Support while and do-while loops.

git-svn-id: file://localhost/svn/verilator/trunk/verilator@905 77ca24e4-aefa-0310-84f0-b9a241c72d87

Changes

@@ -5,6 +5,8 @@ indicates the contributor was also the author of the fix; Thanks!
 
 * Verilator 3.64**
 
+***  Support while and do-while loops.
+
 **** Fix dotted bit reference to local memory.  [Eugene Weber]
 
 * Verilator 3.640 3/12/2007

bin/verilator

@@ -1373,12 +1373,13 @@ This section describes specific limitations for each language keyword.
 
 =over 4
 
-=item always always_comb always_ff always_latch and assign begin buf case
-casex casez default defparam else end endcase endfunction endgenerate
-endmodule endspecify endtask final for function generate genvar if initial
-inout input integer localparam macromodule module nand negedge nor not or
-output parameter posedge reg scalared signed supply0 supply1 task tri
-vectored wire xnor xor
+=item always, always_comb, always_ff, always_latch, and, assign, begin,
+buf, case, casex, casez, default, defparam, do-while, else, end, endcase,
+endfunction, endgenerate, endmodule, endspecify, endtask, final, for,
+function, generate, genvar, if, initial, inout, input, integer, localparam,
+macromodule, module, nand, negedge, nor, not, or, output, parameter,
+posedge, reg, scalared, signed, supply0, supply1, task, tri, vectored,
+while, wire, xnor, xor
 
 Generally supported.
 

src/verilog.l

@@ -180,6 +180,7 @@ escid	\\[^ \t\f\r\n]+
   "task"		{yylval.fileline = CRELINE(); return yTASK;}
   "tri"			{yylval.fileline = CRELINE(); return yTRI;}
   "vectored"		{yylval.fileline = CRELINE(); return yVECTORED;}
+  "while"		{yylval.fileline = CRELINE(); return yWHILE;}
   "wire"		{yylval.fileline = CRELINE(); return yWIRE;}
   "xnor"		{yylval.fileline = CRELINE(); return yXNOR;}
   "xor"			{yylval.fileline = CRELINE(); return yXOR;}
@@ -250,7 +251,6 @@ escid	\\[^ \t\f\r\n]+
   "wand"		{yyerrorf("Unsupported: Verilog 1995 reserved word not implemented: %s",yytext);}
   "weak0"		{yyerrorf("Unsupported: Verilog 1995 reserved word not implemented: %s",yytext);}
   "weak1"		{yyerrorf("Unsupported: Verilog 1995 reserved word not implemented: %s",yytext);}
-  "while"		{yyerrorf("Unsupported: Verilog 1995 reserved word not implemented: %s",yytext);}
   "wor"			{yyerrorf("Unsupported: Verilog 1995 reserved word not implemented: %s",yytext);}
 }
 
@@ -308,6 +308,7 @@ escid	\\[^ \t\f\r\n]+
   "always_comb"		{yylval.fileline = CRELINE(); return yALWAYS;}
   "always_ff"		{yylval.fileline = CRELINE(); return yALWAYS;}
   "always_latch"	{yylval.fileline = CRELINE(); return yALWAYS;}
+  "do"			{yylval.fileline = CRELINE(); return yDO;}
   "final"		{yylval.fileline = CRELINE(); return yFINAL;}
   /*     Generic unsupported warnings */
   /* Note assert_strobe was in SystemVerilog 3.1, but removed for SystemVerilog 2005 */
@@ -328,7 +329,6 @@ escid	\\[^ \t\f\r\n]+
   "coverpoint"		{yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext);}
   "cross"		{yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext);}
   "dist"		{yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext);}
-  "do"			{yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext);}
   "endcass"		{yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext);}
   "endclocking"		{yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext);}
   "endgroup"		{yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext);}

src/verilog.y

@@ -140,10 +140,12 @@ class AstSenTree;
 %token<fileline>	yASSERT		"assert"
 %token<fileline>	yCLOCK		"clock"
 %token<fileline>	yCOVER		"cover"
+%token<fileline>	yDO		"do"
 %token<fileline>	yFINAL		"final"
 %token<fileline>	yPSL		"psl"
 %token<fileline>	yREPORT		"report"
 %token<fileline>	yTRUE		"true"
+%token<fileline>	yWHILE		"while"
 
 %token<fileline>	yPSL_ASSERT	"PSL assert"
 
@@ -716,6 +718,8 @@ stateCaseForIf: caseStmt caseAttrE caseList yENDCASE	{ $$ = $1; $1->addItemsp($3
 							{ $$ = new AstFor($1, new AstAssign($4,$3,$5)
 									  ,$7, new AstAssign($10,$9,$11)
 									  ,$13);}
+	|	yWHILE '(' expr ')' stmtBlock		{ $$ = new AstWhile($1,$3,$5);}
+	|	yDO stmtBlock yWHILE '(' expr ')'	{ $$ = $2->cloneTree(true); $$->addNext(new AstWhile($1,$5,$2));}
 	;
 
 assertStmt:	yASSERT '(' expr ')' stmtBlock %prec yLOWER_THAN_ELSE	{ $$ = new AstVAssert($1,$3,$5, V3Parse::createDisplayError($1)); }

test_regress/t/t_for_count.v

@@ -1,4 +1,4 @@
-// $Id:$
+// $Id$
 // DESCRIPTION: Verilator: Verilog Test module
 //
 // This file ONLY is placed into the Public Domain, for any use,
@@ -34,6 +34,27 @@ module t (/*AUTOARG*/
       end
    end
 
+   // While loop
+   integer w;
+   initial begin
+      while (w<10) w=w+1;
+      if (w!=10) $stop;
+      while (w<20) begin w=w+2; end
+      while (w<20) begin w=w+99999; end  // NEVER
+      if (w!=20) $stop;
+   end
+
+   // Do-While loop
+   integer dw;
+   initial begin
+      do dw=dw+1; while (dw<10);
+      if (dw!=10) $stop;
+      do dw=dw+2; while (dw<20);
+      if (dw!=20) $stop;
+      do dw=dw+5; while (dw<20);  // Once
+      if (dw!=25) $stop;
+   end
+
    always @ (posedge clk) begin
       cam_lookup_hit_vector <= 0;
       if (cyc!=0) begin
@@ -49,7 +70,7 @@ module t (/*AUTOARG*/
 	    if (hit_count != 32'd5) $stop;
 	    if (wide_for_count != 32'h80) $stop;
 	 end
-	 if (cyc==4) begin
+	 if (cyc==9) begin
 	    $write("*-* All Finished *-*\n");
 	    $finish;
 	 end