Adding an option to write Verilog with LUT instances (compiler warnings).

src/base/io/io.c

@@ -3039,7 +3039,7 @@ int IoCommandWriteVerilog( Abc_Frame_t * pAbc, int argc, char **argv )
 usage:
     fprintf( pAbc->Err, "usage: write_verilog [-K num] [-ah] <file>\n" );
     fprintf( pAbc->Err, "\t         writes the current network in Verilog format\n" );
-    fprintf( pAbc->Err, "\t-K num : write the network using instances of K-LUTs (2 <= K <= %d) [default = not used]\n", 6, nLutSize );
+    fprintf( pAbc->Err, "\t-K num : write the network using instances of K-LUTs (2 <= K <= 6) [default = not used]\n" );
     fprintf( pAbc->Err, "\t-a     : toggle writing expressions with only ANDs (without XORs and MUXes) [default = %s]\n", fOnlyAnds? "yes":"no" );
     fprintf( pAbc->Err, "\t-h     : print the help massage\n" );
     fprintf( pAbc->Err, "\tfile   : the name of the file to write\n" );

src/base/io/ioWriteVerilog.c

@@ -718,7 +718,7 @@ void Io_WriteVerilogObjectsLut( FILE * pFile, Abc_Ntk_t * pNtk, int nLutSize )
         if ( nLutSize == 6 )
             fprintf( pFile, "%08x%08x", (unsigned)(Truth >> 32), (unsigned)Truth );
         else
-            fprintf( pFile, "%0*x", 1<<(nLutSize-2), Abc_InfoMask(1 << nLutSize) & Truth );
+            fprintf( pFile, "%0*x", 1<<(nLutSize-2), Abc_InfoMask(1 << nLutSize) & (unsigned)Truth );
         fprintf( pFile, ") lut_%0*d ( {", nDigits, Counter++ );
         for ( k = nLutSize - 1; k >= Abc_ObjFaninNum(pObj); k-- )
             fprintf( pFile, "%*s, ", Length, "1\'b0" );
@@ -804,7 +804,7 @@ void Io_WriteVerilogLut( Abc_Ntk_t * pNtk, char * pFileName, int nLutSize )
         }
     if ( Counter )
     {
-        printf( "In total, %d internal logic nodes exceeded the fanout count limit.\n", Counter );
+        printf( "In total, %d internal logic nodes exceed the fanin count limit. Verilog is not written.\n", Counter );
         return;
     }