luke/verilator
1
0
Fork 0
mirror of https://github.com/verilator/verilator.git synced 2026-10-06 01:54:01 +02:00
Code Issues Packages Projects Releases Wiki Activity

Improve Dfg type system (#6390)

Browse Source 
Added a mini type system for Dfg using DfgDataType to replace Dfg's use
of AstNodeDType. This is much more restricted and represents only the
types Dfg can handle in a canonical form. This will be needed when
adding more support for unpacked arrays and maybe unpacked structs one
day.

Also added an internal type checker for DfgGraphs which encodes all the
assumptions the code makes about type relationships in the graph. Run
this in a few places with --debug-check. Fix resulting fallout.
This commit is contained in:
Geza Lore
2025-09-07 20:38:50 +01:00
committed by GitHub
parent f67534069c
commit 6bc48fcdb3
27 changed files with 778 additions and 394 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/V3DfgPasses.cpp
+9 -10
View File
@@ -219,11 +219,9 @@ void V3DfgPasses::binToOneHot(DfgGraph& dfg, V3DfgBinToOneHotContext& ctx) {
FileLine* const flp = srcp->fileline();
// Required data types
AstNodeDType* const idxDTypep = srcp->dtypep();
AstNodeDType* const bitDTypep = V3Dfg::dtypePacked(1);
AstUnpackArrayDType* const tabDTypep = new AstUnpackArrayDType{
flp, bitDTypep, new AstRange{flp, static_cast<int>(nBits - 1), 0}};
v3Global.rootp()->typeTablep()->addTypesp(tabDTypep);
const DfgDataType& idxDType = srcp->dtype();
const DfgDataType& bitDType = DfgDataType::packed(1);
const DfgDataType& tabDType = DfgDataType::array(bitDType, nBits);
// The index variable
AstVar* const idxVarp = [&]() {
@@ -233,7 +231,7 @@ void V3DfgPasses::binToOneHot(DfgGraph& dfg, V3DfgBinToOneHotContext& ctx) {
varp = vp->as<DfgVarPacked>();
} else {
const std::string name = dfg.makeUniqueName("BinToOneHot_Idx", nTables);
varp = dfg.makeNewVar(flp, name, idxDTypep, nullptr)->as<DfgVarPacked>();
varp = dfg.makeNewVar(flp, name, idxDType, nullptr)->as<DfgVarPacked>();
varp->varp()->isInternal(true);
varp->srcp(srcp);
}
@@ -243,7 +241,7 @@ void V3DfgPasses::binToOneHot(DfgGraph& dfg, V3DfgBinToOneHotContext& ctx) {
// The previous index variable - we don't need a vertex for this
AstVar* const preVarp = [&]() {
const std::string name = dfg.makeUniqueName("BinToOneHot_Pre", nTables);
AstVar* const varp = new AstVar{flp, VVarType::MODULETEMP, name, idxDTypep};
AstVar* const varp = new AstVar{flp, VVarType::MODULETEMP, name, idxDType.astDtypep()};
dfg.modulep()->addStmtsp(varp);
varp->isInternal(true);
varp->noReset(true);
@@ -254,7 +252,7 @@ void V3DfgPasses::binToOneHot(DfgGraph& dfg, V3DfgBinToOneHotContext& ctx) {
DfgVarArray* const tabVtxp = [&]() {
const std::string name = dfg.makeUniqueName("BinToOneHot_Tab", nTables);
DfgVarArray* const varp
= dfg.makeNewVar(flp, name, tabDTypep, nullptr)->as<DfgVarArray>();
= dfg.makeNewVar(flp, name, tabDType, nullptr)->as<DfgVarArray>();
varp->varp()->isInternal(true);
varp->varp()->noReset(true);
varp->setHasModWrRefs();
@@ -310,7 +308,7 @@ void V3DfgPasses::binToOneHot(DfgGraph& dfg, V3DfgBinToOneHotContext& ctx) {
const std::vector<Term>& terms = pair.second;
// Create the ArraySel
FileLine* const aflp = terms.front().m_vtxp->fileline();
DfgArraySel* const aselp = new DfgArraySel{dfg, aflp, bitDTypep};
DfgArraySel* const aselp = new DfgArraySel{dfg, aflp, bitDType};
aselp->fromp(tabVtxp);
aselp->bitp(new DfgConst{dfg, aflp, width, val});
// The inverted value, if needed
@@ -319,7 +317,7 @@ void V3DfgPasses::binToOneHot(DfgGraph& dfg, V3DfgBinToOneHotContext& ctx) {
for (const Term& term : terms) {
if (term.m_inv) {
if (!notp) {
notp = new DfgNot{dfg, aflp, bitDTypep};
notp = new DfgNot{dfg, aflp, bitDType};
notp->srcp(aselp);
}
term.m_vtxp->replaceWith(notp);
@@ -448,6 +446,7 @@ void V3DfgPasses::optimize(DfgGraph& dfg, V3DfgContext& ctx) {
= ctx.prefix() + "pass-" + cvtToStr(passNumber) + "-" + strippedName;
dfg.dumpDotFilePrefixed(label);
}
if (v3Global.opt.debugCheck()) V3DfgPasses::typeCheck(dfg);
++passNumber;
};