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

// 

// OpenSPARC T1 Processor File: sparc_exu_alu.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_alu

*/

module sparc_exu_alu

(

 /*AUTOARG*/

   // Outputs

   so, alu_byp_rd_data_e, exu_ifu_brpc_e, exu_lsu_ldst_va_e,

   exu_lsu_early_va_e, exu_mmu_early_va_e, alu_ecl_add_n64_e,

   alu_ecl_add_n32_e, alu_ecl_log_n64_e, alu_ecl_log_n32_e,

   alu_ecl_zhigh_e, alu_ecl_zlow_e, exu_ifu_regz_e, exu_ifu_regn_e,

   alu_ecl_adderin2_63_e, alu_ecl_adderin2_31_e,

   alu_ecl_adder_out_63_e, alu_ecl_cout32_e, alu_ecl_cout64_e_l,

   alu_ecl_mem_addr_invalid_e_l,

   // Inputs

   rclk, se, si, byp_alu_rs1_data_e, byp_alu_rs2_data_e_l,

   byp_alu_rs3_data_e, byp_alu_rcc_data_e, ecl_alu_cin_e,

   ifu_exu_invert_d, ecl_alu_log_sel_and_e, ecl_alu_log_sel_or_e,

   ecl_alu_log_sel_xor_e, ecl_alu_log_sel_move_e,

   ecl_alu_out_sel_sum_e_l, ecl_alu_out_sel_rs3_e_l,

   ecl_alu_out_sel_shift_e_l, ecl_alu_out_sel_logic_e_l,

   shft_alu_shift_out_e, ecl_alu_sethi_inst_e, ifu_lsu_casa_e

   );

   input rclk;

   input se;

   input si;

   input [63:0] byp_alu_rs1_data_e;   // source operand 1

   input [63:0] byp_alu_rs2_data_e_l;  // source operand 2

   input [63:0] byp_alu_rs3_data_e;  // source operand 3

   input [63:0] byp_alu_rcc_data_e;  // source operand for reg condition codes

   input        ecl_alu_cin_e;            // cin for adder

   input        ifu_exu_invert_d;

   input  ecl_alu_log_sel_and_e;// These 4 wires are select lines for the logic

   input  ecl_alu_log_sel_or_e;// block mux.  They are active high and choose the

   input  ecl_alu_log_sel_xor_e;// output they describe.

   input  ecl_alu_log_sel_move_e;

   input  ecl_alu_out_sel_sum_e_l;// The following 4 are select lines for 

   input  ecl_alu_out_sel_rs3_e_l;// the output stage mux.  They are active high

   input  ecl_alu_out_sel_shift_e_l;// and choose the output of the respective block.

   input  ecl_alu_out_sel_logic_e_l;

   input [63:0] shft_alu_shift_out_e;// result from shifter

   input        ecl_alu_sethi_inst_e;

   input        ifu_lsu_casa_e;

   output       so;

   output [63:0] alu_byp_rd_data_e;          // alu result

   output [47:0] exu_ifu_brpc_e;// branch pc output

   output [47:0] exu_lsu_ldst_va_e; // address for lsu

   output [10:3] exu_lsu_early_va_e; // faster bits for cache

   output [7:0]  exu_mmu_early_va_e;

   output        alu_ecl_add_n64_e;

   output        alu_ecl_add_n32_e;

   output        alu_ecl_log_n64_e;

   output        alu_ecl_log_n32_e;

   output        alu_ecl_zhigh_e;

   output        alu_ecl_zlow_e;

   output    exu_ifu_regz_e;              // rs1_data == 0 

   output    exu_ifu_regn_e;

   output    alu_ecl_adderin2_63_e;

   output    alu_ecl_adderin2_31_e;

   output    alu_ecl_adder_out_63_e;

   output    alu_ecl_cout32_e;       // To ecl of sparc_exu_ecl.v

   output    alu_ecl_cout64_e_l;       // To ecl of sparc_exu_ecl.v

   output    alu_ecl_mem_addr_invalid_e_l;// adder_out[63:48] not all 1 or all 0

   wire         clk;

   wire [63:0] logic_out;       // result of logic block

   wire [63:0] adder_out;       // result of adder

   wire [63:0] spr_out;         // result of sum predict

   wire [63:0] zcomp_in;        // result going to zcompare

   wire [63:0] va_e;            // complete va

   wire [63:0] byp_alu_rs2_data_e;

   wire        invert_e;

   wire        ecl_alu_out_sel_sum_e;

   wire        ecl_alu_out_sel_rs3_e;

   wire        ecl_alu_out_sel_shift_e;

   wire        ecl_alu_out_sel_logic_e;

   assign      clk = rclk;

   assign      byp_alu_rs2_data_e[63:0] = ~byp_alu_rs2_data_e_l[63:0];

   assign      ecl_alu_out_sel_sum_e = ~ecl_alu_out_sel_sum_e_l;

   assign      ecl_alu_out_sel_rs3_e = ~ecl_alu_out_sel_rs3_e_l;

   assign      ecl_alu_out_sel_shift_e = ~ecl_alu_out_sel_shift_e_l;

   assign      ecl_alu_out_sel_logic_e = ~ecl_alu_out_sel_logic_e_l;

   // Zero comparison for exu_ifu_regz_e

   sparc_exu_aluzcmp64 regzcmp(.in(byp_alu_rcc_data_e[63:0]), .zero64(exu_ifu_regz_e));

   assign     exu_ifu_regn_e = byp_alu_rcc_data_e[63];

   // mux between adder output and rs1 (for casa) for lsu va

   dp_mux2es #(64)  lsu_va_mux(.dout(va_e[63:0]),

                               .in0(adder_out[63:0]),

                               .in1(byp_alu_rs1_data_e[63:0]),

                               .sel(ifu_lsu_casa_e));

   assign     exu_lsu_ldst_va_e[47:0] = va_e[47:0];

   // for bits 10:4 we have a separate bus that is not used for cas

   assign     exu_lsu_early_va_e[10:3] = adder_out[10:3];

   // mmu needs bits 7:0

   assign     exu_mmu_early_va_e[7:0] = adder_out[7:0];

   // Adder

   assign     exu_ifu_brpc_e[47:0] = adder_out[47:0];

   assign     alu_ecl_adder_out_63_e = adder_out[63];

   sparc_exu_aluaddsub addsub(.adder_out(adder_out[63:0]),

                              /*AUTOINST*/

                              // Outputs

                              .spr_out  (spr_out[63:0]),

                              .alu_ecl_cout64_e_l(alu_ecl_cout64_e_l),

                              .alu_ecl_cout32_e(alu_ecl_cout32_e),

                              .alu_ecl_adderin2_63_e(alu_ecl_adderin2_63_e),

                              .alu_ecl_adderin2_31_e(alu_ecl_adderin2_31_e),

                              // Inputs

                              .clk      (clk),

                              .se       (se),

                              .byp_alu_rs1_data_e(byp_alu_rs1_data_e[63:0]),

                              .byp_alu_rs2_data_e(byp_alu_rs2_data_e[63:0]),

                              .ecl_alu_cin_e(ecl_alu_cin_e),

                              .ifu_exu_invert_d(ifu_exu_invert_d));

   // Logic/pass rs2_data

   dff_s invert_d2e(.din(ifu_exu_invert_d), .clk(clk), .q(invert_e), .se(se), .si(), .so());

   sparc_exu_alulogic logic(.rs1_data(byp_alu_rs1_data_e[63:0]),

                            .rs2_data(byp_alu_rs2_data_e[63:0]),

                            .isand(ecl_alu_log_sel_and_e),

                            .isor(ecl_alu_log_sel_or_e),

                            .isxor(ecl_alu_log_sel_xor_e),

                            .pass_rs2_data(ecl_alu_log_sel_move_e),

                            .inv_logic(invert_e), .logic_out(logic_out[63:0]),

                            .ifu_exu_sethi_inst_e(ecl_alu_sethi_inst_e));

   // Mux between sum predict and logic outputs for zcc

   dp_mux2es #(64)  zcompmux(.dout(zcomp_in[63:0]),

                           .in0(logic_out[63:0]),

                           .in1(spr_out[63:0]),

                           .sel(ecl_alu_out_sel_sum_e));

   // Zero comparison for zero cc

//   sparc_exu_aluzcmp64 zcccmp(.in(zcomp_in[63:0]), .zero64(alu_ecl_z64_e),

//                          .zero32(alu_ecl_z32_e));

   assign        alu_ecl_zlow_e = ~(|zcomp_in[31:0]);

   assign        alu_ecl_zhigh_e = ~(|zcomp_in[63:32]);

   // Get Negative ccs

   assign   alu_ecl_add_n64_e = adder_out[63];

   assign   alu_ecl_add_n32_e = adder_out[31];

   assign   alu_ecl_log_n64_e = logic_out[63];

   assign   alu_ecl_log_n32_e = logic_out[31];

   // Mux for output

   mux4ds #(64) output_mux(.dout(alu_byp_rd_data_e[63:0]),

                         .in0(adder_out[63:0]),

                         .in1(byp_alu_rs3_data_e[63:0]),

                         .in2(shft_alu_shift_out_e[63:0]),

                         .in3(logic_out[63:0]),

                         .sel0(ecl_alu_out_sel_sum_e),

                         .sel1(ecl_alu_out_sel_rs3_e),

                         .sel2(ecl_alu_out_sel_shift_e),

                         .sel3(ecl_alu_out_sel_logic_e));

   // memory address checks

   sparc_exu_alu_16eql chk_mem_addr(.equal(alu_ecl_mem_addr_invalid_e_l),

                                    .in(va_e[63:47]));

endmodule  // sparc_exu_alu