[LLVMdev] Performance regression on ARM (original) (raw)

Joerg Sonnenberger joerg at britannica.bec.de
Mon Oct 20 03:10:43 PDT 2014

On Sun, Oct 19, 2014 at 06:10:26PM -0700, Stephen Checkoway wrote:

In general, multiplying complex numbers in rectangular form is pretty straight-forward: (a+ib)(c+id) = ac - bd + i(ad+bc).

Division is a little more of a hassle: (a+ib)/(c+id) = (a+ib)(c-id)/(c^2 + d^2) = (ac + bd)/(c^2 + d^2) + i(bc - ad)/(c^2 + d^2).

Both forms are problematic if you are about overflow and NaN. Which is exactly what my question is about.

Joerg

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