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Initialize long with floats binary representation

Jürgen Breuer

Hello,

how can I achieve


long l = WHAT_EVER_MACRO (-12.5);

main()
{
  printf("%X",l);
}

resulting in output "0xC1480000" the binary representation of the float -12.5 .
Without that MACRO the value is 0xFFFFFFF4 = -12 for integers .

Because of given circumstances in an existing project I have to store float values during initialization in long variables.

Is there any possibility?

Thanks in advance

Jürgen

Parents
  • 0 in reply to ImPer Westermark

    Now I got you!

    I tryed

    float f32ConstInitval = -12.5;
uint32_t ui32Testvalue = (*(uint32_t *)&f32ConstInitval);


    and got: 'scalar': initializer is not a constant :-(

    With

    static const float f32ConstInitval = -12.5;
uint32_t ui32Testvalue = f32ConstInitval);


    I got ui32Testvalue = 0xFFFFFFF4 as I asked my debugger :-(

    but with

    static const float f32ConstInitval = -12.5;
uint32_t ui32Testvalue = (*(uint32_t *)&f32ConstInitval);

    I yielded my desired ui32Testvalue = 0xC1480000 :-D
    with a litte overhead of 4 Bytes in far flash.

    Thanks a lot

    Jürgen

Reply
  • 0 in reply to ImPer Westermark

    Now I got you!

    I tryed

    float f32ConstInitval = -12.5;
uint32_t ui32Testvalue = (*(uint32_t *)&f32ConstInitval);


    and got: 'scalar': initializer is not a constant :-(

    With

    static const float f32ConstInitval = -12.5;
uint32_t ui32Testvalue = f32ConstInitval);


    I got ui32Testvalue = 0xFFFFFFF4 as I asked my debugger :-(

    but with

    static const float f32ConstInitval = -12.5;
uint32_t ui32Testvalue = (*(uint32_t *)&f32ConstInitval);

    I yielded my desired ui32Testvalue = 0xC1480000 :-D
    with a litte overhead of 4 Bytes in far flash.

    Thanks a lot

    Jürgen

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