luke/verilator
1
0
Fork 0
mirror of https://github.com/verilator/verilator.git synced 2026-10-06 10:03:44 +02:00
Code Issues Packages Projects Releases Wiki Activity

Fix force unpacked bitselect (#7744) (#7745)

Browse Source 
Fixes #7744.
This commit is contained in:
Nikolai Kumar
2026-06-15 21:57:59 -04:00
committed by GitHub
parent 0e4a3a92b0
commit a5fad9882f
4 changed files with 265 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/V3Force.cpp
+24 -26
View File
@@ -870,30 +870,8 @@ class ForceDiscoveryVisitor final : public VNVisitorConst {
ForceState::ForceRangeInfo rangeInfo
= m_state.getForceRangeInfo(nodep->lhsp(), forcedVarp, true);
// Start from a cloned RHS expression; adjust below for partial bit selects.
const AstSel* const selLhsp = VN_CAST(nodep->lhsp(), Sel);
AstNodeExpr* rhsExprp = nodep->rhsp()->cloneTreePure(false);
// For bitwise selects inside arrays, merge updated bits with preserved base bits.
if (rangeInfo.m_hasArraySel && rangeInfo.m_arrayInfo.m_hasBitSel && selLhsp
&& ForceState::isBitwiseDType(selLhsp->fromp())) {
AstNodeExpr* const baseExprp = selLhsp->fromp()->cloneTreePure(false);
baseExprp->foreach(
[](AstVarRef* const refp) { ForceState::markNonReplaceable(refp); });
// Pad the selected value back to full base width before masking/or-ing.
rhsExprp = ForceState::zeroPadToBaseWidth(rhsExprp, selLhsp->fromp()->width(),
rangeInfo.m_padLsb, rangeInfo.m_padMsb);
// Keep untouched base bits and insert the newly forced bit range.
// rhsExpr = (baseExpr & ~mask(range)) | (zeroPad(force_rhs) & mask(range));
AstConst* const maskConstp = ForceState::makeRangeMaskConst(
nodep->lhsp(), selLhsp->fromp()->width(), rangeInfo.m_padLsb, rangeInfo.m_padMsb);
AstNodeExpr* const maskedOldp
= new AstAnd{nodep->lhsp()->fileline(), baseExprp,
new AstNot{nodep->lhsp()->fileline(), maskConstp}};
rhsExprp = new AstOr{nodep->lhsp()->fileline(), maskedOldp, rhsExprp};
}
// Keep narrow rhs, VlForceVec blends unpacked-array bit-select forces at read time
AstNodeExpr* const rhsExprp = nodep->rhsp()->cloneTreePure(false);
m_state.addForceAssignment(forcedVarp, lhsVarRefp->varScopep(), rhsExprp, nodep,
rangeInfo.m_rangeLsb, rangeInfo.m_rangeMsb, rangeInfo.m_padLsb,
@@ -1114,6 +1092,11 @@ class ForceConvertVisitor final : public VNVisitor {
// Verilog pseudocode:
// forceVec.addForce(range_lsb, range_msb, &forceRHS[id], rhs_lsb);
const AstSel* const selLhsp = VN_CAST(lhsp, Sel);
const bool arrayBitSel
= info.m_hasArraySel && selLhsp && ForceState::getArraySelInfo(lhsp).m_hasBitSel
&& ForceState::isBitwiseDType(selLhsp->fromp())
&& (info.m_padMsb - info.m_padLsb + 1) < selLhsp->fromp()->width();
AstNodeExpr* const rhsDatap = ForceState::buildRhsDataExpr(flp, info);
AstCExpr* const rhsAddrp = new AstCExpr{flp};
rhsAddrp->add("&(");
@@ -1124,7 +1107,13 @@ class ForceConvertVisitor final : public VNVisitor {
ForceState::makeConst32(flp, info.m_rangeLsb)};
addForceCallp->addPinsp(ForceState::makeConst32(flp, info.m_rangeMsb));
addForceCallp->addPinsp(rhsAddrp);
addForceCallp->addPinsp(ForceState::makeConst32(flp, info.m_rangeLsb));
addForceCallp->addPinsp(
ForceState::makeConst32(flp, arrayBitSel ? info.m_padLsb : info.m_rangeLsb));
if (arrayBitSel) {
addForceCallp->addPinsp(ForceState::makeConst32(flp, info.m_padLsb));
addForceCallp->addPinsp(ForceState::makeConst32(flp, info.m_padMsb));
addForceCallp->addPinsp(ForceState::makeConst32(flp, selLhsp->fromp()->width()));
}
addForceCallp->dtypeSetVoid();
AstNodeStmt* const stmtp = addForceCallp->makeStmt();
@@ -1164,12 +1153,21 @@ class ForceConvertVisitor final : public VNVisitor {
const ForceState::ForceRangeInfo rangeInfo
= m_state.getForceRangeInfo(lhsp, releasedVarp, false);
const AstSel* const selLhsp = VN_CAST(lhsp, Sel);
const bool arrayBitSel
= rangeInfo.m_hasArraySel && selLhsp && rangeInfo.m_arrayInfo.m_hasBitSel
&& ForceState::isBitwiseDType(selLhsp->fromp())
&& (rangeInfo.m_padMsb - rangeInfo.m_padLsb + 1) < selLhsp->fromp()->width();
AstCMethodHard* const releaseCallp = new AstCMethodHard{
flp, new AstVarRef{flp, varInfo->m_forceVecVscp, VAccess::WRITE},
VCMethod::FORCE_RELEASE, ForceState::makeConst32(flp, rangeInfo.m_rangeLsb)};
releaseCallp->addPinsp(ForceState::makeConst32(flp, rangeInfo.m_rangeMsb));
if (arrayBitSel) {
releaseCallp->addPinsp(ForceState::makeConst32(flp, rangeInfo.m_padLsb));
releaseCallp->addPinsp(ForceState::makeConst32(flp, rangeInfo.m_padMsb));
}
releaseCallp->dtypeSetVoid();
// forceVec.release(range_lsb, range_msb);
// forceVec.release(range_lsb, range_msb [, bit_lsb, bit_msb]);
AstNodeStmt* const releasep = releaseCallp->makeStmt();
AstAssign* clearEnp = nullptr;