float>small-bits ( x fraction-bits exponent-bits -- bits )

Vocabulary

math.floats.small.private

Inputs

x	an object
fraction-bits	an object
exponent-bits	an object

Outputs

bits

an object

Definition

USING: kernel math math.bitwise ;

IN: math.floats.small.private

:: float>small-bits
    ( x fraction-bits exponent-bits -- bits )
    x >float double>bits :> raw raw -48 shift 32768 bitand
    :> sign raw -52 shift 2047 bitand :> exponent raw 52 bits
    :> fraction exponent-bits 2^ 1 -
    :> max-exponent exponent-bits 1 - 2^ 1 -
    :> bias exponent 2047 = [
        fraction zero?
        [ sign max-exponent fraction-bits shift bitor ] [
            max-exponent fraction-bits shift 1 fraction-bits 1 -
            shift bitor
        ] if
    ] [
        exponent zero?
        [ fraction -1074 ]
        [ fraction 52 2^ bitor exponent 1075 - ] if
        :> ( significand power ) significand zero?
        [ sign ] [
            significand log2 :> top top power + bias +
            :> target-exponent! target-exponent max-exponent >=
            [ sign max-exponent fraction-bits shift bitor ] [
                target-exponent 0 <= [
                    significand power bias + fraction-bits + 1 -
                    round-binary-shift sign bitor
                ] [
                    significand fraction-bits top -
                    round-binary-shift
                    :> rounded! rounded fraction-bits 1 + 2^ >= 
                    [
                        rounded -1 shift
                        rounded! target-exponent 1 +
                        target-exponent!
                    ] when target-exponent max-exponent >= [
                        sign max-exponent fraction-bits shift
                        bitor
                    ] [
                        sign target-exponent fraction-bits shift
                        bitor rounded fraction-bits 2^ - bitor
                    ] if
                ] if
            ] if
        ] if
    ] if ;