From 8f40d6617e300ed47cf3f4b94ad1ce2294fdab1b Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Thu, 26 Jan 2012 08:29:55 -0500
Subject: [PATCH] For generated variables, opt towards 2-state so zero init

---
 src/V3Ast.h        |  1 +
 src/V3AstNodes.h   | 13 +++++++++++++
 src/V3Delayed.cpp  |  4 ++--
 src/V3EmitC.cpp    |  2 +-
 src/V3LinkJump.cpp |  2 +-
 src/V3Table.cpp    |  4 ++--
 src/V3Trace.cpp    |  2 +-
 7 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/src/V3Ast.h b/src/V3Ast.h
index ef0444b7c..bc55221f9 100644
--- a/src/V3Ast.h
+++ b/src/V3Ast.h
@@ -36,6 +36,7 @@
 
 // Hint class so we can choose constructors
 class AstLogicPacked {};
+class AstBitPacked {};
 
 //######################################################################
 
diff --git a/src/V3AstNodes.h b/src/V3AstNodes.h
index 3314a2eea..c03d1f9b6 100644
--- a/src/V3AstNodes.h
+++ b/src/V3AstNodes.h
@@ -254,6 +254,11 @@ public:
 	init(AstBasicDTypeKwd::LOGIC, signedst_NOP,
 	     ((wantwidth > 1) ? new AstRange(fl, wantwidth-1, 0) : NULL));
     }
+    AstBasicDType(FileLine* fl, AstBitPacked, int wantwidth)
+	: AstNodeDType(fl) {
+	init(AstBasicDTypeKwd::BIT, signedst_NOP,
+	     ((wantwidth > 1) ? new AstRange(fl, wantwidth-1, 0) : NULL));
+    }
     // See also addRange in verilog.y
 private:
     void init(AstBasicDTypeKwd kwd, AstSignedState signst, AstRange* rangep) {
@@ -626,6 +631,14 @@ public:
 	setOp1p(new AstBasicDType(fl, AstLogicPacked(), wantwidth));
 	width(wantwidth,0);
     }
+    AstVar(FileLine* fl, AstVarType type, const string& name, AstBitPacked, int wantwidth)
+	:AstNode(fl)
+	, m_name(name) {
+	init();
+	combineType(type);
+	setOp1p(new AstBasicDType(fl, AstBitPacked(), wantwidth));
+	width(wantwidth,0);
+    }
     AstVar(FileLine* fl, AstVarType type, const string& name, AstVar* examplep)
 	:AstNode(fl)
 	, m_name(name) {
diff --git a/src/V3Delayed.cpp b/src/V3Delayed.cpp
index 5469e04fd..4abc458b3 100644
--- a/src/V3Delayed.cpp
+++ b/src/V3Delayed.cpp
@@ -133,8 +133,8 @@ private:
 	    if (width==0) {
 		varp = new AstVar (oldvarscp->fileline(), AstVarType::BLOCKTEMP, name, oldvarscp->varp());
 		varp->widthSignedFrom(oldvarscp);
-	    } else {
-		varp = new AstVar (oldvarscp->fileline(), AstVarType::BLOCKTEMP, name, AstLogicPacked(), width);
+	    } else { // Used for vset and dimensions, so can zero init
+		varp = new AstVar (oldvarscp->fileline(), AstVarType::BLOCKTEMP, name, AstBitPacked(), width);
 	    }
 	    addmodp->addStmtp(varp);
 	    m_modVarMap.insert(make_pair(make_pair(addmodp, name), varp));
diff --git a/src/V3EmitC.cpp b/src/V3EmitC.cpp
index dcde232c6..0c3bd55c6 100644
--- a/src/V3EmitC.cpp
+++ b/src/V3EmitC.cpp
@@ -1353,7 +1353,7 @@ void EmitCImp::emitVarResets(AstNodeModule* modp) {
 		    puts(varp->name());
 		    for (int v=0; v<vects; ++v) puts( "[__Vi"+cvtToStr(v)+"]");
 		    if (zeroit) {
-			puts("= 0;\n");
+			puts(" = 0;\n");
 		    } else {
 			puts(" = VL_RAND_RESET_");
 			emitIQW(varp);
diff --git a/src/V3LinkJump.cpp b/src/V3LinkJump.cpp
index 8fb9c6704..75704af29 100644
--- a/src/V3LinkJump.cpp
+++ b/src/V3LinkJump.cpp
@@ -139,7 +139,7 @@ private:
    	string name = string("__Vrepeat")+cvtToStr(m_repeatNum++);
 	// Spec says value is integral, if negative is ignored
 	AstVar* varp = new AstVar(nodep->fileline(), AstVarType::BLOCKTEMP, name,
-				  AstLogicPacked(), 32);
+				  AstBitPacked(), 32);
 	varp->numeric(AstNumeric::SIGNED);
 	varp->dtypep()->numeric(AstNumeric::SIGNED);
 	varp->usedLoopIdx(true);
diff --git a/src/V3Table.cpp b/src/V3Table.cpp
index a141743df..0be0a9b30 100644
--- a/src/V3Table.cpp
+++ b/src/V3Table.cpp
@@ -182,7 +182,7 @@ private:
 	// Index into our table
 	AstVar* indexVarp = new AstVar (nodep->fileline(), AstVarType::BLOCKTEMP,
 					"__Vtableidx" + cvtToStr(m_modTables),
-					AstLogicPacked(), m_inWidth);
+					AstBitPacked(), m_inWidth);
 	m_modp->addStmtp(indexVarp);
 	AstVarScope* indexVscp = new AstVarScope (indexVarp->fileline(), m_scopep, indexVarp);
 	m_scopep->addVarp(indexVscp);
@@ -193,7 +193,7 @@ private:
 	    = new AstVar (fl, AstVarType::MODULETEMP,
 			  "__Vtablechg" + cvtToStr(m_modTables),
 			  new AstArrayDType (fl,
-					     new AstBasicDType(fl, AstLogicPacked(), m_outVarps.size()),
+					     new AstBasicDType(fl, AstBitPacked(), m_outVarps.size()),
 					     new AstRange (fl, VL_MASK_I(m_inWidth), 0)));
 	chgVarp->isConst(true);
 	chgVarp->valuep(new AstInitArray (nodep->fileline(), NULL));
diff --git a/src/V3Trace.cpp b/src/V3Trace.cpp
index 172e50a1d..19aad0900 100644
--- a/src/V3Trace.cpp
+++ b/src/V3Trace.cpp
@@ -313,7 +313,7 @@ private:
 	if (!activityNumber) activityNumber++;   // For simplicity, always create it
 	int activityBits = VL_WORDS_I(activityNumber)*VL_WORDSIZE;   // For tighter code; round to next 32 bit point.
 	AstVar* newvarp = new AstVar (m_chgFuncp->fileline(), AstVarType::MODULETEMP,
-				      "__Vm_traceActivity", AstLogicPacked(), activityBits);
+				      "__Vm_traceActivity", AstBitPacked(), activityBits);
 	m_topModp->addStmtp(newvarp);
 	AstVarScope* newvscp = new AstVarScope(newvarp->fileline(), m_highScopep, newvarp);
 	m_highScopep->addVarp(newvscp);