if (!pi)
return true;
+ /* ??? This does not use TBAA to prune globals ptr may not access. */
return pt_solution_includes_global (&pi->pt);
}
-/* Return true if dereferencing PTR may alias DECL. */
+/* Return true if dereferencing PTR may alias DECL.
+ The caller is responsible for applying TBAA to see if PTR
+ may access DECL at all. */
static bool
ptr_deref_may_alias_decl_p (tree ptr, tree decl)
{
struct ptr_info_def *pi;
- /* ??? During SCCVN/PRE we can end up with *&x during valueizing
- operands. Likewise we can end up with dereferencing constant
- pointers. Just bail out in these cases for now. */
- if (TREE_CODE (ptr) == ADDR_EXPR
- || TREE_CODE (ptr) == INTEGER_CST)
- return true;
-
- gcc_assert (TREE_CODE (ptr) == SSA_NAME
+ gcc_assert ((TREE_CODE (ptr) == SSA_NAME
+ || TREE_CODE (ptr) == ADDR_EXPR
+ || TREE_CODE (ptr) == INTEGER_CST)
&& (TREE_CODE (decl) == VAR_DECL
|| TREE_CODE (decl) == PARM_DECL
|| TREE_CODE (decl) == RESULT_DECL));
if (!may_be_aliased (decl))
return false;
+ /* ADDR_EXPR pointers either just offset another pointer or directly
+ specify the pointed-to set. */
+ if (TREE_CODE (ptr) == ADDR_EXPR)
+ {
+ tree base = get_base_address (TREE_OPERAND (ptr, 0));
+ if (base
+ && INDIRECT_REF_P (base))
+ ptr = TREE_OPERAND (base, 0);
+ else if (base
+ && SSA_VAR_P (base))
+ return operand_equal_p (base, decl, 0);
+ else if (base
+ && CONSTANT_CLASS_P (base))
+ return false;
+ else
+ return true;
+ }
+
+ /* We can end up with dereferencing constant pointers.
+ Just bail out in this case. */
+ if (TREE_CODE (ptr) == INTEGER_CST)
+ return true;
+
/* If we do not have useful points-to information for this pointer
we cannot disambiguate anything else. */
pi = SSA_NAME_PTR_INFO (ptr);
if (!pi)
return true;
+ /* If the decl can be used as a restrict tag and we have a restrict
+ pointer and that pointers points-to set doesn't contain this decl
+ then they can't alias. */
+ if (DECL_RESTRICTED_P (decl)
+ && TYPE_RESTRICT (TREE_TYPE (ptr))
+ && pi->pt.vars_contains_restrict)
+ return bitmap_bit_p (pi->pt.vars, DECL_UID (decl));
+
return pt_solution_includes (&pi->pt, decl);
}
-/* Return true if dereferenced PTR1 and PTR2 may alias. */
+/* Return true if dereferenced PTR1 and PTR2 may alias.
+ The caller is responsible for applying TBAA to see if accesses
+ through PTR1 and PTR2 may conflict at all. */
static bool
ptr_derefs_may_alias_p (tree ptr1, tree ptr2)
{
struct ptr_info_def *pi1, *pi2;
- /* ??? During SCCVN/PRE we can end up with *&x during valueizing
- operands. Likewise we can end up with dereferencing constant
- pointers. Just bail out in these cases for now. */
- if (TREE_CODE (ptr1) == ADDR_EXPR
- || TREE_CODE (ptr1) == INTEGER_CST
- || TREE_CODE (ptr2) == ADDR_EXPR
+ gcc_assert ((TREE_CODE (ptr1) == SSA_NAME
+ || TREE_CODE (ptr1) == ADDR_EXPR
+ || TREE_CODE (ptr1) == INTEGER_CST)
+ && (TREE_CODE (ptr2) == SSA_NAME
+ || TREE_CODE (ptr2) == ADDR_EXPR
+ || TREE_CODE (ptr2) == INTEGER_CST));
+
+ /* ADDR_EXPR pointers either just offset another pointer or directly
+ specify the pointed-to set. */
+ if (TREE_CODE (ptr1) == ADDR_EXPR)
+ {
+ tree base = get_base_address (TREE_OPERAND (ptr1, 0));
+ if (base
+ && INDIRECT_REF_P (base))
+ ptr1 = TREE_OPERAND (base, 0);
+ else if (base
+ && SSA_VAR_P (base))
+ return ptr_deref_may_alias_decl_p (ptr2, base);
+ else
+ return true;
+ }
+ if (TREE_CODE (ptr2) == ADDR_EXPR)
+ {
+ tree base = get_base_address (TREE_OPERAND (ptr2, 0));
+ if (base
+ && INDIRECT_REF_P (base))
+ ptr2 = TREE_OPERAND (base, 0);
+ else if (base
+ && SSA_VAR_P (base))
+ return ptr_deref_may_alias_decl_p (ptr1, base);
+ else
+ return true;
+ }
+
+ /* We can end up with dereferencing constant pointers.
+ Just bail out in this case. */
+ if (TREE_CODE (ptr1) == INTEGER_CST
|| TREE_CODE (ptr2) == INTEGER_CST)
return true;
- gcc_assert (TREE_CODE (ptr1) == SSA_NAME
- && TREE_CODE (ptr2) == SSA_NAME);
-
/* We may end up with two empty points-to solutions for two same pointers.
In this case we still want to say both pointers alias, so shortcut
that here. */
if (!pi1 || !pi2)
return true;
+ /* If both pointers are restrict-qualified try to disambiguate
+ with restrict information. */
+ if (TYPE_RESTRICT (TREE_TYPE (ptr1))
+ && TYPE_RESTRICT (TREE_TYPE (ptr2))
+ && !pt_solutions_same_restrict_base (&pi1->pt, &pi2->pt))
+ return false;
+
+ /* ??? This does not use TBAA to prune decls from the intersection
+ that not both pointers may access. */
return pt_solutions_intersect (&pi1->pt, &pi2->pt);
}
-/* Return true if STMT is an "escape" site from the current function. Escape
- sites those statements which might expose the address of a variable
- outside the current function. STMT is an escape site iff:
-
- 1- STMT is a function call, or
- 2- STMT is an __asm__ expression, or
- 3- STMT is an assignment to a non-local variable, or
- 4- STMT is a return statement.
-
- Return the type of escape site found, if we found one, or NO_ESCAPE
- if none. */
+/* Return true if dereferencing PTR may alias *REF.
+ The caller is responsible for applying TBAA to see if PTR
+ may access *REF at all. */
-enum escape_type
-is_escape_site (gimple stmt)
+static bool
+ptr_deref_may_alias_ref_p_1 (tree ptr, ao_ref *ref)
{
- if (is_gimple_call (stmt))
- {
- if (gimple_call_flags (stmt) & (ECF_PURE | ECF_CONST))
- return ESCAPE_TO_PURE_CONST;
-
- return ESCAPE_TO_CALL;
- }
- else if (gimple_code (stmt) == GIMPLE_ASM)
- return ESCAPE_TO_ASM;
- else if (is_gimple_assign (stmt))
- {
- tree lhs = gimple_assign_lhs (stmt);
+ tree base = ao_ref_base (ref);
- /* Get to the base of _REF nodes. */
- if (TREE_CODE (lhs) != SSA_NAME)
- lhs = get_base_address (lhs);
+ if (INDIRECT_REF_P (base))
+ return ptr_derefs_may_alias_p (ptr, TREE_OPERAND (base, 0));
+ else if (SSA_VAR_P (base))
+ return ptr_deref_may_alias_decl_p (ptr, base);
- /* If we couldn't recognize the LHS of the assignment, assume that it
- is a non-local store. */
- if (lhs == NULL_TREE)
- return ESCAPE_UNKNOWN;
-
- if (gimple_assign_cast_p (stmt))
- {
- tree from = TREE_TYPE (gimple_assign_rhs1 (stmt));
- tree to = TREE_TYPE (lhs);
-
- /* If the RHS is a conversion between a pointer and an integer, the
- pointer escapes since we can't track the integer. */
- if (POINTER_TYPE_P (from) && !POINTER_TYPE_P (to))
- return ESCAPE_BAD_CAST;
- }
-
- /* If the LHS is an SSA name, it can't possibly represent a non-local
- memory store. */
- if (TREE_CODE (lhs) == SSA_NAME)
- return NO_ESCAPE;
-
- /* If the LHS is a non-global decl, it isn't a non-local memory store.
- If the LHS escapes, the RHS escape is dealt with in the PTA solver. */
- if (DECL_P (lhs)
- && !is_global_var (lhs))
- return NO_ESCAPE;
-
- /* FIXME: LHS is not an SSA_NAME. Even if it's an assignment to a
- local variables we cannot be sure if it will escape, because we
- don't have information about objects not in SSA form. Need to
- implement something along the lines of
-
- J.-D. Choi, M. Gupta, M. J. Serrano, V. C. Sreedhar, and S. P.
- Midkiff, ``Escape analysis for java,'' in Proceedings of the
- Conference on Object-Oriented Programming Systems, Languages, and
- Applications (OOPSLA), pp. 1-19, 1999. */
- return ESCAPE_STORED_IN_GLOBAL;
- }
- else if (gimple_code (stmt) == GIMPLE_RETURN)
- return ESCAPE_TO_RETURN;
-
- return NO_ESCAPE;
+ return true;
}
fprintf (file, "\n\nAlias information for %s\n\n", funcname);
fprintf (file, "Aliased symbols\n\n");
-
+
FOR_EACH_REFERENCED_VAR (var, rvi)
{
if (may_be_aliased (var))
dump_variable (file, var);
}
- fprintf (file, "\n\nFlow-insensitive points-to information for %s\n\n", funcname);
+ fprintf (file, "\nCall clobber information\n");
+
+ fprintf (file, "\nESCAPED");
+ dump_points_to_solution (file, &cfun->gimple_df->escaped);
+ fprintf (file, "\nCALLUSED");
+ dump_points_to_solution (file, &cfun->gimple_df->callused);
+
+ fprintf (file, "\n\nFlow-insensitive points-to information\n\n");
for (i = 1; i < num_ssa_names; i++)
{
tree ptr = ssa_name (i);
struct ptr_info_def *pi;
-
+
if (ptr == NULL_TREE
|| SSA_NAME_IN_FREE_LIST (ptr))
continue;
return pi;
}
-/* Dump points-to information for SSA_NAME PTR into FILE. */
+/* Dump the points-to set *PT into FILE. */
void
-dump_points_to_info_for (FILE *file, tree ptr)
+dump_points_to_solution (FILE *file, struct pt_solution *pt)
{
- struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
+ if (pt->anything)
+ fprintf (file, ", points-to anything");
- print_generic_expr (file, ptr, dump_flags);
+ if (pt->nonlocal)
+ fprintf (file, ", points-to non-local");
- if (pi)
+ if (pt->escaped)
+ fprintf (file, ", points-to escaped");
+
+ if (pt->null)
+ fprintf (file, ", points-to NULL");
+
+ if (pt->vars)
{
- if (pi->pt.anything)
- fprintf (file, ", points-to anything");
+ fprintf (file, ", points-to vars: ");
+ dump_decl_set (file, pt->vars);
+ if (pt->vars_contains_global)
+ fprintf (file, " (includes global vars)");
+ }
+}
- if (pi->pt.nonlocal)
- fprintf (file, ", points-to non-local");
+/* Dump points-to information for SSA_NAME PTR into FILE. */
- if (pi->pt.escaped)
- fprintf (file, ", points-to escaped");
+void
+dump_points_to_info_for (FILE *file, tree ptr)
+{
+ struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
- if (pi->pt.null)
- fprintf (file, ", points-to NULL");
+ print_generic_expr (file, ptr, dump_flags);
- if (pi->pt.vars)
- {
- fprintf (file, ", points-to vars: ");
- dump_decl_set (file, pi->pt.vars);
- if (pi->pt.vars_contains_global)
- fprintf (file, " (includes global vars)");
- }
- }
+ if (pi)
+ dump_points_to_solution (file, &pi->pt);
+ else
+ fprintf (file, ", points-to anything");
fprintf (file, "\n");
}
dump_points_to_info_for (stderr, var);
}
+
+/* Initializes the alias-oracle reference representation *R from REF. */
+
+void
+ao_ref_init (ao_ref *r, tree ref)
+{
+ r->ref = ref;
+ r->base = NULL_TREE;
+ r->offset = 0;
+ r->size = -1;
+ r->max_size = -1;
+ r->ref_alias_set = -1;
+ r->base_alias_set = -1;
+}
+
+/* Returns the base object of the memory reference *REF. */
+
+tree
+ao_ref_base (ao_ref *ref)
+{
+ if (ref->base)
+ return ref->base;
+ ref->base = get_ref_base_and_extent (ref->ref, &ref->offset, &ref->size,
+ &ref->max_size);
+ return ref->base;
+}
+
+/* Returns the base object alias set of the memory reference *REF. */
+
+static alias_set_type ATTRIBUTE_UNUSED
+ao_ref_base_alias_set (ao_ref *ref)
+{
+ if (ref->base_alias_set != -1)
+ return ref->base_alias_set;
+ ref->base_alias_set = get_alias_set (ao_ref_base (ref));
+ return ref->base_alias_set;
+}
+
+/* Returns the reference alias set of the memory reference *REF. */
+
+alias_set_type
+ao_ref_alias_set (ao_ref *ref)
+{
+ if (ref->ref_alias_set != -1)
+ return ref->ref_alias_set;
+ ref->ref_alias_set = get_alias_set (ref->ref);
+ return ref->ref_alias_set;
+}
+
+/* Init an alias-oracle reference representation from a gimple pointer
+ PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE the the
+ size is assumed to be unknown. The access is assumed to be only
+ to or after of the pointer target, not before it. */
+
+void
+ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size)
+{
+ HOST_WIDE_INT t1, t2;
+ ref->ref = NULL_TREE;
+ if (TREE_CODE (ptr) == ADDR_EXPR)
+ ref->base = get_ref_base_and_extent (TREE_OPERAND (ptr, 0),
+ &ref->offset, &t1, &t2);
+ else
+ {
+ ref->base = build1 (INDIRECT_REF, char_type_node, ptr);
+ ref->offset = 0;
+ }
+ if (size
+ && host_integerp (size, 0)
+ && TREE_INT_CST_LOW (size) * 8 / 8 == TREE_INT_CST_LOW (size))
+ ref->max_size = ref->size = TREE_INT_CST_LOW (size) * 8;
+ else
+ ref->max_size = ref->size = -1;
+ ref->ref_alias_set = 0;
+ ref->base_alias_set = 0;
+}
+
/* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the
purpose of TBAA. Return 0 if they are distinct and -1 if we cannot
decide. */
if (TYPE_CANONICAL (type1) == TYPE_CANONICAL (type2))
return 1;
- /* ??? Array types are not properly unified in all cases as we have
+ /* ??? Array types are not properly unified in all cases as we have
spurious changes in the index types for example. Removing this
causes all sorts of problems with the Fortran frontend. */
if (TREE_CODE (type1) == ARRAY_TYPE
&& TREE_CODE (type2) == ARRAY_TYPE)
return -1;
+ /* ??? In Ada, an lvalue of an unconstrained type can be used to access an
+ object of one of its constrained subtypes, e.g. when a function with an
+ unconstrained parameter passed by reference is called on an object and
+ inlined. But, even in the case of a fixed size, type and subtypes are
+ not equivalent enough as to share the same TYPE_CANONICAL, since this
+ would mean that conversions between them are useless, whereas they are
+ not (e.g. type and subtypes can have different modes). So, in the end,
+ they are only guaranteed to have the same alias set. */
+ if (get_alias_set (type1) == get_alias_set (type2))
+ return -1;
+
/* The types are known to be not equal. */
return 0;
}
on an indirect reference may alias. */
static bool
-nonaliasing_component_refs_p (tree ref1, tree type1,
- HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1,
- tree ref2, tree type2,
- HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2)
+aliasing_component_refs_p (tree ref1, tree type1,
+ HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1,
+ tree ref2, tree type2,
+ HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2)
{
/* If one reference is a component references through pointers try to find a
common base and apply offset based disambiguation. This handles
/* Now search for the type1 in the access path of ref2. This
would be a common base for doing offset based disambiguation on. */
- /* Skip the outermost ref - we would have caught that earlier. */
- refp = &TREE_OPERAND (ref2, 0);
+ refp = &ref2;
while (handled_component_p (*refp)
&& same_type_for_tbaa (TREE_TYPE (*refp), type1) == 0)
refp = &TREE_OPERAND (*refp, 0);
return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
}
/* If we didn't find a common base, try the other way around. */
- refp = &TREE_OPERAND (ref1, 0);
+ refp = &ref1;
while (handled_component_p (*refp)
&& same_type_for_tbaa (TREE_TYPE (*refp), type2) == 0)
refp = &TREE_OPERAND (*refp, 0);
}
/* Return true if two memory references based on the variables BASE1
- and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1[ and
- [OFFSET2, OFFSET2 + MAX_SIZE2[ may alias. */
+ and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
+ [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. */
static bool
decl_refs_may_alias_p (tree base1,
}
/* Return true if an indirect reference based on *PTR1 constrained
- to [OFFSET1, OFFSET1 + MAX_SIZE1[ may alias a variable based on BASE2
- constrained to [OFFSET2, OFFSET2 + MAX_SIZE2[. *PTR1 and BASE2 have
+ to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2
+ constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have
the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
in which case they are computed on-demand. REF1 and REF2
if non-NULL are the complete memory reference trees. */
if (ref1 && ref2
&& handled_component_p (ref1)
&& handled_component_p (ref2))
- return nonaliasing_component_refs_p (ref1, TREE_TYPE (TREE_TYPE (ptr1)),
- offset1, max_size1,
- ref2, TREE_TYPE (base2),
- offset2, max_size2);
+ return aliasing_component_refs_p (ref1, TREE_TYPE (TREE_TYPE (ptr1)),
+ offset1, max_size1,
+ ref2, TREE_TYPE (base2),
+ offset2, max_size2);
return true;
}
/* Return true if two indirect references based on *PTR1
- and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1[ and
- [OFFSET2, OFFSET2 + MAX_SIZE2[ may alias. *PTR1 and *PTR2 have
+ and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
+ [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have
the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
in which case they are computed on-demand. REF1 and REF2
if non-NULL are the complete memory reference trees. */
if (ref1 && ref2
&& handled_component_p (ref1)
&& handled_component_p (ref2))
- return nonaliasing_component_refs_p (ref1, TREE_TYPE (TREE_TYPE (ptr1)),
- offset1, max_size1,
- ref2, TREE_TYPE (TREE_TYPE (ptr2)),
- offset2, max_size2);
+ return aliasing_component_refs_p (ref1, TREE_TYPE (TREE_TYPE (ptr1)),
+ offset1, max_size1,
+ ref2, TREE_TYPE (TREE_TYPE (ptr2)),
+ offset2, max_size2);
return true;
}
/* Return true, if the two memory references REF1 and REF2 may alias. */
-static bool
-refs_may_alias_p_1 (tree ref1, tree ref2)
+bool
+refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p)
{
tree base1, base2;
HOST_WIDE_INT offset1 = 0, offset2 = 0;
- HOST_WIDE_INT size1 = -1, size2 = -1;
HOST_WIDE_INT max_size1 = -1, max_size2 = -1;
bool var1_p, var2_p, ind1_p, ind2_p;
-
- gcc_assert ((SSA_VAR_P (ref1)
- || handled_component_p (ref1)
- || INDIRECT_REF_P (ref1)
- || TREE_CODE (ref1) == TARGET_MEM_REF)
- && (SSA_VAR_P (ref2)
- || handled_component_p (ref2)
- || INDIRECT_REF_P (ref2)
- || TREE_CODE (ref2) == TARGET_MEM_REF));
+ alias_set_type set;
+
+ gcc_assert ((!ref1->ref
+ || SSA_VAR_P (ref1->ref)
+ || handled_component_p (ref1->ref)
+ || INDIRECT_REF_P (ref1->ref)
+ || TREE_CODE (ref1->ref) == TARGET_MEM_REF
+ || TREE_CODE (ref1->ref) == CONST_DECL)
+ && (!ref2->ref
+ || SSA_VAR_P (ref2->ref)
+ || handled_component_p (ref2->ref)
+ || INDIRECT_REF_P (ref2->ref)
+ || TREE_CODE (ref2->ref) == TARGET_MEM_REF
+ || TREE_CODE (ref2->ref) == CONST_DECL));
/* Decompose the references into their base objects and the access. */
- base1 = get_ref_base_and_extent (ref1, &offset1, &size1, &max_size1);
- base2 = get_ref_base_and_extent (ref2, &offset2, &size2, &max_size2);
+ base1 = ao_ref_base (ref1);
+ offset1 = ref1->offset;
+ max_size1 = ref1->max_size;
+ base2 = ao_ref_base (ref2);
+ offset2 = ref2->offset;
+ max_size2 = ref2->max_size;
/* We can end up with registers or constants as bases for example from
*D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59);
which is seen as a struct copy. */
if (TREE_CODE (base1) == SSA_NAME
|| TREE_CODE (base2) == SSA_NAME
+ || TREE_CODE (base1) == CONST_DECL
+ || TREE_CODE (base2) == CONST_DECL
|| is_gimple_min_invariant (base1)
|| is_gimple_min_invariant (base2))
return false;
+ /* We can end up refering to code via function decls. As we likely
+ do not properly track code aliases conservatively bail out. */
+ if (TREE_CODE (base1) == FUNCTION_DECL
+ || TREE_CODE (base2) == FUNCTION_DECL)
+ return true;
+
/* Defer to simple offset based disambiguation if we have
references based on two decls. Do this before defering to
TBAA to handle must-alias cases in conformance with the
return decl_refs_may_alias_p (base1, offset1, max_size1,
base2, offset2, max_size2);
+ ind1_p = INDIRECT_REF_P (base1);
+ ind2_p = INDIRECT_REF_P (base2);
+ /* Canonicalize the pointer-vs-decl case. */
+ if (ind1_p && var2_p)
+ {
+ HOST_WIDE_INT tmp1;
+ tree tmp2;
+ ao_ref *tmp3;
+ tmp1 = offset1; offset1 = offset2; offset2 = tmp1;
+ tmp1 = max_size1; max_size1 = max_size2; max_size2 = tmp1;
+ tmp2 = base1; base1 = base2; base2 = tmp2;
+ tmp3 = ref1; ref1 = ref2; ref2 = tmp3;
+ var1_p = true;
+ ind1_p = false;
+ var2_p = false;
+ ind2_p = true;
+ }
+
+ /* If we are about to disambiguate pointer-vs-decl try harder to
+ see must-aliases and give leeway to some invalid cases.
+ This covers a pretty minimal set of cases only and does not
+ when called from the RTL oracle. It handles cases like
+
+ int i = 1;
+ return *(float *)&i;
+
+ and also fixes gfortran.dg/lto/pr40725. */
+ if (var1_p && ind2_p
+ && cfun
+ && gimple_in_ssa_p (cfun)
+ && TREE_CODE (TREE_OPERAND (base2, 0)) == SSA_NAME)
+ {
+ gimple def_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (base2, 0));
+ while (is_gimple_assign (def_stmt)
+ && (gimple_assign_rhs_code (def_stmt) == SSA_NAME
+ || CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))))
+ {
+ tree rhs = gimple_assign_rhs1 (def_stmt);
+ HOST_WIDE_INT offset, size, max_size;
+
+ /* Look through SSA name copies and pointer conversions. */
+ if (TREE_CODE (rhs) == SSA_NAME
+ && POINTER_TYPE_P (TREE_TYPE (rhs)))
+ {
+ def_stmt = SSA_NAME_DEF_STMT (rhs);
+ continue;
+ }
+ if (TREE_CODE (rhs) != ADDR_EXPR)
+ break;
+
+ /* If the pointer is defined as an address based on a decl
+ use plain offset disambiguation and ignore TBAA. */
+ rhs = TREE_OPERAND (rhs, 0);
+ rhs = get_ref_base_and_extent (rhs, &offset, &size, &max_size);
+ if (SSA_VAR_P (rhs))
+ {
+ base2 = rhs;
+ offset2 += offset;
+ if (size != max_size
+ || max_size == -1)
+ max_size2 = -1;
+ return decl_refs_may_alias_p (base1, offset1, max_size1,
+ base2, offset2, max_size2);
+ }
+
+ /* Do not continue looking through &p->x to limit time
+ complexity. */
+ break;
+ }
+ }
+
/* First defer to TBAA if possible. */
- if (flag_strict_aliasing
- && !alias_sets_conflict_p (get_alias_set (ref1), get_alias_set (ref2)))
+ if (tbaa_p
+ && flag_strict_aliasing
+ && !alias_sets_conflict_p (ao_ref_alias_set (ref1),
+ ao_ref_alias_set (ref2)))
return false;
/* If one reference is a TARGET_MEM_REF weird things are allowed. Still
TBAA disambiguation based on the access type is possible, so bail
out only after that check. */
- if (TREE_CODE (ref1) == TARGET_MEM_REF
- || TREE_CODE (ref2) == TARGET_MEM_REF)
+ if ((ref1->ref && TREE_CODE (ref1->ref) == TARGET_MEM_REF)
+ || (ref2->ref && TREE_CODE (ref2->ref) == TARGET_MEM_REF))
return true;
/* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */
- ind1_p = INDIRECT_REF_P (base1);
- ind2_p = INDIRECT_REF_P (base2);
+ set = tbaa_p ? -1 : 0;
if (var1_p && ind2_p)
- return indirect_ref_may_alias_decl_p (ref2, TREE_OPERAND (base2, 0),
- offset2, max_size2, -1,
- ref1, base1,
- offset1, max_size1, -1);
- else if (ind1_p && var2_p)
- return indirect_ref_may_alias_decl_p (ref1, TREE_OPERAND (base1, 0),
- offset1, max_size1, -1,
- ref2, base2,
- offset2, max_size2, -1);
+ return indirect_ref_may_alias_decl_p (ref2->ref, TREE_OPERAND (base2, 0),
+ offset2, max_size2, set,
+ ref1->ref, base1,
+ offset1, max_size1, set);
else if (ind1_p && ind2_p)
- return indirect_refs_may_alias_p (ref1, TREE_OPERAND (base1, 0),
- offset1, max_size1, -1,
- ref2, TREE_OPERAND (base2, 0),
- offset2, max_size2, -1);
+ return indirect_refs_may_alias_p (ref1->ref, TREE_OPERAND (base1, 0),
+ offset1, max_size1, set,
+ ref2->ref, TREE_OPERAND (base2, 0),
+ offset2, max_size2, set);
gcc_unreachable ();
}
bool
refs_may_alias_p (tree ref1, tree ref2)
{
- bool res = refs_may_alias_p_1 (ref1, ref2);
+ ao_ref r1, r2;
+ bool res;
+ ao_ref_init (&r1, ref1);
+ ao_ref_init (&r2, ref2);
+ res = refs_may_alias_p_1 (&r1, &r2, true);
if (res)
++alias_stats.refs_may_alias_p_may_alias;
else
return res;
}
+/* Returns true if there is a anti-dependence for the STORE that
+ executes after the LOAD. */
+
+bool
+refs_anti_dependent_p (tree load, tree store)
+{
+ ao_ref r1, r2;
+ ao_ref_init (&r1, load);
+ ao_ref_init (&r2, store);
+ return refs_may_alias_p_1 (&r1, &r2, false);
+}
+
+/* Returns true if there is a output dependence for the stores
+ STORE1 and STORE2. */
+
+bool
+refs_output_dependent_p (tree store1, tree store2)
+{
+ ao_ref r1, r2;
+ ao_ref_init (&r1, store1);
+ ao_ref_init (&r2, store2);
+ return refs_may_alias_p_1 (&r1, &r2, false);
+}
/* If the call CALL may use the memory reference REF return true,
otherwise return false. */
static bool
-ref_maybe_used_by_call_p_1 (gimple call, tree ref)
+ref_maybe_used_by_call_p_1 (gimple call, ao_ref *ref)
{
- tree base;
+ tree base, callee;
unsigned i;
int flags = gimple_call_flags (call);
&& (flags & (ECF_CONST|ECF_NOVOPS)))
goto process_args;
- /* If the reference is not based on a decl give up.
- ??? Handle indirect references by intersecting the call-used
- solution with that of the pointer. */
- base = get_base_address (ref);
- if (!base
- || !DECL_P (base))
+ base = ao_ref_base (ref);
+ if (!base)
return true;
/* If the reference is based on a decl that is not aliased the call
&& !is_global_var (base))
goto process_args;
+ callee = gimple_call_fndecl (call);
+
+ /* Handle those builtin functions explicitly that do not act as
+ escape points. See tree-ssa-structalias.c:find_func_aliases
+ for the list of builtins we might need to handle here. */
+ if (callee != NULL_TREE
+ && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
+ switch (DECL_FUNCTION_CODE (callee))
+ {
+ /* All the following functions clobber memory pointed to by
+ their first argument. */
+ case BUILT_IN_STRCPY:
+ case BUILT_IN_STRNCPY:
+ case BUILT_IN_MEMCPY:
+ case BUILT_IN_MEMMOVE:
+ case BUILT_IN_MEMPCPY:
+ case BUILT_IN_STPCPY:
+ case BUILT_IN_STPNCPY:
+ case BUILT_IN_STRCAT:
+ case BUILT_IN_STRNCAT:
+ {
+ ao_ref dref;
+ tree size = NULL_TREE;
+ if (gimple_call_num_args (call) == 3)
+ size = gimple_call_arg (call, 2);
+ ao_ref_init_from_ptr_and_size (&dref,
+ gimple_call_arg (call, 1),
+ size);
+ return refs_may_alias_p_1 (&dref, ref, false);
+ }
+ case BUILT_IN_BCOPY:
+ {
+ ao_ref dref;
+ tree size = gimple_call_arg (call, 2);
+ ao_ref_init_from_ptr_and_size (&dref,
+ gimple_call_arg (call, 0),
+ size);
+ return refs_may_alias_p_1 (&dref, ref, false);
+ }
+ /* The following builtins do not read from memory. */
+ case BUILT_IN_FREE:
+ case BUILT_IN_MALLOC:
+ case BUILT_IN_CALLOC:
+ case BUILT_IN_MEMSET:
+ case BUILT_IN_FREXP:
+ case BUILT_IN_FREXPF:
+ case BUILT_IN_FREXPL:
+ case BUILT_IN_GAMMA_R:
+ case BUILT_IN_GAMMAF_R:
+ case BUILT_IN_GAMMAL_R:
+ case BUILT_IN_LGAMMA_R:
+ case BUILT_IN_LGAMMAF_R:
+ case BUILT_IN_LGAMMAL_R:
+ case BUILT_IN_MODF:
+ case BUILT_IN_MODFF:
+ case BUILT_IN_MODFL:
+ case BUILT_IN_REMQUO:
+ case BUILT_IN_REMQUOF:
+ case BUILT_IN_REMQUOL:
+ case BUILT_IN_SINCOS:
+ case BUILT_IN_SINCOSF:
+ case BUILT_IN_SINCOSL:
+ return false;
+
+ default:
+ /* Fallthru to general call handling. */;
+ }
+
/* Check if base is a global static variable that is not read
by the function. */
if (TREE_CODE (base) == VAR_DECL
&& TREE_STATIC (base)
&& !TREE_PUBLIC (base))
{
- tree callee = gimple_call_fndecl (call);
bitmap not_read;
if (callee != NULL_TREE
it may be used. */
if (flags & (ECF_PURE|ECF_CONST|ECF_LOOPING_CONST_OR_PURE|ECF_NOVOPS))
{
- if (is_call_used (base))
+ if (DECL_P (base))
+ {
+ if (is_call_used (base))
+ return true;
+ }
+ else if (INDIRECT_REF_P (base)
+ && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
+ {
+ struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
+ if (!pi)
+ return true;
+
+ if (pt_solution_includes_global (&pi->pt)
+ || pt_solutions_intersect (&cfun->gimple_df->callused, &pi->pt)
+ || pt_solutions_intersect (&cfun->gimple_df->escaped, &pi->pt))
+ return true;
+ }
+ else
return true;
}
else
{
- if (is_call_clobbered (base))
+ if (DECL_P (base))
+ {
+ if (is_call_clobbered (base))
+ return true;
+ }
+ else if (INDIRECT_REF_P (base)
+ && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
+ {
+ struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
+ if (!pi)
+ return true;
+
+ if (pt_solution_includes_global (&pi->pt)
+ || pt_solutions_intersect (&cfun->gimple_df->escaped, &pi->pt))
+ return true;
+ }
+ else
return true;
}
{
tree op = gimple_call_arg (call, i);
- if (TREE_CODE (op) == EXC_PTR_EXPR
- || TREE_CODE (op) == FILTER_EXPR)
- continue;
-
if (TREE_CODE (op) == WITH_SIZE_EXPR)
op = TREE_OPERAND (op, 0);
if (TREE_CODE (op) != SSA_NAME
- && !is_gimple_min_invariant (op)
- && refs_may_alias_p (op, ref))
- return true;
+ && !is_gimple_min_invariant (op))
+ {
+ ao_ref r;
+ ao_ref_init (&r, op);
+ if (refs_may_alias_p_1 (&r, ref, true))
+ return true;
+ }
}
return false;
static bool
ref_maybe_used_by_call_p (gimple call, tree ref)
{
- bool res = ref_maybe_used_by_call_p_1 (call, ref);
+ ao_ref r;
+ bool res;
+ ao_ref_init (&r, ref);
+ res = ref_maybe_used_by_call_p_1 (call, &r);
if (res)
++alias_stats.ref_maybe_used_by_call_p_may_alias;
else
return true, otherwise return false. */
static bool
-call_may_clobber_ref_p_1 (gimple call, tree ref)
+call_may_clobber_ref_p_1 (gimple call, ao_ref *ref)
{
tree base;
+ tree callee;
/* If the call is pure or const it cannot clobber anything. */
if (gimple_call_flags (call)
& (ECF_PURE|ECF_CONST|ECF_LOOPING_CONST_OR_PURE|ECF_NOVOPS))
return false;
- base = get_base_address (ref);
+ base = ao_ref_base (ref);
if (!base)
return true;
|| !is_global_var (base)))
return false;
+ callee = gimple_call_fndecl (call);
+
+ /* Handle those builtin functions explicitly that do not act as
+ escape points. See tree-ssa-structalias.c:find_func_aliases
+ for the list of builtins we might need to handle here. */
+ if (callee != NULL_TREE
+ && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
+ switch (DECL_FUNCTION_CODE (callee))
+ {
+ /* All the following functions clobber memory pointed to by
+ their first argument. */
+ case BUILT_IN_STRCPY:
+ case BUILT_IN_STRNCPY:
+ case BUILT_IN_MEMCPY:
+ case BUILT_IN_MEMMOVE:
+ case BUILT_IN_MEMPCPY:
+ case BUILT_IN_STPCPY:
+ case BUILT_IN_STPNCPY:
+ case BUILT_IN_STRCAT:
+ case BUILT_IN_STRNCAT:
+ case BUILT_IN_MEMSET:
+ {
+ ao_ref dref;
+ tree size = NULL_TREE;
+ if (gimple_call_num_args (call) == 3)
+ size = gimple_call_arg (call, 2);
+ ao_ref_init_from_ptr_and_size (&dref,
+ gimple_call_arg (call, 0),
+ size);
+ return refs_may_alias_p_1 (&dref, ref, false);
+ }
+ case BUILT_IN_BCOPY:
+ {
+ ao_ref dref;
+ tree size = gimple_call_arg (call, 2);
+ ao_ref_init_from_ptr_and_size (&dref,
+ gimple_call_arg (call, 1),
+ size);
+ return refs_may_alias_p_1 (&dref, ref, false);
+ }
+ /* Allocating memory does not have any side-effects apart from
+ being the definition point for the pointer. */
+ case BUILT_IN_MALLOC:
+ case BUILT_IN_CALLOC:
+ /* Unix98 specifies that errno is set on allocation failure.
+ Until we properly can track the errno location assume it
+ is not a local decl but external or anonymous storage in
+ a different translation unit. Also assume it is of
+ type int as required by the standard. */
+ if (flag_errno_math
+ && TREE_TYPE (base) == integer_type_node)
+ {
+ struct ptr_info_def *pi;
+ if (DECL_P (base)
+ && !TREE_STATIC (base))
+ return true;
+ else if (INDIRECT_REF_P (base)
+ && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME
+ && (pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0))))
+ return pi->pt.anything || pi->pt.nonlocal;
+ }
+ return false;
+ /* Freeing memory kills the pointed-to memory. More importantly
+ the call has to serve as a barrier for moving loads and stores
+ across it. */
+ case BUILT_IN_FREE:
+ {
+ tree ptr = gimple_call_arg (call, 0);
+ return ptr_deref_may_alias_ref_p_1 (ptr, ref);
+ }
+ case BUILT_IN_GAMMA_R:
+ case BUILT_IN_GAMMAF_R:
+ case BUILT_IN_GAMMAL_R:
+ case BUILT_IN_LGAMMA_R:
+ case BUILT_IN_LGAMMAF_R:
+ case BUILT_IN_LGAMMAL_R:
+ {
+ tree out = gimple_call_arg (call, 1);
+ if (ptr_deref_may_alias_ref_p_1 (out, ref))
+ return true;
+ if (flag_errno_math)
+ break;
+ return false;
+ }
+ case BUILT_IN_FREXP:
+ case BUILT_IN_FREXPF:
+ case BUILT_IN_FREXPL:
+ case BUILT_IN_MODF:
+ case BUILT_IN_MODFF:
+ case BUILT_IN_MODFL:
+ {
+ tree out = gimple_call_arg (call, 1);
+ return ptr_deref_may_alias_ref_p_1 (out, ref);
+ }
+ case BUILT_IN_REMQUO:
+ case BUILT_IN_REMQUOF:
+ case BUILT_IN_REMQUOL:
+ {
+ tree out = gimple_call_arg (call, 2);
+ if (ptr_deref_may_alias_ref_p_1 (out, ref))
+ return true;
+ if (flag_errno_math)
+ break;
+ return false;
+ }
+ case BUILT_IN_SINCOS:
+ case BUILT_IN_SINCOSF:
+ case BUILT_IN_SINCOSL:
+ {
+ tree sin = gimple_call_arg (call, 1);
+ tree cos = gimple_call_arg (call, 2);
+ return (ptr_deref_may_alias_ref_p_1 (sin, ref)
+ || ptr_deref_may_alias_ref_p_1 (cos, ref));
+ }
+ default:
+ /* Fallthru to general call handling. */;
+ }
+
/* Check if base is a global static variable that is not written
by the function. */
- if (TREE_CODE (base) == VAR_DECL
+ if (callee != NULL_TREE
+ && TREE_CODE (base) == VAR_DECL
&& TREE_STATIC (base)
&& !TREE_PUBLIC (base))
{
- tree callee = gimple_call_fndecl (call);
bitmap not_written;
- if (callee != NULL_TREE
- && (not_written
- = ipa_reference_get_not_written_global (cgraph_node (callee)))
+ if ((not_written
+ = ipa_reference_get_not_written_global (cgraph_node (callee)))
&& bitmap_bit_p (not_written, DECL_UID (base)))
return false;
}
if (DECL_P (base))
return is_call_clobbered (base);
+ else if (INDIRECT_REF_P (base)
+ && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
+ {
+ struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
+ if (!pi)
+ return true;
+
+ return (pt_solution_includes_global (&pi->pt)
+ || pt_solutions_intersect (&cfun->gimple_df->escaped, &pi->pt));
+ }
return true;
}
-static bool
+static bool ATTRIBUTE_UNUSED
call_may_clobber_ref_p (gimple call, tree ref)
{
- bool res = call_may_clobber_ref_p_1 (call, ref);
+ bool res;
+ ao_ref r;
+ ao_ref_init (&r, ref);
+ res = call_may_clobber_ref_p_1 (call, &r);
if (res)
++alias_stats.call_may_clobber_ref_p_may_alias;
else
otherwise return false. */
bool
-stmt_may_clobber_ref_p (gimple stmt, tree ref)
+stmt_may_clobber_ref_p_1 (gimple stmt, ao_ref *ref)
{
if (is_gimple_call (stmt))
{
tree lhs = gimple_call_lhs (stmt);
if (lhs
- && !is_gimple_reg (lhs)
- && refs_may_alias_p (ref, lhs))
- return true;
+ && !is_gimple_reg (lhs))
+ {
+ ao_ref r;
+ ao_ref_init (&r, lhs);
+ if (refs_may_alias_p_1 (ref, &r, true))
+ return true;
+ }
- return call_may_clobber_ref_p (stmt, ref);
+ return call_may_clobber_ref_p_1 (stmt, ref);
}
else if (is_gimple_assign (stmt))
- return refs_may_alias_p (ref, gimple_assign_lhs (stmt));
+ {
+ ao_ref r;
+ ao_ref_init (&r, gimple_assign_lhs (stmt));
+ return refs_may_alias_p_1 (ref, &r, true);
+ }
else if (gimple_code (stmt) == GIMPLE_ASM)
return true;
return false;
}
-static tree get_continuation_for_phi (gimple, tree, bitmap *);
+bool
+stmt_may_clobber_ref_p (gimple stmt, tree ref)
+{
+ ao_ref r;
+ ao_ref_init (&r, ref);
+ return stmt_may_clobber_ref_p_1 (stmt, &r);
+}
+
/* Walk the virtual use-def chain of VUSE until hitting the virtual operand
TARGET or a statement clobbering the memory reference REF in which
case false is returned. The walk starts with VUSE, one argument of PHI. */
static bool
-maybe_skip_until (gimple phi, tree target, tree ref, tree vuse, bitmap *visited)
+maybe_skip_until (gimple phi, tree target, ao_ref *ref,
+ tree vuse, bitmap *visited)
{
if (!*visited)
*visited = BITMAP_ALLOC (NULL);
}
/* A clobbering statement or the end of the IL ends it failing. */
else if (gimple_nop_p (def_stmt)
- || stmt_may_clobber_ref_p (def_stmt, ref))
+ || stmt_may_clobber_ref_p_1 (def_stmt, ref))
return false;
vuse = gimple_vuse (def_stmt);
}
clobber REF. Returns NULL_TREE if no suitable virtual operand can
be found. */
-static tree
-get_continuation_for_phi (gimple phi, tree ref, bitmap *visited)
+tree
+get_continuation_for_phi (gimple phi, ao_ref *ref, bitmap *visited)
{
unsigned nargs = gimple_phi_num_args (phi);
tree arg1 = PHI_ARG_DEF (phi, 1);
gimple def0 = SSA_NAME_DEF_STMT (arg0);
gimple def1 = SSA_NAME_DEF_STMT (arg1);
+ tree common_vuse;
if (arg0 == arg1)
return arg0;
if (maybe_skip_until (phi, arg1, ref, arg0, visited))
return arg1;
}
+ /* Special case of a diamond:
+ MEM_1 = ...
+ goto (cond) ? L1 : L2
+ L1: store1 = ... #MEM_2 = vuse(MEM_1)
+ goto L3
+ L2: store2 = ... #MEM_3 = vuse(MEM_1)
+ L3: MEM_4 = PHI<MEM_2, MEM_3>
+ We were called with the PHI at L3, MEM_2 and MEM_3 don't
+ dominate each other, but still we can easily skip this PHI node
+ if we recognize that the vuse MEM operand is the same for both,
+ and that we can skip both statements (they don't clobber us).
+ This is still linear. Don't use maybe_skip_until, that might
+ potentially be slow. */
+ else if ((common_vuse = gimple_vuse (def0))
+ && common_vuse == gimple_vuse (def1))
+ {
+ if (!stmt_may_clobber_ref_p_1 (def0, ref)
+ && !stmt_may_clobber_ref_p_1 (def1, ref))
+ return common_vuse;
+ }
}
return NULL_TREE;
WALKER returns non-NULL the walk stops and its result is returned.
At the end of a non-successful walk NULL is returned.
+ TRANSLATE if non-NULL is called with a pointer to REF, the virtual
+ use which definition is a statement that may clobber REF and DATA.
+ If TRANSLATE returns (void *)-1 the walk stops and NULL is returned.
+ If TRANSLATE returns non-NULL the walk stops and its result is returned.
+ If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed
+ to adjust REF and *DATA to make that valid.
+
TODO: Cache the vector of equivalent vuses per ref, vuse pair. */
void *
-walk_non_aliased_vuses (tree ref, tree vuse,
- void *(*walker)(tree, tree, void *), void *data)
+walk_non_aliased_vuses (ao_ref *ref, tree vuse,
+ void *(*walker)(ao_ref *, tree, void *),
+ void *(*translate)(ao_ref *, tree, void *), void *data)
{
bitmap visited = NULL;
void *res;
vuse = get_continuation_for_phi (def_stmt, ref, &visited);
else
{
- if (stmt_may_clobber_ref_p (def_stmt, ref))
- break;
+ if (stmt_may_clobber_ref_p_1 (def_stmt, ref))
+ {
+ if (!translate)
+ break;
+ res = (*translate) (ref, vuse, data);
+ /* Failed lookup and translation. */
+ if (res == (void *)-1)
+ {
+ res = NULL;
+ break;
+ }
+ /* Lookup succeeded. */
+ else if (res != NULL)
+ break;
+ /* Translation succeeded, continue walking. */
+ }
vuse = gimple_vuse (def_stmt);
}
}
The function returns the number of statements walked. */
static unsigned int
-walk_aliased_vdefs_1 (tree ref, tree vdef,
- bool (*walker)(tree, tree, void *), void *data,
+walk_aliased_vdefs_1 (ao_ref *ref, tree vdef,
+ bool (*walker)(ao_ref *, tree, void *), void *data,
bitmap *visited, unsigned int cnt)
{
do
/* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
cnt++;
if ((!ref
- || stmt_may_clobber_ref_p (def_stmt, ref))
+ || stmt_may_clobber_ref_p_1 (def_stmt, ref))
&& (*walker) (ref, vdef, data))
return cnt;
}
unsigned int
-walk_aliased_vdefs (tree ref, tree vdef,
- bool (*walker)(tree, tree, void *), void *data,
+walk_aliased_vdefs (ao_ref *ref, tree vdef,
+ bool (*walker)(ao_ref *, tree, void *), void *data,
bitmap *visited)
{
bitmap local_visited = NULL;
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