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P1011 : simple precision floatting multiplication

Question asked by Paulo DA SILVA PINTO on Jul 13, 2018
Latest reply on Aug 17, 2018 by Paulo DA SILVA PINTO

Hello,

in the E500CORERM, I can read the following for double floatting point operation:

"Additionally, an implementation may also signal overflow by comparing the exponents of the

operands. In this case, the hardware examines both exponents ignoring the fractional values. If it

is determined that the operation to be performed may overflow (ignoring the fractional values), an

overflow may be said to occur."

I'm using a simple floatting point operation (multiplication) but it seems I have the same behaviour as with double:

the assembly operation is efsmul r5,r0,r5

with r0=0x40A00000 and r5=0x7E05A364

the obtained result in target is r5=0x7F7FFFFF instead of 0x7F270C3D while it is correct in simulation

Does anyone knows if there is any errata/issue/known limitation that could explain this behaviour ?

 

Thanks

Paulo.

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