[Bug fortran/126386] matmul in combination with multiplication and transpose fails to correctly reallocate result array
"kargl at gcc dot gnu.org via Gcc-bugs" <[email protected]>
| Newsgroups | gmane.comp.gcc.bugs |
|---|---|
| Message-ID | <[email protected]/bugzilla/> |
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126386
Steve Kargl <kargl at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to fail| |15.3.1, 16.1.1, 17.0
Last reconfirmed| |2026-07-24
CC| |kargl at gcc dot gnu.org
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
--- Comment #1 from Steve Kargl <kargl at gcc dot gnu.org> ---
It is related to the frontend optimized pass.
% gfcx -o z -O u6.f90 && ./z
Result size (expected 2): 3
% gfcx -o z -O u6.f90 -fno-frontend-optimize && ./z
Result size (expected 2): 2
If I change the code to
a = 2*a
y = matmul(transpose(A),x)
one gets the expected answer. The frontend pass appears
to miss handle the expression in transpose().