PTO-ARCH-DATA-TYPES-FORMAT-FP32

1// PTO-UNIT: {"id":"PTO-ARCH-DATA-TYPES-FORMAT-FP32","surface":"arch","classification":["data-types","formats","fp32"],"depends_on":["PTO-ARCH-DATA-TYPES-FORMAT-DESCRIPTOR"]}2// DOC-BEGIN: operation3// PTO-REQ-HARDWARE-NUMERIC-001: exact FP32 encoding and finite values.4
5pure func FP32NumericFormatDescriptor() => NumericFormatDescriptor6begin7    return NumericFormatDescriptor {8        available = TRUE, kind = NumericFormatKind_FixedBinary,9        carrier_bits = 32, lane_bits = 32, lanes_per_carrier = 1,10        sign_bits = 1, sign_bit = 31,11        exponent_bits_min = 8, exponent_bits_max = 8,12        fraction_bits_min = 23, fraction_bits_max = 23,13        exponent_bias_available = TRUE, exponent_bias = 127,14        required_low_zero_bits = 0, required_high_zero_bits = 0,15        has_zero = TRUE, has_signed_zero = TRUE, has_subnormal = TRUE,16        has_infinity = TRUE, has_quiet_nan = TRUE,17        has_signaling_nan = TRUE18    };19end;20
21pure func FP32FiniteDecomposition(value: bits(32))22    => (boolean, boolean, Word, integer {-1074..1023})23begin24    let exponent = value[30:23];25    let fraction = value[22:0];26    if exponent == Ones{8} then27        return (FALSE, FALSE, Zeros{PTO_XLEN}, 0);28    elsif exponent == Zeros{8} then29        if fraction == Zeros{23} then30            return (TRUE, value[31] == '1', Zeros{PTO_XLEN}, 0);31        else return (TRUE, value[31] == '1',32                     ZeroExtend{PTO_XLEN}(fraction), -149);33        end;34    else return (TRUE, value[31] == '1',35                 LSL(Zeros{PTO_XLEN} + 1, 23) +36                     ZeroExtend{PTO_XLEN}(fraction),37                 (UInt(exponent) - (127 + 23))38                     as integer {-1074..1023});39    end;40end;41pure func ClassifyFP32(value: bits(32)) => NumericValueClass42begin43    let exponent = value[30:23];44    let fraction = value[22:0];45    if exponent == Ones{8} then46        if fraction == Zeros{23} then47            if value[31] == '1' then return NumericValue_NegativeInfinity;48            else return NumericValue_PositiveInfinity;49            end;50        elsif fraction[22] == '1' then return NumericValue_QuietNaN;51        else return NumericValue_SignalingNaN;52        end;53    end;54    return NumericValueClassFromFiniteSign(value[31],55        exponent == Zeros{8} && fraction == Zeros{23},56        exponent == Zeros{8} && fraction != Zeros{23});57end;58
59pure func FP32CanonicalNaN() => Word60begin61    return Zeros{PTO_XLEN} + 0x7fc00000;62end;63
64pure func FP32SignedZeroEncodings() => (Word, Word)65begin66    return (Zeros{PTO_XLEN}, Zeros{PTO_XLEN} + 0x80000000);67end;68// DOC-END: operation69