ch);
usedLetter[ch]++;
}
}
}
}
string paramSmallName(AstNodeModule* modp, AstVar* varp) {
if (varp->user4()<=1) {
makeSmallNames(modp);
}
int index = varp->user4()/256;
char ch = varp->user4()&255;
string st = cvtToStr(ch);
while (index) {
st += cvtToStr(char((index%26)+'A'));
index /= 26;
}
return st;
}
void relinkPins(VarCloneMap* clonemapp, AstPin* startpinp) {
for (AstPin* pinp = startpinp; pinp; pinp=pinp->nextp()->castPin()) {
if (!pinp->modVarp()) pinp->v3fatalSrc("Not linked?\n");
// Find it in the clone structure
//UINFO(8,"Clone find 0x"<<hex<<(uint32_t)pinp->modVarp()<<endl);
VarCloneMap::iterator cloneiter = clonemapp->find(pinp->modVarp());
UASSERT(cloneiter != clonemapp->end(), "Couldn't find pin in clone list");
pinp->modVarp(cloneiter->second);
}
}
// VISITORS
virtual void visit(AstNetlist* nodep, AstNUser*) {
// Modules must be done in top-down-order
nodep->iterateChildren(*this);
}
virtual void visit(AstNodeModule* nodep, AstNUser*) {
UINFO(4," MOD "<<nodep<<endl);
nodep->iterateChildren(*this);
}
virtual void visit(AstCell* nodep, AstNUser*);
// Make sure all parameters are constantified
virtual void visit(AstVar* nodep, AstNUser*) {
if (!nodep->user5Inc()) { // Process once
nodep->iterateChildren(*this);
if (nodep->isParam()) {
if (!nodep->hasSimpleInit()) { nodep->v3fatalSrc("Parameter without initial value"); }
V3Const::constifyParamsEdit(nodep); // The variable, not just the var->init()
}
}
}
// Make sure varrefs cause vars to constify before things above
virtual void visit(AstVarRef* nodep, AstNUser*) {
if (nodep->varp()) nodep->varp()->iterate(*this);
}
// Generate Statements
virtual void visit(AstGenerate* nodep, AstNUser*) {
if (debug()>=9) nodep->dumpTree(cout,"-genin: ");
nodep->iterateChildren(*this);
// After expanding the generate, all statements under it can be moved
// up, and the generate block deleted as it's not relevant
if (AstNode* stmtsp = nodep->stmtsp()) {
stmtsp->unlinkFrBackWithNext();
nodep->replaceWith(stmtsp);
if (debug()>=9) stmtsp->dumpTree(cout,"-genout: ");
} else {
nodep->unlinkFrBack();
}
nodep->deleteTree(); nodep=NULL;
}
virtual void visit(AstGenIf* nodep, AstNUser*) {
nodep->condp()->iterateAndNext(*this);
V3Width::widthParamsEdit(nodep); // Param typed widthing will NOT recurse the body
V3Const::constifyParamsEdit(nodep->condp()); // condp may change
if (AstConst* constp = nodep->condp()->castConst()) {
AstNode* keepp = (constp->isZero()
? nodep->elsesp()
: nodep->ifsp());
if (keepp) {
keepp->unlinkFrBackWithNext();
nodep->replaceWith(keepp);
} else {
nodep->unlinkFrBack();
}
nodep->deleteTree(); nodep=NULL;
// Normal edit rules will now recurse the replacement
} else {
nodep->condp()->v3error("Generate If condition must evaluate to constant");
}
}
virtual void visit(AstGenFor* nodep, AstNUser*) {
// We parse a very limited form of FOR, so we don't need to do a full
// simulation to unroll the loop
V3Width::widthParamsEdit(nodep); // Param typed widthing will NOT recurse the body
// Note V3Unroll will replace some AstVarRef's to the loop variable with constants
V3Unroll::unrollGen(nodep); nodep=NULL;
}
virtual void visit(AstGenCase* nodep, AstNUser*) {
AstNode* keepp = NULL;
nodep->exprp()->iterateAndNext(*this);
V3Case::caseLint(nodep);
V3Width::widthParamsEdit(nodep); // Param typed widthing will NOT recurse the body
V3Const::constifyParamsEdit(nodep->exprp()); // exprp may change
AstConst* exprp = nodep->exprp()->castConst();
// Constify
for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
for (AstNode* ep = itemp->condsp(); ep; ) {
AstNode* nextp = ep->nextp(); //May edit list
ep->iterateAndNext(*this);
V3Const::constifyParamsEdit(ep); ep=NULL; // ep may change
ep = nextp;
}
}
// Item match
for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
if (!itemp->isDefault()) {
for (AstNode* ep = itemp->condsp(); ep; ep=ep->nextp()) {
if (AstConst* ccondp = ep->castConst()) {
V3Number match (nodep->fileline(), 1);
match.opEq(ccondp->num(), exprp->num());
if (!keepp && match.isNeqZero()) {
keepp = itemp->bodysp();
}
} else {
itemp->v3error("Generate Case item does not evaluate to constant");
}
}
}
}
// Else default match
for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
if (itemp->isDefault()) {
if (!keepp) keepp=itemp->bodysp();
}
}
// Replace
if (keepp) {
keepp->unlinkFrBackWithNext();
nodep->replaceWith(keepp);
}
else nodep->unlinkFrBack();
nodep->deleteTree(); nodep=NULL;
}
// Default: Just iterate
virtual void visit(AstNode* nodep, AstNUser*) {
nodep->iterateChildren(*this);
}
public:
// CONSTUCTORS
ParamVisitor(AstNetlist* nodep) {
m_longId = 0;
//
nodep->accept(*this);
}
virtual ~ParamVisitor() {}
};
//----------------------------------------------------------------------
// VISITs
void ParamVisitor::visit(AstCell* nodep, AstNUser*) {
// Cell: Check for parameters in the instantiation.
nodep->iterateChildren(*this);
if (!nodep->modp()) { nodep->dumpTree(cerr,"error:"); nodep->v3fatalSrc("Not linked?"); }
if (nodep->paramsp()) {
UINFO(4,"De-parameterize: "<<nodep<<endl);
// Create new module name with _'s between the constants
if (debug()>9) nodep->dumpTree(cout,"cell:\t");
// Evaluate all module constants
V3Const::constifyParamsEdit(nodep);
// Make sure constification worked
// Must be a separate loop, as constant conversion may have changed some pointers.
//if (debug()) nodep->dumpTree(cout,"cel2:\t");
string longname = nodep->modp()->name();
bool any_overrides = false;
longname += "_";
if (debug()>8) nodep->paramsp()->dumpTreeAndNext(cout,"-cellparams:\t");
for (AstPin* pinp = nodep->paramsp(); pinp; pinp=pinp->nextp()->castPin()) {
if (!pinp) nodep->v3fatalSrc("Non pin under cell params\n");
AstVar* modvarp = pinp->modVarp();
if (!modvarp) {
pinp->v3error("Parameter not found in sub-module: Param "<<pinp->name()<<" of "<<nodep->prettyName());
} else if (!modvarp->isGParam()) {
pinp->v3error("Attempted parameter setting of non-parameter: Param "<<pinp->name()<<" of "<<nodep->prettyName());
} else {
AstConst* constp = pinp->exprp()->castConst();
AstConst* origconstp = modvarp->valuep()->castConst();
if (!constp) {
//if (debug()) pinp->dumpTree(cout,"error:");
pinp->v3error("Can't convert defparam value to constant: Param "<<pinp->name()<<" of "<<nodep->prettyName());
pinp->exprp()->replaceWith(new AstConst(pinp->fileline(), V3Number(pinp->fileline(), pinp->width(), 0)));
} else if (origconstp && constp->sameTree(origconstp)) {
// Setting parameter to its default value. Just ignore it.
// This prevents making additional modules, and makes coverage more
// obvious as it won't show up under a unique module page name.
} else {
longname += "_" + paramSmallName(nodep->modp(),pinp->modVarp())+constp->num().ascii(false);
any_overrides = true;
}
}
}
if (!any_overrides) {
UINFO(8,"Cell parameters all match original values, skipping expansion.\n");
} else {
// If the name is very long, we don't want to overwhelm the filename limit
// We don't do this always, as it aids debugability to have intuitive naming.
string newname = longname;
if (longname.length()>30) {
LongMap::iterator iter = m_longMap.find(longname);
if (iter != m_longMap.end()) {
newname = iter->second;
} else {
newname = nodep->modp()->name();
newname += "__pi"+cvtToStr(++m_longId); // We use all upper case above, so lower here can't conflict
m_longMap.insert(make_pair(longname, newname));
}
}
UINFO(4,"Name: "<<nodep->modp()->name()<<"->"<<longname<<"->"<<newname<<endl);
//
// Already made this flavor?
AstNodeModule* modp = NULL;
ModNameMap::iterator iter = m_modNameMap.find(newname);
if (iter != m_modNameMap.end()) modp = iter->second.m_modp;
if (!modp) {
// Deep clone of new module
// Note all module internal variables will be re-linked to the new modules by clone
// However links outside the module (like on the upper cells) will not.
modp = nodep->modp()->cloneTree(false);
modp->name(newname);
nodep->modp()->addNextHere(modp); // Keep tree sorted by cell occurrences
m_modNameMap.insert(make_pair(modp->name(), ModInfo(modp)));
iter = m_modNameMap.find(newname);
VarCloneMap* clonemapp = &(iter->second.m_cloneMap);
UINFO(4," De-parameterize to new: "<<modp<<endl);
// Grab all I/O so we can remap our pins later
// Note we allow multiple users of a parameterized model, thus we need to stash this info.
for (AstNode* stmtp=modp->stmtsp(); stmtp; stmtp = stmtp->nextp()) {
if (AstVar* varp = stmtp->castVar()) {
if (varp->isIO() || varp->isGParam()) {
// Cloning saved a pointer to the new node for us, so just follow that link.
AstVar* oldvarp = varp->clonep()->castVar();
//UINFO(8,"Clone list 0x"<<hex<<(uint32_t)oldvarp<<" -> 0x"<<(uint32_t)varp<<endl);
clonemapp->insert(make_pair(oldvarp, varp));
}
}
}
// Relink parameter vars to the new module
relinkPins(clonemapp, nodep->paramsp());
// Assign parameters to the constants specified
for (AstPin* pinp = nodep->paramsp(); pinp; pinp=pinp->nextp()->castPin()) {
AstVar* modvarp = pinp->modVarp();
if (modvarp) {
AstConst* constp = pinp->exprp()->castConst();
// Remove any existing parameter
if (modvarp->valuep()) modvarp->valuep()->unlinkFrBack()->deleteTree();
// Set this parameter to value requested by cell
modvarp->valuep(constp->cloneTree(false));
}
}
} else {
UINFO(4," De-parameterize to old: "<<modp<<endl);
}
// Have child use this module instead.
nodep->modp(modp);
nodep->modName(newname);
// We need to relink the pins to the new module
VarCloneMap* clonemapp = &(iter->second.m_cloneMap);
relinkPins(clonemapp, nodep->pinsp());
UINFO(8," Done with "<<modp<<endl);
} // if any_overrides
// Delete the parameters from the cell; they're not relevant any longer.
nodep->paramsp()->unlinkFrBackWithNext()->deleteTree();
UINFO(8," Done with "<<nodep<<endl);
}
}
//######################################################################
// Param class functions
void V3Param::param(AstNetlist* rootp) {
UINFO(2,__FUNCTION__<<": "<<endl);
ParamVisitor visitor (rootp);
}