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// ========== Copyright Header Begin ==========================================

// 

// OpenSPARC T1 Processor File: sparc_exu_aluzcmp64.v

// Copyright (c) 2006 Sun Microsystems, Inc.  All Rights Reserved.

// DO NOT ALTER OR REMOVE COPYRIGHT NOTICES.

// 

// The above named program is free software; you can redistribute it and/or

// modify it under the terms of the GNU General Public

// License version 2 as published by the Free Software Foundation.

// 

// The above named program is distributed in the hope that it will be 

// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

// General Public License for more details.

// 

// You should have received a copy of the GNU General Public

// License along with this work; if not, write to the Free Software

// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.

// 

// ========== Copyright Header End ============================================

////////////////////////////////////////////////////////////////////////

/*

//

//  Module Name: sparc_exu_aluzcmp64

//      Description: This block determines if the input 'source' is zero.

//              It provides to outputs.  zero64 is high if all 64 bits

//              are zero, while zero32 is high if the lower 32 bits are

//              zero.  It uses 2 32 bit or gates and then NORs them.

*/

module sparc_exu_aluzcmp64

  (

   in,

   zero64,

   zero32

   );

   input [63:0] in;         // input operand

   output zero64;               // true if input is zero

   output zero32;               // true if lower 32 bits are zero

   wire   low_nonzero;                                  // low 32 is nonzero

   wire   high_nonzero;         // high 32 is nonzero

   // evaluate each half of the input

   sparc_exu_aluor32 lowcmp(.in(in[31:0]), .out(low_nonzero));

   sparc_exu_aluor32 highcmp(.in(in[63:32]), .out(high_nonzero));

   assign zero32 = ~low_nonzero;

   assign zero64 = ~(low_nonzero | high_nonzero);

endmodule // sparc_exu_aluzcmp64