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`include "core/uarch.sv"
module core_alu_shifter
#(parameter W=16)
(
input alu_control ctrl,
input logic[W - 1:0] base,
input logic[7:0] shift,
input logic c_in,
output logic[W - 1:0] b,
output logic c
);
logic [W - 1:0] b_no_c, b_shl, b_shr, b_ror;
logic [W:0] sign_mask;
logic c_shl, c_shr;
assign sign_mask = {(W + 1){ctrl.sign_extend & base[W - 1]}};
assign {c_shl, b_shl} = {c_in, base} << shift;
assign {b_shr, c_shr} = {base, c_in} >> shift | ~(sign_mask >> shift);
assign b_ror = b_shr | base << (W - shift);
assign b = {b_no_c[W - 1] | (ctrl.put_carry & c_in), b_no_c[W - 2:0]};
assign c = ctrl.shr | ctrl.ror ? c_shr : c_shl;
always_comb
if(ctrl.ror)
b = b_ror;
else if(ctrl.shr)
b = {b_shr[W - 1] | (ctrl.put_carry & c_in), b_shr[W - 2:0]};
else
b = b_shl;
endmodule
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