forked from Github_Repos/cvw
402 lines
18 KiB
Systemverilog
402 lines
18 KiB
Systemverilog
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`include "wally-config.vh"
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module unpackinput (
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input logic [`FLEN-1:0] In, // inputs from register file
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input logic [`FPSIZES/3:0] FmtE, // format signal 00 - single 01 - double 11 - quad 10 - half
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output logic Sgn, // sign bits of XYZ
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output logic [`NE-1:0] Exp, // exponents of XYZ (converted to largest supported precision)
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output logic [`NF:0] Man, // mantissas of XYZ (converted to largest supported precision)
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output logic NaN, // is XYZ a NaN
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output logic SNaN, // is XYZ a signaling NaN
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output logic Denorm, // is XYZ denormalized
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output logic Zero, // is XYZ zero
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output logic Inf, // is XYZ infinity
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output logic ExpMax, // does In have the maximum exponent (NaN or Inf)
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output logic ExpZero // is the exponent zero
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);
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logic [`NF-1:0] Frac; //Fraction of XYZ
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logic ExpNonZero; // is the exponent of XYZ non-zero
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logic FracZero; // is the fraction zero
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if (`FPSIZES == 1) begin // if there is only one floating point format supported
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// sign bit
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assign Sgn = In[`FLEN-1];
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// exponent
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assign Exp = {In[`FLEN-2:`NF+1], In[`NF]|Denorm};
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// fraction (no assumed 1)
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assign Frac = In[`NF-1:0];
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// is the exponent non-zero
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assign ExpNonZero = |Exp;
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// is the exponent all 1's
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assign ExpMax = &Exp;
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// is the input (in it's original format) denormalized
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assign Denorm = ~|In[`FLEN-2:`NF] & ~FracZero;
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end else if (`FPSIZES == 2) begin // if there are 2 floating point formats supported
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//***need better names for these constants
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// largest format | smaller format
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//----------------------------------
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// `FLEN | `LEN1 length of floating point number
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// `NE | `NE1 length of exponent
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// `NF | `NF1 length of fraction
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// `BIAS | `BIAS1 exponent's bias value
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// `FMT | `FMT1 precision's format value - Q=11 D=01 S=00 H=10
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// Possible combinantions specified by spec:
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// double and single
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// single and half
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// Not needed but can also handle:
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// quad and double
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// quad and single
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// quad and half
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// double and half
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logic [`LEN1-1:0] Len1; // Remove NaN boxing or NaN, if not properly NaN boxed
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// Check NaN boxing, If the value is not properly NaN boxed, set the value to a quiet NaN
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assign Len1 = &In[`FLEN-1:`LEN1] ? In[`LEN1-1:0] : {1'b0, {`NE1+1{1'b1}}, (`NF1-1)'(0)};
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// choose sign bit depending on format - 1=larger precsion 0=smaller precision
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assign Sgn = FmtE ? In[`FLEN-1] : Len1[`LEN1-1];
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// example double to single conversion:
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// 1023 = 0011 1111 1111
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// 127 = 0000 0111 1111 (subtract this)
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// 896 = 0011 1000 0000
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// sexp = 0000 bbbb bbbb (add this) b = bit d = ~b
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// dexp = 0bdd dbbb bbbb
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// also need to take into account possible zero/denorm/inf/NaN values
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// extract the exponent, converting the smaller exponent into the larger precision if nessisary
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// - if the original precision had a denormal number convert the exponent value 1
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assign Exp = FmtE ? {In[`FLEN-2:`NF+1], In[`NF]|Denorm} : {Len1[`LEN1-2], {`NE-`NE1{~Len1[`LEN1-2]}}, Len1[`LEN1-3:`NF1+1], Len1[`NF1]|Denorm};
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// is the input (in it's original format) denormalized
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// is the input (in it's original format) denormalized
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assign Denorm = (FmtE ? ~|In[`FLEN-2:`NF] : ~|Len1[`LEN1-2:`NF1]) & ~FracZero;
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// extract the fraction, add trailing zeroes to the mantissa if nessisary
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assign Frac = FmtE ? In[`NF-1:0] : {Len1[`NF1-1:0], (`NF-`NF1)'(0)};
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// is the exponent non-zero
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assign ExpNonZero = FmtE ? |In[`FLEN-2:`NF] : |Len1[`LEN1-2:`NF1];
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// is the exponent all 1's
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assign ExpMax = FmtE ? &In[`FLEN-2:`NF] : &Len1[`LEN1-2:`NF1];
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end else if (`FPSIZES == 3) begin // three floating point precsions supported
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//***need better names for these constants
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// largest format | larger format | smallest format
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//---------------------------------------------------
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// `FLEN | `LEN1 | `LEN2 length of floating point number
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// `NE | `NE1 | `NE2 length of exponent
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// `NF | `NF1 | `NF2 length of fraction
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// `BIAS | `BIAS1 | `BIAS2 exponent's bias value
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// `FMT | `FMT1 | `FMT2 precision's format value - Q=11 D=01 S=00 H=10
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// Possible combinantions specified by spec:
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// quad and double and single
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// double and single and half
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// Not needed but can also handle:
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// quad and double and half
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// quad and single and half
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logic [`LEN1-1:0] Len1; // Remove NaN boxing or NaN, if not properly NaN boxed for larger percision
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logic [`LEN2-1:0] Len2; // Remove NaN boxing or NaN, if not properly NaN boxed for smallest precision
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// Check NaN boxing, If the value is not properly NaN boxed, set the value to a quiet NaN - for larger precision
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assign Len1 = &In[`FLEN-1:`LEN1] ? In[`LEN1-1:0] : {1'b0, {`NE1+1{1'b1}}, (`NF1-1)'(0)};
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// Check NaN boxing, If the value is not properly NaN boxed, set the value to a quiet NaN - for smaller precision
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assign Len2 = &In[`FLEN-1:`LEN2] ? In[`LEN2-1:0] : {1'b0, {`NE2+1{1'b1}}, (`NF2-1)'(0)};
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// There are 2 case statements
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// - one for other singals and one for sgn/exp/frac
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// - need two for the dependencies in the expoenent calculation
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//*** pull out the ~FracZero and and it at the end
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always_comb begin
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case (FmtE)
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`FMT: begin // if input is largest precision (`FLEN - ie quad or double)
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// This is the original format so set OrigDenorm to 0
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Denorm = ~|In[`FLEN-2:`NF] & ~FracZero;
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// is the exponent non-zero
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ExpNonZero = |In[`FLEN-2:`NF];
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// is the exponent all 1's
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ExpMax = &In[`FLEN-2:`NF];
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end
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`FMT1: begin // if input is larger precsion (`LEN1 - double or single)
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// is the input (in it's original format) denormalized
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Denorm = ~|Len1[`LEN1-2:`NF1] & ~FracZero;
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// is the exponent non-zero
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ExpNonZero = |Len1[`LEN1-2:`NF1];
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// is the exponent all 1's
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ExpMax = &Len1[`LEN1-2:`NF1];
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end
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`FMT2: begin // if input is smallest precsion (`LEN2 - single or half)
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// is the input (in it's original format) denormalized
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Denorm = ~|Len2[`LEN2-2:`NF2] & ~FracZero;
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// is the exponent non-zero
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ExpNonZero = |Len2[`LEN2-2:`NF2];
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// is the exponent all 1's
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ExpMax = &Len2[`LEN2-2:`NF2];
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end
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default: begin
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Denorm = 0;
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ExpNonZero = 0;
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ExpMax = 0;
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end
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endcase
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end
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always_comb begin
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case (FmtE)
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`FMT: begin // if input is largest precision (`FLEN - ie quad or double)
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// extract the sign bit
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Sgn = In[`FLEN-1];
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// extract the exponent
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Exp = {In[`FLEN-2:`NF+1], In[`NF]|Denorm};
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// extract the fraction
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Frac = In[`NF-1:0];
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end
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`FMT1: begin // if input is larger precsion (`LEN1 - double or single)
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// extract the sign bit
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Sgn = Len1[`LEN1-1];
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// example double to single conversion:
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// 1023 = 0011 1111 1111
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// 127 = 0000 0111 1111 (subtract this)
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// 896 = 0011 1000 0000
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// sexp = 0000 bbbb bbbb (add this) b = bit d = ~b
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// dexp = 0bdd dbbb bbbb
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// also need to take into account possible zero/denorm/inf/NaN values
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// convert the larger precision's exponent to use the largest precision's bias
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Exp = {Len1[`LEN1-2], {`NE-`NE1{~Len1[`LEN1-2]}}, Len1[`LEN1-3:`NF1+1], Len1[`NF1]|Denorm};
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// extract the fraction and add the nessesary trailing zeros
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Frac = {Len1[`NF1-1:0], (`NF-`NF1)'(0)};
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end
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`FMT2: begin // if input is smallest precsion (`LEN2 - single or half)
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// exctract the sign bit
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Sgn = Len2[`LEN2-1];
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// example double to single conversion:
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// 1023 = 0011 1111 1111
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// 127 = 0000 0111 1111 (subtract this)
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// 896 = 0011 1000 0000
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// sexp = 0000 bbbb bbbb (add this) b = bit d = ~b
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// dexp = 0bdd dbbb bbbb
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// also need to take into account possible zero/denorm/inf/NaN values
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// convert the smallest precision's exponent to use the largest precision's bias
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Exp = Denorm ? {1'b0, {`NE-`NE2{1'b1}}, (`NE2-1)'(1)} : {Len2[`LEN2-2], {`NE-`NE2{~Len2[`LEN2-2]}}, Len2[`LEN2-3:`NF2]};
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// extract the fraction and add the nessesary trailing zeros
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Frac = {Len2[`NF2-1:0], (`NF-`NF2)'(0)};
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end
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default: begin
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Sgn = 0;
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Exp = 0;
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Frac = 0;
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end
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endcase
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end
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end else if (`FPSIZES == 4) begin // if all precsisons are supported - quad, double, single, and half
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// quad | double | single | half
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//-------------------------------------------------------------------
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// `Q_LEN | `D_LEN | `S_LEN | `H_LEN length of floating point number
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// `Q_NE | `D_NE | `S_NE | `H_NE length of exponent
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// `Q_NF | `D_NF | `S_NF | `H_NF length of fraction
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// `Q_BIAS | `D_BIAS | `S_BIAS | `H_BIAS exponent's bias value
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// `Q_FMT | `D_FMT | `S_FMT | `H_FMT precision's format value - Q=11 D=01 S=00 H=10
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logic [`D_LEN-1:0] Len1; // Remove NaN boxing or NaN, if not properly NaN boxed for double percision
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logic [`S_LEN-1:0] Len2; // Remove NaN boxing or NaN, if not properly NaN boxed for single percision
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logic [`H_LEN-1:0] Len3; // Remove NaN boxing or NaN, if not properly NaN boxed for half percision
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// Check NaN boxing, If the value is not properly NaN boxed, set the value to a quiet NaN - for double precision
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assign Len1 = &In[`Q_LEN-1:`D_LEN] ? In[`D_LEN-1:0] : {1'b0, {`D_NE+1{1'b1}}, (`D_NF-1)'(0)};
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// Check NaN boxing, If the value is not properly NaN boxed, set the value to a quiet NaN - for single precision
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assign Len2 = &In[`Q_LEN-1:`S_LEN] ? In[`S_LEN-1:0] : {1'b0, {`S_NE+1{1'b1}}, (`S_NF-1)'(0)};
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// Check NaN boxing, If the value is not properly NaN boxed, set the value to a quiet NaN - for half precision
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assign Len3 = &In[`Q_LEN-1:`H_LEN] ? In[`H_LEN-1:0] : {1'b0, {`H_NE+1{1'b1}}, (`H_NF-1)'(0)};
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// There are 2 case statements
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// - one for other singals and one for sgn/exp/frac
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// - need two for the dependencies in the expoenent calculation
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always_comb begin
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case (FmtE)
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2'b11: begin // if input is quad percision
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// is the input (in it's original format) denormalized
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Denorm = ~|In[`Q_LEN-2:`Q_NF] & ~FracZero;
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// is the exponent non-zero
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ExpNonZero = |In[`Q_LEN-2:`Q_NF];
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// is the exponent all 1's
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ExpMax = &In[`Q_LEN-2:`Q_NF];
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end
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2'b01: begin // if input is double percision
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// is the exponent all 1's
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ExpMax = &Len1[`D_LEN-2:`D_NF];
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// is the input (in it's original format) denormalized
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Denorm = ~|Len1[`D_LEN-2:`D_NF] & ~FracZero;
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// is the exponent non-zero
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ExpNonZero = |Len1[`D_LEN-2:`D_NF];
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end
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2'b00: begin // if input is single percision
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// is the exponent all 1's
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ExpMax = &Len2[`S_LEN-2:`S_NF];
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// is the input (in it's original format) denormalized
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Denorm = ~|Len2[`S_LEN-2:`S_NF] & ~FracZero;
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// is the exponent non-zero
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ExpNonZero = |Len2[`S_LEN-2:`S_NF];
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end
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2'b10: begin // if input is half percision
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// is the exponent all 1's
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ExpMax = &Len3[`H_LEN-2:`H_NF];
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// is the input (in it's original format) denormalized
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Denorm = ~|Len3[`H_LEN-2:`H_NF] & ~FracZero;
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// is the exponent non-zero
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ExpNonZero = |Len3[`H_LEN-2:`H_NF];
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end
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endcase
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end
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always_comb begin
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case (FmtE)
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2'b11: begin // if input is quad percision
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// extract sign bit
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Sgn = In[`Q_LEN-1];
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// extract the exponent
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Exp = {In[`Q_LEN-2:`Q_NF+1], In[`Q_NF]|Denorm};
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// extract the fraction
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Frac = In[`Q_NF-1:0];
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end
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2'b01: begin // if input is double percision
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// extract sign bit
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Sgn = Len1[`D_LEN-1];
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// example double to single conversion:
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// 1023 = 0011 1111 1111
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// 127 = 0000 0111 1111 (subtract this)
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// 896 = 0011 1000 0000
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// sexp = 0000 bbbb bbbb (add this) b = bit d = ~b
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// dexp = 0bdd dbbb bbbb
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|
|
// also need to take into account possible zero/denorm/inf/NaN values
|
||
|
|
|
||
|
|
// convert the double precsion exponent into quad precsion
|
||
|
|
|
||
|
|
Exp = {Len1[`D_LEN-2], {`Q_NE-`D_NE{~Len1[`D_LEN-2]}}, Len1[`D_LEN-3:`D_NF+1], Len1[`D_NF]|Denorm};
|
||
|
|
|
||
|
|
// extract the fraction and add the nessesary trailing zeros
|
||
|
|
Frac = {Len1[`D_NF-1:0], (`Q_NF-`D_NF)'(0)};
|
||
|
|
end
|
||
|
|
2'b00: begin // if input is single percision
|
||
|
|
// extract sign bit
|
||
|
|
Sgn = Len2[`S_LEN-1];
|
||
|
|
|
||
|
|
// example double to single conversion:
|
||
|
|
// 1023 = 0011 1111 1111
|
||
|
|
// 127 = 0000 0111 1111 (subtract this)
|
||
|
|
// 896 = 0011 1000 0000
|
||
|
|
// sexp = 0000 bbbb bbbb (add this) b = bit d = ~b
|
||
|
|
// dexp = 0bdd dbbb bbbb
|
||
|
|
// also need to take into account possible zero/denorm/inf/NaN values
|
||
|
|
|
||
|
|
// convert the single precsion exponent into quad precsion
|
||
|
|
Exp = {Len2[`S_LEN-2], {`Q_NE-`S_NE{~Len2[`S_LEN-2]}}, Len2[`S_LEN-3:`S_NF+1], Len2[`S_NF]|Denorm};
|
||
|
|
|
||
|
|
// extract the fraction and add the nessesary trailing zeros
|
||
|
|
Frac = {Len2[`S_NF-1:0], (`Q_NF-`S_NF)'(0)};
|
||
|
|
end
|
||
|
|
2'b10: begin // if input is half percision
|
||
|
|
// extract sign bit
|
||
|
|
Sgn = Len3[`H_LEN-1];
|
||
|
|
|
||
|
|
// example double to single conversion:
|
||
|
|
// 1023 = 0011 1111 1111
|
||
|
|
// 127 = 0000 0111 1111 (subtract this)
|
||
|
|
// 896 = 0011 1000 0000
|
||
|
|
// sexp = 0000 bbbb bbbb (add this) b = bit d = ~b
|
||
|
|
// dexp = 0bdd dbbb bbbb
|
||
|
|
// also need to take into account possible zero/denorm/inf/NaN values
|
||
|
|
|
||
|
|
// convert the half precsion exponent into quad precsion
|
||
|
|
Exp = {Len3[`H_LEN-2], {`Q_NE-`H_NE{~Len3[`H_LEN-2]}}, Len3[`H_LEN-3:`H_NF+1], Len3[`H_NF]|Denorm};
|
||
|
|
|
||
|
|
// extract the fraction and add the nessesary trailing zeros
|
||
|
|
Frac = {Len3[`H_NF-1:0], (`Q_NF-`H_NF)'(0)};
|
||
|
|
end
|
||
|
|
endcase
|
||
|
|
end
|
||
|
|
|
||
|
|
end
|
||
|
|
|
||
|
|
// is the exponent all 0's
|
||
|
|
assign ExpZero = ~ExpNonZero;
|
||
|
|
|
||
|
|
// is the fraction zero
|
||
|
|
assign FracZero = ~|Frac;
|
||
|
|
|
||
|
|
// add the assumed one (or zero if denormal or zero) to create the mantissa
|
||
|
|
assign Man = {ExpNonZero, Frac};
|
||
|
|
|
||
|
|
// is the input a NaN
|
||
|
|
// - force to be a NaN if it isn't properly Nan Boxed
|
||
|
|
assign NaN = ExpMax & ~FracZero;
|
||
|
|
|
||
|
|
// is the input a singnaling NaN
|
||
|
|
assign SNaN = NaN&~Frac[`NF-1];
|
||
|
|
|
||
|
|
// is the input infinity
|
||
|
|
assign Inf = ExpMax & FracZero;
|
||
|
|
|
||
|
|
// is the input zero
|
||
|
|
assign Zero = ExpZero & FracZero;
|
||
|
|
|
||
|
|
endmodule
|