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performance of floating point

jinhong

hi.

I have a question about floating point performance relative with fpsr register.

When i initialize hardware, there is floating point exception(inexactly floating-point exception).

I did not set fpcr.IXE=0, so fpsr.IXC is set. not occur exception.

After that, my floating point instruction(fmadd) is faster than before.

Why fmadd instruction is faster(fpsr.IXC=1) than before(fpsr.IXC=0)?

Can you help me?

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    Just a guess: Checking needs time.

    From the manual (ARM DDI 0406C.d, A2.69):
    FPSCR.IXC  Inexact. The bit is set to 1 if the result of an operation is not equivalent to the value that would be
    produced if the operation were performed with unbounded precision and exponent range.

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  • 0

    Just a guess: Checking needs time.

    From the manual (ARM DDI 0406C.d, A2.69):
    FPSCR.IXC  Inexact. The bit is set to 1 if the result of an operation is not equivalent to the value that would be
    produced if the operation were performed with unbounded precision and exponent range.

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