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

Vocabulary

math.floats.small.private

Inputs

raw	an object
fraction-bits	an object
exponent-bits	an object

Outputs

x

an object

Definition

USING: kernel math math.bitwise ;

IN: math.floats.small.private

:: small-bits>float ( raw fraction-bits exponent-bits -- x )
    raw 32768 bitand 48 shift :> sign exponent-bits 2^ 1 -
    :> max-exponent raw fraction-bits neg shift
    max-exponent bitand :> exponent raw fraction-bits bits
    :> fraction exponent-bits 1 - 2^ 1 -
    :> bias exponent max-exponent = [
        fraction zero?
        [ sign 9218868437227405312 bitor ]
        [ 9221120237041090560 ] if bits>double
    ] [
        exponent zero?
        [ fraction 1 bias - fraction-bits - ] [
            fraction fraction-bits 2^ bitor exponent bias -
            fraction-bits -
        ] if :> ( significand power ) significand zero?
        [ sign bits>double ] [
            significand log2 :> top sign top power + 1023 +
            52 shift bitor significand top 2^ - 52 top - shift
            bitor bits>double
        ] if
    ] if ;