/* Support routines for Value Range Propagation (VRP).
- Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+ Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
Contributed by Diego Novillo <dnovillo@redhat.com>.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
+the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to
-the Free Software Foundation, 51 Franklin Street, Fifth Floor,
-Boston, MA 02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "tree-dump.h"
#include "timevar.h"
#include "diagnostic.h"
+#include "toplev.h"
+#include "intl.h"
#include "cfgloop.h"
#include "tree-scalar-evolution.h"
#include "tree-ssa-propagate.h"
/* Local functions. */
static int compare_values (tree val1, tree val2);
+static int compare_values_warnv (tree val1, tree val2, bool *);
+static void vrp_meet (value_range_t *, value_range_t *);
+static tree vrp_evaluate_conditional_warnv (tree, bool, bool *);
/* Location information for ASSERT_EXPRs. Each instance of this
structure describes an ASSERT_EXPR for an SSA name. Since a single
of values that SSA name N_I may take. */
static value_range_t **vr_value;
+/* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the
+ number of executable edges we saw the last time we visited the
+ node. */
+static int *vr_phi_edge_counts;
+
+
+/* Return whether TYPE should use an overflow infinity distinct from
+ TYPE_{MIN,MAX}_VALUE. We use an overflow infinity value to
+ represent a signed overflow during VRP computations. An infinity
+ is distinct from a half-range, which will go from some number to
+ TYPE_{MIN,MAX}_VALUE. */
+
+static inline bool
+needs_overflow_infinity (const_tree type)
+{
+ return INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type);
+}
+
+/* Return whether TYPE can support our overflow infinity
+ representation: we use the TREE_OVERFLOW flag, which only exists
+ for constants. If TYPE doesn't support this, we don't optimize
+ cases which would require signed overflow--we drop them to
+ VARYING. */
+
+static inline bool
+supports_overflow_infinity (const_tree type)
+{
+#ifdef ENABLE_CHECKING
+ gcc_assert (needs_overflow_infinity (type));
+#endif
+ return (TYPE_MIN_VALUE (type) != NULL_TREE
+ && CONSTANT_CLASS_P (TYPE_MIN_VALUE (type))
+ && TYPE_MAX_VALUE (type) != NULL_TREE
+ && CONSTANT_CLASS_P (TYPE_MAX_VALUE (type)));
+}
+
+/* VAL is the maximum or minimum value of a type. Return a
+ corresponding overflow infinity. */
+
+static inline tree
+make_overflow_infinity (tree val)
+{
+#ifdef ENABLE_CHECKING
+ gcc_assert (val != NULL_TREE && CONSTANT_CLASS_P (val));
+#endif
+ val = copy_node (val);
+ TREE_OVERFLOW (val) = 1;
+ return val;
+}
+
+/* Return a negative overflow infinity for TYPE. */
+
+static inline tree
+negative_overflow_infinity (tree type)
+{
+#ifdef ENABLE_CHECKING
+ gcc_assert (supports_overflow_infinity (type));
+#endif
+ return make_overflow_infinity (TYPE_MIN_VALUE (type));
+}
+
+/* Return a positive overflow infinity for TYPE. */
+
+static inline tree
+positive_overflow_infinity (tree type)
+{
+#ifdef ENABLE_CHECKING
+ gcc_assert (supports_overflow_infinity (type));
+#endif
+ return make_overflow_infinity (TYPE_MAX_VALUE (type));
+}
+
+/* Return whether VAL is a negative overflow infinity. */
+
+static inline bool
+is_negative_overflow_infinity (const_tree val)
+{
+ return (needs_overflow_infinity (TREE_TYPE (val))
+ && CONSTANT_CLASS_P (val)
+ && TREE_OVERFLOW (val)
+ && operand_equal_p (val, TYPE_MIN_VALUE (TREE_TYPE (val)), 0));
+}
+
+/* Return whether VAL is a positive overflow infinity. */
+
+static inline bool
+is_positive_overflow_infinity (const_tree val)
+{
+ return (needs_overflow_infinity (TREE_TYPE (val))
+ && CONSTANT_CLASS_P (val)
+ && TREE_OVERFLOW (val)
+ && operand_equal_p (val, TYPE_MAX_VALUE (TREE_TYPE (val)), 0));
+}
+
+/* Return whether VAL is a positive or negative overflow infinity. */
+
+static inline bool
+is_overflow_infinity (const_tree val)
+{
+ return (needs_overflow_infinity (TREE_TYPE (val))
+ && CONSTANT_CLASS_P (val)
+ && TREE_OVERFLOW (val)
+ && (operand_equal_p (val, TYPE_MAX_VALUE (TREE_TYPE (val)), 0)
+ || operand_equal_p (val, TYPE_MIN_VALUE (TREE_TYPE (val)), 0)));
+}
+
+/* If VAL is now an overflow infinity, return VAL. Otherwise, return
+ the same value with TREE_OVERFLOW clear. This can be used to avoid
+ confusing a regular value with an overflow value. */
+
+static inline tree
+avoid_overflow_infinity (tree val)
+{
+ if (!is_overflow_infinity (val))
+ return val;
+
+ if (operand_equal_p (val, TYPE_MAX_VALUE (TREE_TYPE (val)), 0))
+ return TYPE_MAX_VALUE (TREE_TYPE (val));
+ else
+ {
+#ifdef ENABLE_CHECKING
+ gcc_assert (operand_equal_p (val, TYPE_MIN_VALUE (TREE_TYPE (val)), 0));
+#endif
+ return TYPE_MIN_VALUE (TREE_TYPE (val));
+ }
+}
+
+
+/* Return whether VAL is equal to the maximum value of its type. This
+ will be true for a positive overflow infinity. We can't do a
+ simple equality comparison with TYPE_MAX_VALUE because C typedefs
+ and Ada subtypes can produce types whose TYPE_MAX_VALUE is not ==
+ to the integer constant with the same value in the type. */
+
+static inline bool
+vrp_val_is_max (const_tree val)
+{
+ tree type_max = TYPE_MAX_VALUE (TREE_TYPE (val));
+
+ return (val == type_max
+ || (type_max != NULL_TREE
+ && operand_equal_p (val, type_max, 0)));
+}
+
+/* Return whether VAL is equal to the minimum value of its type. This
+ will be true for a negative overflow infinity. */
+
+static inline bool
+vrp_val_is_min (const_tree val)
+{
+ tree type_min = TYPE_MIN_VALUE (TREE_TYPE (val));
+
+ return (val == type_min
+ || (type_min != NULL_TREE
+ && operand_equal_p (val, type_min, 0)));
+}
+
/* Return true if ARG is marked with the nonnull attribute in the
current function signature. */
static bool
-nonnull_arg_p (tree arg)
+nonnull_arg_p (const_tree arg)
{
tree t, attrs, fntype;
unsigned HOST_WIDE_INT arg_num;
gcc_assert (TREE_CODE (arg) == PARM_DECL && POINTER_TYPE_P (TREE_TYPE (arg)));
+ /* The static chain decl is always non null. */
+ if (arg == cfun->static_chain_decl)
+ return true;
+
fntype = TREE_TYPE (current_function_decl);
attrs = lookup_attribute ("nonnull", TYPE_ATTRIBUTES (fntype));
gcc_assert (min && max);
if (INTEGRAL_TYPE_P (TREE_TYPE (min)) && t == VR_ANTI_RANGE)
- gcc_assert (min != TYPE_MIN_VALUE (TREE_TYPE (min))
- || max != TYPE_MAX_VALUE (TREE_TYPE (max)));
+ gcc_assert (!vrp_val_is_min (min) || !vrp_val_is_max (max));
cmp = compare_values (min, max);
gcc_assert (cmp == 0 || cmp == -1 || cmp == -2);
+
+ if (needs_overflow_infinity (TREE_TYPE (min)))
+ gcc_assert (!is_overflow_infinity (min)
+ || !is_overflow_infinity (max));
}
if (t == VR_UNDEFINED || t == VR_VARYING)
/* Since updating the equivalence set involves deep copying the
bitmaps, only do it if absolutely necessary. */
- if (vr->equiv == NULL)
+ if (vr->equiv == NULL
+ && equiv != NULL)
vr->equiv = BITMAP_ALLOC (NULL);
if (equiv != vr->equiv)
set_value_range (to, from->type, from->min, from->max, from->equiv);
}
-/* Set value range VR to a non-negative range of type TYPE. */
+
+/* Set value range VR to VR_VARYING. */
static inline void
-set_value_range_to_nonnegative (value_range_t *vr, tree type)
+set_value_range_to_varying (value_range_t *vr)
{
- tree zero = build_int_cst (type, 0);
- set_value_range (vr, VR_RANGE, zero, TYPE_MAX_VALUE (type), vr->equiv);
+ vr->type = VR_VARYING;
+ vr->min = vr->max = NULL_TREE;
+ if (vr->equiv)
+ bitmap_clear (vr->equiv);
+}
+
+/* Set value range VR to a single value. This function is only called
+ with values we get from statements, and exists to clear the
+ TREE_OVERFLOW flag so that we don't think we have an overflow
+ infinity when we shouldn't. */
+
+static inline void
+set_value_range_to_value (value_range_t *vr, tree val, bitmap equiv)
+{
+ gcc_assert (is_gimple_min_invariant (val));
+ val = avoid_overflow_infinity (val);
+ set_value_range (vr, VR_RANGE, val, val, equiv);
+}
+
+/* Set value range VR to a non-negative range of type TYPE.
+ OVERFLOW_INFINITY indicates whether to use an overflow infinity
+ rather than TYPE_MAX_VALUE; this should be true if we determine
+ that the range is nonnegative based on the assumption that signed
+ overflow does not occur. */
+
+static inline void
+set_value_range_to_nonnegative (value_range_t *vr, tree type,
+ bool overflow_infinity)
+{
+ tree zero;
+
+ if (overflow_infinity && !supports_overflow_infinity (type))
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+
+ zero = build_int_cst (type, 0);
+ set_value_range (vr, VR_RANGE, zero,
+ (overflow_infinity
+ ? positive_overflow_infinity (type)
+ : TYPE_MAX_VALUE (type)),
+ vr->equiv);
}
/* Set value range VR to a non-NULL range of type TYPE. */
static inline void
set_value_range_to_null (value_range_t *vr, tree type)
{
- tree zero = build_int_cst (type, 0);
- set_value_range (vr, VR_RANGE, zero, zero, vr->equiv);
+ set_value_range_to_value (vr, build_int_cst (type, 0), vr->equiv);
}
-/* Set value range VR to VR_VARYING. */
+/* Set value range VR to a range of a truthvalue of type TYPE. */
static inline void
-set_value_range_to_varying (value_range_t *vr)
+set_value_range_to_truthvalue (value_range_t *vr, tree type)
{
- vr->type = VR_VARYING;
- vr->min = vr->max = NULL_TREE;
- if (vr->equiv)
- bitmap_clear (vr->equiv);
+ if (TYPE_PRECISION (type) == 1)
+ set_value_range_to_varying (vr);
+ else
+ set_value_range (vr, VR_RANGE,
+ build_int_cst (type, 0), build_int_cst (type, 1),
+ vr->equiv);
}
return NULL. Otherwise create an empty range if none existed for VAR. */
static value_range_t *
-get_value_range (tree var)
+get_value_range (const_tree var)
{
value_range_t *vr;
tree sym;
return vr;
/* Create a default value range. */
- vr_value[ver] = vr = XNEW (value_range_t);
- memset (vr, 0, sizeof (*vr));
+ vr_value[ver] = vr = XCNEW (value_range_t);
- /* Allocate an equivalence set. */
- vr->equiv = BITMAP_ALLOC (NULL);
+ /* Defer allocating the equivalence set. */
+ vr->equiv = NULL;
/* If VAR is a default definition, the variable can take any value
in VAR's type. */
sym = SSA_NAME_VAR (var);
- if (var == default_def (sym))
+ if (SSA_NAME_IS_DEFAULT_DEF (var))
{
/* Try to use the "nonnull" attribute to create ~[0, 0]
anti-ranges for pointers. Note that this is only valid with
/* Return true, if VAL1 and VAL2 are equal values for VRP purposes. */
static inline bool
-vrp_operand_equal_p (tree val1, tree val2)
+vrp_operand_equal_p (const_tree val1, const_tree val2)
{
- return (val1 == val2
- || (val1 && val2
- && operand_equal_p (val1, val2, 0)));
+ if (val1 == val2)
+ return true;
+ if (!val1 || !val2 || !operand_equal_p (val1, val2, 0))
+ return false;
+ if (is_overflow_infinity (val1))
+ return is_overflow_infinity (val2);
+ return true;
}
/* Return true, if the bitmaps B1 and B2 are equal. */
static inline bool
-vrp_bitmap_equal_p (bitmap b1, bitmap b2)
+vrp_bitmap_equal_p (const_bitmap b1, const_bitmap b2)
{
return (b1 == b2
|| (b1 && b2
is the range object associated with another SSA name. */
static inline bool
-update_value_range (tree var, value_range_t *new_vr)
+update_value_range (const_tree var, value_range_t *new_vr)
{
value_range_t *old_vr;
bool is_new;
new_vr->equiv);
BITMAP_FREE (new_vr->equiv);
- new_vr->equiv = NULL;
return is_new;
}
-/* Add VAR and VAR's equivalence set to EQUIV. */
+/* Add VAR and VAR's equivalence set to EQUIV. This is the central
+ point where equivalence processing can be turned on/off. */
static void
-add_equivalence (bitmap equiv, tree var)
+add_equivalence (bitmap *equiv, const_tree var)
{
unsigned ver = SSA_NAME_VERSION (var);
value_range_t *vr = vr_value[ver];
- bitmap_set_bit (equiv, ver);
+ if (*equiv == NULL)
+ *equiv = BITMAP_ALLOC (NULL);
+ bitmap_set_bit (*equiv, ver);
if (vr && vr->equiv)
- bitmap_ior_into (equiv, vr->equiv);
+ bitmap_ior_into (*equiv, vr->equiv);
}
|| !is_gimple_min_invariant (vr->max));
}
-/* Like tree_expr_nonnegative_p, but this function uses value ranges
- obtained so far. */
+/* Return true if value range VR uses an overflow infinity. */
+
+static inline bool
+overflow_infinity_range_p (value_range_t *vr)
+{
+ return (vr->type == VR_RANGE
+ && (is_overflow_infinity (vr->min)
+ || is_overflow_infinity (vr->max)));
+}
+
+/* Return false if we can not make a valid comparison based on VR;
+ this will be the case if it uses an overflow infinity and overflow
+ is not undefined (i.e., -fno-strict-overflow is in effect).
+ Otherwise return true, and set *STRICT_OVERFLOW_P to true if VR
+ uses an overflow infinity. */
+
+static bool
+usable_range_p (value_range_t *vr, bool *strict_overflow_p)
+{
+ gcc_assert (vr->type == VR_RANGE);
+ if (is_overflow_infinity (vr->min))
+ {
+ *strict_overflow_p = true;
+ if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr->min)))
+ return false;
+ }
+ if (is_overflow_infinity (vr->max))
+ {
+ *strict_overflow_p = true;
+ if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr->max)))
+ return false;
+ }
+ return true;
+}
+
+
+/* Like tree_expr_nonnegative_warnv_p, but this function uses value
+ ranges obtained so far. */
static bool
-vrp_expr_computes_nonnegative (tree expr)
+vrp_expr_computes_nonnegative (tree expr, bool *strict_overflow_p)
{
- return tree_expr_nonnegative_p (expr);
+ return tree_expr_nonnegative_warnv_p (expr, strict_overflow_p);
}
-/* Like tree_expr_nonzero_p, but this function uses value ranges
+/* Like tree_expr_nonzero_warnv_p, but this function uses value ranges
obtained so far. */
static bool
-vrp_expr_computes_nonzero (tree expr)
+vrp_expr_computes_nonzero (tree expr, bool *strict_overflow_p)
{
- if (tree_expr_nonzero_p (expr))
+ if (tree_expr_nonzero_warnv_p (expr, strict_overflow_p))
return true;
/* If we have an expression of the form &X->a, then the expression
return is_gimple_min_invariant (expr);
}
+/* Return
+ 1 if VAL < VAL2
+ 0 if !(VAL < VAL2)
+ -2 if those are incomparable. */
+static inline int
+operand_less_p (tree val, tree val2)
+{
+ /* LT is folded faster than GE and others. Inline the common case. */
+ if (TREE_CODE (val) == INTEGER_CST && TREE_CODE (val2) == INTEGER_CST)
+ {
+ if (TYPE_UNSIGNED (TREE_TYPE (val)))
+ return INT_CST_LT_UNSIGNED (val, val2);
+ else
+ {
+ if (INT_CST_LT (val, val2))
+ return 1;
+ }
+ }
+ else
+ {
+ tree tcmp;
+
+ fold_defer_overflow_warnings ();
+
+ tcmp = fold_binary_to_constant (LT_EXPR, boolean_type_node, val, val2);
+
+ fold_undefer_and_ignore_overflow_warnings ();
+
+ if (!tcmp)
+ return -2;
+
+ if (!integer_zerop (tcmp))
+ return 1;
+ }
+
+ /* val >= val2, not considering overflow infinity. */
+ if (is_negative_overflow_infinity (val))
+ return is_negative_overflow_infinity (val2) ? 0 : 1;
+ else if (is_positive_overflow_infinity (val2))
+ return is_positive_overflow_infinity (val) ? 0 : 1;
+
+ return 0;
+}
+
/* Compare two values VAL1 and VAL2. Return
-2 if VAL1 and VAL2 cannot be compared at compile-time,
+2 if VAL1 != VAL2
This is similar to tree_int_cst_compare but supports pointer values
- and values that cannot be compared at compile time. */
+ and values that cannot be compared at compile time.
+
+ If STRICT_OVERFLOW_P is not NULL, then set *STRICT_OVERFLOW_P to
+ true if the return value is only valid if we assume that signed
+ overflow is undefined. */
static int
-compare_values (tree val1, tree val2)
+compare_values_warnv (tree val1, tree val2, bool *strict_overflow_p)
{
if (val1 == val2)
return 0;
both integers. */
gcc_assert (POINTER_TYPE_P (TREE_TYPE (val1))
== POINTER_TYPE_P (TREE_TYPE (val2)));
+ /* Convert the two values into the same type. This is needed because
+ sizetype causes sign extension even for unsigned types. */
+ val2 = fold_convert (TREE_TYPE (val1), val2);
+ STRIP_USELESS_TYPE_CONVERSION (val2);
if ((TREE_CODE (val1) == SSA_NAME
|| TREE_CODE (val1) == PLUS_EXPR
c1 = TREE_OPERAND (val1, 1);
if (tree_int_cst_sgn (c1) == -1)
{
+ if (is_negative_overflow_infinity (c1))
+ return -2;
c1 = fold_unary_to_constant (NEGATE_EXPR, TREE_TYPE (c1), c1);
if (!c1)
return -2;
c2 = TREE_OPERAND (val2, 1);
if (tree_int_cst_sgn (c2) == -1)
{
+ if (is_negative_overflow_infinity (c2))
+ return -2;
c2 = fold_unary_to_constant (NEGATE_EXPR, TREE_TYPE (c2), c2);
if (!c2)
return -2;
return 0;
/* If overflow is defined we cannot simplify more. */
- if (TYPE_UNSIGNED (TREE_TYPE (val1))
- || flag_wrapv)
+ if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1)))
return -2;
+ if (strict_overflow_p != NULL
+ && (code1 == SSA_NAME || !TREE_NO_WARNING (val1))
+ && (code2 == SSA_NAME || !TREE_NO_WARNING (val2)))
+ *strict_overflow_p = true;
+
if (code1 == SSA_NAME)
{
if (code2 == PLUS_EXPR)
return 1;
else if (code2 == PLUS_EXPR)
/* NAME + CST1 > NAME + CST2, if CST1 > CST2 */
- return compare_values (c1, c2);
+ return compare_values_warnv (c1, c2, strict_overflow_p);
else if (code2 == MINUS_EXPR)
/* NAME + CST1 > NAME - CST2 */
return 1;
else if (code2 == MINUS_EXPR)
/* NAME - CST1 > NAME - CST2, if CST1 < CST2. Notice that
C1 and C2 are swapped in the call to compare_values. */
- return compare_values (c2, c1);
+ return compare_values_warnv (c2, c1, strict_overflow_p);
}
gcc_unreachable ();
if (!POINTER_TYPE_P (TREE_TYPE (val1)))
{
- /* We cannot compare overflowed values. */
+ /* We cannot compare overflowed values, except for overflow
+ infinities. */
if (TREE_OVERFLOW (val1) || TREE_OVERFLOW (val2))
- return -2;
+ {
+ if (strict_overflow_p != NULL)
+ *strict_overflow_p = true;
+ if (is_negative_overflow_infinity (val1))
+ return is_negative_overflow_infinity (val2) ? 0 : -1;
+ else if (is_negative_overflow_infinity (val2))
+ return 1;
+ else if (is_positive_overflow_infinity (val1))
+ return is_positive_overflow_infinity (val2) ? 0 : 1;
+ else if (is_positive_overflow_infinity (val2))
+ return -1;
+ return -2;
+ }
return tree_int_cst_compare (val1, val2);
}
return 0;
/* If VAL1 is a lower address than VAL2, return -1. */
- t = fold_binary (LT_EXPR, boolean_type_node, val1, val2);
- if (t == boolean_true_node)
+ if (operand_less_p (val1, val2) == 1)
return -1;
/* If VAL1 is a higher address than VAL2, return +1. */
- t = fold_binary (GT_EXPR, boolean_type_node, val1, val2);
- if (t == boolean_true_node)
+ if (operand_less_p (val2, val1) == 1)
return 1;
- /* If VAL1 is different than VAL2, return +2. */
- t = fold_binary (NE_EXPR, boolean_type_node, val1, val2);
- if (t == boolean_true_node)
- return 2;
+ /* If VAL1 is different than VAL2, return +2.
+ For integer constants we either have already returned -1 or 1
+ or they are equivalent. We still might succeed in proving
+ something about non-trivial operands. */
+ if (TREE_CODE (val1) != INTEGER_CST
+ || TREE_CODE (val2) != INTEGER_CST)
+ {
+ t = fold_binary_to_constant (NE_EXPR, boolean_type_node, val1, val2);
+ if (t && tree_expr_nonzero_p (t))
+ return 2;
+ }
return -2;
}
}
+/* Compare values like compare_values_warnv, but treat comparisons of
+ nonconstants which rely on undefined overflow as incomparable. */
+
+static int
+compare_values (tree val1, tree val2)
+{
+ bool sop;
+ int ret;
+
+ sop = false;
+ ret = compare_values_warnv (val1, val2, &sop);
+ if (sop
+ && (!is_gimple_min_invariant (val1) || !is_gimple_min_invariant (val2)))
+ ret = -2;
+ return ret;
+}
+
/* Return 1 if VAL is inside value range VR (VR->MIN <= VAL <= VR->MAX),
0 if VAL is not inside VR,
This also applies to value_ranges_intersect_p and
range_includes_zero_p. The semantics of VR_RANGE and
VR_ANTI_RANGE should be encoded here, but that also means
- adapting the users of these functions to the new semantics. */
+ adapting the users of these functions to the new semantics.
+
+ Benchmark compile/20001226-1.c compilation time after changing this
+ function. */
static inline int
-value_inside_range (tree val, value_range_t *vr)
+value_inside_range (tree val, value_range_t * vr)
{
- tree cmp1, cmp2;
+ int cmp1, cmp2;
- cmp1 = fold_binary_to_constant (GE_EXPR, boolean_type_node, val, vr->min);
- if (!cmp1)
+ cmp1 = operand_less_p (val, vr->min);
+ if (cmp1 == -2)
return -2;
+ if (cmp1 == 1)
+ return 0;
- cmp2 = fold_binary_to_constant (LE_EXPR, boolean_type_node, val, vr->max);
- if (!cmp2)
+ cmp2 = operand_less_p (vr->max, val);
+ if (cmp2 == -2)
return -2;
- return cmp1 == boolean_true_node && cmp2 == boolean_true_node;
+ return !cmp2;
}
/* Return true if value ranges VR0 and VR1 have a non-empty
- intersection. */
+ intersection.
+
+ Benchmark compile/20001226-1.c compilation time after changing this
+ function.
+ */
static inline bool
value_ranges_intersect_p (value_range_t *vr0, value_range_t *vr1)
{
- return (value_inside_range (vr1->min, vr0) == 1
- || value_inside_range (vr1->max, vr0) == 1
- || value_inside_range (vr0->min, vr1) == 1
- || value_inside_range (vr0->max, vr1) == 1);
+ /* The value ranges do not intersect if the maximum of the first range is
+ less than the minimum of the second range or vice versa.
+ When those relations are unknown, we can't do any better. */
+ if (operand_less_p (vr0->max, vr1->min) != 0)
+ return false;
+ if (operand_less_p (vr1->max, vr0->min) != 0)
+ return false;
+ return true;
}
false otherwise or if no value range information is available. */
bool
-ssa_name_nonnegative_p (tree t)
+ssa_name_nonnegative_p (const_tree t)
{
value_range_t *vr = get_value_range (t);
false otherwise or if no value range information is available. */
bool
-ssa_name_nonzero_p (tree t)
+ssa_name_nonzero_p (const_tree t)
{
value_range_t *vr = get_value_range (t);
}
-/* When extracting ranges from X_i = ASSERT_EXPR <Y_j, pred>, we will
- initially consider X_i and Y_j equivalent, so the equivalence set
- of Y_j is added to the equivalence set of X_i. However, it is
- possible to have a chain of ASSERT_EXPRs whose predicates are
- actually incompatible. This is usually the result of nesting of
- contradictory if-then-else statements. For instance, in PR 24670:
-
- count_4 has range [-INF, 63]
-
- if (count_4 != 0)
- {
- count_19 = ASSERT_EXPR <count_4, count_4 != 0>
- if (count_19 > 63)
- {
- count_18 = ASSERT_EXPR <count_19, count_19 > 63>
- if (count_18 <= 63)
- ...
- }
- }
-
- Notice that 'if (count_19 > 63)' is trivially false and will be
- folded out at the end. However, during propagation, the flowgraph
- is not cleaned up and so, VRP will evaluate predicates more
- predicates than necessary, so it must support these
- inconsistencies. The problem here is that because of the chaining
- of ASSERT_EXPRs, the equivalency set for count_18 includes count_4.
- Since count_4 has an incompatible range, we ICE when evaluating the
- ranges in the equivalency set. So, we need to remove count_4 from
- it. */
-
-static void
-fix_equivalence_set (value_range_t *vr_p)
-{
- bitmap_iterator bi;
- unsigned i;
- bitmap e = vr_p->equiv;
- bitmap to_remove;
-
- /* Only detect inconsistencies on numeric ranges. */
- if (vr_p->type == VR_VARYING
- || vr_p->type == VR_UNDEFINED
- || symbolic_range_p (vr_p))
- return;
-
- to_remove = BITMAP_ALLOC (NULL);
- EXECUTE_IF_SET_IN_BITMAP (e, 0, i, bi)
- {
- value_range_t *equiv_vr = vr_value[i];
-
- if (equiv_vr->type == VR_VARYING
- || equiv_vr->type == VR_UNDEFINED)
- continue;
-
- if (vr_p->type == VR_RANGE
- && equiv_vr->type == VR_RANGE)
- {
- /* Two ranges have an empty intersection if their end points
- are outside of the other range. */
- if (compare_values (equiv_vr->min, vr_p->max) == 1
- || compare_values (equiv_vr->max, vr_p->min) == -1)
- bitmap_set_bit (to_remove, i);
- }
- else if ((equiv_vr->type == VR_RANGE && vr_p->type == VR_ANTI_RANGE)
- || (equiv_vr->type == VR_ANTI_RANGE && vr_p->type == VR_RANGE))
- {
- /* A range and an anti-range have an empty intersection if
- their end points are the same. FIXME,
- value_ranges_intersect_p should handle this
- automatically. */
- if (compare_values (equiv_vr->min, vr_p->min) == 0
- && compare_values (equiv_vr->max, vr_p->max) == 0)
- bitmap_set_bit (to_remove, i);
- }
- }
-
- bitmap_and_compl_into (vr_p->equiv, to_remove);
- BITMAP_FREE (to_remove);
-}
-
-
/* Extract value range information from an ASSERT_EXPR EXPR and store
it in *VR_P. */
cond_code = swap_tree_comparison (TREE_CODE (cond));
}
+ limit = avoid_overflow_infinity (limit);
+
type = TREE_TYPE (limit);
gcc_assert (limit != var);
predicates, we will need to trim the set of equivalences before
we are done. */
gcc_assert (vr_p->equiv == NULL);
- vr_p->equiv = BITMAP_ALLOC (NULL);
- add_equivalence (vr_p->equiv, var);
+ add_equivalence (&vr_p->equiv, var);
/* Extract a new range based on the asserted comparison for VAR and
LIMIT's value range. Notice that if LIMIT has an anti-range, we
SSA name, the new range will also inherit the equivalence set
from LIMIT. */
if (TREE_CODE (limit) == SSA_NAME)
- add_equivalence (vr_p->equiv, limit);
+ add_equivalence (&vr_p->equiv, limit);
}
else if (cond_code == NE_EXPR)
{
/* If MIN and MAX cover the whole range for their type, then
just use the original LIMIT. */
if (INTEGRAL_TYPE_P (type)
- && min == TYPE_MIN_VALUE (type)
- && max == TYPE_MAX_VALUE (type))
+ && vrp_val_is_min (min)
+ && vrp_val_is_max (max))
min = max = limit;
set_value_range (vr_p, VR_ANTI_RANGE, min, max, vr_p->equiv);
/* If the maximum value forces us to be out of bounds, simply punt.
It would be pointless to try and do anything more since this
all should be optimized away above us. */
- if (cond_code == LT_EXPR && compare_values (max, min) == 0)
+ if ((cond_code == LT_EXPR
+ && compare_values (max, min) == 0)
+ || is_overflow_infinity (max))
set_value_range_to_varying (vr_p);
else
{
{
tree one = build_int_cst (type, 1);
max = fold_build2 (MINUS_EXPR, type, max, one);
+ if (EXPR_P (max))
+ TREE_NO_WARNING (max) = 1;
}
set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
/* If the minimum value forces us to be out of bounds, simply punt.
It would be pointless to try and do anything more since this
all should be optimized away above us. */
- if (cond_code == GT_EXPR && compare_values (min, max) == 0)
+ if ((cond_code == GT_EXPR
+ && compare_values (min, max) == 0)
+ || is_overflow_infinity (min))
set_value_range_to_varying (vr_p);
else
{
{
tree one = build_int_cst (type, 1);
min = fold_build2 (PLUS_EXPR, type, min, one);
+ if (EXPR_P (min))
+ TREE_NO_WARNING (min) = 1;
}
set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
|| var_vr->type == VR_UNDEFINED
|| symbolic_range_p (vr_p)
|| symbolic_range_p (var_vr))
- goto done;
+ return;
if (var_vr->type == VR_RANGE && vr_p->type == VR_RANGE)
{
else
{
tree min, max, anti_min, anti_max, real_min, real_max;
+ int cmp;
/* We want to compute the logical AND of the two ranges;
there are three cases to consider.
/* Case 3a, the anti-range extends into the low
part of the real range. Thus creating a new
low for the real range. */
- else if ((compare_values (anti_max, real_min) == 1
- || compare_values (anti_max, real_min) == 0)
+ else if (((cmp = compare_values (anti_max, real_min)) == 1
+ || cmp == 0)
&& compare_values (anti_max, real_max) == -1)
{
- min = fold_build2 (PLUS_EXPR, TREE_TYPE (var_vr->min),
- anti_max,
- build_int_cst (TREE_TYPE (var_vr->min), 1));
+ gcc_assert (!is_positive_overflow_infinity (anti_max));
+ if (needs_overflow_infinity (TREE_TYPE (anti_max))
+ && vrp_val_is_max (anti_max))
+ {
+ if (!supports_overflow_infinity (TREE_TYPE (var_vr->min)))
+ {
+ set_value_range_to_varying (vr_p);
+ return;
+ }
+ min = positive_overflow_infinity (TREE_TYPE (var_vr->min));
+ }
+ else if (!POINTER_TYPE_P (TREE_TYPE (var_vr->min)))
+ min = fold_build2 (PLUS_EXPR, TREE_TYPE (var_vr->min),
+ anti_max,
+ build_int_cst (TREE_TYPE (var_vr->min), 1));
+ else
+ min = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (var_vr->min),
+ anti_max, size_int (1));
max = real_max;
set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
}
part of the real range. Thus creating a new
higher for the real range. */
else if (compare_values (anti_min, real_min) == 1
- && (compare_values (anti_min, real_max) == -1
- || compare_values (anti_min, real_max) == 0))
+ && ((cmp = compare_values (anti_min, real_max)) == -1
+ || cmp == 0))
{
- max = fold_build2 (MINUS_EXPR, TREE_TYPE (var_vr->min),
- anti_min,
- build_int_cst (TREE_TYPE (var_vr->min), 1));
+ gcc_assert (!is_negative_overflow_infinity (anti_min));
+ if (needs_overflow_infinity (TREE_TYPE (anti_min))
+ && vrp_val_is_min (anti_min))
+ {
+ if (!supports_overflow_infinity (TREE_TYPE (var_vr->min)))
+ {
+ set_value_range_to_varying (vr_p);
+ return;
+ }
+ max = negative_overflow_infinity (TREE_TYPE (var_vr->min));
+ }
+ else if (!POINTER_TYPE_P (TREE_TYPE (var_vr->min)))
+ max = fold_build2 (MINUS_EXPR, TREE_TYPE (var_vr->min),
+ anti_min,
+ build_int_cst (TREE_TYPE (var_vr->min), 1));
+ else
+ max = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (var_vr->min),
+ anti_min,
+ size_int (-1));
min = real_min;
set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
}
}
}
-
- /* Remove names from the equivalence set that have ranges
- incompatible with VR_P. */
-done:
- fix_equivalence_set (vr_p);
}
else
set_value_range (vr, VR_RANGE, var, var, NULL);
- add_equivalence (vr->equiv, var);
+ add_equivalence (&vr->equiv, var);
}
/* Wrapper around int_const_binop. If the operation overflows and we
are not using wrapping arithmetic, then adjust the result to be
- -INF or +INF depending on CODE, VAL1 and VAL2. */
+ -INF or +INF depending on CODE, VAL1 and VAL2. This can return
+ NULL_TREE if we need to use an overflow infinity representation but
+ the type does not support it. */
-static inline tree
+static tree
vrp_int_const_binop (enum tree_code code, tree val1, tree val2)
{
tree res;
/* If we are not using wrapping arithmetic, operate symbolically
on -INF and +INF. */
- if (TYPE_UNSIGNED (TREE_TYPE (val1))
- || flag_wrapv)
+ if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (val1)))
{
int checkz = compare_values (res, val1);
bool overflow = false;
else if (code == MULT_EXPR && !integer_zerop (val1))
{
tree tmp = int_const_binop (TRUNC_DIV_EXPR,
- TYPE_MAX_VALUE (TREE_TYPE (val1)),
+ res,
val1, 0);
int check = compare_values (tmp, val2);
}
}
- else if (TREE_OVERFLOW (res)
- && !TREE_OVERFLOW (val1)
- && !TREE_OVERFLOW (val2))
+ else if ((TREE_OVERFLOW (res)
+ && !TREE_OVERFLOW (val1)
+ && !TREE_OVERFLOW (val2))
+ || is_overflow_infinity (val1)
+ || is_overflow_infinity (val2))
{
/* If the operation overflowed but neither VAL1 nor VAL2 are
overflown, return -INF or +INF depending on the operation
int sgn1 = tree_int_cst_sgn (val1);
int sgn2 = tree_int_cst_sgn (val2);
+ if (needs_overflow_infinity (TREE_TYPE (res))
+ && !supports_overflow_infinity (TREE_TYPE (res)))
+ return NULL_TREE;
+
+ /* We have to punt on adding infinities of different signs,
+ since we can't tell what the sign of the result should be.
+ Likewise for subtracting infinities of the same sign. */
+ if (((code == PLUS_EXPR && sgn1 != sgn2)
+ || (code == MINUS_EXPR && sgn1 == sgn2))
+ && is_overflow_infinity (val1)
+ && is_overflow_infinity (val2))
+ return NULL_TREE;
+
+ /* Don't try to handle division or shifting of infinities. */
+ if ((code == TRUNC_DIV_EXPR
+ || code == FLOOR_DIV_EXPR
+ || code == CEIL_DIV_EXPR
+ || code == EXACT_DIV_EXPR
+ || code == ROUND_DIV_EXPR
+ || code == RSHIFT_EXPR)
+ && (is_overflow_infinity (val1)
+ || is_overflow_infinity (val2)))
+ return NULL_TREE;
+
/* Notice that we only need to handle the restricted set of
operations handled by extract_range_from_binary_expr.
Among them, only multiplication, addition and subtraction
if ((code == MULT_EXPR && sgn1 == sgn2)
/* For addition, the operands must be of the same sign
to yield an overflow. Its sign is therefore that
- of one of the operands, for example the first. */
- || (code == PLUS_EXPR && sgn1 > 0)
- /* For subtraction, the operands must be of different
- signs to yield an overflow. Its sign is therefore
- that of the first operand or the opposite of that
- of the second operand. A first operand of 0 counts
- as positive here, for the corner case 0 - (-INF),
- which overflows, but must yield +INF. */
- || (code == MINUS_EXPR && sgn1 >= 0)
+ of one of the operands, for example the first. For
+ infinite operands X + -INF is negative, not positive. */
+ || (code == PLUS_EXPR
+ && (sgn1 >= 0
+ ? !is_negative_overflow_infinity (val2)
+ : is_positive_overflow_infinity (val2)))
+ /* For subtraction, non-infinite operands must be of
+ different signs to yield an overflow. Its sign is
+ therefore that of the first operand or the opposite of
+ that of the second operand. A first operand of 0 counts
+ as positive here, for the corner case 0 - (-INF), which
+ overflows, but must yield +INF. For infinite operands 0
+ - INF is negative, not positive. */
+ || (code == MINUS_EXPR
+ && (sgn1 >= 0
+ ? !is_positive_overflow_infinity (val2)
+ : is_negative_overflow_infinity (val2)))
+ /* We only get in here with positive shift count, so the
+ overflow direction is the same as the sign of val1.
+ Actually rshift does not overflow at all, but we only
+ handle the case of shifting overflowed -INF and +INF. */
+ || (code == RSHIFT_EXPR
+ && sgn1 >= 0)
/* For division, the only case is -INF / -1 = +INF. */
|| code == TRUNC_DIV_EXPR
|| code == FLOOR_DIV_EXPR
|| code == CEIL_DIV_EXPR
|| code == EXACT_DIV_EXPR
|| code == ROUND_DIV_EXPR)
- return TYPE_MAX_VALUE (TREE_TYPE (res));
+ return (needs_overflow_infinity (TREE_TYPE (res))
+ ? positive_overflow_infinity (TREE_TYPE (res))
+ : TYPE_MAX_VALUE (TREE_TYPE (res)));
else
- return TYPE_MIN_VALUE (TREE_TYPE (res));
+ return (needs_overflow_infinity (TREE_TYPE (res))
+ ? negative_overflow_infinity (TREE_TYPE (res))
+ : TYPE_MIN_VALUE (TREE_TYPE (res)));
}
return res;
meaningful way. Handle only arithmetic operations. */
if (code != PLUS_EXPR
&& code != MINUS_EXPR
+ && code != POINTER_PLUS_EXPR
&& code != MULT_EXPR
&& code != TRUNC_DIV_EXPR
&& code != FLOOR_DIV_EXPR
&& code != CEIL_DIV_EXPR
&& code != EXACT_DIV_EXPR
&& code != ROUND_DIV_EXPR
+ && code != RSHIFT_EXPR
&& code != MIN_EXPR
&& code != MAX_EXPR
&& code != BIT_AND_EXPR
if (TREE_CODE (op0) == SSA_NAME)
vr0 = *(get_value_range (op0));
else if (is_gimple_min_invariant (op0))
- set_value_range (&vr0, VR_RANGE, op0, op0, NULL);
+ set_value_range_to_value (&vr0, op0, NULL);
else
set_value_range_to_varying (&vr0);
if (TREE_CODE (op1) == SSA_NAME)
vr1 = *(get_value_range (op1));
else if (is_gimple_min_invariant (op1))
- set_value_range (&vr1, VR_RANGE, op1, op1, NULL);
+ set_value_range_to_value (&vr1, op1, NULL);
else
set_value_range_to_varying (&vr1);
|| POINTER_TYPE_P (TREE_TYPE (op0))
|| POINTER_TYPE_P (TREE_TYPE (op1)))
{
- /* For pointer types, we are really only interested in asserting
- whether the expression evaluates to non-NULL. FIXME, we used
- to gcc_assert (code == PLUS_EXPR || code == MINUS_EXPR), but
- ivopts is generating expressions with pointer multiplication
- in them. */
- if (code == PLUS_EXPR)
+ if (code == MIN_EXPR || code == MAX_EXPR)
{
- if (range_is_nonnull (&vr0) || range_is_nonnull (&vr1))
+ /* For MIN/MAX expressions with pointers, we only care about
+ nullness, if both are non null, then the result is nonnull.
+ If both are null, then the result is null. Otherwise they
+ are varying. */
+ if (range_is_nonnull (&vr0) && range_is_nonnull (&vr1))
set_value_range_to_nonnull (vr, TREE_TYPE (expr));
else if (range_is_null (&vr0) && range_is_null (&vr1))
set_value_range_to_null (vr, TREE_TYPE (expr));
else
set_value_range_to_varying (vr);
+
+ return;
}
+ gcc_assert (code == POINTER_PLUS_EXPR);
+ /* For pointer types, we are really only interested in asserting
+ whether the expression evaluates to non-NULL. */
+ if (range_is_nonnull (&vr0) || range_is_nonnull (&vr1))
+ set_value_range_to_nonnull (vr, TREE_TYPE (expr));
+ else if (range_is_null (&vr0) && range_is_null (&vr1))
+ set_value_range_to_null (vr, TREE_TYPE (expr));
else
- {
- /* Subtracting from a pointer, may yield 0, so just drop the
- resulting range to varying. */
- set_value_range_to_varying (vr);
- }
+ set_value_range_to_varying (vr);
return;
}
&& vr1.type != VR_VARYING
&& vr0.type == vr1.type
&& !symbolic_range_p (&vr0)
- && !symbolic_range_p (&vr1))
+ && !overflow_infinity_range_p (&vr0)
+ && !symbolic_range_p (&vr1)
+ && !overflow_infinity_range_p (&vr1))
{
/* Boolean expressions cannot be folded with int_const_binop. */
min = fold_binary (code, TREE_TYPE (expr), vr0.min, vr1.min);
}
else
{
- set_value_range_to_varying (vr);
+ /* The result of a TRUTH_*_EXPR is always true or false. */
+ set_value_range_to_truthvalue (vr, TREE_TYPE (expr));
return;
}
}
|| code == FLOOR_DIV_EXPR
|| code == CEIL_DIV_EXPR
|| code == EXACT_DIV_EXPR
- || code == ROUND_DIV_EXPR)
+ || code == ROUND_DIV_EXPR
+ || code == RSHIFT_EXPR)
{
tree val[4];
size_t i;
+ bool sop;
/* If we have an unsigned MULT_EXPR with two VR_ANTI_RANGEs,
drop to VR_VARYING. It would take more effort to compute a
point. */
if (code == MULT_EXPR
&& vr0.type == VR_ANTI_RANGE
- && (flag_wrapv || TYPE_UNSIGNED (TREE_TYPE (op0))))
+ && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0)))
{
set_value_range_to_varying (vr);
return;
}
+ /* If we have a RSHIFT_EXPR with any shift values outside [0..prec-1],
+ then drop to VR_VARYING. Outside of this range we get undefined
+ behavior from the shift operation. We cannot even trust
+ SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl
+ shifts, and the operation at the tree level may be widened. */
+ if (code == RSHIFT_EXPR)
+ {
+ if (vr1.type == VR_ANTI_RANGE
+ || !vrp_expr_computes_nonnegative (op1, &sop)
+ || (operand_less_p
+ (build_int_cst (TREE_TYPE (vr1.max),
+ TYPE_PRECISION (TREE_TYPE (expr)) - 1),
+ vr1.max) != 0))
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+ }
+
/* Multiplications and divisions are a bit tricky to handle,
depending on the mix of signs we have in the two ranges, we
need to operate on different values to get the minimum and
the new range. */
/* Divisions by zero result in a VARYING value. */
- if (code != MULT_EXPR
- && (vr0.type == VR_ANTI_RANGE || range_includes_zero_p (&vr1)))
+ else if (code != MULT_EXPR
+ && (vr0.type == VR_ANTI_RANGE || range_includes_zero_p (&vr1)))
{
set_value_range_to_varying (vr);
return;
}
/* Compute the 4 cross operations. */
+ sop = false;
val[0] = vrp_int_const_binop (code, vr0.min, vr1.min);
+ if (val[0] == NULL_TREE)
+ sop = true;
- val[1] = (vr1.max != vr1.min)
- ? vrp_int_const_binop (code, vr0.min, vr1.max)
- : NULL_TREE;
-
- val[2] = (vr0.max != vr0.min)
- ? vrp_int_const_binop (code, vr0.max, vr1.min)
- : NULL_TREE;
-
- val[3] = (vr0.min != vr0.max && vr1.min != vr1.max)
- ? vrp_int_const_binop (code, vr0.max, vr1.max)
- : NULL_TREE;
+ if (vr1.max == vr1.min)
+ val[1] = NULL_TREE;
+ else
+ {
+ val[1] = vrp_int_const_binop (code, vr0.min, vr1.max);
+ if (val[1] == NULL_TREE)
+ sop = true;
+ }
- /* Set MIN to the minimum of VAL[i] and MAX to the maximum
- of VAL[i]. */
- min = val[0];
- max = val[0];
- for (i = 1; i < 4; i++)
+ if (vr0.max == vr0.min)
+ val[2] = NULL_TREE;
+ else
{
- if (!is_gimple_min_invariant (min) || TREE_OVERFLOW (min)
- || !is_gimple_min_invariant (max) || TREE_OVERFLOW (max))
- break;
+ val[2] = vrp_int_const_binop (code, vr0.max, vr1.min);
+ if (val[2] == NULL_TREE)
+ sop = true;
+ }
+
+ if (vr0.min == vr0.max || vr1.min == vr1.max)
+ val[3] = NULL_TREE;
+ else
+ {
+ val[3] = vrp_int_const_binop (code, vr0.max, vr1.max);
+ if (val[3] == NULL_TREE)
+ sop = true;
+ }
+
+ if (sop)
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+
+ /* Set MIN to the minimum of VAL[i] and MAX to the maximum
+ of VAL[i]. */
+ min = val[0];
+ max = val[0];
+ for (i = 1; i < 4; i++)
+ {
+ if (!is_gimple_min_invariant (min)
+ || (TREE_OVERFLOW (min) && !is_overflow_infinity (min))
+ || !is_gimple_min_invariant (max)
+ || (TREE_OVERFLOW (max) && !is_overflow_infinity (max)))
+ break;
if (val[i])
{
- if (!is_gimple_min_invariant (val[i]) || TREE_OVERFLOW (val[i]))
+ if (!is_gimple_min_invariant (val[i])
+ || (TREE_OVERFLOW (val[i])
+ && !is_overflow_infinity (val[i])))
{
/* If we found an overflowed value, set MIN and MAX
to it so that we set the resulting range to
{
if (vr0.type == VR_RANGE
&& vr0.min == vr0.max
- && tree_expr_nonnegative_p (vr0.max)
- && TREE_CODE (vr0.max) == INTEGER_CST)
+ && TREE_CODE (vr0.max) == INTEGER_CST
+ && !TREE_OVERFLOW (vr0.max)
+ && tree_int_cst_sgn (vr0.max) >= 0)
{
min = build_int_cst (TREE_TYPE (expr), 0);
max = vr0.max;
}
else if (vr1.type == VR_RANGE
- && vr1.min == vr1.max
- && tree_expr_nonnegative_p (vr1.max)
- && TREE_CODE (vr1.max) == INTEGER_CST)
+ && vr1.min == vr1.max
+ && TREE_CODE (vr1.max) == INTEGER_CST
+ && !TREE_OVERFLOW (vr1.max)
+ && tree_int_cst_sgn (vr1.max) >= 0)
{
type = VR_RANGE;
min = build_int_cst (TREE_TYPE (expr), 0);
gcc_unreachable ();
/* If either MIN or MAX overflowed, then set the resulting range to
- VARYING. */
- if (!is_gimple_min_invariant (min) || TREE_OVERFLOW (min)
- || !is_gimple_min_invariant (max) || TREE_OVERFLOW (max))
+ VARYING. But we do accept an overflow infinity
+ representation. */
+ if (min == NULL_TREE
+ || !is_gimple_min_invariant (min)
+ || (TREE_OVERFLOW (min) && !is_overflow_infinity (min))
+ || max == NULL_TREE
+ || !is_gimple_min_invariant (max)
+ || (TREE_OVERFLOW (max) && !is_overflow_infinity (max)))
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+
+ /* We punt if:
+ 1) [-INF, +INF]
+ 2) [-INF, +-INF(OVF)]
+ 3) [+-INF(OVF), +INF]
+ 4) [+-INF(OVF), +-INF(OVF)]
+ We learn nothing when we have INF and INF(OVF) on both sides.
+ Note that we do accept [-INF, -INF] and [+INF, +INF] without
+ overflow. */
+ if ((vrp_val_is_min (min) || is_overflow_infinity (min))
+ && (vrp_val_is_max (max) || is_overflow_infinity (max)))
{
set_value_range_to_varying (vr);
return;
/* Refuse to operate on certain unary expressions for which we
cannot easily determine a resulting range. */
if (code == FIX_TRUNC_EXPR
- || code == FIX_CEIL_EXPR
- || code == FIX_FLOOR_EXPR
- || code == FIX_ROUND_EXPR
|| code == FLOAT_EXPR
|| code == BIT_NOT_EXPR
|| code == NON_LVALUE_EXPR
if (TREE_CODE (op0) == SSA_NAME)
vr0 = *(get_value_range (op0));
else if (is_gimple_min_invariant (op0))
- set_value_range (&vr0, VR_RANGE, op0, op0, NULL);
+ set_value_range_to_value (&vr0, op0, NULL);
else
set_value_range_to_varying (&vr0);
determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */
if (POINTER_TYPE_P (TREE_TYPE (expr)) || POINTER_TYPE_P (TREE_TYPE (op0)))
{
- if (range_is_nonnull (&vr0) || tree_expr_nonzero_p (expr))
+ bool sop;
+
+ sop = false;
+ if (range_is_nonnull (&vr0)
+ || (tree_expr_nonzero_warnv_p (expr, &sop)
+ && !sop))
set_value_range_to_nonnull (vr, TREE_TYPE (expr));
else if (range_is_null (&vr0))
set_value_range_to_null (vr, TREE_TYPE (expr));
or equal to the new max, then we can safely use the newly
computed range for EXPR. This allows us to compute
accurate ranges through many casts. */
- if (vr0.type == VR_RANGE
+ if ((vr0.type == VR_RANGE
+ && !overflow_infinity_range_p (&vr0))
|| (vr0.type == VR_VARYING
&& TYPE_PRECISION (outer_type) > TYPE_PRECISION (inner_type)))
{
&& is_gimple_val (new_max)
&& tree_int_cst_equal (new_min, orig_min)
&& tree_int_cst_equal (new_max, orig_max)
- && compare_values (new_min, new_max) <= 0
- && compare_values (new_min, new_max) >= -1)
+ && (!is_overflow_infinity (new_min)
+ || !is_overflow_infinity (new_max))
+ && (cmp = compare_values (new_min, new_max)) <= 0
+ && cmp >= -1)
{
set_value_range (vr, VR_RANGE, new_min, new_max, vr->equiv);
return;
&& !TYPE_UNSIGNED (TREE_TYPE (expr)))
{
/* NEGATE_EXPR flips the range around. We need to treat
- TYPE_MIN_VALUE specially dependent on wrapping, range type
- and if it was used as minimum or maximum value:
- -~[MIN, MIN] == ~[MIN, MIN]
- -[MIN, 0] == [0, MAX] for -fno-wrapv
- -[MIN, 0] == [0, MIN] for -fwrapv (will be set to varying later) */
- min = vr0.max == TYPE_MIN_VALUE (TREE_TYPE (expr))
- ? TYPE_MIN_VALUE (TREE_TYPE (expr))
- : fold_unary_to_constant (code, TREE_TYPE (expr), vr0.max);
-
- max = vr0.min == TYPE_MIN_VALUE (TREE_TYPE (expr))
- ? (vr0.type == VR_ANTI_RANGE || flag_wrapv
- ? TYPE_MIN_VALUE (TREE_TYPE (expr))
- : TYPE_MAX_VALUE (TREE_TYPE (expr)))
- : fold_unary_to_constant (code, TREE_TYPE (expr), vr0.min);
-
+ TYPE_MIN_VALUE specially. */
+ if (is_positive_overflow_infinity (vr0.max))
+ min = negative_overflow_infinity (TREE_TYPE (expr));
+ else if (is_negative_overflow_infinity (vr0.max))
+ min = positive_overflow_infinity (TREE_TYPE (expr));
+ else if (!vrp_val_is_min (vr0.max))
+ min = fold_unary_to_constant (code, TREE_TYPE (expr), vr0.max);
+ else if (needs_overflow_infinity (TREE_TYPE (expr)))
+ {
+ if (supports_overflow_infinity (TREE_TYPE (expr))
+ && !is_overflow_infinity (vr0.min)
+ && !vrp_val_is_min (vr0.min))
+ min = positive_overflow_infinity (TREE_TYPE (expr));
+ else
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+ }
+ else
+ min = TYPE_MIN_VALUE (TREE_TYPE (expr));
+
+ if (is_positive_overflow_infinity (vr0.min))
+ max = negative_overflow_infinity (TREE_TYPE (expr));
+ else if (is_negative_overflow_infinity (vr0.min))
+ max = positive_overflow_infinity (TREE_TYPE (expr));
+ else if (!vrp_val_is_min (vr0.min))
+ max = fold_unary_to_constant (code, TREE_TYPE (expr), vr0.min);
+ else if (needs_overflow_infinity (TREE_TYPE (expr)))
+ {
+ if (supports_overflow_infinity (TREE_TYPE (expr)))
+ max = positive_overflow_infinity (TREE_TYPE (expr));
+ else
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+ }
+ else
+ max = TYPE_MIN_VALUE (TREE_TYPE (expr));
}
else if (code == NEGATE_EXPR
&& TYPE_UNSIGNED (TREE_TYPE (expr)))
{
/* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a
useful range. */
- if (flag_wrapv
+ if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (expr))
&& ((vr0.type == VR_RANGE
- && vr0.min == TYPE_MIN_VALUE (TREE_TYPE (expr)))
+ && vrp_val_is_min (vr0.min))
|| (vr0.type == VR_ANTI_RANGE
- && vr0.min != TYPE_MIN_VALUE (TREE_TYPE (expr))
+ && !vrp_val_is_min (vr0.min)
&& !range_includes_zero_p (&vr0))))
{
set_value_range_to_varying (vr);
/* ABS_EXPR may flip the range around, if the original range
included negative values. */
- min = (vr0.min == TYPE_MIN_VALUE (TREE_TYPE (expr)))
- ? TYPE_MAX_VALUE (TREE_TYPE (expr))
- : fold_unary_to_constant (code, TREE_TYPE (expr), vr0.min);
+ if (is_overflow_infinity (vr0.min))
+ min = positive_overflow_infinity (TREE_TYPE (expr));
+ else if (!vrp_val_is_min (vr0.min))
+ min = fold_unary_to_constant (code, TREE_TYPE (expr), vr0.min);
+ else if (!needs_overflow_infinity (TREE_TYPE (expr)))
+ min = TYPE_MAX_VALUE (TREE_TYPE (expr));
+ else if (supports_overflow_infinity (TREE_TYPE (expr)))
+ min = positive_overflow_infinity (TREE_TYPE (expr));
+ else
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
- max = fold_unary_to_constant (code, TREE_TYPE (expr), vr0.max);
+ if (is_overflow_infinity (vr0.max))
+ max = positive_overflow_infinity (TREE_TYPE (expr));
+ else if (!vrp_val_is_min (vr0.max))
+ max = fold_unary_to_constant (code, TREE_TYPE (expr), vr0.max);
+ else if (!needs_overflow_infinity (TREE_TYPE (expr)))
+ max = TYPE_MAX_VALUE (TREE_TYPE (expr));
+ else if (supports_overflow_infinity (TREE_TYPE (expr)))
+ max = positive_overflow_infinity (TREE_TYPE (expr));
+ else
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
cmp = compare_values (min, max);
{
if (range_includes_zero_p (&vr0))
{
- tree type_min_value = TYPE_MIN_VALUE (TREE_TYPE (expr));
-
/* Take the lower of the two values. */
if (cmp != 1)
max = min;
or ~[-INF + 1, min (abs(MIN), abs(MAX))] when
flag_wrapv is set and the original anti-range doesn't include
TYPE_MIN_VALUE, remember -TYPE_MIN_VALUE = TYPE_MIN_VALUE. */
- min = (flag_wrapv && vr0.min != type_min_value
- ? int_const_binop (PLUS_EXPR,
- type_min_value,
- integer_one_node, 0)
- : type_min_value);
+ if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (expr)))
+ {
+ tree type_min_value = TYPE_MIN_VALUE (TREE_TYPE (expr));
+
+ min = (vr0.min != type_min_value
+ ? int_const_binop (PLUS_EXPR, type_min_value,
+ integer_one_node, 0)
+ : type_min_value);
+ }
+ else
+ {
+ if (overflow_infinity_range_p (&vr0))
+ min = negative_overflow_infinity (TREE_TYPE (expr));
+ else
+ min = TYPE_MIN_VALUE (TREE_TYPE (expr));
+ }
}
else
{
anti-range. */
vr0.type = VR_RANGE;
min = build_int_cst (TREE_TYPE (expr), 0);
- max = TYPE_MAX_VALUE (TREE_TYPE (expr));
+ if (needs_overflow_infinity (TREE_TYPE (expr)))
+ {
+ if (supports_overflow_infinity (TREE_TYPE (expr)))
+ max = positive_overflow_infinity (TREE_TYPE (expr));
+ else
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+ }
+ else
+ max = TYPE_MAX_VALUE (TREE_TYPE (expr));
}
}
/* Otherwise, operate on each end of the range. */
min = fold_unary_to_constant (code, TREE_TYPE (expr), vr0.min);
max = fold_unary_to_constant (code, TREE_TYPE (expr), vr0.max);
+
+ if (needs_overflow_infinity (TREE_TYPE (expr)))
+ {
+ gcc_assert (code != NEGATE_EXPR && code != ABS_EXPR);
+
+ /* If both sides have overflowed, we don't know
+ anything. */
+ if ((is_overflow_infinity (vr0.min)
+ || TREE_OVERFLOW (min))
+ && (is_overflow_infinity (vr0.max)
+ || TREE_OVERFLOW (max)))
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+
+ if (is_overflow_infinity (vr0.min))
+ min = vr0.min;
+ else if (TREE_OVERFLOW (min))
+ {
+ if (supports_overflow_infinity (TREE_TYPE (expr)))
+ min = (tree_int_cst_sgn (min) >= 0
+ ? positive_overflow_infinity (TREE_TYPE (min))
+ : negative_overflow_infinity (TREE_TYPE (min)));
+ else
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+ }
+
+ if (is_overflow_infinity (vr0.max))
+ max = vr0.max;
+ else if (TREE_OVERFLOW (max))
+ {
+ if (supports_overflow_infinity (TREE_TYPE (expr)))
+ max = (tree_int_cst_sgn (max) >= 0
+ ? positive_overflow_infinity (TREE_TYPE (max))
+ : negative_overflow_infinity (TREE_TYPE (max)));
+ else
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+ }
+ }
}
cmp = compare_values (min, max);
}
+/* Extract range information from a conditional expression EXPR based on
+ the ranges of each of its operands and the expression code. */
+
+static void
+extract_range_from_cond_expr (value_range_t *vr, tree expr)
+{
+ tree op0, op1;
+ value_range_t vr0 = { VR_UNDEFINED, NULL_TREE, NULL_TREE, NULL };
+ value_range_t vr1 = { VR_UNDEFINED, NULL_TREE, NULL_TREE, NULL };
+
+ /* Get value ranges for each operand. For constant operands, create
+ a new value range with the operand to simplify processing. */
+ op0 = COND_EXPR_THEN (expr);
+ if (TREE_CODE (op0) == SSA_NAME)
+ vr0 = *(get_value_range (op0));
+ else if (is_gimple_min_invariant (op0))
+ set_value_range_to_value (&vr0, op0, NULL);
+ else
+ set_value_range_to_varying (&vr0);
+
+ op1 = COND_EXPR_ELSE (expr);
+ if (TREE_CODE (op1) == SSA_NAME)
+ vr1 = *(get_value_range (op1));
+ else if (is_gimple_min_invariant (op1))
+ set_value_range_to_value (&vr1, op1, NULL);
+ else
+ set_value_range_to_varying (&vr1);
+
+ /* The resulting value range is the union of the operand ranges */
+ vrp_meet (&vr0, &vr1);
+ copy_value_range (vr, &vr0);
+}
+
+
/* Extract range information from a comparison expression EXPR based
on the range of its operand and the expression code. */
static void
extract_range_from_comparison (value_range_t *vr, tree expr)
{
- tree val = vrp_evaluate_conditional (expr, false);
- if (val)
+ bool sop = false;
+ tree val = vrp_evaluate_conditional_warnv (expr, false, &sop);
+
+ /* A disadvantage of using a special infinity as an overflow
+ representation is that we lose the ability to record overflow
+ when we don't have an infinity. So we have to ignore a result
+ which relies on overflow. */
+
+ if (val && !is_overflow_infinity (val) && !sop)
{
/* Since this expression was found on the RHS of an assignment,
its type may be different from _Bool. Convert VAL to EXPR's
type. */
val = fold_convert (TREE_TYPE (expr), val);
- set_value_range (vr, VR_RANGE, val, val, vr->equiv);
+ if (is_gimple_min_invariant (val))
+ set_value_range_to_value (vr, val, vr->equiv);
+ else
+ set_value_range (vr, VR_RANGE, val, val, vr->equiv);
}
else
- set_value_range_to_varying (vr);
+ /* The result of a comparison is always true or false. */
+ set_value_range_to_truthvalue (vr, TREE_TYPE (expr));
}
extract_range_from_binary_expr (vr, expr);
else if (TREE_CODE_CLASS (code) == tcc_unary)
extract_range_from_unary_expr (vr, expr);
+ else if (code == COND_EXPR)
+ extract_range_from_cond_expr (vr, expr);
else if (TREE_CODE_CLASS (code) == tcc_comparison)
extract_range_from_comparison (vr, expr);
else if (is_gimple_min_invariant (expr))
- set_value_range (vr, VR_RANGE, expr, expr, NULL);
+ set_value_range_to_value (vr, expr, NULL);
else
set_value_range_to_varying (vr);
with range data. */
if (vr->type == VR_VARYING)
{
+ bool sop = false;
+
if (INTEGRAL_TYPE_P (TREE_TYPE (expr))
- && vrp_expr_computes_nonnegative (expr))
- set_value_range_to_nonnegative (vr, TREE_TYPE (expr));
- else if (vrp_expr_computes_nonzero (expr))
+ && vrp_expr_computes_nonnegative (expr, &sop))
+ set_value_range_to_nonnegative (vr, TREE_TYPE (expr),
+ sop || is_overflow_infinity (expr));
+ else if (vrp_expr_computes_nonzero (expr, &sop)
+ && !sop)
set_value_range_to_nonnull (vr, TREE_TYPE (expr));
}
}
if (vr->type == VR_ANTI_RANGE)
return;
+ /* Ensure that there are not values in the scev cache based on assumptions
+ on ranges of ssa names that were changed
+ (in set_value_range/set_value_range_to_varying). Preserve cached numbers
+ of iterations, that were computed before the start of VRP (we do not
+ recompute these each time to save the compile time). */
+ scev_reset_except_niters ();
+
chrec = instantiate_parameters (loop, analyze_scalar_evolution (loop, var));
+
+ /* Like in PR19590, scev can return a constant function. */
+ if (is_gimple_min_invariant (chrec))
+ {
+ set_value_range_to_value (vr, chrec, vr->equiv);
+ return;
+ }
+
if (TREE_CODE (chrec) != POLYNOMIAL_CHREC)
return;
or decreases, ... */
dir == EV_DIR_UNKNOWN
/* ... or if it may wrap. */
- || scev_probably_wraps_p (init, step, stmt,
- current_loops->parray[CHREC_VARIABLE (chrec)],
+ || scev_probably_wraps_p (init, step, stmt, get_chrec_loop (chrec),
true))
return;
+ /* We use TYPE_MIN_VALUE and TYPE_MAX_VALUE here instead of
+ negative_overflow_infinity and positive_overflow_infinity,
+ because we have concluded that the loop probably does not
+ wrap. */
+
type = TREE_TYPE (var);
if (POINTER_TYPE_P (type) || !TYPE_MIN_VALUE (type))
tmin = lower_bound_in_type (type, type);
if (compare_values (min, max) == 1)
return;
}
+
+ /* According to the loop information, the variable does not
+ overflow. If we think it does, probably because of an
+ overflow due to arithmetic on a different INF value,
+ reset now. */
+ if (is_negative_overflow_infinity (min))
+ min = tmin;
}
else
{
if (compare_values (min, max) == 1)
return;
}
+
+ if (is_positive_overflow_infinity (max))
+ max = tmax;
}
set_value_range (vr, VR_RANGE, min, max, vr->equiv);
}
}
+/* Return true if VAR may overflow at STMT. This checks any available
+ loop information to see if we can determine that VAR does not
+ overflow. */
+
+static bool
+vrp_var_may_overflow (tree var, tree stmt)
+{
+ struct loop *l;
+ tree chrec, init, step;
+
+ if (current_loops == NULL)
+ return true;
+
+ l = loop_containing_stmt (stmt);
+ if (l == NULL)
+ return true;
+
+ chrec = instantiate_parameters (l, analyze_scalar_evolution (l, var));
+ if (TREE_CODE (chrec) != POLYNOMIAL_CHREC)
+ return true;
+
+ init = initial_condition_in_loop_num (chrec, l->num);
+ step = evolution_part_in_loop_num (chrec, l->num);
+
+ if (step == NULL_TREE
+ || !is_gimple_min_invariant (step)
+ || !valid_value_p (init))
+ return true;
+
+ /* If we get here, we know something useful about VAR based on the
+ loop information. If it wraps, it may overflow. */
+
+ if (scev_probably_wraps_p (init, step, stmt, get_chrec_loop (chrec),
+ true))
+ return true;
+
+ if (dump_file && (dump_flags & TDF_DETAILS) != 0)
+ {
+ print_generic_expr (dump_file, var, 0);
+ fprintf (dump_file, ": loop information indicates does not overflow\n");
+ }
+
+ return false;
+}
+
/* Given two numeric value ranges VR0, VR1 and a comparison code COMP:
- Return BOOLEAN_FALSE_NODE if the comparison always returns false.
- Return NULL_TREE if it is not always possible to determine the
- value of the comparison. */
+ value of the comparison.
+
+ Also set *STRICT_OVERFLOW_P to indicate whether a range with an
+ overflow infinity was used in the test. */
static tree
-compare_ranges (enum tree_code comp, value_range_t *vr0, value_range_t *vr1)
+compare_ranges (enum tree_code comp, value_range_t *vr0, value_range_t *vr1,
+ bool *strict_overflow_p)
{
/* VARYING or UNDEFINED ranges cannot be compared. */
if (vr0->type == VR_VARYING
gcc_assert (comp == NE_EXPR || comp == EQ_EXPR);
- if (compare_values (vr0->min, vr1->min) == 0
- && compare_values (vr0->max, vr1->max) == 0)
+ if (compare_values_warnv (vr0->min, vr1->min, strict_overflow_p) == 0
+ && compare_values_warnv (vr0->max, vr1->max, strict_overflow_p) == 0)
return (comp == NE_EXPR) ? boolean_true_node : boolean_false_node;
return NULL_TREE;
}
+ if (!usable_range_p (vr0, strict_overflow_p)
+ || !usable_range_p (vr1, strict_overflow_p))
+ return NULL_TREE;
+
/* Simplify processing. If COMP is GT_EXPR or GE_EXPR, switch the
operands around and change the comparison code. */
if (comp == GT_EXPR || comp == GE_EXPR)
{
/* Equality may only be computed if both ranges represent
exactly one value. */
- if (compare_values (vr0->min, vr0->max) == 0
- && compare_values (vr1->min, vr1->max) == 0)
+ if (compare_values_warnv (vr0->min, vr0->max, strict_overflow_p) == 0
+ && compare_values_warnv (vr1->min, vr1->max, strict_overflow_p) == 0)
{
- int cmp_min = compare_values (vr0->min, vr1->min);
- int cmp_max = compare_values (vr0->max, vr1->max);
+ int cmp_min = compare_values_warnv (vr0->min, vr1->min,
+ strict_overflow_p);
+ int cmp_max = compare_values_warnv (vr0->max, vr1->max,
+ strict_overflow_p);
if (cmp_min == 0 && cmp_max == 0)
return boolean_true_node;
else if (cmp_min != -2 && cmp_max != -2)
return boolean_false_node;
}
/* If [V0_MIN, V1_MAX] < [V1_MIN, V1_MAX] then V0 != V1. */
- else if (compare_values (vr0->min, vr1->max) == 1
- || compare_values (vr1->min, vr0->max) == 1)
+ else if (compare_values_warnv (vr0->min, vr1->max,
+ strict_overflow_p) == 1
+ || compare_values_warnv (vr1->min, vr0->max,
+ strict_overflow_p) == 1)
return boolean_false_node;
return NULL_TREE;
make sure that both comparisons yield similar results to
avoid comparing values that cannot be compared at
compile-time. */
- cmp1 = compare_values (vr0->max, vr1->min);
- cmp2 = compare_values (vr0->min, vr1->max);
+ cmp1 = compare_values_warnv (vr0->max, vr1->min, strict_overflow_p);
+ cmp2 = compare_values_warnv (vr0->min, vr1->max, strict_overflow_p);
if ((cmp1 == -1 && cmp2 == -1) || (cmp1 == 1 && cmp2 == 1))
return boolean_true_node;
/* If VR0 and VR1 represent a single value and are identical,
return false. */
- else if (compare_values (vr0->min, vr0->max) == 0
- && compare_values (vr1->min, vr1->max) == 0
- && compare_values (vr0->min, vr1->min) == 0
- && compare_values (vr0->max, vr1->max) == 0)
+ else if (compare_values_warnv (vr0->min, vr0->max,
+ strict_overflow_p) == 0
+ && compare_values_warnv (vr1->min, vr1->max,
+ strict_overflow_p) == 0
+ && compare_values_warnv (vr0->min, vr1->min,
+ strict_overflow_p) == 0
+ && compare_values_warnv (vr0->max, vr1->max,
+ strict_overflow_p) == 0)
return boolean_false_node;
/* Otherwise, they may or may not be different. */
int tst;
/* If VR0 is to the left of VR1, return true. */
- tst = compare_values (vr0->max, vr1->min);
+ tst = compare_values_warnv (vr0->max, vr1->min, strict_overflow_p);
if ((comp == LT_EXPR && tst == -1)
|| (comp == LE_EXPR && (tst == -1 || tst == 0)))
- return boolean_true_node;
+ {
+ if (overflow_infinity_range_p (vr0)
+ || overflow_infinity_range_p (vr1))
+ *strict_overflow_p = true;
+ return boolean_true_node;
+ }
/* If VR0 is to the right of VR1, return false. */
- tst = compare_values (vr0->min, vr1->max);
+ tst = compare_values_warnv (vr0->min, vr1->max, strict_overflow_p);
if ((comp == LT_EXPR && (tst == 0 || tst == 1))
|| (comp == LE_EXPR && tst == 1))
- return boolean_false_node;
+ {
+ if (overflow_infinity_range_p (vr0)
+ || overflow_infinity_range_p (vr1))
+ *strict_overflow_p = true;
+ return boolean_false_node;
+ }
/* Otherwise, we don't know. */
return NULL_TREE;
BOOLEAN_TRUE_NODE if VR COMP VAL always returns true for all the
values in VR. Return BOOLEAN_FALSE_NODE if the comparison
always returns false. Return NULL_TREE if it is not always
- possible to determine the value of the comparison. */
+ possible to determine the value of the comparison. Also set
+ *STRICT_OVERFLOW_P to indicate whether a range with an overflow
+ infinity was used in the test. */
static tree
-compare_range_with_value (enum tree_code comp, value_range_t *vr, tree val)
+compare_range_with_value (enum tree_code comp, value_range_t *vr, tree val,
+ bool *strict_overflow_p)
{
if (vr->type == VR_VARYING || vr->type == VR_UNDEFINED)
return NULL_TREE;
return NULL_TREE;
}
+ if (!usable_range_p (vr, strict_overflow_p))
+ return NULL_TREE;
+
if (comp == EQ_EXPR)
{
/* EQ_EXPR may only be computed if VR represents exactly
one value. */
- if (compare_values (vr->min, vr->max) == 0)
+ if (compare_values_warnv (vr->min, vr->max, strict_overflow_p) == 0)
{
- int cmp = compare_values (vr->min, val);
+ int cmp = compare_values_warnv (vr->min, val, strict_overflow_p);
if (cmp == 0)
return boolean_true_node;
else if (cmp == -1 || cmp == 1 || cmp == 2)
return boolean_false_node;
}
- else if (compare_values (val, vr->min) == -1
- || compare_values (vr->max, val) == -1)
+ else if (compare_values_warnv (val, vr->min, strict_overflow_p) == -1
+ || compare_values_warnv (vr->max, val, strict_overflow_p) == -1)
return boolean_false_node;
return NULL_TREE;
else if (comp == NE_EXPR)
{
/* If VAL is not inside VR, then they are always different. */
- if (compare_values (vr->max, val) == -1
- || compare_values (vr->min, val) == 1)
+ if (compare_values_warnv (vr->max, val, strict_overflow_p) == -1
+ || compare_values_warnv (vr->min, val, strict_overflow_p) == 1)
return boolean_true_node;
/* If VR represents exactly one value equal to VAL, then return
false. */
- if (compare_values (vr->min, vr->max) == 0
- && compare_values (vr->min, val) == 0)
+ if (compare_values_warnv (vr->min, vr->max, strict_overflow_p) == 0
+ && compare_values_warnv (vr->min, val, strict_overflow_p) == 0)
return boolean_false_node;
/* Otherwise, they may or may not be different. */
int tst;
/* If VR is to the left of VAL, return true. */
- tst = compare_values (vr->max, val);
+ tst = compare_values_warnv (vr->max, val, strict_overflow_p);
if ((comp == LT_EXPR && tst == -1)
|| (comp == LE_EXPR && (tst == -1 || tst == 0)))
- return boolean_true_node;
+ {
+ if (overflow_infinity_range_p (vr))
+ *strict_overflow_p = true;
+ return boolean_true_node;
+ }
/* If VR is to the right of VAL, return false. */
- tst = compare_values (vr->min, val);
+ tst = compare_values_warnv (vr->min, val, strict_overflow_p);
if ((comp == LT_EXPR && (tst == 0 || tst == 1))
|| (comp == LE_EXPR && tst == 1))
- return boolean_false_node;
+ {
+ if (overflow_infinity_range_p (vr))
+ *strict_overflow_p = true;
+ return boolean_false_node;
+ }
/* Otherwise, we don't know. */
return NULL_TREE;
int tst;
/* If VR is to the right of VAL, return true. */
- tst = compare_values (vr->min, val);
+ tst = compare_values_warnv (vr->min, val, strict_overflow_p);
if ((comp == GT_EXPR && tst == 1)
|| (comp == GE_EXPR && (tst == 0 || tst == 1)))
- return boolean_true_node;
+ {
+ if (overflow_infinity_range_p (vr))
+ *strict_overflow_p = true;
+ return boolean_true_node;
+ }
/* If VR is to the left of VAL, return false. */
- tst = compare_values (vr->max, val);
+ tst = compare_values_warnv (vr->max, val, strict_overflow_p);
if ((comp == GT_EXPR && (tst == -1 || tst == 0))
|| (comp == GE_EXPR && tst == -1))
- return boolean_false_node;
+ {
+ if (overflow_infinity_range_p (vr))
+ *strict_overflow_p = true;
+ return boolean_false_node;
+ }
/* Otherwise, we don't know. */
return NULL_TREE;
fprintf (file, "%s[", (vr->type == VR_ANTI_RANGE) ? "~" : "");
- if (INTEGRAL_TYPE_P (type)
- && !TYPE_UNSIGNED (type)
- && vr->min == TYPE_MIN_VALUE (type))
+ if (is_negative_overflow_infinity (vr->min))
+ fprintf (file, "-INF(OVF)");
+ else if (INTEGRAL_TYPE_P (type)
+ && !TYPE_UNSIGNED (type)
+ && vrp_val_is_min (vr->min))
fprintf (file, "-INF");
else
print_generic_expr (file, vr->min, 0);
fprintf (file, ", ");
- if (INTEGRAL_TYPE_P (type)
- && vr->max == TYPE_MAX_VALUE (type))
+ if (is_positive_overflow_infinity (vr->max))
+ fprintf (file, "+INF(OVF)");
+ else if (INTEGRAL_TYPE_P (type)
+ && vrp_val_is_max (vr->max))
fprintf (file, "+INF");
else
print_generic_expr (file, vr->max, 0);
debug_value_range (value_range_t *vr)
{
dump_value_range (stderr, vr);
+ fprintf (stderr, "\n");
}
if (COMPARISON_CLASS_P (cond))
{
tree a = build2 (ASSERT_EXPR, TREE_TYPE (v), v, cond);
- assertion = build2 (MODIFY_EXPR, TREE_TYPE (v), n, a);
+ assertion = build_gimple_modify_stmt (n, a);
}
else if (TREE_CODE (cond) == TRUTH_NOT_EXPR)
{
/* Given !V, build the assignment N = false. */
tree op0 = TREE_OPERAND (cond, 0);
gcc_assert (op0 == v);
- assertion = build2 (MODIFY_EXPR, TREE_TYPE (v), n, boolean_false_node);
+ assertion = build_gimple_modify_stmt (n, boolean_false_node);
}
else if (TREE_CODE (cond) == SSA_NAME)
{
/* Given V, build the assignment N = true. */
gcc_assert (v == cond);
- assertion = build2 (MODIFY_EXPR, TREE_TYPE (v), n, boolean_true_node);
+ assertion = build_gimple_modify_stmt (n, boolean_true_node);
}
else
gcc_unreachable ();
point values. */
static inline bool
-fp_predicate (tree expr)
+fp_predicate (const_tree expr)
{
return (COMPARISON_CLASS_P (expr)
&& FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 0))));
non-NULL if -fdelete-null-pointer-checks is enabled. */
if (flag_delete_null_pointer_checks && POINTER_TYPE_P (TREE_TYPE (op)))
{
- bool is_store;
- unsigned num_uses, num_derefs;
+ unsigned num_uses, num_loads, num_stores;
- count_uses_and_derefs (op, stmt, &num_uses, &num_derefs, &is_store);
- if (num_derefs > 0)
+ count_uses_and_derefs (op, stmt, &num_uses, &num_loads, &num_stores);
+ if (num_loads + num_stores > 0)
{
*val_p = build_int_cst (TREE_TYPE (op), 0);
*comp_code_p = NE_EXPR;
bitmap_set_bit (need_assert_for, SSA_NAME_VERSION (name));
}
+/* COND is a predicate which uses NAME. Extract a suitable test code
+ and value and store them into *CODE_P and *VAL_P so the predicate
+ is normalized to NAME *CODE_P *VAL_P.
-/* Try to register an edge assertion for SSA name NAME on edge E for
- the conditional jump pointed to by SI. Return true if an assertion
- for NAME could be registered. */
+ If no extraction was possible, return FALSE, otherwise return TRUE.
+
+ If INVERT is true, then we invert the result stored into *CODE_P. */
static bool
-register_edge_assert_for (tree name, edge e, block_stmt_iterator si)
+extract_code_and_val_from_cond (tree name, tree cond, bool invert,
+ enum tree_code *code_p, tree *val_p)
{
- tree val, stmt;
enum tree_code comp_code;
+ tree val;
- stmt = bsi_stmt (si);
+ /* Predicates may be a single SSA name or NAME OP VAL. */
+ if (cond == name)
+ {
+ /* If the predicate is a name, it must be NAME, in which
+ case we create the predicate NAME == true or
+ NAME == false accordingly. */
+ comp_code = EQ_EXPR;
+ val = invert ? boolean_false_node : boolean_true_node;
+ }
+ else
+ {
+ /* Otherwise, we have a comparison of the form NAME COMP VAL
+ or VAL COMP NAME. */
+ if (name == TREE_OPERAND (cond, 1))
+ {
+ /* If the predicate is of the form VAL COMP NAME, flip
+ COMP around because we need to register NAME as the
+ first operand in the predicate. */
+ comp_code = swap_tree_comparison (TREE_CODE (cond));
+ val = TREE_OPERAND (cond, 0);
+ }
+ else
+ {
+ /* The comparison is of the form NAME COMP VAL, so the
+ comparison code remains unchanged. */
+ comp_code = TREE_CODE (cond);
+ val = TREE_OPERAND (cond, 1);
+ }
- /* Do not attempt to infer anything in names that flow through
- abnormal edges. */
- if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
- return false;
+ /* Invert the comparison code as necessary. */
+ if (invert)
+ comp_code = invert_tree_comparison (comp_code, 0);
+
+ /* VRP does not handle float types. */
+ if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (val)))
+ return false;
+
+ /* Do not register always-false predicates.
+ FIXME: this works around a limitation in fold() when dealing with
+ enumerations. Given 'enum { N1, N2 } x;', fold will not
+ fold 'if (x > N2)' to 'if (0)'. */
+ if ((comp_code == GT_EXPR || comp_code == LT_EXPR)
+ && INTEGRAL_TYPE_P (TREE_TYPE (val)))
+ {
+ tree min = TYPE_MIN_VALUE (TREE_TYPE (val));
+ tree max = TYPE_MAX_VALUE (TREE_TYPE (val));
+
+ if (comp_code == GT_EXPR
+ && (!max
+ || compare_values (val, max) == 0))
+ return false;
+
+ if (comp_code == LT_EXPR
+ && (!min
+ || compare_values (val, min) == 0))
+ return false;
+ }
+ }
+ *code_p = comp_code;
+ *val_p = val;
+ return true;
+}
+
+/* OP is an operand of a truth value expression which is known to have
+ a particular value. Register any asserts for OP and for any
+ operands in OP's defining statement.
- /* If NAME was not found in the sub-graph reachable from E, then
- there's nothing to do. */
- if (!TEST_BIT (found_in_subgraph, SSA_NAME_VERSION (name)))
+ If CODE is EQ_EXPR, then we want to register OP is zero (false),
+ if CODE is NE_EXPR, then we want to register OP is nonzero (true). */
+
+static bool
+register_edge_assert_for_1 (tree op, enum tree_code code,
+ edge e, block_stmt_iterator bsi)
+{
+ bool retval = false;
+ tree op_def, rhs, val;
+
+ /* We only care about SSA_NAMEs. */
+ if (TREE_CODE (op) != SSA_NAME)
return false;
- /* We found a use of NAME in the sub-graph rooted at E->DEST.
- Register an assertion for NAME according to the value that NAME
- takes on edge E. */
- if (TREE_CODE (stmt) == COND_EXPR)
+ /* We know that OP will have a zero or nonzero value. If OP is used
+ more than once go ahead and register an assert for OP.
+
+ The FOUND_IN_SUBGRAPH support is not helpful in this situation as
+ it will always be set for OP (because OP is used in a COND_EXPR in
+ the subgraph). */
+ if (!has_single_use (op))
+ {
+ val = build_int_cst (TREE_TYPE (op), 0);
+ register_new_assert_for (op, code, val, NULL, e, bsi);
+ retval = true;
+ }
+
+ /* Now look at how OP is set. If it's set from a comparison,
+ a truth operation or some bit operations, then we may be able
+ to register information about the operands of that assignment. */
+ op_def = SSA_NAME_DEF_STMT (op);
+ if (TREE_CODE (op_def) != GIMPLE_MODIFY_STMT)
+ return retval;
+
+ rhs = GIMPLE_STMT_OPERAND (op_def, 1);
+
+ if (COMPARISON_CLASS_P (rhs))
{
- /* If BB ends in a COND_EXPR then NAME then we should insert
- the original predicate on EDGE_TRUE_VALUE and the
- opposite predicate on EDGE_FALSE_VALUE. */
- tree cond = COND_EXPR_COND (stmt);
- bool is_else_edge = (e->flags & EDGE_FALSE_VALUE) != 0;
+ bool invert = (code == EQ_EXPR ? true : false);
+ tree op0 = TREE_OPERAND (rhs, 0);
+ tree op1 = TREE_OPERAND (rhs, 1);
- /* Predicates may be a single SSA name or NAME OP VAL. */
- if (cond == name)
+ /* Conditionally register an assert for each SSA_NAME in the
+ comparison. */
+ if (TREE_CODE (op0) == SSA_NAME
+ && !has_single_use (op0)
+ && extract_code_and_val_from_cond (op0, rhs,
+ invert, &code, &val))
{
- /* If the predicate is a name, it must be NAME, in which
- case we create the predicate NAME == true or
- NAME == false accordingly. */
- comp_code = EQ_EXPR;
- val = (is_else_edge) ? boolean_false_node : boolean_true_node;
+ register_new_assert_for (op0, code, val, NULL, e, bsi);
+ retval = true;
}
- else
+
+ /* Similarly for the second operand of the comparison. */
+ if (TREE_CODE (op1) == SSA_NAME
+ && !has_single_use (op1)
+ && extract_code_and_val_from_cond (op1, rhs,
+ invert, &code, &val))
{
- /* Otherwise, we have a comparison of the form NAME COMP VAL
- or VAL COMP NAME. */
- if (name == TREE_OPERAND (cond, 1))
- {
- /* If the predicate is of the form VAL COMP NAME, flip
- COMP around because we need to register NAME as the
- first operand in the predicate. */
- comp_code = swap_tree_comparison (TREE_CODE (cond));
- val = TREE_OPERAND (cond, 0);
- }
- else
- {
- /* The comparison is of the form NAME COMP VAL, so the
- comparison code remains unchanged. */
- comp_code = TREE_CODE (cond);
- val = TREE_OPERAND (cond, 1);
- }
+ register_new_assert_for (op1, code, val, NULL, e, bsi);
+ retval = true;
+ }
+ }
+ else if ((code == NE_EXPR
+ && (TREE_CODE (rhs) == TRUTH_AND_EXPR
+ || TREE_CODE (rhs) == BIT_AND_EXPR))
+ || (code == EQ_EXPR
+ && (TREE_CODE (rhs) == TRUTH_OR_EXPR
+ || TREE_CODE (rhs) == BIT_IOR_EXPR)))
+ {
+ /* Recurse on each operand. */
+ retval |= register_edge_assert_for_1 (TREE_OPERAND (rhs, 0),
+ code, e, bsi);
+ retval |= register_edge_assert_for_1 (TREE_OPERAND (rhs, 1),
+ code, e, bsi);
+ }
+ else if (TREE_CODE (rhs) == TRUTH_NOT_EXPR)
+ {
+ /* Recurse, flipping CODE. */
+ code = invert_tree_comparison (code, false);
+ retval |= register_edge_assert_for_1 (TREE_OPERAND (rhs, 0),
+ code, e, bsi);
+ }
+ else if (TREE_CODE (rhs) == SSA_NAME)
+ {
+ /* Recurse through the copy. */
+ retval |= register_edge_assert_for_1 (rhs, code, e, bsi);
+ }
+ else if (TREE_CODE (rhs) == NOP_EXPR
+ || TREE_CODE (rhs) == CONVERT_EXPR
+ || TREE_CODE (rhs) == NON_LVALUE_EXPR)
+ {
+ /* Recurse through the type conversion. */
+ retval |= register_edge_assert_for_1 (TREE_OPERAND (rhs, 0),
+ code, e, bsi);
+ }
- /* If we are inserting the assertion on the ELSE edge, we
- need to invert the sign comparison. */
- if (is_else_edge)
- comp_code = invert_tree_comparison (comp_code, 0);
-
- /* Do not register always-false predicates. FIXME, this
- works around a limitation in fold() when dealing with
- enumerations. Given 'enum { N1, N2 } x;', fold will not
- fold 'if (x > N2)' to 'if (0)'. */
- if ((comp_code == GT_EXPR || comp_code == LT_EXPR)
- && (INTEGRAL_TYPE_P (TREE_TYPE (val))
- || SCALAR_FLOAT_TYPE_P (TREE_TYPE (val))))
- {
- tree min = TYPE_MIN_VALUE (TREE_TYPE (val));
- tree max = TYPE_MAX_VALUE (TREE_TYPE (val));
+ return retval;
+}
- if (comp_code == GT_EXPR && compare_values (val, max) == 0)
- return false;
+/* Try to register an edge assertion for SSA name NAME on edge E for
+ the condition COND contributing to the conditional jump pointed to by SI.
+ Return true if an assertion for NAME could be registered. */
- if (comp_code == LT_EXPR && compare_values (val, min) == 0)
- return false;
- }
+static bool
+register_edge_assert_for (tree name, edge e, block_stmt_iterator si, tree cond)
+{
+ tree val;
+ enum tree_code comp_code;
+ bool retval = false;
+ bool is_else_edge = (e->flags & EDGE_FALSE_VALUE) != 0;
+
+ /* Do not attempt to infer anything in names that flow through
+ abnormal edges. */
+ if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
+ return false;
+
+ if (!extract_code_and_val_from_cond (name, cond, is_else_edge,
+ &comp_code, &val))
+ return false;
+
+ /* Only register an ASSERT_EXPR if NAME was found in the sub-graph
+ reachable from E. */
+ if (TEST_BIT (found_in_subgraph, SSA_NAME_VERSION (name)))
+ {
+ register_new_assert_for (name, comp_code, val, NULL, e, si);
+ retval = true;
+ }
+
+ /* If COND is effectively an equality test of an SSA_NAME against
+ the value zero or one, then we may be able to assert values
+ for SSA_NAMEs which flow into COND. */
+
+ /* In the case of NAME == 1 or NAME != 0, for TRUTH_AND_EXPR defining
+ statement of NAME we can assert both operands of the TRUTH_AND_EXPR
+ have nonzero value. */
+ if (((comp_code == EQ_EXPR && integer_onep (val))
+ || (comp_code == NE_EXPR && integer_zerop (val))))
+ {
+ tree def_stmt = SSA_NAME_DEF_STMT (name);
+
+ if (TREE_CODE (def_stmt) == GIMPLE_MODIFY_STMT
+ && (TREE_CODE (GIMPLE_STMT_OPERAND (def_stmt, 1)) == TRUTH_AND_EXPR
+ || TREE_CODE (GIMPLE_STMT_OPERAND (def_stmt, 1)) == BIT_AND_EXPR))
+ {
+ tree op0 = TREE_OPERAND (GIMPLE_STMT_OPERAND (def_stmt, 1), 0);
+ tree op1 = TREE_OPERAND (GIMPLE_STMT_OPERAND (def_stmt, 1), 1);
+ retval |= register_edge_assert_for_1 (op0, NE_EXPR, e, si);
+ retval |= register_edge_assert_for_1 (op1, NE_EXPR, e, si);
}
}
- else
+
+ /* In the case of NAME == 0 or NAME != 1, for TRUTH_OR_EXPR defining
+ statement of NAME we can assert both operands of the TRUTH_OR_EXPR
+ have zero value. */
+ if (((comp_code == EQ_EXPR && integer_zerop (val))
+ || (comp_code == NE_EXPR && integer_onep (val))))
{
- /* FIXME. Handle SWITCH_EXPR. */
- gcc_unreachable ();
+ tree def_stmt = SSA_NAME_DEF_STMT (name);
+
+ if (TREE_CODE (def_stmt) == GIMPLE_MODIFY_STMT
+ && (TREE_CODE (GIMPLE_STMT_OPERAND (def_stmt, 1)) == TRUTH_OR_EXPR
+ || TREE_CODE (GIMPLE_STMT_OPERAND (def_stmt, 1)) == BIT_IOR_EXPR))
+ {
+ tree op0 = TREE_OPERAND (GIMPLE_STMT_OPERAND (def_stmt, 1), 0);
+ tree op1 = TREE_OPERAND (GIMPLE_STMT_OPERAND (def_stmt, 1), 1);
+ retval |= register_edge_assert_for_1 (op0, EQ_EXPR, e, si);
+ retval |= register_edge_assert_for_1 (op1, EQ_EXPR, e, si);
+ }
}
- register_new_assert_for (name, comp_code, val, NULL, e, si);
- return true;
+ return retval;
}
static bool find_assert_locations (basic_block bb);
/* Determine whether the outgoing edges of BB should receive an
- ASSERT_EXPR for each of the operands of BB's last statement. The
- last statement of BB must be a COND_EXPR or a SWITCH_EXPR.
+ ASSERT_EXPR for each of the operands of BB's LAST statement.
+ The last statement of BB must be a COND_EXPR.
If any of the sub-graphs rooted at BB have an interesting use of
the predicate operands, an assert location node is added to the
list of assertions for the corresponding operands. */
static bool
-find_conditional_asserts (basic_block bb)
+find_conditional_asserts (basic_block bb, tree last)
{
bool need_assert;
- block_stmt_iterator last_si;
- tree op, last;
+ block_stmt_iterator bsi;
+ tree op;
edge_iterator ei;
edge e;
ssa_op_iter iter;
need_assert = false;
- last_si = bsi_last (bb);
- last = bsi_stmt (last_si);
+ bsi = bsi_for_stmt (last);
/* Look for uses of the operands in each of the sub-graphs
rooted at BB. We need to check each of the outgoing edges
insert. */
FOR_EACH_EDGE (e, ei, bb->succs)
{
- if (e->dest == bb)
- continue;
+ if (e->dest == bb)
+ continue;
+
+ /* Remove the COND_EXPR operands from the FOUND_IN_SUBGRAPH bitmap.
+ Otherwise, when we finish traversing each of the sub-graphs, we
+ won't know whether the variables were found in the sub-graphs or
+ if they had been found in a block upstream from BB.
+
+ This is actually a bad idea is some cases, particularly jump
+ threading. Consider a CFG like the following:
+
+ 0
+ /|
+ 1 |
+ \|
+ 2
+ / \
+ 3 4
+
+ Assume that one or more operands in the conditional at the
+ end of block 0 are used in a conditional in block 2, but not
+ anywhere in block 1. In this case we will not insert any
+ assert statements in block 1, which may cause us to miss
+ opportunities to optimize, particularly for jump threading. */
+ FOR_EACH_SSA_TREE_OPERAND (op, last, iter, SSA_OP_USE)
+ RESET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));
+
+ /* Traverse the strictly dominated sub-graph rooted at E->DEST
+ to determine if any of the operands in the conditional
+ predicate are used. */
+ need_assert |= find_assert_locations (e->dest);
+
+ /* Register the necessary assertions for each operand in the
+ conditional predicate. */
+ FOR_EACH_SSA_TREE_OPERAND (op, last, iter, SSA_OP_USE)
+ need_assert |= register_edge_assert_for (op, e, bsi,
+ COND_EXPR_COND (last));
+ }
+
+ /* Finally, indicate that we have found the operands in the
+ conditional. */
+ FOR_EACH_SSA_TREE_OPERAND (op, last, iter, SSA_OP_USE)
+ SET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));
+
+ return need_assert;
+}
+
+/* Compare two case labels sorting first by the destination label uid
+ and then by the case value. */
+
+static int
+compare_case_labels (const void *p1, const void *p2)
+{
+ const_tree const case1 = *(const_tree const*)p1;
+ const_tree const case2 = *(const_tree const*)p2;
+ unsigned int uid1 = DECL_UID (CASE_LABEL (case1));
+ unsigned int uid2 = DECL_UID (CASE_LABEL (case2));
+
+ if (uid1 < uid2)
+ return -1;
+ else if (uid1 == uid2)
+ {
+ /* Make sure the default label is first in a group. */
+ if (!CASE_LOW (case1))
+ return -1;
+ else if (!CASE_LOW (case2))
+ return 1;
+ else
+ return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
+ }
+ else
+ return 1;
+}
+
+/* Determine whether the outgoing edges of BB should receive an
+ ASSERT_EXPR for each of the operands of BB's LAST statement.
+ The last statement of BB must be a SWITCH_EXPR.
+
+ If any of the sub-graphs rooted at BB have an interesting use of
+ the predicate operands, an assert location node is added to the
+ list of assertions for the corresponding operands. */
+
+static bool
+find_switch_asserts (basic_block bb, tree last)
+{
+ bool need_assert;
+ block_stmt_iterator bsi;
+ tree op, cond;
+ edge e;
+ tree vec = SWITCH_LABELS (last), vec2;
+ size_t n = TREE_VEC_LENGTH (vec);
+ unsigned int idx;
+
+ need_assert = false;
+ bsi = bsi_for_stmt (last);
+ op = TREE_OPERAND (last, 0);
+ if (TREE_CODE (op) != SSA_NAME)
+ return false;
+
+ /* Build a vector of case labels sorted by destination label. */
+ vec2 = make_tree_vec (n);
+ for (idx = 0; idx < n; ++idx)
+ TREE_VEC_ELT (vec2, idx) = TREE_VEC_ELT (vec, idx);
+ qsort (&TREE_VEC_ELT (vec2, 0), n, sizeof (tree), compare_case_labels);
+
+ for (idx = 0; idx < n; ++idx)
+ {
+ tree min, max;
+ tree cl = TREE_VEC_ELT (vec2, idx);
- /* Remove the COND_EXPR operands from the FOUND_IN_SUBGRAPH bitmap.
- Otherwise, when we finish traversing each of the sub-graphs, we
- won't know whether the variables were found in the sub-graphs or
- if they had been found in a block upstream from BB.
+ min = CASE_LOW (cl);
+ max = CASE_HIGH (cl);
- This is actually a bad idea is some cases, particularly jump
- threading. Consider a CFG like the following:
+ /* If there are multiple case labels with the same destination
+ we need to combine them to a single value range for the edge. */
+ if (idx + 1 < n
+ && CASE_LABEL (cl) == CASE_LABEL (TREE_VEC_ELT (vec2, idx + 1)))
+ {
+ /* Skip labels until the last of the group. */
+ do {
+ ++idx;
+ } while (idx < n
+ && CASE_LABEL (cl) == CASE_LABEL (TREE_VEC_ELT (vec2, idx)));
+ --idx;
+
+ /* Pick up the maximum of the case label range. */
+ if (CASE_HIGH (TREE_VEC_ELT (vec2, idx)))
+ max = CASE_HIGH (TREE_VEC_ELT (vec2, idx));
+ else
+ max = CASE_LOW (TREE_VEC_ELT (vec2, idx));
+ }
- 0
- /|
- 1 |
- \|
- 2
- / \
- 3 4
+ /* Nothing to do if the range includes the default label until we
+ can register anti-ranges. */
+ if (min == NULL_TREE)
+ continue;
- Assume that one or more operands in the conditional at the
- end of block 0 are used in a conditional in block 2, but not
- anywhere in block 1. In this case we will not insert any
- assert statements in block 1, which may cause us to miss
- opportunities to optimize, particularly for jump threading. */
- FOR_EACH_SSA_TREE_OPERAND (op, last, iter, SSA_OP_USE)
- RESET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));
+ /* Find the edge to register the assert expr on. */
+ e = find_edge (bb, label_to_block (CASE_LABEL (cl)));
+
+ /* Remove the SWITCH_EXPR operand from the FOUND_IN_SUBGRAPH bitmap.
+ Otherwise, when we finish traversing each of the sub-graphs, we
+ won't know whether the variables were found in the sub-graphs or
+ if they had been found in a block upstream from BB. */
+ RESET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));
/* Traverse the strictly dominated sub-graph rooted at E->DEST
to determine if any of the operands in the conditional
if (e->dest != bb)
need_assert |= find_assert_locations (e->dest);
- /* Register the necessary assertions for each operand in the
- conditional predicate. */
- FOR_EACH_SSA_TREE_OPERAND (op, last, iter, SSA_OP_USE)
- need_assert |= register_edge_assert_for (op, e, last_si);
+ /* Register the necessary assertions for the operand in the
+ SWITCH_EXPR. */
+ cond = build2 (max ? GE_EXPR : EQ_EXPR, boolean_type_node,
+ op, fold_convert (TREE_TYPE (op), min));
+ need_assert |= register_edge_assert_for (op, e, bsi, cond);
+ if (max)
+ {
+ cond = build2 (LE_EXPR, boolean_type_node,
+ op, fold_convert (TREE_TYPE (op), max));
+ need_assert |= register_edge_assert_for (op, e, bsi, cond);
+ }
}
- /* Finally, indicate that we have found the operands in the
- conditional. */
- FOR_EACH_SSA_TREE_OPERAND (op, last, iter, SSA_OP_USE)
- SET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));
+ /* Finally, indicate that we have found the operand in the
+ SWITCH_EXPR. */
+ SET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));
return need_assert;
}
If this function returns true, then it means that there are names
for which we need to generate ASSERT_EXPRs. Those assertions are
- inserted by process_assert_insertions.
-
- TODO. Handle SWITCH_EXPR. */
+ inserted by process_assert_insertions. */
static bool
find_assert_locations (basic_block bb)
tree t = op;
tree def_stmt = SSA_NAME_DEF_STMT (t);
- while (TREE_CODE (def_stmt) == MODIFY_EXPR
- && TREE_CODE (TREE_OPERAND (def_stmt, 1)) == NOP_EXPR
- && TREE_CODE (TREE_OPERAND (TREE_OPERAND (def_stmt, 1), 0)) == SSA_NAME
- && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (def_stmt, 1), 0))))
+ while (TREE_CODE (def_stmt) == GIMPLE_MODIFY_STMT
+ && TREE_CODE
+ (GIMPLE_STMT_OPERAND (def_stmt, 1)) == NOP_EXPR
+ && TREE_CODE
+ (TREE_OPERAND (GIMPLE_STMT_OPERAND (def_stmt, 1),
+ 0)) == SSA_NAME
+ && POINTER_TYPE_P
+ (TREE_TYPE (TREE_OPERAND
+ (GIMPLE_STMT_OPERAND (def_stmt,
+ 1), 0))))
{
- t = TREE_OPERAND (TREE_OPERAND (def_stmt, 1), 0);
+ t = TREE_OPERAND (GIMPLE_STMT_OPERAND (def_stmt, 1), 0);
def_stmt = SSA_NAME_DEF_STMT (t);
/* Note we want to register the assert for the
&& TREE_CODE (last) == COND_EXPR
&& !fp_predicate (COND_EXPR_COND (last))
&& !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
- need_assert |= find_conditional_asserts (bb);
+ need_assert |= find_conditional_asserts (bb, last);
+
+ if (last
+ && TREE_CODE (last) == SWITCH_EXPR
+ && !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
+ need_assert |= find_switch_asserts (bb, last);
/* Recurse into the dominator children of BB. */
for (son = first_dom_son (CDI_DOMINATORS, bb);
sbitmap_zero (blocks_visited);
need_assert_for = BITMAP_ALLOC (NULL);
- asserts_for = XNEWVEC (assert_locus_t, num_ssa_names);
- memset (asserts_for, 0, num_ssa_names * sizeof (assert_locus_t));
+ asserts_for = XCNEWVEC (assert_locus_t, num_ssa_names);
calculate_dominance_info (CDI_DOMINATORS);
BITMAP_FREE (need_assert_for);
}
+/* Checks one ARRAY_REF in REF, located at LOCUS. Ignores flexible arrays
+ and "struct" hacks. If VRP can determine that the
+ array subscript is a constant, check if it is outside valid
+ range. If the array subscript is a RANGE, warn if it is
+ non-overlapping with valid range.
+ IGNORE_OFF_BY_ONE is true if the ARRAY_REF is inside a ADDR_EXPR. */
+
+static void
+check_array_ref (tree ref, location_t* locus, bool ignore_off_by_one)
+{
+ value_range_t* vr = NULL;
+ tree low_sub, up_sub;
+ tree low_bound, up_bound = array_ref_up_bound (ref);
+
+ low_sub = up_sub = TREE_OPERAND (ref, 1);
+
+ if (!up_bound || TREE_NO_WARNING (ref)
+ || TREE_CODE (up_bound) != INTEGER_CST
+ /* Can not check flexible arrays. */
+ || (TYPE_SIZE (TREE_TYPE (ref)) == NULL_TREE
+ && TYPE_DOMAIN (TREE_TYPE (ref)) != NULL_TREE
+ && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (ref))) == NULL_TREE)
+ /* Accesses after the end of arrays of size 0 (gcc
+ extension) and 1 are likely intentional ("struct
+ hack"). */
+ || compare_tree_int (up_bound, 1) <= 0)
+ return;
+
+ low_bound = array_ref_low_bound (ref);
+
+ if (TREE_CODE (low_sub) == SSA_NAME)
+ {
+ vr = get_value_range (low_sub);
+ if (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE)
+ {
+ low_sub = vr->type == VR_RANGE ? vr->max : vr->min;
+ up_sub = vr->type == VR_RANGE ? vr->min : vr->max;
+ }
+ }
+
+ if (vr && vr->type == VR_ANTI_RANGE)
+ {
+ if (TREE_CODE (up_sub) == INTEGER_CST
+ && tree_int_cst_lt (up_bound, up_sub)
+ && TREE_CODE (low_sub) == INTEGER_CST
+ && tree_int_cst_lt (low_sub, low_bound))
+ {
+ warning (OPT_Warray_bounds,
+ "%Harray subscript is outside array bounds", locus);
+ TREE_NO_WARNING (ref) = 1;
+ }
+ }
+ else if (TREE_CODE (up_sub) == INTEGER_CST
+ && tree_int_cst_lt (up_bound, up_sub)
+ && !tree_int_cst_equal (up_bound, up_sub)
+ && (!ignore_off_by_one
+ || !tree_int_cst_equal (int_const_binop (PLUS_EXPR,
+ up_bound,
+ integer_one_node,
+ 0),
+ up_sub)))
+ {
+ warning (OPT_Warray_bounds, "%Harray subscript is above array bounds",
+ locus);
+ TREE_NO_WARNING (ref) = 1;
+ }
+ else if (TREE_CODE (low_sub) == INTEGER_CST
+ && tree_int_cst_lt (low_sub, low_bound))
+ {
+ warning (OPT_Warray_bounds, "%Harray subscript is below array bounds",
+ locus);
+ TREE_NO_WARNING (ref) = 1;
+ }
+}
+
+/* Searches if the expr T, located at LOCATION computes
+ address of an ARRAY_REF, and call check_array_ref on it. */
+
+static void
+search_for_addr_array(tree t, location_t* location)
+{
+ while (TREE_CODE (t) == SSA_NAME)
+ {
+ t = SSA_NAME_DEF_STMT (t);
+ if (TREE_CODE (t) != GIMPLE_MODIFY_STMT)
+ return;
+ t = GIMPLE_STMT_OPERAND (t, 1);
+ }
+
+
+ /* We are only interested in addresses of ARRAY_REF's. */
+ if (TREE_CODE (t) != ADDR_EXPR)
+ return;
+
+ /* Check each ARRAY_REFs in the reference chain. */
+ do
+ {
+ if (TREE_CODE (t) == ARRAY_REF)
+ check_array_ref (t, location, true /*ignore_off_by_one*/);
+
+ t = TREE_OPERAND(t,0);
+ }
+ while (handled_component_p (t));
+}
+
+/* walk_tree() callback that checks if *TP is
+ an ARRAY_REF inside an ADDR_EXPR (in which an array
+ subscript one outside the valid range is allowed). Call
+ check_array_ref for each ARRAY_REF found. The location is
+ passed in DATA. */
+
+static tree
+check_array_bounds (tree *tp, int *walk_subtree, void *data)
+{
+ tree t = *tp;
+ tree stmt = (tree)data;
+ location_t *location = EXPR_LOCUS (stmt);
+
+ if (!EXPR_HAS_LOCATION (stmt))
+ {
+ *walk_subtree = FALSE;
+ return NULL_TREE;
+ }
+
+ *walk_subtree = TRUE;
+
+ if (TREE_CODE (t) == ARRAY_REF)
+ check_array_ref (t, location, false /*ignore_off_by_one*/);
+
+ if (TREE_CODE (t) == INDIRECT_REF
+ || (TREE_CODE (t) == RETURN_EXPR && TREE_OPERAND (t, 0)))
+ search_for_addr_array (TREE_OPERAND (t, 0), location);
+ else if (TREE_CODE (t) == CALL_EXPR)
+ {
+ tree arg;
+ call_expr_arg_iterator iter;
+
+ FOR_EACH_CALL_EXPR_ARG (arg, iter, t)
+ search_for_addr_array (arg, location);
+ }
+
+ if (TREE_CODE (t) == ADDR_EXPR)
+ *walk_subtree = FALSE;
+
+ return NULL_TREE;
+}
+
+/* Walk over all statements of all reachable BBs and call check_array_bounds
+ on them. */
+
+static void
+check_all_array_refs (void)
+{
+ basic_block bb;
+ block_stmt_iterator si;
+
+ FOR_EACH_BB (bb)
+ {
+ /* Skip bb's that are clearly unreachable. */
+ if (single_pred_p (bb))
+ {
+ basic_block pred_bb = EDGE_PRED (bb, 0)->src;
+ tree ls = NULL_TREE;
+
+ if (!bsi_end_p (bsi_last (pred_bb)))
+ ls = bsi_stmt (bsi_last (pred_bb));
+
+ if (ls && TREE_CODE (ls) == COND_EXPR
+ && ((COND_EXPR_COND (ls) == boolean_false_node
+ && (EDGE_PRED (bb, 0)->flags & EDGE_TRUE_VALUE))
+ || (COND_EXPR_COND (ls) == boolean_true_node
+ && (EDGE_PRED (bb, 0)->flags & EDGE_FALSE_VALUE))))
+ continue;
+ }
+ for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
+ walk_tree (bsi_stmt_ptr (si), check_array_bounds,
+ bsi_stmt (si), NULL);
+ }
+}
/* Convert range assertion expressions into the implied copies and
copy propagate away the copies. Doing the trivial copy propagation
tree stmt = bsi_stmt (si);
tree use_stmt;
- if (TREE_CODE (stmt) == MODIFY_EXPR
- && TREE_CODE (TREE_OPERAND (stmt, 1)) == ASSERT_EXPR)
+ if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
+ && TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1)) == ASSERT_EXPR)
{
- tree rhs = TREE_OPERAND (stmt, 1), var;
+ tree rhs = GIMPLE_STMT_OPERAND (stmt, 1), var;
tree cond = fold (ASSERT_EXPR_COND (rhs));
use_operand_p use_p;
imm_use_iterator iter;
/* Propagate the RHS into every use of the LHS. */
var = ASSERT_EXPR_VAR (rhs);
- FOR_EACH_IMM_USE_STMT (use_stmt, iter, TREE_OPERAND (stmt, 0))
+ FOR_EACH_IMM_USE_STMT (use_stmt, iter,
+ GIMPLE_STMT_OPERAND (stmt, 0))
FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
{
SET_USE (use_p, var);
/* And finally, remove the copy, it is not needed. */
bsi_remove (&si, true);
+ release_defs (stmt);
}
else
bsi_next (&si);
&& (INTEGRAL_TYPE_P (TREE_TYPE (PHI_RESULT (stmt)))
|| POINTER_TYPE_P (TREE_TYPE (PHI_RESULT (stmt)))))
return true;
- else if (TREE_CODE (stmt) == MODIFY_EXPR)
+ else if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
{
- tree lhs = TREE_OPERAND (stmt, 0);
- tree rhs = TREE_OPERAND (stmt, 1);
+ tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
+ tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
/* In general, assignments with virtual operands are not useful
for deriving ranges, with the obvious exception of calls to
&& (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
|| POINTER_TYPE_P (TREE_TYPE (lhs)))
&& ((TREE_CODE (rhs) == CALL_EXPR
- && TREE_CODE (TREE_OPERAND (rhs, 0)) == ADDR_EXPR
- && DECL_P (TREE_OPERAND (TREE_OPERAND (rhs, 0), 0))
- && DECL_IS_BUILTIN (TREE_OPERAND (TREE_OPERAND (rhs, 0), 0)))
+ && TREE_CODE (CALL_EXPR_FN (rhs)) == ADDR_EXPR
+ && DECL_P (TREE_OPERAND (CALL_EXPR_FN (rhs), 0))
+ && DECL_IS_BUILTIN (TREE_OPERAND (CALL_EXPR_FN (rhs), 0)))
|| ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS)))
return true;
}
{
basic_block bb;
- vr_value = XNEWVEC (value_range_t *, num_ssa_names);
- memset (vr_value, 0, num_ssa_names * sizeof (value_range_t *));
+ vr_value = XCNEWVEC (value_range_t *, num_ssa_names);
+ vr_phi_edge_counts = XCNEWVEC (int, num_ssa_names);
FOR_EACH_BB (bb)
{
tree lhs, rhs, def;
ssa_op_iter iter;
- lhs = TREE_OPERAND (stmt, 0);
- rhs = TREE_OPERAND (stmt, 1);
+ lhs = GIMPLE_STMT_OPERAND (stmt, 0);
+ rhs = GIMPLE_STMT_OPERAND (stmt, 1);
/* We only keep track of ranges in integral and pointer types. */
if (TREE_CODE (lhs) == SSA_NAME
return SSA_PROP_VARYING;
}
+/* Helper that gets the value range of the SSA_NAME with version I
+ or a symbolic range containing the SSA_NAME only if the value range
+ is varying or undefined. */
+
+static inline value_range_t
+get_vr_for_comparison (int i)
+{
+ value_range_t vr = *(vr_value[i]);
+
+ /* If name N_i does not have a valid range, use N_i as its own
+ range. This allows us to compare against names that may
+ have N_i in their ranges. */
+ if (vr.type == VR_VARYING || vr.type == VR_UNDEFINED)
+ {
+ vr.type = VR_RANGE;
+ vr.min = ssa_name (i);
+ vr.max = ssa_name (i);
+ }
+
+ return vr;
+}
/* Compare all the value ranges for names equivalent to VAR with VAL
using comparison code COMP. Return the same value returned by
- compare_range_with_value. */
+ compare_range_with_value, including the setting of
+ *STRICT_OVERFLOW_P. */
static tree
-compare_name_with_value (enum tree_code comp, tree var, tree val)
+compare_name_with_value (enum tree_code comp, tree var, tree val,
+ bool *strict_overflow_p)
{
bitmap_iterator bi;
unsigned i;
bitmap e;
tree retval, t;
-
- t = retval = NULL_TREE;
+ int used_strict_overflow;
+ bool sop;
+ value_range_t equiv_vr;
/* Get the set of equivalences for VAR. */
e = get_value_range (var)->equiv;
- /* Add VAR to its own set of equivalences so that VAR's value range
- is processed by this loop (otherwise, we would have to replicate
- the body of the loop just to check VAR's value range). */
- bitmap_set_bit (e, SSA_NAME_VERSION (var));
+ /* Start at -1. Set it to 0 if we do a comparison without relying
+ on overflow, or 1 if all comparisons rely on overflow. */
+ used_strict_overflow = -1;
- EXECUTE_IF_SET_IN_BITMAP (e, 0, i, bi)
- {
- value_range_t equiv_vr = *(vr_value[i]);
+ /* Compare vars' value range with val. */
+ equiv_vr = get_vr_for_comparison (SSA_NAME_VERSION (var));
+ sop = false;
+ retval = compare_range_with_value (comp, &equiv_vr, val, &sop);
+ if (retval)
+ used_strict_overflow = sop ? 1 : 0;
- /* If name N_i does not have a valid range, use N_i as its own
- range. This allows us to compare against names that may
- have N_i in their ranges. */
- if (equiv_vr.type == VR_VARYING || equiv_vr.type == VR_UNDEFINED)
- {
- equiv_vr.type = VR_RANGE;
- equiv_vr.min = ssa_name (i);
- equiv_vr.max = ssa_name (i);
- }
+ /* If the equiv set is empty we have done all work we need to do. */
+ if (e == NULL)
+ {
+ if (retval
+ && used_strict_overflow > 0)
+ *strict_overflow_p = true;
+ return retval;
+ }
- t = compare_range_with_value (comp, &equiv_vr, val);
+ EXECUTE_IF_SET_IN_BITMAP (e, 0, i, bi)
+ {
+ equiv_vr = get_vr_for_comparison (i);
+ sop = false;
+ t = compare_range_with_value (comp, &equiv_vr, val, &sop);
if (t)
{
- /* All the ranges should compare the same against VAL. */
- gcc_assert (retval == NULL || t == retval);
+ /* If we get different answers from different members
+ of the equivalence set this check must be in a dead
+ code region. Folding it to a trap representation
+ would be correct here. For now just return don't-know. */
+ if (retval != NULL
+ && t != retval)
+ {
+ retval = NULL_TREE;
+ break;
+ }
retval = t;
+
+ if (!sop)
+ used_strict_overflow = 0;
+ else if (used_strict_overflow < 0)
+ used_strict_overflow = 1;
}
}
- /* Remove VAR from its own equivalence set. */
- bitmap_clear_bit (e, SSA_NAME_VERSION (var));
-
- if (retval)
- return retval;
+ if (retval
+ && used_strict_overflow > 0)
+ *strict_overflow_p = true;
- /* We couldn't find a non-NULL value for the predicate. */
- return NULL_TREE;
+ return retval;
}
/* Given a comparison code COMP and names N1 and N2, compare all the
ranges equivalent to N1 against all the ranges equivalent to N2
to determine the value of N1 COMP N2. Return the same value
- returned by compare_ranges. */
+ returned by compare_ranges. Set *STRICT_OVERFLOW_P to indicate
+ whether we relied on an overflow infinity in the comparison. */
+
static tree
-compare_names (enum tree_code comp, tree n1, tree n2)
+compare_names (enum tree_code comp, tree n1, tree n2,
+ bool *strict_overflow_p)
{
tree t, retval;
bitmap e1, e2;
bitmap_iterator bi1, bi2;
unsigned i1, i2;
+ int used_strict_overflow;
+ static bitmap_obstack *s_obstack = NULL;
+ static bitmap s_e1 = NULL, s_e2 = NULL;
/* Compare the ranges of every name equivalent to N1 against the
ranges of every name equivalent to N2. */
e1 = get_value_range (n1)->equiv;
e2 = get_value_range (n2)->equiv;
+ /* Use the fake bitmaps if e1 or e2 are not available. */
+ if (s_obstack == NULL)
+ {
+ s_obstack = XNEW (bitmap_obstack);
+ bitmap_obstack_initialize (s_obstack);
+ s_e1 = BITMAP_ALLOC (s_obstack);
+ s_e2 = BITMAP_ALLOC (s_obstack);
+ }
+ if (e1 == NULL)
+ e1 = s_e1;
+ if (e2 == NULL)
+ e2 = s_e2;
+
/* Add N1 and N2 to their own set of equivalences to avoid
duplicating the body of the loop just to check N1 and N2
ranges. */
: boolean_false_node;
}
+ /* Start at -1. Set it to 0 if we do a comparison without relying
+ on overflow, or 1 if all comparisons rely on overflow. */
+ used_strict_overflow = -1;
+
/* Otherwise, compare all the equivalent ranges. First, add N1 and
N2 to their own set of equivalences to avoid duplicating the body
of the loop just to check N1 and N2 ranges. */
EXECUTE_IF_SET_IN_BITMAP (e1, 0, i1, bi1)
{
- value_range_t vr1 = *(vr_value[i1]);
-
- /* If the range is VARYING or UNDEFINED, use the name itself. */
- if (vr1.type == VR_VARYING || vr1.type == VR_UNDEFINED)
- {
- vr1.type = VR_RANGE;
- vr1.min = ssa_name (i1);
- vr1.max = ssa_name (i1);
- }
+ value_range_t vr1 = get_vr_for_comparison (i1);
t = retval = NULL_TREE;
EXECUTE_IF_SET_IN_BITMAP (e2, 0, i2, bi2)
{
- value_range_t vr2 = *(vr_value[i2]);
+ bool sop = false;
- if (vr2.type == VR_VARYING || vr2.type == VR_UNDEFINED)
- {
- vr2.type = VR_RANGE;
- vr2.min = ssa_name (i2);
- vr2.max = ssa_name (i2);
- }
+ value_range_t vr2 = get_vr_for_comparison (i2);
- t = compare_ranges (comp, &vr1, &vr2);
+ t = compare_ranges (comp, &vr1, &vr2, &sop);
if (t)
{
- /* All the ranges in the equivalent sets should compare
- the same. */
- gcc_assert (retval == NULL || t == retval);
+ /* If we get different answers from different members
+ of the equivalence set this check must be in a dead
+ code region. Folding it to a trap representation
+ would be correct here. For now just return don't-know. */
+ if (retval != NULL
+ && t != retval)
+ {
+ bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
+ bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
+ return NULL_TREE;
+ }
retval = t;
+
+ if (!sop)
+ used_strict_overflow = 0;
+ else if (used_strict_overflow < 0)
+ used_strict_overflow = 1;
}
}
{
bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
+ if (used_strict_overflow > 0)
+ *strict_overflow_p = true;
return retval;
}
}
If USE_EQUIV_P is true, the ranges of all the names equivalent with
the operands in COND are used when trying to compute its value.
This is only used during final substitution. During propagation,
- we only check the range of each variable and not its equivalents. */
+ we only check the range of each variable and not its equivalents.
-tree
-vrp_evaluate_conditional (tree cond, bool use_equiv_p)
+ Set *STRICT_OVERFLOW_P to indicate whether we relied on an overflow
+ infinity to produce the result. */
+
+static tree
+vrp_evaluate_conditional_warnv (tree cond, bool use_equiv_p,
+ bool *strict_overflow_p)
{
gcc_assert (TREE_CODE (cond) == SSA_NAME
|| TREE_CODE_CLASS (TREE_CODE (cond)) == tcc_comparison);
tree retval;
if (use_equiv_p)
- retval = compare_name_with_value (NE_EXPR, cond, boolean_false_node);
+ retval = compare_name_with_value (NE_EXPR, cond, boolean_false_node,
+ strict_overflow_p);
else
{
value_range_t *vr = get_value_range (cond);
- retval = compare_range_with_value (NE_EXPR, vr, boolean_false_node);
+ retval = compare_range_with_value (NE_EXPR, vr, boolean_false_node,
+ strict_overflow_p);
}
/* If COND has a known boolean range, return it. */
if (use_equiv_p)
{
if (TREE_CODE (op0) == SSA_NAME && TREE_CODE (op1) == SSA_NAME)
- return compare_names (TREE_CODE (cond), op0, op1);
+ return compare_names (TREE_CODE (cond), op0, op1,
+ strict_overflow_p);
else if (TREE_CODE (op0) == SSA_NAME)
- return compare_name_with_value (TREE_CODE (cond), op0, op1);
+ return compare_name_with_value (TREE_CODE (cond), op0, op1,
+ strict_overflow_p);
else if (TREE_CODE (op1) == SSA_NAME)
- return compare_name_with_value (
- swap_tree_comparison (TREE_CODE (cond)), op1, op0);
+ return (compare_name_with_value
+ (swap_tree_comparison (TREE_CODE (cond)), op1, op0,
+ strict_overflow_p));
}
else
{
vr1 = (TREE_CODE (op1) == SSA_NAME) ? get_value_range (op1) : NULL;
if (vr0 && vr1)
- return compare_ranges (TREE_CODE (cond), vr0, vr1);
+ return compare_ranges (TREE_CODE (cond), vr0, vr1,
+ strict_overflow_p);
else if (vr0 && vr1 == NULL)
- return compare_range_with_value (TREE_CODE (cond), vr0, op1);
+ return compare_range_with_value (TREE_CODE (cond), vr0, op1,
+ strict_overflow_p);
else if (vr0 == NULL && vr1)
- return compare_range_with_value (
- swap_tree_comparison (TREE_CODE (cond)), vr1, op0);
+ return (compare_range_with_value
+ (swap_tree_comparison (TREE_CODE (cond)), vr1, op0,
+ strict_overflow_p));
}
}
return NULL_TREE;
}
+/* Given COND within STMT, try to simplify it based on value range
+ information. Return NULL if the conditional can not be evaluated.
+ The ranges of all the names equivalent with the operands in COND
+ will be used when trying to compute the value. If the result is
+ based on undefined signed overflow, issue a warning if
+ appropriate. */
+
+tree
+vrp_evaluate_conditional (tree cond, tree stmt)
+{
+ bool sop;
+ tree ret;
+
+ sop = false;
+ ret = vrp_evaluate_conditional_warnv (cond, true, &sop);
+
+ if (ret && sop)
+ {
+ enum warn_strict_overflow_code wc;
+ const char* warnmsg;
+
+ if (is_gimple_min_invariant (ret))
+ {
+ wc = WARN_STRICT_OVERFLOW_CONDITIONAL;
+ warnmsg = G_("assuming signed overflow does not occur when "
+ "simplifying conditional to constant");
+ }
+ else
+ {
+ wc = WARN_STRICT_OVERFLOW_COMPARISON;
+ warnmsg = G_("assuming signed overflow does not occur when "
+ "simplifying conditional");
+ }
+
+ if (issue_strict_overflow_warning (wc))
+ {
+ location_t locus;
+
+ if (!EXPR_HAS_LOCATION (stmt))
+ locus = input_location;
+ else
+ locus = EXPR_LOCATION (stmt);
+ warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
+ }
+ }
+
+ if (warn_type_limits
+ && ret
+ && TREE_CODE_CLASS (TREE_CODE (cond)) == tcc_comparison)
+ {
+ /* If the comparison is being folded and the operand on the LHS
+ is being compared against a constant value that is outside of
+ the natural range of OP0's type, then the predicate will
+ always fold regardless of the value of OP0. If -Wtype-limits
+ was specified, emit a warning. */
+ const char *warnmsg = NULL;
+ tree op0 = TREE_OPERAND (cond, 0);
+ tree op1 = TREE_OPERAND (cond, 1);
+ tree type = TREE_TYPE (op0);
+ value_range_t *vr0 = get_value_range (op0);
+
+ if (vr0->type != VR_VARYING
+ && INTEGRAL_TYPE_P (type)
+ && vrp_val_is_min (vr0->min)
+ && vrp_val_is_max (vr0->max)
+ && is_gimple_min_invariant (op1))
+ {
+ if (integer_zerop (ret))
+ warnmsg = G_("comparison always false due to limited range of "
+ "data type");
+ else
+ warnmsg = G_("comparison always true due to limited range of "
+ "data type");
+ }
+
+ if (warnmsg)
+ {
+ location_t locus;
+
+ if (!EXPR_HAS_LOCATION (stmt))
+ locus = input_location;
+ else
+ locus = EXPR_LOCATION (stmt);
+
+ warning (OPT_Wextra, "%H%s", &locus, warnmsg);
+ }
+ }
+
+ return ret;
+}
+
/* Visit conditional statement STMT. If we can determine which edge
will be taken out of STMT's basic block, record it in
vrp_visit_cond_stmt (tree stmt, edge *taken_edge_p)
{
tree cond, val;
+ bool sop;
*taken_edge_p = NULL;
- /* FIXME. Handle SWITCH_EXPRs. But first, the assert pass needs to
- add ASSERT_EXPRs for them. */
+ /* FIXME. Handle SWITCH_EXPRs. */
if (TREE_CODE (stmt) == SWITCH_EXPR)
return SSA_PROP_VARYING;
additional checking. Testing on several code bases (GCC, DLV,
MICO, TRAMP3D and SPEC2000) showed that doing this results in
4 more predicates folded in SPEC. */
- val = vrp_evaluate_conditional (cond, false);
+ sop = false;
+ val = vrp_evaluate_conditional_warnv (cond, false, &sop);
if (val)
- *taken_edge_p = find_taken_edge (bb_for_stmt (stmt), val);
+ {
+ if (!sop)
+ *taken_edge_p = find_taken_edge (bb_for_stmt (stmt), val);
+ else
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "\nIgnoring predicate evaluation because "
+ "it assumes that signed overflow is undefined");
+ val = NULL_TREE;
+ }
+ }
if (dump_file && (dump_flags & TDF_DETAILS))
{
}
ann = stmt_ann (stmt);
- if (TREE_CODE (stmt) == MODIFY_EXPR)
+ if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
{
- tree rhs = TREE_OPERAND (stmt, 1);
+ tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
/* In general, assignments with virtual operands are not useful
for deriving ranges, with the obvious exception of calls to
builtin functions. */
if ((TREE_CODE (rhs) == CALL_EXPR
- && TREE_CODE (TREE_OPERAND (rhs, 0)) == ADDR_EXPR
- && DECL_P (TREE_OPERAND (TREE_OPERAND (rhs, 0), 0))
- && DECL_IS_BUILTIN (TREE_OPERAND (TREE_OPERAND (rhs, 0), 0)))
+ && TREE_CODE (CALL_EXPR_FN (rhs)) == ADDR_EXPR
+ && DECL_P (TREE_OPERAND (CALL_EXPR_FN (rhs), 0))
+ && DECL_IS_BUILTIN (TREE_OPERAND (CALL_EXPR_FN (rhs), 0)))
|| ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
return vrp_visit_assignment (stmt, output_p);
}
/* Meet operation for value ranges. Given two value ranges VR0 and
- VR1, store in VR0 the result of meeting VR0 and VR1.
-
- The meeting rules are as follows:
-
- 1- If VR0 and VR1 have an empty intersection, set VR0 to VR_VARYING.
-
- 2- If VR0 and VR1 have a non-empty intersection, set VR0 to the
- union of VR0 and VR1. */
+ VR1, store in VR0 a range that contains both VR0 and VR1. This
+ may not be the smallest possible such range. */
static void
vrp_meet (value_range_t *vr0, value_range_t *vr1)
if (vr0->type == VR_RANGE && vr1->type == VR_RANGE)
{
- /* If VR0 and VR1 have a non-empty intersection, compute the
- union of both ranges. */
- if (value_ranges_intersect_p (vr0, vr1))
- {
- int cmp;
- tree min, max;
-
- /* The lower limit of the new range is the minimum of the
- two ranges. If they cannot be compared, the result is
- VARYING. */
- cmp = compare_values (vr0->min, vr1->min);
- if (cmp == 0 || cmp == 1)
- min = vr1->min;
- else if (cmp == -1)
- min = vr0->min;
- else
- {
- set_value_range_to_varying (vr0);
- return;
- }
-
- /* Similarly, the upper limit of the new range is the
- maximum of the two ranges. If they cannot be compared,
- the result is VARYING. */
- cmp = compare_values (vr0->max, vr1->max);
- if (cmp == 0 || cmp == -1)
- max = vr1->max;
- else if (cmp == 1)
- max = vr0->max;
- else
- {
- set_value_range_to_varying (vr0);
- return;
- }
-
- /* The resulting set of equivalences is the intersection of
- the two sets. */
- if (vr0->equiv && vr1->equiv && vr0->equiv != vr1->equiv)
- bitmap_and_into (vr0->equiv, vr1->equiv);
- else if (vr0->equiv && !vr1->equiv)
- bitmap_clear (vr0->equiv);
-
- set_value_range (vr0, vr0->type, min, max, vr0->equiv);
- }
+ int cmp;
+ tree min, max;
+
+ /* Compute the convex hull of the ranges. The lower limit of
+ the new range is the minimum of the two ranges. If they
+ cannot be compared, then give up. */
+ cmp = compare_values (vr0->min, vr1->min);
+ if (cmp == 0 || cmp == 1)
+ min = vr1->min;
+ else if (cmp == -1)
+ min = vr0->min;
+ else
+ goto give_up;
+
+ /* Similarly, the upper limit of the new range is the maximum
+ of the two ranges. If they cannot be compared, then
+ give up. */
+ cmp = compare_values (vr0->max, vr1->max);
+ if (cmp == 0 || cmp == -1)
+ max = vr1->max;
+ else if (cmp == 1)
+ max = vr0->max;
else
- goto no_meet;
+ goto give_up;
+
+ /* Check for useless ranges. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (min))
+ && ((vrp_val_is_min (min) || is_overflow_infinity (min))
+ && (vrp_val_is_max (max) || is_overflow_infinity (max))))
+ goto give_up;
+
+ /* The resulting set of equivalences is the intersection of
+ the two sets. */
+ if (vr0->equiv && vr1->equiv && vr0->equiv != vr1->equiv)
+ bitmap_and_into (vr0->equiv, vr1->equiv);
+ else if (vr0->equiv && !vr1->equiv)
+ bitmap_clear (vr0->equiv);
+
+ set_value_range (vr0, vr0->type, min, max, vr0->equiv);
}
else if (vr0->type == VR_ANTI_RANGE && vr1->type == VR_ANTI_RANGE)
{
- /* Two anti-ranges meet only if they are both identical. */
+ /* Two anti-ranges meet only if their complements intersect.
+ Only handle the case of identical ranges. */
if (compare_values (vr0->min, vr1->min) == 0
&& compare_values (vr0->max, vr1->max) == 0
&& compare_values (vr0->min, vr0->max) == 0)
bitmap_clear (vr0->equiv);
}
else
- goto no_meet;
+ goto give_up;
}
else if (vr0->type == VR_ANTI_RANGE || vr1->type == VR_ANTI_RANGE)
{
- /* A numeric range [VAL1, VAL2] and an anti-range ~[VAL3, VAL4]
- meet only if the ranges have an empty intersection. The
- result of the meet operation is the anti-range. */
+ /* For a numeric range [VAL1, VAL2] and an anti-range ~[VAL3, VAL4],
+ only handle the case where the ranges have an empty intersection.
+ The result of the meet operation is the anti-range. */
if (!symbolic_range_p (vr0)
&& !symbolic_range_p (vr1)
&& !value_ranges_intersect_p (vr0, vr1))
bitmap_clear (vr0->equiv);
}
else
- goto no_meet;
+ goto give_up;
}
else
gcc_unreachable ();
return;
-no_meet:
- /* The two range VR0 and VR1 do not meet. Before giving up and
- setting the result to VARYING, see if we can at least derive a
- useful anti-range. FIXME, all this nonsense about distinguishing
+give_up:
+ /* Failed to find an efficient meet. Before giving up and setting
+ the result to VARYING, see if we can at least derive a useful
+ anti-range. FIXME, all this nonsense about distinguishing
anti-ranges from ranges is necessary because of the odd
semantics of range_includes_zero_p and friends. */
if (!symbolic_range_p (vr0)
tree lhs = PHI_RESULT (phi);
value_range_t *lhs_vr = get_value_range (lhs);
value_range_t vr_result = { VR_UNDEFINED, NULL_TREE, NULL_TREE, NULL };
+ int edges, old_edges;
copy_value_range (&vr_result, lhs_vr);
print_generic_expr (dump_file, phi, dump_flags);
}
+ edges = 0;
for (i = 0; i < PHI_NUM_ARGS (phi); i++)
{
edge e = PHI_ARG_EDGE (phi, i);
tree arg = PHI_ARG_DEF (phi, i);
value_range_t vr_arg;
+ ++edges;
+
if (TREE_CODE (arg) == SSA_NAME)
- vr_arg = *(get_value_range (arg));
+ {
+ vr_arg = *(get_value_range (arg));
+ }
else
{
+ if (is_overflow_infinity (arg))
+ {
+ arg = copy_node (arg);
+ TREE_OVERFLOW (arg) = 0;
+ }
+
vr_arg.type = VR_RANGE;
vr_arg.min = arg;
vr_arg.max = arg;
if (vr_result.type == VR_VARYING)
goto varying;
+ old_edges = vr_phi_edge_counts[SSA_NAME_VERSION (lhs)];
+ vr_phi_edge_counts[SSA_NAME_VERSION (lhs)] = edges;
+
/* To prevent infinite iterations in the algorithm, derive ranges
when the new value is slightly bigger or smaller than the
- previous one. */
- if (lhs_vr->type == VR_RANGE && vr_result.type == VR_RANGE)
+ previous one. We don't do this if we have seen a new executable
+ edge; this helps us avoid an overflow infinity for conditionals
+ which are not in a loop. */
+ if (lhs_vr->type == VR_RANGE && vr_result.type == VR_RANGE
+ && edges <= old_edges)
{
if (!POINTER_TYPE_P (TREE_TYPE (lhs)))
{
other case to avoid infinite bouncing between different
minimums. */
if (cmp_min > 0 || cmp_min < 0)
- vr_result.min = TYPE_MIN_VALUE (TREE_TYPE (vr_result.min));
+ {
+ /* If we will end up with a (-INF, +INF) range, set it
+ to VARYING. */
+ if (vrp_val_is_max (vr_result.max))
+ goto varying;
+
+ if (!needs_overflow_infinity (TREE_TYPE (vr_result.min))
+ || !vrp_var_may_overflow (lhs, phi))
+ vr_result.min = TYPE_MIN_VALUE (TREE_TYPE (vr_result.min));
+ else if (supports_overflow_infinity (TREE_TYPE (vr_result.min)))
+ vr_result.min =
+ negative_overflow_infinity (TREE_TYPE (vr_result.min));
+ else
+ goto varying;
+ }
/* Similarly, if the new maximum is smaller or larger than
the previous one, go all the way to +INF. */
if (cmp_max < 0 || cmp_max > 0)
- vr_result.max = TYPE_MAX_VALUE (TREE_TYPE (vr_result.max));
-
- /* If we ended up with a (-INF, +INF) range, set it to
- VARYING. */
- if (vr_result.min == TYPE_MIN_VALUE (TREE_TYPE (vr_result.min))
- && vr_result.max == TYPE_MAX_VALUE (TREE_TYPE (vr_result.max)))
- goto varying;
+ {
+ /* If we will end up with a (-INF, +INF) range, set it
+ to VARYING. */
+ if (vrp_val_is_min (vr_result.min))
+ goto varying;
+
+ if (!needs_overflow_infinity (TREE_TYPE (vr_result.max))
+ || !vrp_var_may_overflow (lhs, phi))
+ vr_result.max = TYPE_MAX_VALUE (TREE_TYPE (vr_result.max));
+ else if (supports_overflow_infinity (TREE_TYPE (vr_result.max)))
+ vr_result.max =
+ positive_overflow_infinity (TREE_TYPE (vr_result.max));
+ else
+ goto varying;
+ }
}
}
}
else
{
- val = compare_range_with_value (GT_EXPR, vr, integer_zero_node);
+ bool sop = false;
+
+ val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, &sop);
+
+ if (val
+ && sop
+ && integer_onep (val)
+ && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC))
+ {
+ location_t locus;
+
+ if (!EXPR_HAS_LOCATION (stmt))
+ locus = input_location;
+ else
+ locus = EXPR_LOCATION (stmt);
+ warning (OPT_Wstrict_overflow,
+ ("%Hassuming signed overflow does not occur when "
+ "simplifying / or %% to >> or &"),
+ &locus);
+ }
}
if (val && integer_onep (val))
t = build2 (BIT_AND_EXPR, TREE_TYPE (op0), op0, t);
}
- TREE_OPERAND (stmt, 1) = t;
+ GIMPLE_STMT_OPERAND (stmt, 1) = t;
update_stmt (stmt);
}
}
}
else if (vr)
{
- val = compare_range_with_value (LE_EXPR, vr, integer_zero_node);
+ bool sop = false;
+
+ val = compare_range_with_value (LE_EXPR, vr, integer_zero_node, &sop);
if (!val)
{
- val = compare_range_with_value (GE_EXPR, vr, integer_zero_node);
+ sop = false;
+ val = compare_range_with_value (GE_EXPR, vr, integer_zero_node,
+ &sop);
if (val)
{
{
tree t;
+ if (sop && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC))
+ {
+ location_t locus;
+
+ if (!EXPR_HAS_LOCATION (stmt))
+ locus = input_location;
+ else
+ locus = EXPR_LOCATION (stmt);
+ warning (OPT_Wstrict_overflow,
+ ("%Hassuming signed overflow does not occur when "
+ "simplifying abs (X) to X or -X"),
+ &locus);
+ }
+
if (integer_onep (val))
t = build1 (NEGATE_EXPR, TREE_TYPE (op), op);
else
t = op;
- TREE_OPERAND (stmt, 1) = t;
+ GIMPLE_STMT_OPERAND (stmt, 1) = t;
update_stmt (stmt);
}
}
the conditional as it was written. */
if (cond_code == LE_EXPR || cond_code == LT_EXPR)
{
+ /* This should not be negative infinity; there is no overflow
+ here. */
min = TYPE_MIN_VALUE (TREE_TYPE (op0));
max = op1;
- if (cond_code == LT_EXPR)
+ if (cond_code == LT_EXPR && !is_overflow_infinity (max))
{
tree one = build_int_cst (TREE_TYPE (op0), 1);
max = fold_build2 (MINUS_EXPR, TREE_TYPE (op0), max, one);
+ if (EXPR_P (max))
+ TREE_NO_WARNING (max) = 1;
}
}
else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
{
+ /* This should not be positive infinity; there is no overflow
+ here. */
max = TYPE_MAX_VALUE (TREE_TYPE (op0));
min = op1;
- if (cond_code == GT_EXPR)
+ if (cond_code == GT_EXPR && !is_overflow_infinity (min))
{
tree one = build_int_cst (TREE_TYPE (op0), 1);
min = fold_build2 (PLUS_EXPR, TREE_TYPE (op0), min, one);
+ if (EXPR_P (min))
+ TREE_NO_WARNING (min) = 1;
}
}
void
simplify_stmt_using_ranges (tree stmt)
{
- if (TREE_CODE (stmt) == MODIFY_EXPR)
+ if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
{
- tree rhs = TREE_OPERAND (stmt, 1);
+ tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
enum tree_code rhs_code = TREE_CODE (rhs);
/* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
restored. */
static VEC(tree,heap) *stack;
-/* A trivial wrapper so that we can present the generic jump
- threading code with a simple API for simplifying statements. */
+/* A trivial wrapper so that we can present the generic jump threading
+ code with a simple API for simplifying statements. STMT is the
+ statement we want to simplify, WITHIN_STMT provides the location
+ for any overflow warnings. */
+
static tree
-simplify_stmt_for_jump_threading (tree stmt)
+simplify_stmt_for_jump_threading (tree stmt, tree within_stmt)
{
/* We only use VRP information to simplify conditionals. This is
overly conservative, but it's unclear if doing more would be
if (TREE_CODE (stmt) != COND_EXPR)
return NULL;
- return vrp_evaluate_conditional (COND_EXPR_COND (stmt), true);
+ return vrp_evaluate_conditional (COND_EXPR_COND (stmt), within_stmt);
}
/* Blocks which have more than one predecessor and more than
static void
finalize_jump_threads (void)
{
- bool cfg_altered = false;
- cfg_altered = thread_through_all_blocks ();
-
- /* If we threaded jumps, then we need to recompute the dominance
- information, to safely do that we must clean up the CFG first. */
- if (cfg_altered)
- {
- free_dominance_info (CDI_DOMINATORS);
- cleanup_tree_cfg ();
- calculate_dominance_info (CDI_DOMINATORS);
- }
+ thread_through_all_blocks (false);
VEC_free (tree, heap, stack);
}
/* We may have ended with ranges that have exactly one value. Those
values can be substituted as any other copy/const propagated
value using substitute_and_fold. */
- single_val_range = XNEWVEC (prop_value_t, num_ssa_names);
- memset (single_val_range, 0, num_ssa_names * sizeof (*single_val_range));
+ single_val_range = XCNEWVEC (prop_value_t, num_ssa_names);
do_value_subst_p = false;
for (i = 0; i < num_ssa_names; i++)
substitute_and_fold (single_val_range, true);
+ if (warn_array_bounds)
+ check_all_array_refs ();
+
/* We must identify jump threading opportunities before we release
the datastructures built by VRP. */
identify_jump_threads ();
free (single_val_range);
free (vr_value);
+ free (vr_phi_edge_counts);
/* So that we can distinguish between VRP data being available
and not available. */
vr_value = NULL;
+ vr_phi_edge_counts = NULL;
}
+/* Calculates number of iterations for all loops, to ensure that they are
+ cached. */
+
+static void
+record_numbers_of_iterations (void)
+{
+ loop_iterator li;
+ struct loop *loop;
+
+ FOR_EACH_LOOP (li, loop, 0)
+ {
+ number_of_latch_executions (loop);
+ }
+}
/* Main entry point to VRP (Value Range Propagation). This pass is
loosely based on J. R. C. Patterson, ``Accurate Static Branch
static unsigned int
execute_vrp (void)
{
+ loop_optimizer_init (LOOPS_NORMAL | LOOPS_HAVE_RECORDED_EXITS);
+ rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
+ scev_initialize ();
+
insert_range_assertions ();
- current_loops = loop_optimizer_init (LOOPS_NORMAL);
- if (current_loops)
- scev_initialize (current_loops);
+ /* Compute the # of iterations for each loop before we start the VRP
+ analysis. The value ranges determined by VRP are used in expression
+ simplification, that is also used by the # of iterations analysis.
+ However, in the middle of the VRP analysis, the value ranges do not take
+ all the possible paths in CFG into account, so they do not have to be
+ correct, and the # of iterations analysis can obtain wrong results.
+ This is a problem, since the results of the # of iterations analysis
+ are cached, so these mistakes would not be corrected when the value
+ ranges are corrected. */
+ record_numbers_of_iterations ();
vrp_initialize ();
ssa_propagate (vrp_visit_stmt, vrp_visit_phi_node);
vrp_finalize ();
- if (current_loops)
- {
- scev_finalize ();
- loop_optimizer_finalize (current_loops);
- current_loops = NULL;
- }
-
/* ASSERT_EXPRs must be removed before finalizing jump threads
as finalizing jump threads calls the CFG cleanup code which
does not properly handle ASSERT_EXPRs. */
update_ssa (TODO_update_ssa);
finalize_jump_threads ();
+ scev_finalize ();
+ loop_optimizer_finalize ();
+
return 0;
}
TV_TREE_VRP, /* tv_id */
PROP_ssa | PROP_alias, /* properties_required */
0, /* properties_provided */
- PROP_smt_usage, /* properties_destroyed */
+ 0, /* properties_destroyed */
0, /* todo_flags_start */
TODO_cleanup_cfg
| TODO_ggc_collect
| TODO_verify_ssa
| TODO_dump_func
- | TODO_update_ssa
- | TODO_update_smt_usage, /* todo_flags_finish */
+ | TODO_update_ssa, /* todo_flags_finish */
0 /* letter */
};
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