/* Alias analysis for trees.
- Copyright (C) 2004-2015 Free Software Foundation, Inc.
+ Copyright (C) 2004-2019 Free Software Foundation, Inc.
Contributed by Diego Novillo <dnovillo@redhat.com>
This file is part of GCC.
#include "system.h"
#include "coretypes.h"
#include "backend.h"
+#include "target.h"
+#include "rtl.h"
#include "tree.h"
#include "gimple.h"
-#include "rtl.h"
+#include "timevar.h" /* for TV_ALIAS_STMT_WALK */
#include "ssa.h"
+#include "cgraph.h"
+#include "tree-pretty-print.h"
#include "alias.h"
#include "fold-const.h"
-#include "tm_p.h"
-#include "target.h"
-
-#include "dominance.h"
-#include "timevar.h" /* for TV_ALIAS_STMT_WALK */
#include "langhooks.h"
-#include "flags.h"
-#include "tree-pretty-print.h"
#include "dumpfile.h"
-#include "internal-fn.h"
#include "tree-eh.h"
-#include "insn-config.h"
-#include "expmed.h"
-#include "dojump.h"
-#include "explow.h"
-#include "calls.h"
-#include "emit-rtl.h"
-#include "varasm.h"
-#include "stmt.h"
-#include "expr.h"
#include "tree-dfa.h"
-#include "tree-inline.h"
-#include "params.h"
-#include "alloc-pool.h"
-#include "cgraph.h"
#include "ipa-reference.h"
+#include "varasm.h"
/* Broad overview of how alias analysis on gimple works:
&& TREE_CODE (ptr) != ADDR_EXPR
&& TREE_CODE (ptr) != POINTER_PLUS_EXPR)
|| !POINTER_TYPE_P (TREE_TYPE (ptr))
- || (TREE_CODE (decl) != VAR_DECL
+ || (!VAR_P (decl)
&& TREE_CODE (decl) != PARM_DECL
&& TREE_CODE (decl) != RESULT_DECL))
return true;
ptr = TREE_OPERAND (base, 0);
else if (base
&& DECL_P (base))
- return base == decl;
+ return compare_base_decls (base, decl) != 0;
else if (base
&& CONSTANT_CLASS_P (base))
return false;
return true;
}
- /* Non-aliased variables can not be pointed to. */
+ /* Non-aliased variables cannot be pointed to. */
if (!may_be_aliased (decl))
return false;
return true;
}
+/* Returns true if PTR1 and PTR2 compare unequal because of points-to. */
+
+bool
+ptrs_compare_unequal (tree ptr1, tree ptr2)
+{
+ /* First resolve the pointers down to a SSA name pointer base or
+ a VAR_DECL, PARM_DECL or RESULT_DECL. This explicitely does
+ not yet try to handle LABEL_DECLs, FUNCTION_DECLs, CONST_DECLs
+ or STRING_CSTs which needs points-to adjustments to track them
+ in the points-to sets. */
+ tree obj1 = NULL_TREE;
+ tree obj2 = NULL_TREE;
+ if (TREE_CODE (ptr1) == ADDR_EXPR)
+ {
+ tree tem = get_base_address (TREE_OPERAND (ptr1, 0));
+ if (! tem)
+ return false;
+ if (VAR_P (tem)
+ || TREE_CODE (tem) == PARM_DECL
+ || TREE_CODE (tem) == RESULT_DECL)
+ obj1 = tem;
+ else if (TREE_CODE (tem) == MEM_REF)
+ ptr1 = TREE_OPERAND (tem, 0);
+ }
+ if (TREE_CODE (ptr2) == ADDR_EXPR)
+ {
+ tree tem = get_base_address (TREE_OPERAND (ptr2, 0));
+ if (! tem)
+ return false;
+ if (VAR_P (tem)
+ || TREE_CODE (tem) == PARM_DECL
+ || TREE_CODE (tem) == RESULT_DECL)
+ obj2 = tem;
+ else if (TREE_CODE (tem) == MEM_REF)
+ ptr2 = TREE_OPERAND (tem, 0);
+ }
+
+ /* Canonicalize ptr vs. object. */
+ if (TREE_CODE (ptr1) == SSA_NAME && obj2)
+ {
+ std::swap (ptr1, ptr2);
+ std::swap (obj1, obj2);
+ }
+
+ if (obj1 && obj2)
+ /* Other code handles this correctly, no need to duplicate it here. */;
+ else if (obj1 && TREE_CODE (ptr2) == SSA_NAME)
+ {
+ struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr2);
+ /* We may not use restrict to optimize pointer comparisons.
+ See PR71062. So we have to assume that restrict-pointed-to
+ may be in fact obj1. */
+ if (!pi
+ || pi->pt.vars_contains_restrict
+ || pi->pt.vars_contains_interposable)
+ return false;
+ if (VAR_P (obj1)
+ && (TREE_STATIC (obj1) || DECL_EXTERNAL (obj1)))
+ {
+ varpool_node *node = varpool_node::get (obj1);
+ /* If obj1 may bind to NULL give up (see below). */
+ if (! node
+ || ! node->nonzero_address ()
+ || ! decl_binds_to_current_def_p (obj1))
+ return false;
+ }
+ return !pt_solution_includes (&pi->pt, obj1);
+ }
+
+ /* ??? We'd like to handle ptr1 != NULL and ptr1 != ptr2
+ but those require pt.null to be conservatively correct. */
+
+ return false;
+}
+
/* Returns whether reference REF to BASE may refer to global memory. */
static bool
dump_alias_info (FILE *file)
{
unsigned i;
+ tree ptr;
const char *funcname
= lang_hooks.decl_printable_name (current_function_decl, 2);
tree var;
fprintf (file, "\n\nFlow-insensitive points-to information\n\n");
- for (i = 1; i < num_ssa_names; i++)
+ FOR_EACH_SSA_NAME (i, ptr, cfun)
{
- tree ptr = ssa_name (i);
struct ptr_info_def *pi;
- if (ptr == NULL_TREE
- || !POINTER_TYPE_P (TREE_TYPE (ptr))
+ if (!POINTER_TYPE_P (TREE_TYPE (ptr))
|| SSA_NAME_IN_FREE_LIST (ptr))
continue;
fprintf (file, ", points-to vars: ");
dump_decl_set (file, pt->vars);
if (pt->vars_contains_nonlocal
- && pt->vars_contains_escaped_heap)
- fprintf (file, " (nonlocal, escaped heap)");
- else if (pt->vars_contains_nonlocal
- && pt->vars_contains_escaped)
- fprintf (file, " (nonlocal, escaped)");
- else if (pt->vars_contains_nonlocal)
- fprintf (file, " (nonlocal)");
- else if (pt->vars_contains_escaped_heap)
- fprintf (file, " (escaped heap)");
- else if (pt->vars_contains_escaped)
- fprintf (file, " (escaped)");
+ || pt->vars_contains_escaped
+ || pt->vars_contains_escaped_heap
+ || pt->vars_contains_restrict)
+ {
+ const char *comma = "";
+ fprintf (file, " (");
+ if (pt->vars_contains_nonlocal)
+ {
+ fprintf (file, "nonlocal");
+ comma = ", ";
+ }
+ if (pt->vars_contains_escaped)
+ {
+ fprintf (file, "%sescaped", comma);
+ comma = ", ";
+ }
+ if (pt->vars_contains_escaped_heap)
+ {
+ fprintf (file, "%sescaped heap", comma);
+ comma = ", ";
+ }
+ if (pt->vars_contains_restrict)
+ {
+ fprintf (file, "%srestrict", comma);
+ comma = ", ";
+ }
+ if (pt->vars_contains_interposable)
+ fprintf (file, "%sinterposable", comma);
+ fprintf (file, ")");
+ }
}
}
tree
ao_ref_base (ao_ref *ref)
{
+ bool reverse;
+
if (ref->base)
return ref->base;
ref->base = get_ref_base_and_extent (ref->ref, &ref->offset, &ref->size,
- &ref->max_size);
+ &ref->max_size, &reverse);
return ref->base;
}
void
ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size)
{
- HOST_WIDE_INT t, size_hwi, extra_offset = 0;
+ poly_int64 t, size_hwi, extra_offset = 0;
ref->ref = NULL_TREE;
if (TREE_CODE (ptr) == SSA_NAME)
{
ptr = gimple_assign_rhs1 (stmt);
else if (is_gimple_assign (stmt)
&& gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR
- && TREE_CODE (gimple_assign_rhs2 (stmt)) == INTEGER_CST)
+ && ptrdiff_tree_p (gimple_assign_rhs2 (stmt), &extra_offset))
{
ptr = gimple_assign_rhs1 (stmt);
- extra_offset = BITS_PER_UNIT
- * int_cst_value (gimple_assign_rhs2 (stmt));
+ extra_offset *= BITS_PER_UNIT;
}
}
}
else
{
+ gcc_assert (POINTER_TYPE_P (TREE_TYPE (ptr)));
ref->base = build2 (MEM_REF, char_type_node,
ptr, null_pointer_node);
ref->offset = 0;
}
ref->offset += extra_offset;
if (size
- && tree_fits_shwi_p (size)
- && (size_hwi = tree_to_shwi (size)) <= HOST_WIDE_INT_MAX / BITS_PER_UNIT)
+ && poly_int_tree_p (size, &size_hwi)
+ && coeffs_in_range_p (size_hwi, 0, HOST_WIDE_INT_MAX / BITS_PER_UNIT))
ref->max_size = ref->size = size_hwi * BITS_PER_UNIT;
else
ref->max_size = ref->size = -1;
aliasing_component_refs_p (tree ref1,
alias_set_type ref1_alias_set,
alias_set_type base1_alias_set,
- HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1,
+ poly_int64 offset1, poly_int64 max_size1,
tree ref2,
alias_set_type ref2_alias_set,
alias_set_type base2_alias_set,
- HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2,
+ poly_int64 offset2, poly_int64 max_size2,
bool ref2_is_decl)
{
/* If one reference is a component references through pointers try to find a
return true;
else if (same_p == 1)
{
- HOST_WIDE_INT offadj, sztmp, msztmp;
- get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp);
+ poly_int64 offadj, sztmp, msztmp;
+ bool reverse;
+ get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp, &reverse);
offset2 -= offadj;
- get_ref_base_and_extent (base1, &offadj, &sztmp, &msztmp);
+ get_ref_base_and_extent (base1, &offadj, &sztmp, &msztmp, &reverse);
offset1 -= offadj;
- return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
+ return ranges_maybe_overlap_p (offset1, max_size1, offset2, max_size2);
}
/* If we didn't find a common base, try the other way around. */
refp = &ref1;
return true;
else if (same_p == 1)
{
- HOST_WIDE_INT offadj, sztmp, msztmp;
- get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp);
+ poly_int64 offadj, sztmp, msztmp;
+ bool reverse;
+ get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp, &reverse);
offset1 -= offadj;
- get_ref_base_and_extent (base2, &offadj, &sztmp, &msztmp);
+ get_ref_base_and_extent (base2, &offadj, &sztmp, &msztmp, &reverse);
offset2 -= offadj;
- return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
+ return ranges_maybe_overlap_p (offset1, max_size1, offset2, max_size2);
}
/* If we have two type access paths B1.path1 and B2.path2 they may
if (TREE_CODE (ref1) == MEM_REF)
{
if (!integer_zerop (TREE_OPERAND (ref1, 1)))
- goto may_overlap;
+ return false;
ref1 = TREE_OPERAND (TREE_OPERAND (ref1, 0), 0);
}
if (TREE_CODE (ref2) == MEM_REF)
{
if (!integer_zerop (TREE_OPERAND (ref2, 1)))
- goto may_overlap;
+ return false;
ref2 = TREE_OPERAND (TREE_OPERAND (ref2, 0), 0);
}
- /* We must have the same base DECL. */
- gcc_assert (ref1 == ref2);
+ /* Bases must be either same or uncomparable. */
+ gcc_checking_assert (ref1 == ref2
+ || (DECL_P (ref1) && DECL_P (ref2)
+ && compare_base_decls (ref1, ref2) != 0));
/* Pop the stacks in parallel and examine the COMPONENT_REFs of the same
rank. This is sufficient because we start from the same DECL and you
do
{
if (component_refs1.is_empty ())
- goto may_overlap;
+ return false;
ref1 = component_refs1.pop ();
}
while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref1, 0))));
do
{
if (component_refs2.is_empty ())
- goto may_overlap;
+ return false;
ref2 = component_refs2.pop ();
}
while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref2, 0))));
/* Beware of BIT_FIELD_REF. */
if (TREE_CODE (ref1) != COMPONENT_REF
|| TREE_CODE (ref2) != COMPONENT_REF)
- goto may_overlap;
+ return false;
tree field1 = TREE_OPERAND (ref1, 1);
tree field2 = TREE_OPERAND (ref2, 1);
/* We cannot disambiguate fields in a union or qualified union. */
if (type1 != type2 || TREE_CODE (type1) != RECORD_TYPE)
- goto may_overlap;
+ return false;
- /* Different fields of the same record type cannot overlap.
- ??? Bitfields can overlap at RTL level so punt on them. */
if (field1 != field2)
{
- component_refs1.release ();
- component_refs2.release ();
- return !(DECL_BIT_FIELD (field1) && DECL_BIT_FIELD (field2));
+ /* A field and its representative need to be considered the
+ same. */
+ if (DECL_BIT_FIELD_REPRESENTATIVE (field1) == field2
+ || DECL_BIT_FIELD_REPRESENTATIVE (field2) == field1)
+ return false;
+ /* Different fields of the same record type cannot overlap.
+ ??? Bitfields can overlap at RTL level so punt on them. */
+ if (DECL_BIT_FIELD (field1) && DECL_BIT_FIELD (field2))
+ return false;
+ return true;
}
}
-may_overlap:
- component_refs1.release ();
- component_refs2.release ();
return false;
}
if (typex == typey)
{
/* We're left with accessing different fields of a structure,
- no possible overlap, unless they are both bitfields. */
+ no possible overlap. */
if (fieldx != fieldy)
- return !(DECL_BIT_FIELD (fieldx) && DECL_BIT_FIELD (fieldy));
+ {
+ /* A field and its representative need to be considered the
+ same. */
+ if (DECL_BIT_FIELD_REPRESENTATIVE (fieldx) == fieldy
+ || DECL_BIT_FIELD_REPRESENTATIVE (fieldy) == fieldx)
+ return false;
+ /* Different fields of the same record type cannot overlap.
+ ??? Bitfields can overlap at RTL level so punt on them. */
+ if (DECL_BIT_FIELD (fieldx) && DECL_BIT_FIELD (fieldy))
+ return false;
+ return true;
+ }
}
if (TYPE_UID (typex) < TYPE_UID (typey))
{
static bool
decl_refs_may_alias_p (tree ref1, tree base1,
- HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1,
+ poly_int64 offset1, poly_int64 max_size1,
tree ref2, tree base2,
- HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2)
+ poly_int64 offset2, poly_int64 max_size2)
{
gcc_checking_assert (DECL_P (base1) && DECL_P (base2));
/* If both references are based on different variables, they cannot alias. */
- if (base1 != base2)
+ if (compare_base_decls (base1, base2) == 0)
return false;
/* If both references are based on the same variable, they cannot alias if
the accesses do not overlap. */
- if (!ranges_overlap_p (offset1, max_size1, offset2, max_size2))
+ if (!ranges_maybe_overlap_p (offset1, max_size1, offset2, max_size2))
return false;
/* For components with variable position, the above test isn't sufficient,
static bool
indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED, tree base1,
- HOST_WIDE_INT offset1,
- HOST_WIDE_INT max_size1 ATTRIBUTE_UNUSED,
+ poly_int64 offset1, poly_int64 max_size1,
alias_set_type ref1_alias_set,
alias_set_type base1_alias_set,
tree ref2 ATTRIBUTE_UNUSED, tree base2,
- HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2,
+ poly_int64 offset2, poly_int64 max_size2,
alias_set_type ref2_alias_set,
alias_set_type base2_alias_set, bool tbaa_p)
{
tree ptr1;
tree ptrtype1, dbase2;
- HOST_WIDE_INT offset1p = offset1, offset2p = offset2;
- HOST_WIDE_INT doffset1, doffset2;
gcc_checking_assert ((TREE_CODE (base1) == MEM_REF
|| TREE_CODE (base1) == TARGET_MEM_REF)
&& DECL_P (base2));
ptr1 = TREE_OPERAND (base1, 0);
-
- /* The offset embedded in MEM_REFs can be negative. Bias them
- so that the resulting offset adjustment is positive. */
- offset_int moff = mem_ref_offset (base1);
- moff = wi::lshift (moff, LOG2_BITS_PER_UNIT);
- if (wi::neg_p (moff))
- offset2p += (-moff).to_short_addr ();
- else
- offset1p += moff.to_short_addr ();
+ poly_offset_int moff = mem_ref_offset (base1) << LOG2_BITS_PER_UNIT;
/* If only one reference is based on a variable, they cannot alias if
the pointer access is beyond the extent of the variable access.
??? IVOPTs creates bases that do not honor this restriction,
so do not apply this optimization for TARGET_MEM_REFs. */
if (TREE_CODE (base1) != TARGET_MEM_REF
- && !ranges_overlap_p (MAX (0, offset1p), -1, offset2p, max_size2))
+ && !ranges_maybe_overlap_p (offset1 + moff, -1, offset2, max_size2))
return false;
/* They also cannot alias if the pointer may not point to the decl. */
if (!ptr_deref_may_alias_decl_p (ptr1, base2))
ptrtype1 = TREE_TYPE (TREE_OPERAND (base1, 1));
/* If the alias set for a pointer access is zero all bets are off. */
- if (base1_alias_set == -1)
- base1_alias_set = get_deref_alias_set (ptrtype1);
if (base1_alias_set == 0)
return true;
- if (base2_alias_set == -1)
- base2_alias_set = get_alias_set (base2);
/* When we are trying to disambiguate an access with a pointer dereference
as base versus one with a decl as base we can use both the size
is bigger than the size of the decl we can't possibly access the
decl via that pointer. */
if (DECL_SIZE (base2) && COMPLETE_TYPE_P (TREE_TYPE (ptrtype1))
- && TREE_CODE (DECL_SIZE (base2)) == INTEGER_CST
- && TREE_CODE (TYPE_SIZE (TREE_TYPE (ptrtype1))) == INTEGER_CST
+ && poly_int_tree_p (DECL_SIZE (base2))
+ && poly_int_tree_p (TYPE_SIZE (TREE_TYPE (ptrtype1)))
/* ??? This in turn may run afoul when a decl of type T which is
a member of union type U is accessed through a pointer to
type U and sizeof T is smaller than sizeof U. */
&& TREE_CODE (TREE_TYPE (ptrtype1)) != UNION_TYPE
&& TREE_CODE (TREE_TYPE (ptrtype1)) != QUAL_UNION_TYPE
- && tree_int_cst_lt (DECL_SIZE (base2), TYPE_SIZE (TREE_TYPE (ptrtype1))))
+ && known_lt (wi::to_poly_widest (DECL_SIZE (base2)),
+ wi::to_poly_widest (TYPE_SIZE (TREE_TYPE (ptrtype1)))))
return false;
if (!ref2)
dbase2 = ref2;
while (handled_component_p (dbase2))
dbase2 = TREE_OPERAND (dbase2, 0);
- doffset1 = offset1;
- doffset2 = offset2;
+ poly_int64 doffset1 = offset1;
+ poly_offset_int doffset2 = offset2;
if (TREE_CODE (dbase2) == MEM_REF
|| TREE_CODE (dbase2) == TARGET_MEM_REF)
- {
- offset_int moff = mem_ref_offset (dbase2);
- moff = wi::lshift (moff, LOG2_BITS_PER_UNIT);
- if (wi::neg_p (moff))
- doffset1 -= (-moff).to_short_addr ();
- else
- doffset2 -= moff.to_short_addr ();
- }
+ doffset2 -= mem_ref_offset (dbase2) << LOG2_BITS_PER_UNIT;
/* If either reference is view-converted, give up now. */
if (same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) != 1
if ((TREE_CODE (base1) != TARGET_MEM_REF
|| (!TMR_INDEX (base1) && !TMR_INDEX2 (base1)))
&& same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (dbase2)) == 1)
- return ranges_overlap_p (doffset1, max_size1, doffset2, max_size2);
+ return ranges_maybe_overlap_p (doffset1, max_size1, doffset2, max_size2);
if (ref1 && ref2
&& nonoverlapping_component_refs_p (ref1, ref2))
static bool
indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED, tree base1,
- HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1,
+ poly_int64 offset1, poly_int64 max_size1,
alias_set_type ref1_alias_set,
alias_set_type base1_alias_set,
tree ref2 ATTRIBUTE_UNUSED, tree base2,
- HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2,
+ poly_int64 offset2, poly_int64 max_size2,
alias_set_type ref2_alias_set,
alias_set_type base2_alias_set, bool tbaa_p)
{
&& operand_equal_p (TMR_INDEX2 (base1),
TMR_INDEX2 (base2), 0))))))
{
- offset_int moff;
- /* The offset embedded in MEM_REFs can be negative. Bias them
- so that the resulting offset adjustment is positive. */
- moff = mem_ref_offset (base1);
- moff = wi::lshift (moff, LOG2_BITS_PER_UNIT);
- if (wi::neg_p (moff))
- offset2 += (-moff).to_short_addr ();
- else
- offset1 += moff.to_shwi ();
- moff = mem_ref_offset (base2);
- moff = wi::lshift (moff, LOG2_BITS_PER_UNIT);
- if (wi::neg_p (moff))
- offset1 += (-moff).to_short_addr ();
- else
- offset2 += moff.to_short_addr ();
- return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
+ poly_offset_int moff1 = mem_ref_offset (base1) << LOG2_BITS_PER_UNIT;
+ poly_offset_int moff2 = mem_ref_offset (base2) << LOG2_BITS_PER_UNIT;
+ return ranges_maybe_overlap_p (offset1 + moff1, max_size1,
+ offset2 + moff2, max_size2);
}
if (!ptr_derefs_may_alias_p (ptr1, ptr2))
return false;
ptrtype2 = TREE_TYPE (TREE_OPERAND (base2, 1));
/* If the alias set for a pointer access is zero all bets are off. */
- if (base1_alias_set == -1)
- base1_alias_set = get_deref_alias_set (ptrtype1);
- if (base1_alias_set == 0)
- return true;
- if (base2_alias_set == -1)
- base2_alias_set = get_deref_alias_set (ptrtype2);
- if (base2_alias_set == 0)
+ if (base1_alias_set == 0
+ || base2_alias_set == 0)
return true;
/* If both references are through the same type, they do not alias
&& same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1
&& same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) == 1
&& same_type_for_tbaa (TREE_TYPE (ptrtype1),
- TREE_TYPE (ptrtype2)) == 1)
- return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
+ TREE_TYPE (ptrtype2)) == 1
+ /* But avoid treating arrays as "objects", instead assume they
+ can overlap by an exact multiple of their element size. */
+ && TREE_CODE (TREE_TYPE (ptrtype1)) != ARRAY_TYPE)
+ return ranges_maybe_overlap_p (offset1, max_size1, offset2, max_size2);
/* Do type-based disambiguation. */
if (base1_alias_set != base2_alias_set
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 max_size1 = -1, max_size2 = -1;
+ poly_int64 offset1 = 0, offset2 = 0;
+ poly_int64 max_size1 = -1, max_size2 = -1;
bool var1_p, var2_p, ind1_p, ind2_p;
gcc_checking_assert ((!ref1->ref
ao_ref_alias_set (ref2)))
return false;
+ /* If the reference is based on a pointer that points to memory
+ that may not be written to then the other reference cannot possibly
+ clobber it. */
+ if ((TREE_CODE (TREE_OPERAND (base2, 0)) == SSA_NAME
+ && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base2, 0)))
+ || (ind1_p
+ && TREE_CODE (TREE_OPERAND (base1, 0)) == SSA_NAME
+ && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base1, 0))))
+ return false;
+
/* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */
if (var1_p && ind2_p)
return indirect_ref_may_alias_decl_p (ref2->ref, base2,
offset2, max_size2,
- ao_ref_alias_set (ref2), -1,
+ ao_ref_alias_set (ref2),
+ ao_ref_base_alias_set (ref2),
ref1->ref, base1,
offset1, max_size1,
ao_ref_alias_set (ref1),
else if (ind1_p && ind2_p)
return indirect_refs_may_alias_p (ref1->ref, base1,
offset1, max_size1,
- ao_ref_alias_set (ref1), -1,
+ ao_ref_alias_set (ref1),
+ ao_ref_base_alias_set (ref1),
ref2->ref, base2,
offset2, max_size2,
- ao_ref_alias_set (ref2), -1,
+ ao_ref_alias_set (ref2),
+ ao_ref_base_alias_set (ref2),
tbaa_p);
- /* We really do not want to end up here, but returning true is safe. */
-#ifdef ENABLE_CHECKING
gcc_unreachable ();
-#else
- return true;
-#endif
}
static bool
-refs_may_alias_p (tree ref1, ao_ref *ref2)
+refs_may_alias_p (tree ref1, ao_ref *ref2, bool tbaa_p)
{
ao_ref r1;
ao_ref_init (&r1, ref1);
- return refs_may_alias_p_1 (&r1, ref2, true);
+ return refs_may_alias_p_1 (&r1, ref2, tbaa_p);
}
bool
-refs_may_alias_p (tree ref1, tree ref2)
+refs_may_alias_p (tree ref1, tree ref2, bool tbaa_p)
{
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);
+ res = refs_may_alias_p_1 (&r1, &r2, tbaa_p);
if (res)
++alias_stats.refs_may_alias_p_may_alias;
else
otherwise return false. */
static bool
-ref_maybe_used_by_call_p_1 (gcall *call, ao_ref *ref)
+ref_maybe_used_by_call_p_1 (gcall *call, ao_ref *ref, bool tbaa_p)
{
tree base, callee;
unsigned i;
case BUILT_IN_POSIX_MEMALIGN:
case BUILT_IN_ALIGNED_ALLOC:
case BUILT_IN_CALLOC:
- case BUILT_IN_ALLOCA:
- case BUILT_IN_ALLOCA_WITH_ALIGN:
+ CASE_BUILT_IN_ALLOCA:
case BUILT_IN_STACK_SAVE:
case BUILT_IN_STACK_RESTORE:
case BUILT_IN_MEMSET:
/* Check if base is a global static variable that is not read
by the function. */
- if (callee != NULL_TREE
- && TREE_CODE (base) == VAR_DECL
- && TREE_STATIC (base))
+ if (callee != NULL_TREE && VAR_P (base) && TREE_STATIC (base))
{
struct cgraph_node *node = cgraph_node::get (callee);
bitmap not_read;
IL and remove this check instead. */
if (node
&& (not_read = ipa_reference_get_not_read_global (node))
- && bitmap_bit_p (not_read, DECL_UID (base)))
+ && bitmap_bit_p (not_read, ipa_reference_var_uid (base)))
goto process_args;
}
{
ao_ref r;
ao_ref_init (&r, op);
- if (refs_may_alias_p_1 (&r, ref, true))
+ if (refs_may_alias_p_1 (&r, ref, tbaa_p))
return true;
}
}
}
static bool
-ref_maybe_used_by_call_p (gcall *call, ao_ref *ref)
+ref_maybe_used_by_call_p (gcall *call, ao_ref *ref, bool tbaa_p)
{
bool res;
- res = ref_maybe_used_by_call_p_1 (call, ref);
+ res = ref_maybe_used_by_call_p_1 (call, ref, tbaa_p);
if (res)
++alias_stats.ref_maybe_used_by_call_p_may_alias;
else
true, otherwise return false. */
bool
-ref_maybe_used_by_stmt_p (gimple *stmt, ao_ref *ref)
+ref_maybe_used_by_stmt_p (gimple *stmt, ao_ref *ref, bool tbaa_p)
{
if (is_gimple_assign (stmt))
{
|| gimple_assign_rhs_code (stmt) == CONSTRUCTOR)
return false;
- return refs_may_alias_p (rhs, ref);
+ return refs_may_alias_p (rhs, ref, tbaa_p);
}
else if (is_gimple_call (stmt))
- return ref_maybe_used_by_call_p (as_a <gcall *> (stmt), ref);
+ return ref_maybe_used_by_call_p (as_a <gcall *> (stmt), ref, tbaa_p);
else if (greturn *return_stmt = dyn_cast <greturn *> (stmt))
{
tree retval = gimple_return_retval (return_stmt);
if (retval
&& TREE_CODE (retval) != SSA_NAME
&& !is_gimple_min_invariant (retval)
- && refs_may_alias_p (retval, ref))
+ && refs_may_alias_p (retval, ref, tbaa_p))
return true;
/* If ref escapes the function then the return acts as a use. */
tree base = ao_ref_base (ref);
}
bool
-ref_maybe_used_by_stmt_p (gimple *stmt, tree ref)
+ref_maybe_used_by_stmt_p (gimple *stmt, tree ref, bool tbaa_p)
{
ao_ref r;
ao_ref_init (&r, ref);
- return ref_maybe_used_by_stmt_p (stmt, &r);
+ return ref_maybe_used_by_stmt_p (stmt, &r, tbaa_p);
}
/* If the call in statement CALL may clobber the memory reference REF
case IFN_UBSAN_BOUNDS:
case IFN_UBSAN_VPTR:
case IFN_UBSAN_OBJECT_SIZE:
+ case IFN_UBSAN_PTR:
case IFN_ASAN_CHECK:
return false;
default:
|| !is_global_var (base)))
return false;
+ /* If the reference is based on a pointer that points to memory
+ that may not be written to then the call cannot possibly clobber it. */
+ if ((TREE_CODE (base) == MEM_REF
+ || TREE_CODE (base) == TARGET_MEM_REF)
+ && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME
+ && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base, 0)))
+ return false;
+
callee = gimple_call_fndecl (call);
/* Handle those builtin functions explicitly that do not act as
return true;
return false;
case BUILT_IN_STACK_SAVE:
- case BUILT_IN_ALLOCA:
- case BUILT_IN_ALLOCA_WITH_ALIGN:
+ CASE_BUILT_IN_ALLOCA:
case BUILT_IN_ASSUME_ALIGNED:
return false;
/* But posix_memalign stores a pointer into the memory pointed to
/* Check if base is a global static variable that is not written
by the function. */
- if (callee != NULL_TREE
- && TREE_CODE (base) == VAR_DECL
- && TREE_STATIC (base))
+ if (callee != NULL_TREE && VAR_P (base) && TREE_STATIC (base))
{
struct cgraph_node *node = cgraph_node::get (callee);
bitmap not_written;
if (node
&& (not_written = ipa_reference_get_not_written_global (node))
- && bitmap_bit_p (not_written, DECL_UID (base)))
+ && bitmap_bit_p (not_written, ipa_reference_var_uid (base)))
return false;
}
otherwise return false. */
bool
-stmt_may_clobber_ref_p_1 (gimple *stmt, ao_ref *ref)
+stmt_may_clobber_ref_p_1 (gimple *stmt, ao_ref *ref, bool tbaa_p)
{
if (is_gimple_call (stmt))
{
{
ao_ref r;
ao_ref_init (&r, lhs);
- if (refs_may_alias_p_1 (ref, &r, true))
+ if (refs_may_alias_p_1 (ref, &r, tbaa_p))
return true;
}
{
ao_ref r;
ao_ref_init (&r, lhs);
- return refs_may_alias_p_1 (ref, &r, true);
+ return refs_may_alias_p_1 (ref, &r, tbaa_p);
}
}
else if (gimple_code (stmt) == GIMPLE_ASM)
}
bool
-stmt_may_clobber_ref_p (gimple *stmt, tree ref)
+stmt_may_clobber_ref_p (gimple *stmt, tree ref, bool tbaa_p)
{
ao_ref r;
ao_ref_init (&r, ref);
- return stmt_may_clobber_ref_p_1 (stmt, &r);
+ return stmt_may_clobber_ref_p_1 (stmt, &r, tbaa_p);
+}
+
+/* Return true if store1 and store2 described by corresponding tuples
+ <BASE, OFFSET, SIZE, MAX_SIZE> have the same size and store to the same
+ address. */
+
+static bool
+same_addr_size_stores_p (tree base1, poly_int64 offset1, poly_int64 size1,
+ poly_int64 max_size1,
+ tree base2, poly_int64 offset2, poly_int64 size2,
+ poly_int64 max_size2)
+{
+ /* Offsets need to be 0. */
+ if (maybe_ne (offset1, 0)
+ || maybe_ne (offset2, 0))
+ return false;
+
+ bool base1_obj_p = SSA_VAR_P (base1);
+ bool base2_obj_p = SSA_VAR_P (base2);
+
+ /* We need one object. */
+ if (base1_obj_p == base2_obj_p)
+ return false;
+ tree obj = base1_obj_p ? base1 : base2;
+
+ /* And we need one MEM_REF. */
+ bool base1_memref_p = TREE_CODE (base1) == MEM_REF;
+ bool base2_memref_p = TREE_CODE (base2) == MEM_REF;
+ if (base1_memref_p == base2_memref_p)
+ return false;
+ tree memref = base1_memref_p ? base1 : base2;
+
+ /* Sizes need to be valid. */
+ if (!known_size_p (max_size1)
+ || !known_size_p (max_size2)
+ || !known_size_p (size1)
+ || !known_size_p (size2))
+ return false;
+
+ /* Max_size needs to match size. */
+ if (maybe_ne (max_size1, size1)
+ || maybe_ne (max_size2, size2))
+ return false;
+
+ /* Sizes need to match. */
+ if (maybe_ne (size1, size2))
+ return false;
+
+
+ /* Check that memref is a store to pointer with singleton points-to info. */
+ if (!integer_zerop (TREE_OPERAND (memref, 1)))
+ return false;
+ tree ptr = TREE_OPERAND (memref, 0);
+ if (TREE_CODE (ptr) != SSA_NAME)
+ return false;
+ struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
+ unsigned int pt_uid;
+ if (pi == NULL
+ || !pt_solution_singleton_or_null_p (&pi->pt, &pt_uid))
+ return false;
+
+ /* Be conservative with non-call exceptions when the address might
+ be NULL. */
+ if (cfun->can_throw_non_call_exceptions && pi->pt.null)
+ return false;
+
+ /* Check that ptr points relative to obj. */
+ unsigned int obj_uid = DECL_PT_UID (obj);
+ if (obj_uid != pt_uid)
+ return false;
+
+ /* Check that the object size is the same as the store size. That ensures us
+ that ptr points to the start of obj. */
+ return (DECL_SIZE (obj)
+ && poly_int_tree_p (DECL_SIZE (obj))
+ && known_eq (wi::to_poly_offset (DECL_SIZE (obj)), size1));
}
/* If STMT kills the memory reference REF return true, otherwise
??? We only need to care about the RHS throwing. For aggregate
assignments or similar calls and non-call exceptions the LHS
might throw as well. */
- && !stmt_can_throw_internal (stmt))
+ && !stmt_can_throw_internal (cfun, stmt))
{
tree lhs = gimple_get_lhs (stmt);
/* If LHS is literally a base of the access we are done. */
if (ref->ref)
{
tree base = ref->ref;
+ tree innermost_dropped_array_ref = NULL_TREE;
if (handled_component_p (base))
{
tree saved_lhs0 = NULL_TREE;
TREE_OPERAND (base, 0) = saved_base0;
if (res)
break;
+ /* Remember if we drop an array-ref that we need to
+ double-check not being at struct end. */
+ if (TREE_CODE (base) == ARRAY_REF
+ || TREE_CODE (base) == ARRAY_RANGE_REF)
+ innermost_dropped_array_ref = base;
/* Otherwise drop handled components of the access. */
base = saved_base0;
}
TREE_OPERAND (lhs, 0) = saved_lhs0;
}
/* Finally check if the lhs has the same address and size as the
- base candidate of the access. */
- if (lhs == base
- || (((TYPE_SIZE (TREE_TYPE (lhs))
- == TYPE_SIZE (TREE_TYPE (base)))
- || (TYPE_SIZE (TREE_TYPE (lhs))
- && TYPE_SIZE (TREE_TYPE (base))
- && operand_equal_p (TYPE_SIZE (TREE_TYPE (lhs)),
- TYPE_SIZE (TREE_TYPE (base)), 0)))
- && operand_equal_p (lhs, base, OEP_ADDRESS_OF)))
+ base candidate of the access. Watch out if we have dropped
+ an array-ref that was at struct end, this means ref->ref may
+ be outside of the TYPE_SIZE of its base. */
+ if ((! innermost_dropped_array_ref
+ || ! array_at_struct_end_p (innermost_dropped_array_ref))
+ && (lhs == base
+ || (((TYPE_SIZE (TREE_TYPE (lhs))
+ == TYPE_SIZE (TREE_TYPE (base)))
+ || (TYPE_SIZE (TREE_TYPE (lhs))
+ && TYPE_SIZE (TREE_TYPE (base))
+ && operand_equal_p (TYPE_SIZE (TREE_TYPE (lhs)),
+ TYPE_SIZE (TREE_TYPE (base)),
+ 0)))
+ && operand_equal_p (lhs, base,
+ OEP_ADDRESS_OF
+ | OEP_MATCH_SIDE_EFFECTS))))
return true;
}
handling constant offset and size. */
/* For a must-alias check we need to be able to constrain
the access properly. */
- if (ref->max_size == -1)
+ if (!ref->max_size_known_p ())
return false;
- HOST_WIDE_INT size, offset, max_size, ref_offset = ref->offset;
- tree base = get_ref_base_and_extent (lhs, &offset, &size, &max_size);
+ poly_int64 size, offset, max_size, ref_offset = ref->offset;
+ bool reverse;
+ tree base = get_ref_base_and_extent (lhs, &offset, &size, &max_size,
+ &reverse);
/* We can get MEM[symbol: sZ, index: D.8862_1] here,
so base == ref->base does not always hold. */
if (base != ref->base)
{
+ /* Try using points-to info. */
+ if (same_addr_size_stores_p (base, offset, size, max_size, ref->base,
+ ref->offset, ref->size, ref->max_size))
+ return true;
+
/* If both base and ref->base are MEM_REFs, only compare the
first operand, and if the second operand isn't equal constant,
try to add the offsets into offset and ref_offset. */
if (!tree_int_cst_equal (TREE_OPERAND (base, 1),
TREE_OPERAND (ref->base, 1)))
{
- offset_int off1 = mem_ref_offset (base);
- off1 = wi::lshift (off1, LOG2_BITS_PER_UNIT);
+ poly_offset_int off1 = mem_ref_offset (base);
+ off1 <<= LOG2_BITS_PER_UNIT;
off1 += offset;
- offset_int off2 = mem_ref_offset (ref->base);
- off2 = wi::lshift (off2, LOG2_BITS_PER_UNIT);
+ poly_offset_int off2 = mem_ref_offset (ref->base);
+ off2 <<= LOG2_BITS_PER_UNIT;
off2 += ref_offset;
- if (wi::fits_shwi_p (off1) && wi::fits_shwi_p (off2))
- {
- offset = off1.to_shwi ();
- ref_offset = off2.to_shwi ();
- }
- else
+ if (!off1.to_shwi (&offset) || !off2.to_shwi (&ref_offset))
size = -1;
}
}
}
/* For a must-alias check we need to be able to constrain
the access properly. */
- if (size != -1 && size == max_size)
- {
- if (offset <= ref_offset
- && offset + size >= ref_offset + ref->max_size)
- return true;
- }
+ if (known_eq (size, max_size)
+ && known_subrange_p (ref_offset, ref->max_size, offset, size))
+ return true;
}
if (is_gimple_call (stmt))
case BUILT_IN_MEMPCPY_CHK:
case BUILT_IN_MEMMOVE_CHK:
case BUILT_IN_MEMSET_CHK:
+ case BUILT_IN_STRNCPY:
+ case BUILT_IN_STPNCPY:
{
/* For a must-alias check we need to be able to constrain
the access properly. */
- if (ref->max_size == -1)
+ if (!ref->max_size_known_p ())
return false;
tree dest = gimple_call_arg (stmt, 0);
tree len = gimple_call_arg (stmt, 2);
- if (!tree_fits_shwi_p (len))
+ if (!poly_int_tree_p (len))
return false;
tree rbase = ref->base;
- offset_int roffset = ref->offset;
+ poly_offset_int roffset = ref->offset;
ao_ref dref;
ao_ref_init_from_ptr_and_size (&dref, dest, len);
tree base = ao_ref_base (&dref);
- offset_int offset = dref.offset;
- if (!base || dref.size == -1)
+ poly_offset_int offset = dref.offset;
+ if (!base || !known_size_p (dref.size))
return false;
if (TREE_CODE (base) == MEM_REF)
{
if (TREE_CODE (rbase) != MEM_REF)
return false;
// Compare pointers.
- offset += wi::lshift (mem_ref_offset (base),
- LOG2_BITS_PER_UNIT);
- roffset += wi::lshift (mem_ref_offset (rbase),
- LOG2_BITS_PER_UNIT);
+ offset += mem_ref_offset (base) << LOG2_BITS_PER_UNIT;
+ roffset += mem_ref_offset (rbase) << LOG2_BITS_PER_UNIT;
base = TREE_OPERAND (base, 0);
rbase = TREE_OPERAND (rbase, 0);
}
if (base == rbase
- && wi::les_p (offset, roffset)
- && wi::les_p (roffset + ref->max_size,
- offset + wi::lshift (wi::to_offset (len),
- LOG2_BITS_PER_UNIT)))
+ && known_subrange_p (roffset, ref->max_size, offset,
+ wi::to_poly_offset (len)
+ << LOG2_BITS_PER_UNIT))
return true;
break;
}
return true;
}
-/* For two PHI arguments ARG0 and ARG1 try to skip non-aliasing code
- until we hit the phi argument definition that dominates the other one.
- Return that, or NULL_TREE if there is no such definition. */
-
-static tree
-get_continuation_for_phi_1 (gimple *phi, tree arg0, tree arg1,
- ao_ref *ref, unsigned int *cnt,
- bitmap *visited, bool abort_on_visited,
- void *(*translate)(ao_ref *, tree, void *, bool *),
- void *data)
-{
- gimple *def0 = SSA_NAME_DEF_STMT (arg0);
- gimple *def1 = SSA_NAME_DEF_STMT (arg1);
- tree common_vuse;
-
- if (arg0 == arg1)
- return arg0;
- else if (gimple_nop_p (def0)
- || (!gimple_nop_p (def1)
- && dominated_by_p (CDI_DOMINATORS,
- gimple_bb (def1), gimple_bb (def0))))
- {
- if (maybe_skip_until (phi, arg0, ref, arg1, cnt,
- visited, abort_on_visited, translate, data))
- return arg0;
- }
- else if (gimple_nop_p (def1)
- || dominated_by_p (CDI_DOMINATORS,
- gimple_bb (def0), gimple_bb (def1)))
- {
- if (maybe_skip_until (phi, arg1, ref, arg0, cnt,
- visited, abort_on_visited, translate, data))
- 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))
- {
- bool disambiguate_only = true;
- *cnt += 2;
- if ((!stmt_may_clobber_ref_p_1 (def0, ref)
- || (translate
- && (*translate) (ref, arg0, data, &disambiguate_only) == NULL))
- && (!stmt_may_clobber_ref_p_1 (def1, ref)
- || (translate
- && (*translate) (ref, arg1, data, &disambiguate_only) == NULL)))
- return common_vuse;
- }
-
- return NULL_TREE;
-}
-
/* Starting from a PHI node for the virtual operand of the memory reference
REF find a continuation virtual operand that allows to continue walking
/* For two or more arguments try to pairwise skip non-aliasing code
until we hit the phi argument definition that dominates the other one. */
- else if (nargs >= 2)
+ basic_block phi_bb = gimple_bb (phi);
+ tree arg0, arg1;
+ unsigned i;
+
+ /* Find a candidate for the virtual operand which definition
+ dominates those of all others. */
+ /* First look if any of the args themselves satisfy this. */
+ for (i = 0; i < nargs; ++i)
{
- tree arg0, arg1;
- unsigned i;
-
- /* Find a candidate for the virtual operand which definition
- dominates those of all others. */
- arg0 = PHI_ARG_DEF (phi, 0);
- if (!SSA_NAME_IS_DEFAULT_DEF (arg0))
- for (i = 1; i < nargs; ++i)
+ arg0 = PHI_ARG_DEF (phi, i);
+ if (SSA_NAME_IS_DEFAULT_DEF (arg0))
+ break;
+ basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (arg0));
+ if (def_bb != phi_bb
+ && dominated_by_p (CDI_DOMINATORS, phi_bb, def_bb))
+ break;
+ arg0 = NULL_TREE;
+ }
+ /* If not, look if we can reach such candidate by walking defs
+ of a PHI arg without crossing other PHIs. */
+ if (! arg0)
+ for (i = 0; i < nargs; ++i)
+ {
+ arg0 = PHI_ARG_DEF (phi, i);
+ gimple *def = SSA_NAME_DEF_STMT (arg0);
+ /* Backedges can't work. */
+ if (dominated_by_p (CDI_DOMINATORS,
+ gimple_bb (def), phi_bb))
+ continue;
+ /* See below. */
+ if (gimple_code (def) == GIMPLE_PHI)
+ continue;
+ while (! dominated_by_p (CDI_DOMINATORS,
+ phi_bb, gimple_bb (def)))
{
- arg1 = PHI_ARG_DEF (phi, i);
- if (SSA_NAME_IS_DEFAULT_DEF (arg1))
+ arg0 = gimple_vuse (def);
+ if (SSA_NAME_IS_DEFAULT_DEF (arg0))
+ break;
+ def = SSA_NAME_DEF_STMT (arg0);
+ if (gimple_code (def) == GIMPLE_PHI)
{
- arg0 = arg1;
- break;
+ /* Do not try to look through arbitrarily complicated
+ CFGs. For those looking for the first VUSE starting
+ from the end of the immediate dominator of phi_bb
+ is likely faster. */
+ arg0 = NULL_TREE;
+ goto next;
}
- if (dominated_by_p (CDI_DOMINATORS,
- gimple_bb (SSA_NAME_DEF_STMT (arg0)),
- gimple_bb (SSA_NAME_DEF_STMT (arg1))))
- arg0 = arg1;
}
+ break;
+next:;
+ }
+ if (! arg0)
+ return NULL_TREE;
- /* Then pairwise reduce against the found candidate. */
- for (i = 0; i < nargs; ++i)
- {
- arg1 = PHI_ARG_DEF (phi, i);
- arg0 = get_continuation_for_phi_1 (phi, arg0, arg1, ref,
- cnt, visited, abort_on_visited,
- translate, data);
- if (!arg0)
- return NULL_TREE;
- }
-
- return arg0;
+ /* Then check against the found candidate. */
+ for (i = 0; i < nargs; ++i)
+ {
+ arg1 = PHI_ARG_DEF (phi, i);
+ if (arg1 == arg0)
+ ;
+ else if (! maybe_skip_until (phi, arg0, ref, arg1, cnt, visited,
+ abort_on_visited,
+ /* Do not translate when walking over
+ backedges. */
+ dominated_by_p
+ (CDI_DOMINATORS,
+ gimple_bb (SSA_NAME_DEF_STMT (arg1)),
+ phi_bb)
+ ? NULL : translate, data))
+ return NULL_TREE;
}
- return NULL_TREE;
+ return arg0;
}
/* Based on the memory reference REF and its virtual use VUSE call
break;
if (valueize)
- vuse = valueize (vuse);
+ {
+ vuse = valueize (vuse);
+ if (!vuse)
+ {
+ res = NULL;
+ break;
+ }
+ }
def_stmt = SSA_NAME_DEF_STMT (vuse);
if (gimple_nop_p (def_stmt))
break;
PHI argument (but only one walk continues on merge points), the
return value is true if any of the walks was successful.
- The function returns the number of statements walked. */
+ The function returns the number of statements walked or -1 if
+ LIMIT stmts were walked and the walk was aborted at this point.
+ If LIMIT is zero the walk is not aborted. */
-static unsigned int
+static int
walk_aliased_vdefs_1 (ao_ref *ref, tree vdef,
bool (*walker)(ao_ref *, tree, void *), void *data,
bitmap *visited, unsigned int cnt,
- bool *function_entry_reached)
+ bool *function_entry_reached, unsigned limit)
{
do
{
if (!*visited)
*visited = BITMAP_ALLOC (NULL);
for (i = 0; i < gimple_phi_num_args (def_stmt); ++i)
- cnt += walk_aliased_vdefs_1 (ref, gimple_phi_arg_def (def_stmt, i),
- walker, data, visited, 0,
- function_entry_reached);
+ {
+ int res = walk_aliased_vdefs_1 (ref,
+ gimple_phi_arg_def (def_stmt, i),
+ walker, data, visited, cnt,
+ function_entry_reached, limit);
+ if (res == -1)
+ return -1;
+ cnt = res;
+ }
return cnt;
}
/* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
cnt++;
+ if (cnt == limit)
+ return -1;
if ((!ref
|| stmt_may_clobber_ref_p_1 (def_stmt, ref))
&& (*walker) (ref, vdef, data))
while (1);
}
-unsigned int
+int
walk_aliased_vdefs (ao_ref *ref, tree vdef,
bool (*walker)(ao_ref *, tree, void *), void *data,
bitmap *visited,
- bool *function_entry_reached)
+ bool *function_entry_reached, unsigned int limit)
{
bitmap local_visited = NULL;
- unsigned int ret;
+ int ret;
timevar_push (TV_ALIAS_STMT_WALK);
ret = walk_aliased_vdefs_1 (ref, vdef, walker, data,
visited ? visited : &local_visited, 0,
- function_entry_reached);
+ function_entry_reached, limit);
if (local_visited)
BITMAP_FREE (local_visited);
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