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[Bug fortran/30733] New: VOLATILE: Missed optimization - attribute not restricted to scope
- From: "burnus at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 8 Feb 2007 09:40:46 -0000
- Subject: [Bug fortran/30733] New: VOLATILE: Missed optimization - attribute not restricted to scope
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
+++ This bug was initially created as a clone of Bug #30522 +++
Setting the VOLATILE attribute to a host- or use-associated variable currently
marks the variable everywhere as VOLATILE. The attribute should be, however,
restricted to the scope. (This is a missed optimization only.)
Possible implementation:
decl.c: gfc_match_volatile
case MATCH_YES:
/* If the use- or host-associated symbol is not volatile, we
clone it. */
if (!sym->attr.volatile_ && sym->ns != gfc_current_ns)
{
/* note somewhere that in this namespace VOLATILE is needed, e.g. by cloning
the variable here and setting below the attribute only to the cloned variable.
And then put a check in trans-decl.c in e.g. gfc_generate_function_code near
generate_local_vars to actually mark this variable as volatile; be careful that
the variable should be "external volatile" not a new local variable.
*/
}
if (gfc_add_volatile (&sym->attr, sym->name, &gfc_current_locus)
Test case: See PR30522's volatile10.f90 (search for TODO).
Maybe the fact that -fdump-tree-original does not show the VOLATILE attribute
for module variables could be solved as collateral damage.
--
Summary: VOLATILE: Missed optimization - attribute not restricted
to scope
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: burnus at gcc dot gnu dot org
BugsThisDependsOn: 30522
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30733