VUSE for 'b'. */
#define opf_no_vops (1 << 2)
+/* Operand is a "non-specific" kill for call-clobbers and such. This is used
+ to distinguish "reset the world" events from explicit MODIFY_EXPRs. */
+#define opf_non_specific (1 << 3)
+
/* This structure maintain a sorted list of operands which is created by
parse_ssa_operand. */
struct opbuild_list_d GTY (())
bool exact;
if (overlap_subvar (offset, size, sv, &exact))
{
- if (exact)
+ if (!exact)
flags &= ~opf_kill_def;
add_stmt_operand (&sv->var, s_ann, flags);
}
EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i, bi)
{
tree var = referenced_var (i);
- add_stmt_operand (&var, s_ann, opf_is_def);
+ add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
}
/* Now clobber all addressables. */
&& get_subvars_for_var (var) != NULL)
continue;
- add_stmt_operand (&var, s_ann, opf_is_def);
+ add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
}
break;
/* If the variable cannot be modified and this is a V_MAY_DEF change
it into a VUSE. This happens when read-only variables are marked
call-clobbered and/or aliased to writeable variables. So we only
- check that this only happens on stores, and not writes to GIMPLE
- registers.
-
- FIXME: The C++ FE is emitting assignments in the IL stream for
- read-only globals. This is wrong, but for the time being disable
- this transformation on V_MUST_DEF operands (otherwise, we
- mis-optimize SPEC2000's eon). */
- if ((flags & opf_is_def)
- && !(flags & opf_kill_def)
- && unmodifiable_var_p (var))
+ check that this only happens on non-specific stores.
+
+ Note that if this is a specific store, i.e. associated with a
+ modify_expr, then we can't suppress the V_DEF, lest we run into
+ validation problems.
+
+ This can happen when programs cast away const, leaving us with a
+ store to read-only memory. If the statement is actually executed
+ at runtime, then the program is ill formed. If the statement is
+ not executed then all is well. At the very least, we cannot ICE. */
+ if ((flags & opf_non_specific) && unmodifiable_var_p (var))
{
gcc_assert (!is_real_op);
- flags &= ~opf_is_def;
+ flags &= ~(opf_is_def | opf_kill_def);
}
if (is_real_op)
if (unmodifiable_var_p (var))
add_stmt_operand (&var, &empty_ann, opf_none);
else
- add_stmt_operand (&var, &empty_ann, opf_is_def);
+ add_stmt_operand (&var, &empty_ann, opf_is_def | opf_non_specific);
}
clobbered_aliased_loads = empty_ann.makes_aliased_loads;
EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi)
{
tree var = referenced_var (u);
- add_stmt_operand (&var, &empty_ann, opf_none);
+ add_stmt_operand (&var, &empty_ann, opf_none | opf_non_specific);
}
ro_call_aliased_loads = empty_ann.makes_aliased_loads;