Allow isolate_assignments on task input/outputs

git-svn-id: file://localhost/svn/verilator/trunk/verilator@880 77ca24e4-aefa-0310-84f0-b9a241c72d87

Changes

@@ -9,6 +9,8 @@ indicates the contributor was also the author of the fix; Thanks!
 
 **** Fix isolate_assignments when many signals per always. [Mike Shinkarovsky]
 
+**** Fix isolate_assignments across task temporaries. [Mike Shinkarovsky]
+
 * Verilator 3.632 1/17/2007
 
 ***  Add /*verilator isolate_assignments*/ attribute.  [Mike Shinkarovsky]

src/V3Order.cpp

@@ -382,6 +382,14 @@ private:
 	    //nodep->v3warn(GENCLK,"Signal unoptimizable: Generated clock: "<<nodep->prettyName());
 	} else if (nodep->varp()->isSigPublic()) {
 	    nodep->v3warn(UNOPT,"Signal unoptimizable: Feedback to public clock or circular logic: "<<nodep->prettyName());
+	    if (!nodep->fileline()->warnIsOff(V3ErrorCode::UNOPT)) {
+		nodep->fileline()->warnOff(V3ErrorCode::UNOPT, true);  // Complain just once
+		// Give the user an example.
+		bool tempWeight = (edgep && edgep->weight()==0);
+		if (tempWeight) edgep->weight(1);  // Else the below loop detect can't see the loop
+		m_graph.reportLoops(&OrderEdge::followComboConnected, vertexp); // calls OrderGraph::loopsVertexCb
+		if (tempWeight) edgep->weight(0);
+	    }
 	} else {
 	    // We don't use UNOPT, as there are lots of V2 places where it was needed, that aren't any more
 	    // First v3warn not inside warnIsOff so we can see the suppressions with --debug

src/V3Task.cpp

@@ -306,6 +306,7 @@ private:
 	AstVar* newvarp = new AstVar (invarp->fileline(), AstVarType::BLOCKTEMP,
 				      name, invarp);
 	newvarp->funcLocal(false);
+	newvarp->propagateAttrFrom(invarp);
 	m_modp->addStmtp(newvarp);
 	AstVarScope* newvscp = new AstVarScope (newvarp->fileline(), m_scopep, newvarp);
 	m_scopep->addVarp(newvscp);
@@ -628,7 +629,7 @@ private:
 	if (!funcp) nodep->v3fatalSrc("unlinked");
 	// Inline func refs in the function
 	iterateIntoFTask(funcp);
-	// Create output variabls
+	// Create output variable
 	string namePrefix = "__Vfunc_"+funcp->shortName()+"__"+cvtToStr(m_modNCalls++);
 	AstVarScope* outvscp = createVarScope (funcp->fvarp()->castVar(),
 					       namePrefix+"__out");

test_regress/t/t_unopt_combo.v

@@ -54,7 +54,7 @@ module t (/*AUTOARG*/
 	 $write("*-* All Finished *-*\n");
 	 $write("[%0t] cyc==%0d crc=%x %x\n",$time, cyc, crc, sum);
 	 if (crc !== 64'hc77bb9b3784ea091) $stop;
-	 if (sum !== 64'he281f003f6dd16b2) $stop;
+	 if (sum !== 64'h649ee1713d624dd9) $stop;
 	 $finish;
       end
    end
@@ -90,15 +90,23 @@ module file (/*AUTOARG*/
 	   d = {crc[15:0],~c[31:16]};
 	end
 	default: begin
-	   b = ~crc;
+	   set_b_d(crc, c);
-	   set_d(~c); // d = ~c;
 	end
       endcase
    end
 
-   task set_d;
+   task set_b_d;
-      input [31:0] to;
+`ifdef ISOLATE
-      d = to;
+      input [31:0] t_crc	/* verilator isolate_assignments*/;
+      input [31:0] t_c		/* verilator isolate_assignments*/;
+`else
+      input [31:0] t_crc;
+      input [31:0] t_c;
+`endif
+      begin
+	 b = {t_crc[31:16],~t_crc[23:8]};
+	 d = {t_crc[31:16],  ~t_c[23:8]};
+      end
    endtask
 
    always @* begin

test_regress/t/t_unopt_combo_isolate.pl

@@ -14,7 +14,7 @@ compile (
 	 );
 
 if ($Last_Self->{v3}) {
-    file_grep ($Last_Self->{stats}, qr/Optimizations, isolate_assignments blocks\s+1/i);
+    file_grep ($Last_Self->{stats}, qr/Optimizations, isolate_assignments blocks\s+3/i);
 }
 
 execute (