https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107753
Bug ID: 107753
Summary: gfortran returns NaN in complex divisions
(x+x*I)/(x+x*I) and (x+x*I)/(x-x*I)
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: weslley.pereira at ucdenver dot edu
Target Milestone: ---
If `x=huge(0.0d0)` or `x=2.0d0**(dble(maxexponent(0.0d0))-1)`, the GNU Fortran
12.2.0 returns a NaN for the complex divisions `(x+x*I)/(x+x*I)` and
`(x+x*I)/(x-x*I)`. We verified this after running compiler tests for the new
LAPACK 3.11.0 release. All other divisions with `x=2**m`, for for
`MINEXPONENT-1 <= m < MAXEXPONENT` return the expected results:
`(x+x*I)/(x+x*I)=1` and `(x+x*I)/(x-x*I)=I`.
Related links:
How to reproduce this issue: https://godbolt.org/z/b3WKWodvn
Open issue in LAPACK: https://github.com/Reference-LAPACK/lapack/issues/757
Tests added to LAPACK: https://github.com/Reference-LAPACK/lapack/pull/623
