cvw/wally-pipelined/src/fpu/unpacking.sv
Katherine Parry 6c4aa624a5 fpu cleanup
2021-07-24 15:00:56 -04:00

84 lines
3.2 KiB
Systemverilog

module unpacking (
input logic [63:0] X, Y, Z,
input logic FmtE,
input logic [2:0] FOpCtrlE,
output logic XSgnE, YSgnE, ZSgnE,
output logic [10:0] XExpE, YExpE, ZExpE,
output logic [52:0] XManE, YManE, ZManE,
output logic XNormE,
output logic XNaNE, YNaNE, ZNaNE,
output logic XSNaNE, YSNaNE, ZSNaNE,
output logic XDenormE, YDenormE, ZDenormE,
output logic XZeroE, YZeroE, ZZeroE,
output logic [10:0] BiasE,
output logic XInfE, YInfE, ZInfE,
output logic XExpMaxE
);
logic [51:0] XFracE, YFracE, ZFracE;
logic XExpNonzero, YExpNonzero, ZExpNonzero;
logic XFracZero, YFracZero, ZFracZero; // input fraction zero
logic XExpZero, YExpZero, ZExpZero; // input exponent zero
logic YExpMaxE, ZExpMaxE; // input exponent all 1s
assign XSgnE = FmtE ? X[63] : X[31];
assign YSgnE = FmtE ? Y[63] : Y[31];
assign ZSgnE = FmtE ? Z[63] : Z[31];
assign XExpE = FmtE ? X[62:52] : {3'b0, X[30:23]};//{X[30], {3{~X[30]&~XExpZero|XExpMaxE}}, X[29:23]};
assign YExpE = FmtE ? Y[62:52] : {3'b0, Y[30:23]};//{Y[30], {3{~Y[30]&~YExpZero|YExpMaxE}}, Y[29:23]};
assign ZExpE = FmtE ? Z[62:52] : {3'b0, Z[30:23]};//{Z[30], {3{~Z[30]&~ZExpZero|ZExpMaxE}}, Z[29:23]};
/* assign XExpE = FmtE ? X[62:52] : {3'b0, X[30:23]}; // *** maybe convert to full number of bits here?
assign YExpE = FmtE ? Y[62:52] : {3'b0, Y[30:23]};
assign ZExpE = FmtE ? Z[62:52] : {3'b0, Z[30:23]};*/
assign XFracE = FmtE ? X[51:0] : {X[22:0], 29'b0};
assign YFracE = FmtE ? Y[51:0] : {Y[22:0], 29'b0};
assign ZFracE = FmtE ? Z[51:0] : {Z[22:0], 29'b0};
assign XExpNonzero = FmtE ? |X[62:52] : |X[30:23];
assign YExpNonzero = FmtE ? |Y[62:52] : |Y[30:23];
assign ZExpNonzero = FmtE ? |Z[62:52] : |Z[30:23];
assign XExpZero = ~XExpNonzero;
assign YExpZero = ~YExpNonzero;
assign ZExpZero = ~ZExpNonzero;
assign XFracZero = ~|XFracE;
assign YFracZero = ~|YFracE;
assign ZFracZero = ~|ZFracE;
assign XManE = {XExpNonzero, XFracE};
assign YManE = {YExpNonzero, YFracE};
assign ZManE = {ZExpNonzero, ZFracE};
assign XExpMaxE = FmtE ? &X[62:52] : &X[30:23];
assign YExpMaxE = FmtE ? &Y[62:52] : &Y[30:23];
assign ZExpMaxE = FmtE ? &Z[62:52] : &Z[30:23];
assign XNormE = ~(XExpMaxE|XExpZero);
assign XNaNE = XExpMaxE & ~XFracZero;
assign YNaNE = YExpMaxE & ~YFracZero;
assign ZNaNE = ZExpMaxE & ~ZFracZero;
assign XSNaNE = XNaNE&~XFracE[51];
assign YSNaNE = YNaNE&~YFracE[51];
assign ZSNaNE = ZNaNE&~ZFracE[51];
assign XDenormE = XExpZero & ~XFracZero;
assign YDenormE = YExpZero & ~YFracZero;
assign ZDenormE = ZExpZero & ~ZFracZero;
assign XInfE = XExpMaxE & XFracZero;
assign YInfE = YExpMaxE & YFracZero;
assign ZInfE = ZExpMaxE & ZFracZero;
assign XZeroE = XExpZero & XFracZero;
assign YZeroE = YExpZero & YFracZero;
assign ZZeroE = ZExpZero & ZFracZero;
assign BiasE = FmtE ? 13'h3ff : 13'h7f; // *** is it better to convert to full precision exponents so bias isn't needed?
// assign BiasE = 13'h3ff; // always use 1023 because exponents are unpacked to double precision
endmodule