Internals: In AstBasicDType avoid use of Range for constants. No functional change.

src/V3AstNodes.cpp

@@ -269,7 +269,7 @@ AstNodeDType* AstVar::dtypeDimensionp(int dimension) const {
 	}
 	else if (AstBasicDType* adtypep = dtypep->castBasicDType()) {
 	    // AstBasicDType - nothing below, return null
-	    if (adtypep->rangep()) {
+	    if (adtypep->isRanged()) {
 		if ((dim++) == dimension) {
 		    return adtypep;
 		}
@@ -524,6 +524,7 @@ void AstAttrOf::dump(ostream& str) {
 void AstBasicDType::dump(ostream& str) {
     this->AstNodeDType::dump(str);
     str<<" ["<<keyword().ascii()<<"]";
+    if (!rangep() && msb()) str<<" range["<<msb()<<":"<<lsb()<<"]";
     if (implicit()) str<<" [IMPLICIT]";
 }
 void AstCCast::dump(ostream& str) {

src/V3AstNodes.h

@@ -244,35 +244,38 @@ struct AstBasicDType : public AstNodeDType {
 private:
     AstBasicDTypeKwd	m_keyword;	// What keyword created it
     bool		m_implicit;	// Implicitly declared
+    int			m_msb;		// MSB when no range attached
 public:
     AstBasicDType(FileLine* fl, AstBasicDTypeKwd kwd, AstSignedState signst=signedst_NOP)
 	: AstNodeDType(fl) {
-	init(kwd, signst, NULL);
+	init(kwd, signst, 0, NULL);
     }
     AstBasicDType(FileLine* fl, AstLogicPacked, int wantwidth)
 	: AstNodeDType(fl) {
-	init(AstBasicDTypeKwd::LOGIC, signedst_NOP,
+	init(AstBasicDTypeKwd::LOGIC, signedst_NOP, wantwidth, NULL);
-	     ((wantwidth > 1) ? new AstRange(fl, wantwidth-1, 0) : NULL));
     }
     AstBasicDType(FileLine* fl, AstBitPacked, int wantwidth)
 	: AstNodeDType(fl) {
-	init(AstBasicDTypeKwd::BIT, signedst_NOP,
+	init(AstBasicDTypeKwd::BIT, signedst_NOP, wantwidth, NULL);
-	     ((wantwidth > 1) ? new AstRange(fl, wantwidth-1, 0) : NULL));
     }
     // See also addRange in verilog.y
 private:
-    void init(AstBasicDTypeKwd kwd, AstSignedState signst, AstRange* rangep) {
+    void init(AstBasicDTypeKwd kwd, AstSignedState signst, int wantwidth, AstRange* rangep) {
 	m_keyword = kwd;
+	m_msb = 0;
 	// Implicitness: // "parameter X" is implicit and sized from initial value, "parameter reg x" not
 	m_implicit = false;
 	if (keyword()==AstBasicDTypeKwd::LOGIC_IMPLICIT) {
-	    if (!rangep) m_implicit = true;  // Also cleared if range added later
+	    if (!rangep && !wantwidth) m_implicit = true;  // Also cleared if range added later
 	    m_keyword = AstBasicDTypeKwd::LOGIC;
 	}
 	if (signst == signedst_NOP && keyword().isSigned()) signst = signedst_SIGNED;
 	if (keyword().isDouble()) dtypeChgDouble();
 	else setSignedState(signst);
-	if (!rangep) {  // Set based on keyword properties
+	if (!rangep && wantwidth) { // Constant width
+	    m_msb = wantwidth - 1;
+	    width(wantwidth, wantwidth);
+	} else if (!rangep) {  // Set based on keyword properties
 	    // V3Width will pull from this width
 	    if (keyword().width() > 1 && !isOpaque()) rangep = new AstRange(fileline(), keyword().width()-1, 0);
 	    width(keyword().width(), keyword().width());
@@ -305,14 +308,22 @@ public:
     bool	isOpaque() const { return keyword().isOpaque(); }
     bool	isSloppy() const { return keyword().isSloppy(); }
     bool	isZeroInit() const { return keyword().isZeroInit(); }
-    int		msb() const { if (!rangep()) return 0; return rangep()->msbConst(); }
+    bool	isRanged() const { return rangep() || m_msb; }
+    int		msb() const { if (!rangep()) return m_msb; return rangep()->msbConst(); }
     int		lsb() const { if (!rangep()) return 0; return rangep()->lsbConst(); }
-    int		msbEndianed() const { if (!rangep()) return 0; return littleEndian()?rangep()->lsbConst():rangep()->msbConst(); }
+    int		msbEndianed() const { if (!rangep()) return m_msb; return littleEndian()?rangep()->lsbConst():rangep()->msbConst(); }
     int		lsbEndianed() const { if (!rangep()) return 0; return littleEndian()?rangep()->msbConst():rangep()->lsbConst(); }
     int		msbMaxSelect() const { return (lsb()<0 ? msb()-lsb() : msb()); } // Maximum value a [] select may index
     bool	littleEndian() const { return (rangep() && rangep()->littleEndian()); }
     bool	implicit() const { return m_implicit; }
     void	implicit(bool flag) { m_implicit = flag; }
+    void	cvtRangeConst() {  // Convert to smaller represenation
+	if (rangep() && rangep()->castConst() && lsb()==0 && !littleEndian()) {
+	    m_msb = msb();
+	    rangep()->deleteTree();
+	    rangep(NULL);
+	}
+    }
 };
 
 struct AstConstDType : public AstNodeDType {

src/V3Const.cpp

@@ -1627,6 +1627,12 @@ private:
 	}
     }
 
+    // Simplify
+    virtual void visit(AstBasicDType* nodep, AstNUser*) {
+	nodep->iterateChildren(*this);
+	nodep->cvtRangeConst();
+    }
+
     //-----
     // Jump elimination
 

src/V3Coverage.cpp

@@ -193,7 +193,7 @@ private:
 		     const ToggleEnt& above,
 		     AstVar* varp, AstVar* chgVarp) { // Constant
 	if (AstBasicDType* bdtypep = dtypep->castBasicDType()) {
-	    if (bdtypep->rangep()) {
+	    if (bdtypep->isRanged()) {
 		for (int index_docs=bdtypep->lsb(); index_docs<bdtypep->msb()+1; index_docs++) {
 		    int index_code = index_docs - bdtypep->lsb();
 		    ToggleEnt newent (above.m_comment+string("[")+cvtToStr(index_docs)+"]",

src/V3EmitCSyms.cpp

@@ -453,9 +453,9 @@ void EmitCSyms::emitSymImp() {
 	    string bounds;
 	    if (AstBasicDType* basicp = varp->basicp()) {
 		// Range is always first, it's not in "C" order
-		if (basicp->rangep()) {
+		if (basicp->isRanged()) {
-		    bounds += " ,"; bounds += cvtToStr(basicp->rangep()->msbConst());
+		    bounds += " ,"; bounds += cvtToStr(basicp->msb());
-		    bounds += ","; bounds += cvtToStr(basicp->rangep()->lsbConst());
+		    bounds += ","; bounds += cvtToStr(basicp->lsb());
 		    dim++;
 		}
 		for (AstNodeDType* dtypep=varp->dtypep(); dtypep; ) {

src/V3EmitV.cpp

@@ -486,6 +486,7 @@ class EmitVBaseVisitor : public EmitCBaseVisitor {
 	if (nodep->isSigned()) putfs(nodep,"signed ");
 	putfs(nodep,nodep->prettyName());
 	if (nodep->rangep()) { puts(" "); nodep->rangep()->iterateAndNext(*this); puts(" "); }
+	else if (nodep->msb()) { puts(" ["); puts(cvtToStr(nodep->msb())); puts(":0] "); }
     }
     virtual void visit(AstConstDType* nodep, AstNUser*) {
 	putfs(nodep,"const ");

src/V3Premit.cpp

@@ -204,6 +204,7 @@ private:
 		AstNRelinker replaceHandle;
 		nodep->unlinkFrBack(&replaceHandle);
 		AstNode* constzerop;
+		int m1value = nodep->widthMin()-1; // Constant of width-1; not changing dtype width
 		if (nodep->signedFlavor()) {
 		    // Then over shifting gives the sign bit, not all zeros
 		    // Note *NOT* clean output -- just like normal shift!
@@ -212,7 +213,7 @@ private:
 						new AstShiftR(nodep->fileline(),
 							      nodep->lhsp()->cloneTree(false),
 							      new AstConst(nodep->fileline(),
-									   nodep->widthMin()-1),
+									   m1value),
 							      nodep->width()));
 		} else {
 		    V3Number zeronum  (nodep->fileline(), nodep->width(), 0);

src/V3Table.cpp

@@ -237,6 +237,7 @@ private:
 		= new AstVar (fl, AstVarType::MODULETEMP,
 			      "__Vtable" + cvtToStr(m_modTables) +"_"+outvarp->name(),
 			      new AstArrayDType (fl,
+						 // FUTURE: If support more types, below can use outvarp->dtype()
 						 new AstBasicDType(fl, AstLogicPacked(), outvarp->width()),
 						 new AstRange (fl, VL_MASK_I(m_inWidth), 0)));
 	    tablevarp->isConst(true);

src/V3Width.cpp

@@ -405,7 +405,7 @@ private:
 	    int frommsb = nodep->fromp()->width() - 1;
 	    int fromlsb = 0;
 	    AstNodeVarRef* varrp = nodep->fromp()->castNodeVarRef();
-	    if (varrp && varrp->varp()->basicp()->rangep()) {	// Selecting a bit from a multibit register
+	    if (varrp && varrp->varp()->basicp()->isRanged()) {	// Selecting a bit from a multibit register
 		frommsb = varrp->varp()->basicp()->msbMaxSelect();  // Corrected for negative lsb
 		fromlsb = varrp->varp()->basicp()->lsb();
 	    }

src/V3WidthSel.cpp

@@ -83,7 +83,7 @@ private:
 	    return adtypep;
 	}
 	else if (AstBasicDType* adtypep = ddtypep->castBasicDType()) {
-	    if (!adtypep->rangep()) {
+	    if (!adtypep->isRanged()) {
 		nodep->v3error("Illegal bit select; variable does not have a bit range, or bad dimension: "<<varp->prettyName());
 		return NULL;
 	    }
@@ -145,13 +145,13 @@ private:
 	AstVar* varp = varFromBasefrom(basefromp);
 	// SUB #'s Not needed when LSB==0 and MSB>=0 (ie [0:-13] must still get added!)
 	if (!varp->basicp()->rangep()) {
-	    // vector without range is ok, for example a INTEGER x; y = x[21:0];
+	    // vector without range, or 0 lsb is ok, for example a INTEGER x; y = x[21:0];
 	    return underp;
 	} else {
 	    if (!varp->basicp()->rangep()->msbp()->castConst()
 		|| !varp->basicp()->rangep()->lsbp()->castConst())
 		varp->v3fatalSrc("Non-constant variable range; errored earlier");  // in constifyParam(varp)
-	    if (varp->basicp()->rangep()->littleEndian()) {
+	    if (varp->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);
 		return newp;
@@ -263,7 +263,7 @@ private:
 	    }
 	} else if (AstBasicDType* adtypep = ddtypep->castBasicDType()) {
 	    if (adtypep) {} // Unused
-	    if (varp->basicp()->rangep() && varp->basicp()->rangep()->littleEndian()) {
+	    if (varp->basicp()->littleEndian()) {
 		// Below code assumes big bit endian; just works out if we swap
 		int x = msb; msb = lsb; lsb = x;
 	    }
@@ -308,7 +308,7 @@ private:
 	if (AstBasicDType* adtypep = ddtypep->castBasicDType()) {
 	    AstSel* newp = NULL;
 	    if (nodep->castSelPlus()) {
-		if (adtypep->rangep() && adtypep->rangep()->littleEndian()) {
+		if (adtypep->littleEndian()) {
 		    // SELPLUS(from,lsb,width) -> SEL(from, (vector_msb-width+1)-sel, width)
 		    newp = new AstSel (nodep->fileline(),
 				       fromp,
@@ -322,7 +322,7 @@ private:
 				       widthp);
 		}
 	    } else if (nodep->castSelMinus()) {
-		if (adtypep->rangep() && adtypep->rangep()->littleEndian()) {
+		if (adtypep->littleEndian()) {
 		    // SELMINUS(from,msb,width) -> SEL(from, msb-[bit])
 		    newp = new AstSel (nodep->fileline(),
 				       fromp,

src/verilog.y

@@ -122,7 +122,7 @@ public:
 	    // then [1:1] becomes the basicdtype range; everything else is arraying
 	    // the final [5:5][4:4] will be passed in another call to createArray
 	    AstRange* rangearraysp = NULL;
-	    if (dtypep->rangep()) {
+	    if (dtypep->isRanged()) {
 		rangearraysp = rangesp;  // Already a range; everything is an array
 	    } else {
 		AstRange* finalp = rangesp;