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Internals: Rework V3WidthSel func for non-vars. No functional change intended.

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This commit is contained in:
Wilson Snyder 2012-07-25 07:26:41 -04:00
parent de1bb5aeb6
commit 6e219f5831
1 changed files with 31 additions and 26 deletions
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57
src/V3WidthSel.cpp
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@ -75,11 +75,11 @@ private:
AstNodeDType* dtypeForExtractp(AstNode* nodep, AstNode* basefromp, int dimension, bool rangedSelect) {
// Perform error checks on the node
AstVar* varp = varFromBasefrom(basefromp);
//UINFO(9,"SCD\n"); if (debug()>=9) varp->dumpTree(cout,"-dtfexvar: ");
AstNode* errp;
AstNodeDType* bfdtypep = baseDTypeFrom(basefromp, errp/*ref*/);
//UINFO(9,"SCD\n"); if (debug()>=9) bfdtypep->dumpTree(cout,"-dtfexvar: ");
// This may be called on dotted variables before we've completed widthing of the dotted var.
AstNodeDType* ddtypep = varp->dtypep() ? varp->dtypep() : varp->childDTypep();
if (!ddtypep) nodep->v3fatalSrc("No datatype found for variable in select");
AstNodeDType* ddtypep = bfdtypep;
ddtypep = ddtypep->dtypeDimensionp(dimension);
if (debug()>=9 &&ddtypep) ddtypep->dumpTree(cout,"-ddtypep: ");
if (AstArrayDType* adtypep = ddtypep->castArrayDType()) {
@ -87,13 +87,13 @@ private:
}
else if (AstBasicDType* adtypep = ddtypep->castBasicDType()) {
if (!adtypep->isRanged()) {
nodep->v3error("Illegal bit select; variable does not have a bit range, or bad dimension: "<<varp->prettyName());
nodep->v3error("Illegal bit select; variable does not have a bit range, or bad dimension: "<<errp->prettyName());
return NULL;
}
return adtypep;
}
else {
nodep->v3error("Illegal bit or array select; variable already selected, or bad dimension: "<<varp->prettyName());
nodep->v3error("Illegal bit or array select; variable already selected, or bad dimension: "<<errp->prettyName());
}
return NULL;
}
@ -134,34 +134,39 @@ private:
return newp;
}
AstVar* varFromBasefrom(AstNode* basefromp) {
AstNodeDType* baseDTypeFrom(AstNode* basefromp, AstNode*& errpr) {
errpr = basefromp;
AstNodeVarRef* varrefp = basefromp->castNodeVarRef();
if (!varrefp) basefromp->v3fatalSrc("Bit/array selection of non-variable");
AstVar* varp = varrefp->varp(); if (!varp) varrefp->v3fatalSrc("Signal not linked");
return varp;
AstVar* varp = varrefp->varp(); if (!varp) { varrefp->v3fatalSrc("Signal not linked"); return NULL; }
errpr = varp;
AstNodeDType* bfdtypep = varp->subDTypep();
if (!bfdtypep) basefromp->v3fatalSrc("No datatype found for variable in select");
return bfdtypep;
}
AstNode* newSubLsbOf(AstNode* underp, AstNode* basefromp) {
// Account for a variable's LSB in bit selections
// Will likely become SUB(underp, lsb_of_signal)
// Don't report WIDTH warnings etc here, as may be inside a generate branch that will be deleted
AstVar* varp = varFromBasefrom(basefromp);
AstNode* errp;
AstNodeDType* bfdtypep = baseDTypeFrom(basefromp, errp/*ref*/);
// SUB #'s Not needed when LSB==0 and MSB>=0 (ie [0:-13] must still get added!)
if (!varp->basicp()->isRanged()) {
if (!bfdtypep->basicp()->isRanged()) {
// vector without range, or 0 lsb is ok, for example a INTEGER x; y = x[21:0];
return underp;
} else {
if (varp->basicp()->rangep()
&& (!varp->basicp()->rangep()->msbp()->castConst()
|| !varp->basicp()->rangep()->lsbp()->castConst()))
varp->v3fatalSrc("Non-constant variable range; errored earlier"); // in constifyParam(varp)
if (varp->basicp()->littleEndian()) {
if (bfdtypep->basicp()->rangep()
&& (!bfdtypep->basicp()->rangep()->msbp()->castConst()
|| !bfdtypep->basicp()->rangep()->lsbp()->castConst()))
bfdtypep->v3fatalSrc("Non-constant variable range; errored earlier"); // in constifyParam(bfdtypep)
if (bfdtypep->basicp()->littleEndian()) {
// reg [1:3] was swapped to [3:1] (lsbEndianedp==3) and needs a SUB(3,under)
AstNode* newp = newSubNeg(varp->basicp()->msb(), underp);
AstNode* newp = newSubNeg(bfdtypep->basicp()->msb(), underp);
return newp;
} else {
// reg [3:1] needs a SUB(under,1)
AstNode* newp = newSubNeg(underp, varp->basicp()->lsb());
AstNode* newp = newSubNeg(underp, bfdtypep->basicp()->lsb());
return newp;
}
}
@ -205,12 +210,12 @@ private:
int dimension = AstArraySel::dimension(nodep->fromp()); // Not attrp as need hierarchy
AstNodeDType* ddtypep = dtypeForExtractp(nodep, basefromp, dimension, false);
AstNode* fromp = nodep->lhsp()->unlinkFrBack();
AstNode* bitp = nodep->rhsp()->unlinkFrBack();
AstNode* rhsp = nodep->rhsp()->unlinkFrBack(); // bit we're extracting
if (debug()>=9) ddtypep->dumpTree(cout,"-ddtypep: ");
if (debug()>=9) nodep->dumpTree(cout,"-vsbmd: ");
if (AstArrayDType* adtypep = ddtypep->castArrayDType()) {
// SELBIT(array, index) -> ARRAYSEL(array, index)
AstNode* subp = bitp;
AstNode* subp = rhsp;
if (adtypep->lsb()!=0 || adtypep->msb()<0) {
subp = newSubNeg (subp, adtypep->lsb());
}
@ -224,7 +229,7 @@ private:
// SELBIT(range, index) -> SEL(array, index, 1)
AstSel* newp = new AstSel (nodep->fileline(),
fromp,
newSubLsbOf(bitp, basefromp),
newSubLsbOf(rhsp, basefromp),
// Unsized so width from user
new AstConst (nodep->fileline(),AstConst::Unsized32(),1));
UINFO(6," new "<<newp<<endl); if (debug()>=9) newp->dumpTree(cout,"-vsbnw: ");
@ -235,7 +240,7 @@ private:
// How to recover? We'll strip a dimension.
nodep->replaceWith(fromp); pushDeletep(nodep); nodep=NULL;
}
if (!bitp->backp()) pushDeletep(bitp); bitp=NULL;
if (!rhsp->backp()) pushDeletep(rhsp); rhsp=NULL;
}
virtual void visit(AstSelExtract* nodep, AstNUser*) {
@ -253,7 +258,8 @@ private:
AstNode* fromp = nodep->lhsp()->unlinkFrBack();
AstNode* msbp = nodep->rhsp()->unlinkFrBack();
AstNode* lsbp = nodep->thsp()->unlinkFrBack();
AstVar* varp = varFromBasefrom(basefromp);
AstNode* errp;
AstNodeDType* bfdtypep = baseDTypeFrom(basefromp, errp/*ref*/);
vlsint32_t msb = msbp->castConst()->toSInt();
vlsint32_t lsb = lsbp->castConst()->toSInt();
AstNodeDType* ddtypep = dtypeForExtractp(nodep, basefromp, dimension, msb!=lsb);
@ -265,11 +271,11 @@ private:
newp->length((msb - lsb) + 1);
nodep->replaceWith(newp); pushDeletep(nodep); nodep=NULL;
} else {
nodep->v3error("Illegal bit select; can't bit extract from arrayed dimension: "<<varp->prettyName());
nodep->v3error("Illegal bit select; can't bit extract from arrayed dimension: "<<errp->prettyName());
}
} else if (AstBasicDType* adtypep = ddtypep->castBasicDType()) {
if (adtypep) {} // Unused
if (varp->basicp()->littleEndian()) {
if (bfdtypep->basicp()->littleEndian()) {
// Below code assumes big bit endian; just works out if we swap
int x = msb; msb = lsb; lsb = x;
}
@ -310,7 +316,6 @@ private:
AstNode* rhsp = nodep->rhsp()->unlinkFrBack();
AstNode* widthp = nodep->thsp()->unlinkFrBack();
int width = widthp->castConst()->toSInt();
//AstVar* varp = varFromBasefrom(basefromp);
if (width > (1<<28)) nodep->v3error("Width of :+ or :- is huge; vector of over 1billion bits: "<<widthp->prettyName());
if (width<0) nodep->v3error("Width of :+ or :- is < 0: "<<widthp->prettyName());
AstNodeDType* ddtypep = dtypeForExtractp(nodep, basefromp, dimension, width!=1);