https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66141
Bug ID: 66141
Summary: Invalid code generation with -O1, -O2, -O3 for x86_64
target for array reference in Fortran COMMON
Product: gcc
Version: 4.9.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: george at gly dot bris.ac.uk
Target Milestone: ---
Created attachment 35540
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35540&action=edit
Self-contained program to show buggy functionality
Attached short Fortran program functions properly with no optimization or -O0
but not when -O1, -O2, or -O3 used. Code generation for references to storage
in Fortran COMMON incorrect.
Expected output, when compiled with -O0 or no optimization is:
kvalue should be OK but is OK
Output when compiled with -O1, -O2, or -O3 is:
kvalue should be OK but is UNDEFINE
[Program generates warning on compilation, but this is allowed under the
semantics of Fortran COMMON (allocated COMMON storage is longest among any of
its definition).]
