https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98829
Bug ID: 98829
Summary: Different results with -O3 and custom quiet NaN
Product: gcc
Version: 10.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: gnu at nemanjaboric dot com
Target Milestone: ---
Created attachment 50047
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50047&action=edit
Example of the code giving different results
Hi, see the attached code which generates the different code with -O3 (compiled
with various GCC version). Two workarounds are commented in the code: to use
`std::isnan` and to copy the source object.
I couldn't find anything undefined that I'm doing here but I might be wrong.
-ffast-math _is not_ used. Just -O3 yields different result:
https://www.godbolt.org/z/nxPd8W
