tree a85a084dddbd5c1c362264546c57485f149c7acb
parent 1732c29de19c872badec821053de652f6f7a846f
author Santiago Aboy Solanes <solanes@google.com> 1698240305 +0100
committer Treehugger Robot <android-test-infra-autosubmit@system.gserviceaccount.com> 1701263982 +0000

Make periodic loop optimization safe from overflow

The trip number is calculated by doing:
    ((end - start) + (step - 1)) / step
(Note that we add step - 1 as a way of doing ceiling).
This way of calculating can overflow and produce the wrong result
if e.g. end and start are in opposite sides of the spectrum.

We can add checks to make sure that the calculation doesn't overflow.

Bug: 256858062
Fixes: 256858062
Test: art/test/testrunner/testrunner.py --host --64 -b --optimizing
Change-Id: Ib2868406d2aa8f106dab06c0b44ef1b6208ef41a