/* Support routines for Value Range Propagation (VRP).
- Copyright (C) 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+ Copyright (C) 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
Contributed by Diego Novillo <dnovillo@redhat.com>.
This file is part of GCC.
#include "tree-chrec.h"
-/* Set of SSA names found during the dominator traversal of a
- sub-graph in find_assert_locations. */
-static sbitmap found_in_subgraph;
+/* Set of SSA names found live during the RPO traversal of the function
+ for still active basic-blocks. */
+static sbitmap *live;
+
+/* Return true if the SSA name NAME is live on the edge E. */
+
+static bool
+live_on_edge (edge e, tree name)
+{
+ return (live[e->dest->index]
+ && TEST_BIT (live[e->dest->index], SSA_NAME_VERSION (name)));
+}
/* 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_with_ops (enum tree_code,
- tree, tree, bool, bool *);
+ tree, tree, bool, bool *,
+ bool *);
/* Location information for ASSERT_EXPRs. Each instance of this
structure describes an ASSERT_EXPR for an SSA name. Since a single
ASSERT_EXPRs for SSA name N_I should be inserted. */
static assert_locus_t *asserts_for;
-/* Set of blocks visited in find_assert_locations. Used to avoid
- visiting the same block more than once. */
-static sbitmap blocks_visited;
-
/* Value range array. After propagation, VR_VALUE[I] holds the range
of values that SSA name N_I may take. */
static value_range_t **vr_value;
static VEC (switch_update, heap) *to_update_switch_stmts;
-/* Return the maximum value for TYPEs base type. */
+/* Return the maximum value for TYPE. */
static inline tree
vrp_val_max (const_tree type)
if (!INTEGRAL_TYPE_P (type))
return NULL_TREE;
- /* For integer sub-types the values for the base type are relevant. */
- if (TREE_TYPE (type))
- type = TREE_TYPE (type);
-
return TYPE_MAX_VALUE (type);
}
-/* Return the minimum value for TYPEs base type. */
+/* Return the minimum value for TYPE. */
static inline tree
vrp_val_min (const_tree type)
if (!INTEGRAL_TYPE_P (type))
return NULL_TREE;
- /* For integer sub-types the values for the base type are relevant. */
- if (TREE_TYPE (type))
- type = TREE_TYPE (type);
-
return TYPE_MIN_VALUE (type);
}
static inline bool
needs_overflow_infinity (const_tree type)
{
- return (INTEGRAL_TYPE_P (type)
- && !TYPE_OVERFLOW_WRAPS (type)
- /* Integer sub-types never overflow as they are never
- operands of arithmetic operators. */
- && !(TREE_TYPE (type) && TREE_TYPE (type) != type));
+ return INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type);
}
/* Return whether TYPE can support our overflow infinity
}
+/* If abs (min) < abs (max), set VR to [-max, max], if
+ abs (min) >= abs (max), set VR to [-min, min]. */
+
+static void
+abs_extent_range (value_range_t *vr, tree min, tree max)
+{
+ int cmp;
+
+ gcc_assert (TREE_CODE (min) == INTEGER_CST);
+ gcc_assert (TREE_CODE (max) == INTEGER_CST);
+ gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (min)));
+ gcc_assert (!TYPE_UNSIGNED (TREE_TYPE (min)));
+ min = fold_unary (ABS_EXPR, TREE_TYPE (min), min);
+ max = fold_unary (ABS_EXPR, TREE_TYPE (max), max);
+ if (TREE_OVERFLOW (min) || TREE_OVERFLOW (max))
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+ cmp = compare_values (min, max);
+ if (cmp == -1)
+ min = fold_unary (NEGATE_EXPR, TREE_TYPE (min), max);
+ else if (cmp == 0 || cmp == 1)
+ {
+ max = min;
+ min = fold_unary (NEGATE_EXPR, TREE_TYPE (min), min);
+ }
+ else
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+ set_and_canonicalize_value_range (vr, VR_RANGE, min, max, NULL);
+}
+
+
/* Return value range information for VAR.
If we have no values ranges recorded (ie, VRP is not running), then
return false;
}
-/* Return true if T, an SSA_NAME, is known to be nonzero. Return
- false otherwise or if no value range information is available. */
+/* If OP has a value range with a single constant value return that,
+ otherwise return NULL_TREE. This returns OP itself if OP is a
+ constant. */
-bool
-ssa_name_nonzero_p (const_tree t)
+static tree
+op_with_constant_singleton_value_range (tree op)
{
- value_range_t *vr = get_value_range (t);
+ value_range_t *vr;
- if (!vr)
- return false;
+ if (is_gimple_min_invariant (op))
+ return op;
- /* A VR_RANGE which does not include zero is a nonzero value. */
- if (vr->type == VR_RANGE && !symbolic_range_p (vr))
- return ! range_includes_zero_p (vr);
+ if (TREE_CODE (op) != SSA_NAME)
+ return NULL_TREE;
- /* A VR_ANTI_RANGE which does include zero is a nonzero value. */
- if (vr->type == VR_ANTI_RANGE && !symbolic_range_p (vr))
- return range_includes_zero_p (vr);
+ vr = get_value_range (op);
+ if (vr->type == VR_RANGE
+ && operand_equal_p (vr->min, vr->max, 0)
+ && is_gimple_min_invariant (vr->min))
+ return vr->min;
- return false;
+ return NULL_TREE;
}
all should be optimized away above us. */
if ((cond_code == LT_EXPR
&& compare_values (max, min) == 0)
- || is_overflow_infinity (max))
+ || (CONSTANT_CLASS_P (max) && TREE_OVERFLOW (max)))
set_value_range_to_varying (vr_p);
else
{
all should be optimized away above us. */
if ((cond_code == GT_EXPR
&& compare_values (min, max) == 0)
- || is_overflow_infinity (min))
+ || (CONSTANT_CLASS_P (min) && TREE_OVERFLOW (min)))
set_value_range_to_varying (vr_p);
else
{
&& code != MIN_EXPR
&& code != MAX_EXPR
&& code != BIT_AND_EXPR
+ && code != BIT_IOR_EXPR
&& code != TRUTH_AND_EXPR
&& code != TRUTH_OR_EXPR)
{
+ /* We can still do constant propagation here. */
+ tree const_op0 = op_with_constant_singleton_value_range (op0);
+ tree const_op1 = op_with_constant_singleton_value_range (op1);
+ if (const_op0 || const_op1)
+ {
+ tree tem = fold_binary (code, expr_type,
+ const_op0 ? const_op0 : op0,
+ const_op1 ? const_op1 : op1);
+ if (tem
+ && is_gimple_min_invariant (tem)
+ && !is_overflow_infinity (tem))
+ {
+ set_value_range (vr, VR_RANGE, tem, tem, NULL);
+ return;
+ }
+ }
set_value_range_to_varying (vr);
return;
}
/* Refuse to operate on VARYING ranges, ranges of different kinds
and symbolic ranges. As an exception, we allow BIT_AND_EXPR
because we may be able to derive a useful range even if one of
- the operands is VR_VARYING or symbolic range. TODO, we may be
- able to derive anti-ranges in some cases. */
+ the operands is VR_VARYING or symbolic range. Similarly for
+ divisions. TODO, we may be able to derive anti-ranges in
+ some cases. */
if (code != BIT_AND_EXPR
&& code != TRUTH_AND_EXPR
&& code != TRUTH_OR_EXPR
+ && code != TRUNC_DIV_EXPR
+ && code != FLOOR_DIV_EXPR
+ && code != CEIL_DIV_EXPR
+ && code != EXACT_DIV_EXPR
+ && code != ROUND_DIV_EXPR
&& (vr0.type == VR_VARYING
|| vr1.type == VR_VARYING
|| vr0.type != vr1.type
the same end of each range. */
min = vrp_int_const_binop (code, vr0.min, vr1.min);
max = vrp_int_const_binop (code, vr0.max, vr1.max);
+
+ /* If both additions overflowed the range kind is still correct.
+ This happens regularly with subtracting something in unsigned
+ arithmetic.
+ ??? See PR30318 for all the cases we do not handle. */
+ if (code == PLUS_EXPR
+ && (TREE_OVERFLOW (min) && !is_overflow_infinity (min))
+ && (TREE_OVERFLOW (max) && !is_overflow_infinity (max)))
+ {
+ min = build_int_cst_wide (TREE_TYPE (min),
+ TREE_INT_CST_LOW (min),
+ TREE_INT_CST_HIGH (min));
+ max = build_int_cst_wide (TREE_TYPE (max),
+ TREE_INT_CST_LOW (max),
+ TREE_INT_CST_HIGH (max));
+ }
}
else if (code == MULT_EXPR
|| code == TRUNC_DIV_EXPR
}
}
+ else if ((code == TRUNC_DIV_EXPR
+ || code == FLOOR_DIV_EXPR
+ || code == CEIL_DIV_EXPR
+ || code == EXACT_DIV_EXPR
+ || code == ROUND_DIV_EXPR)
+ && (vr0.type != VR_RANGE || symbolic_range_p (&vr0)))
+ {
+ /* For division, if op1 has VR_RANGE but op0 does not, something
+ can be deduced just from that range. Say [min, max] / [4, max]
+ gives [min / 4, max / 4] range. */
+ if (vr1.type == VR_RANGE
+ && !symbolic_range_p (&vr1)
+ && !range_includes_zero_p (&vr1))
+ {
+ vr0.type = type = VR_RANGE;
+ vr0.min = vrp_val_min (TREE_TYPE (op0));
+ vr0.max = vrp_val_max (TREE_TYPE (op1));
+ }
+ else
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+ }
+
+ /* For divisions, if op0 is VR_RANGE, we can deduce a range
+ even if op1 is VR_VARYING, VR_ANTI_RANGE, symbolic or can
+ include 0. */
+ if ((code == TRUNC_DIV_EXPR
+ || code == FLOOR_DIV_EXPR
+ || code == CEIL_DIV_EXPR
+ || code == EXACT_DIV_EXPR
+ || code == ROUND_DIV_EXPR)
+ && vr0.type == VR_RANGE
+ && (vr1.type != VR_RANGE
+ || symbolic_range_p (&vr1)
+ || range_includes_zero_p (&vr1)))
+ {
+ tree zero = build_int_cst (TREE_TYPE (vr0.min), 0);
+ int cmp;
+
+ sop = false;
+ min = NULL_TREE;
+ max = NULL_TREE;
+ if (vrp_expr_computes_nonnegative (op1, &sop) && !sop)
+ {
+ /* For unsigned division or when divisor is known
+ to be non-negative, the range has to cover
+ all numbers from 0 to max for positive max
+ and all numbers from min to 0 for negative min. */
+ cmp = compare_values (vr0.max, zero);
+ if (cmp == -1)
+ max = zero;
+ else if (cmp == 0 || cmp == 1)
+ max = vr0.max;
+ else
+ type = VR_VARYING;
+ cmp = compare_values (vr0.min, zero);
+ if (cmp == 1)
+ min = zero;
+ else if (cmp == 0 || cmp == -1)
+ min = vr0.min;
+ else
+ type = VR_VARYING;
+ }
+ else
+ {
+ /* Otherwise the range is -max .. max or min .. -min
+ depending on which bound is bigger in absolute value,
+ as the division can change the sign. */
+ abs_extent_range (vr, vr0.min, vr0.max);
+ return;
+ }
+ if (type == VR_VARYING)
+ {
+ 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
(MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
MAX1) and then figure the smallest and largest values to form
the new range. */
-
- /* Divisions by zero result in a VARYING value. */
- 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;
-
- 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;
- }
+ gcc_assert ((vr0.type == VR_RANGE
+ || (code == MULT_EXPR && vr0.type == VR_ANTI_RANGE))
+ && vr0.type == vr1.type);
- if (vr0.max == vr0.min)
- val[2] = NULL_TREE;
- else
- {
- val[2] = vrp_int_const_binop (code, vr0.max, vr1.min);
- if (val[2] == NULL_TREE)
+ /* 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;
- }
- 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 (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;
+ }
- if (sop)
- {
- set_value_range_to_varying (vr);
- return;
- }
+ if (vr0.max == vr0.min)
+ val[2] = NULL_TREE;
+ else
+ {
+ val[2] = vrp_int_const_binop (code, vr0.max, vr1.min);
+ if (val[2] == 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 (!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 (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 (val[i])
+ if (sop)
{
- if (!is_gimple_min_invariant (val[i])
- || (TREE_OVERFLOW (val[i])
- && !is_overflow_infinity (val[i])))
+ 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 we found an overflowed value, set MIN and MAX
- to it so that we set the resulting range to
- VARYING. */
- min = max = val[i];
- break;
- }
+ 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
+ VARYING. */
+ min = max = val[i];
+ break;
+ }
- if (compare_values (val[i], min) == -1)
- min = val[i];
+ if (compare_values (val[i], min) == -1)
+ min = val[i];
- if (compare_values (val[i], max) == 1)
- max = val[i];
+ if (compare_values (val[i], max) == 1)
+ max = val[i];
+ }
}
}
}
return;
}
}
+ else if (code == BIT_IOR_EXPR)
+ {
+ if (vr0.type == VR_RANGE
+ && vr1.type == VR_RANGE
+ && TREE_CODE (vr0.min) == INTEGER_CST
+ && TREE_CODE (vr1.min) == INTEGER_CST
+ && TREE_CODE (vr0.max) == INTEGER_CST
+ && TREE_CODE (vr1.max) == INTEGER_CST
+ && tree_int_cst_sgn (vr0.min) >= 0
+ && tree_int_cst_sgn (vr1.min) >= 0)
+ {
+ double_int vr0_max = tree_to_double_int (vr0.max);
+ double_int vr1_max = tree_to_double_int (vr1.max);
+ double_int ior_max;
+
+ /* Set all bits to the right of the most significant one to 1.
+ For example, [0, 4] | [4, 4] = [4, 7]. */
+ ior_max.low = vr0_max.low | vr1_max.low;
+ ior_max.high = vr0_max.high | vr1_max.high;
+ if (ior_max.high != 0)
+ {
+ ior_max.low = ~(unsigned HOST_WIDE_INT)0u;
+ ior_max.high |= ((HOST_WIDE_INT) 1
+ << floor_log2 (ior_max.high)) - 1;
+ }
+ else if (ior_max.low != 0)
+ ior_max.low |= ((unsigned HOST_WIDE_INT) 1u
+ << floor_log2 (ior_max.low)) - 1;
+
+ /* Both of these endpoints are conservative. */
+ min = vrp_int_const_binop (MAX_EXPR, vr0.min, vr1.min);
+ max = double_int_to_tree (expr_type, ior_max);
+ }
+ else
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+ }
else
gcc_unreachable ();
|| code == BIT_NOT_EXPR
|| code == CONJ_EXPR)
{
+ /* We can still do constant propagation here. */
+ if ((op0 = op_with_constant_singleton_value_range (op0)) != NULL_TREE)
+ {
+ tree tem = fold_unary (code, type, op0);
+ if (tem
+ && is_gimple_min_invariant (tem)
+ && !is_overflow_infinity (tem))
+ {
+ set_value_range (vr, VR_RANGE, tem, tem, NULL);
+ return;
+ }
+ }
set_value_range_to_varying (vr);
return;
}
}
/* Handle unary expressions on integer ranges. */
- if ((code == NOP_EXPR
- || code == CONVERT_EXPR)
+ if (CONVERT_EXPR_CODE_P (code)
&& INTEGRAL_TYPE_P (type)
&& INTEGRAL_TYPE_P (TREE_TYPE (op0)))
{
tree inner_type = TREE_TYPE (op0);
tree outer_type = type;
- /* Always use base-types here. This is important for the
- correct signedness. */
- if (TREE_TYPE (inner_type))
- inner_type = TREE_TYPE (inner_type);
- if (TREE_TYPE (outer_type))
- outer_type = TREE_TYPE (outer_type);
-
/* If VR0 is varying and we increase the type precision, assume
a full range for the following transformation. */
if (vr0.type == VR_VARYING
max = fold_unary_to_constant (code, type, vr0.max);
else if (!needs_overflow_infinity (type))
max = TYPE_MAX_VALUE (type);
- else if (supports_overflow_infinity (type))
+ else if (supports_overflow_infinity (type)
+ /* We shouldn't generate [+INF, +INF] as set_value_range
+ doesn't like this and ICEs. */
+ && !is_positive_overflow_infinity (min))
max = positive_overflow_infinity (type);
else
{
bool sop = false;
tree val;
- val = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, false, &sop);
+ val = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, false, &sop,
+ NULL);
/* A disadvantage of using a special infinity as an overflow
representation is that we lose the ability to record overflow
&& gimple_code (gsi_stmt (si)) != GIMPLE_SWITCH);
#endif
+ /* Never build an assert comparing against an integer constant with
+ TREE_OVERFLOW set. This confuses our undefined overflow warning
+ machinery. */
+ if (TREE_CODE (val) == INTEGER_CST
+ && TREE_OVERFLOW (val))
+ val = build_int_cst_wide (TREE_TYPE (val),
+ TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val));
+
/* The new assertion A will be inserted at BB or E. We need to
determine if the new location is dominated by a previously
registered location for A. If we are doing an edge insertion,
/* 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))
+ if (live_on_edge (e, name)
&& !has_single_use (name))
{
register_new_assert_for (name, name, comp_code, val, NULL, e, bsi);
/* Extract NAME2 from the (optional) sign-changing cast. */
if (gimple_assign_cast_p (def_stmt))
{
- if ((gimple_assign_rhs_code (def_stmt) == NOP_EXPR
- || gimple_assign_rhs_code (def_stmt) == CONVERT_EXPR)
+ if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))
&& ! TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (def_stmt)))
&& (TYPE_PRECISION (gimple_expr_type (def_stmt))
== TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt)))))
&& (cst2 == NULL_TREE
|| TREE_CODE (cst2) == INTEGER_CST)
&& INTEGRAL_TYPE_P (TREE_TYPE (name3))
- && TEST_BIT (found_in_subgraph, SSA_NAME_VERSION (name3))
+ && live_on_edge (e, name3)
&& !has_single_use (name3))
{
tree tmp;
&& TREE_CODE (name2) == SSA_NAME
&& TREE_CODE (cst2) == INTEGER_CST
&& INTEGRAL_TYPE_P (TREE_TYPE (name2))
- && TEST_BIT (found_in_subgraph, SSA_NAME_VERSION (name2))
+ && live_on_edge (e, name2)
&& !has_single_use (name2))
{
tree tmp;
retval |= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def),
code, e, bsi);
}
- else if (gimple_assign_rhs_code (op_def) == NOP_EXPR
- || gimple_assign_rhs_code (op_def) == CONVERT_EXPR)
+ else if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (op_def)))
{
/* Recurse through the type conversion. */
retval |= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def),
}
-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.
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)
}
}
- /* 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;
}
edge e;
tree vec2;
size_t n = gimple_switch_num_labels(last);
+#if GCC_VERSION >= 4000
unsigned int idx;
+#else
+ /* Work around GCC 3.4 bug (PR 37086). */
+ volatile unsigned int idx;
+#endif
need_assert = false;
bsi = gsi_for_stmt (last);
/* 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
- predicate are used. */
- if (e->dest != bb)
- need_assert |= find_assert_locations (e->dest);
-
/* Register the necessary assertions for the operand in the
SWITCH_EXPR. */
need_assert |= register_edge_assert_for (op, e, bsi,
}
}
- /* Finally, indicate that we have found the operand in the
- SWITCH_EXPR. */
- SET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));
-
return need_assert;
}
inserted by process_assert_insertions. */
static bool
-find_assert_locations (basic_block bb)
+find_assert_locations_1 (basic_block bb, sbitmap live)
{
gimple_stmt_iterator si;
gimple last;
gimple phi;
bool need_assert;
- basic_block son;
-
- if (TEST_BIT (blocks_visited, bb->index))
- return false;
-
- SET_BIT (blocks_visited, bb->index);
need_assert = false;
+ last = last_stmt (bb);
- /* Traverse all PHI nodes in BB marking used operands. */
- for (si = gsi_start_phis (bb); !gsi_end_p(si); gsi_next (&si))
- {
- use_operand_p arg_p;
- ssa_op_iter i;
- phi = gsi_stmt (si);
+ /* If BB's last statement is a conditional statement involving integer
+ operands, determine if we need to add ASSERT_EXPRs. */
+ if (last
+ && gimple_code (last) == GIMPLE_COND
+ && !fp_predicate (last)
+ && !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
+ need_assert |= find_conditional_asserts (bb, last);
- FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_USE)
- {
- tree arg = USE_FROM_PTR (arg_p);
- if (TREE_CODE (arg) == SSA_NAME)
- {
- gcc_assert (is_gimple_reg (PHI_RESULT (phi)));
- SET_BIT (found_in_subgraph, SSA_NAME_VERSION (arg));
- }
- }
- }
+ /* If BB's last statement is a switch statement involving integer
+ operands, determine if we need to add ASSERT_EXPRs. */
+ if (last
+ && gimple_code (last) == GIMPLE_SWITCH
+ && !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
+ need_assert |= find_switch_asserts (bb, last);
/* Traverse all the statements in BB marking used names and looking
for statements that may infer assertions for their used operands. */
- last = NULL;
for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
{
gimple stmt;
stmt = gsi_stmt (si);
+ if (is_gimple_debug (stmt))
+ continue;
+
/* See if we can derive an assertion for any of STMT's operands. */
FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_USE)
{
tree value;
enum tree_code comp_code;
- /* Mark OP in bitmap FOUND_IN_SUBGRAPH. If STMT is inside
- the sub-graph of a conditional block, when we return from
- this recursive walk, our parent will use the
- FOUND_IN_SUBGRAPH bitset to determine if one of the
- operands it was looking for was present in the sub-graph. */
- SET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));
+ /* Mark OP in our live bitmap. */
+ SET_BIT (live, SSA_NAME_VERSION (op));
/* If OP is used in such a way that we can infer a value
range for it, and we don't find a previous assertion for
}
}
}
-
- /* Remember the last statement of the block. */
- last = stmt;
}
- /* If BB's last statement is a conditional expression
- involving integer operands, recurse into each of the sub-graphs
- rooted at BB to determine if we need to add ASSERT_EXPRs. */
- if (last
- && gimple_code (last) == GIMPLE_COND
- && !fp_predicate (last)
- && !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
- need_assert |= find_conditional_asserts (bb, last);
-
- if (last
- && gimple_code (last) == GIMPLE_SWITCH
- && !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
- need_assert |= find_switch_asserts (bb, last);
+ /* Traverse all PHI nodes in BB marking used operands. */
+ for (si = gsi_start_phis (bb); !gsi_end_p(si); gsi_next (&si))
+ {
+ use_operand_p arg_p;
+ ssa_op_iter i;
+ phi = gsi_stmt (si);
- /* Recurse into the dominator children of BB. */
- for (son = first_dom_son (CDI_DOMINATORS, bb);
- son;
- son = next_dom_son (CDI_DOMINATORS, son))
- need_assert |= find_assert_locations (son);
+ FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_USE)
+ {
+ tree arg = USE_FROM_PTR (arg_p);
+ if (TREE_CODE (arg) == SSA_NAME)
+ SET_BIT (live, SSA_NAME_VERSION (arg));
+ }
+ }
return need_assert;
}
+/* Do an RPO walk over the function computing SSA name liveness
+ on-the-fly and deciding on assert expressions to insert.
+ Returns true if there are assert expressions to be inserted. */
+
+static bool
+find_assert_locations (void)
+{
+ int *rpo = XCNEWVEC (int, last_basic_block + NUM_FIXED_BLOCKS);
+ int *bb_rpo = XCNEWVEC (int, last_basic_block + NUM_FIXED_BLOCKS);
+ int *last_rpo = XCNEWVEC (int, last_basic_block + NUM_FIXED_BLOCKS);
+ int rpo_cnt, i;
+ bool need_asserts;
+
+ live = XCNEWVEC (sbitmap, last_basic_block + NUM_FIXED_BLOCKS);
+ rpo_cnt = pre_and_rev_post_order_compute (NULL, rpo, false);
+ for (i = 0; i < rpo_cnt; ++i)
+ bb_rpo[rpo[i]] = i;
+
+ need_asserts = false;
+ for (i = rpo_cnt-1; i >= 0; --i)
+ {
+ basic_block bb = BASIC_BLOCK (rpo[i]);
+ edge e;
+ edge_iterator ei;
+
+ if (!live[rpo[i]])
+ {
+ live[rpo[i]] = sbitmap_alloc (num_ssa_names);
+ sbitmap_zero (live[rpo[i]]);
+ }
+
+ /* Process BB and update the live information with uses in
+ this block. */
+ need_asserts |= find_assert_locations_1 (bb, live[rpo[i]]);
+
+ /* Merge liveness into the predecessor blocks and free it. */
+ if (!sbitmap_empty_p (live[rpo[i]]))
+ {
+ int pred_rpo = i;
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ {
+ int pred = e->src->index;
+ if (e->flags & EDGE_DFS_BACK)
+ continue;
+
+ if (!live[pred])
+ {
+ live[pred] = sbitmap_alloc (num_ssa_names);
+ sbitmap_zero (live[pred]);
+ }
+ sbitmap_a_or_b (live[pred], live[pred], live[rpo[i]]);
+
+ if (bb_rpo[pred] < pred_rpo)
+ pred_rpo = bb_rpo[pred];
+ }
+
+ /* Record the RPO number of the last visited block that needs
+ live information from this block. */
+ last_rpo[rpo[i]] = pred_rpo;
+ }
+ else
+ {
+ sbitmap_free (live[rpo[i]]);
+ live[rpo[i]] = NULL;
+ }
+
+ /* We can free all successors live bitmaps if all their
+ predecessors have been visited already. */
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (last_rpo[e->dest->index] == i
+ && live[e->dest->index])
+ {
+ sbitmap_free (live[e->dest->index]);
+ live[e->dest->index] = NULL;
+ }
+ }
+
+ XDELETEVEC (rpo);
+ XDELETEVEC (bb_rpo);
+ XDELETEVEC (last_rpo);
+ for (i = 0; i < last_basic_block + NUM_FIXED_BLOCKS; ++i)
+ if (live[i])
+ sbitmap_free (live[i]);
+ XDELETEVEC (live);
+
+ return need_asserts;
+}
/* Create an ASSERT_EXPR for NAME and insert it in the location
indicated by LOC. Return true if we made any edge insertions. */
static void
insert_range_assertions (void)
{
- edge e;
- edge_iterator ei;
- bool update_ssa_p;
-
- found_in_subgraph = sbitmap_alloc (num_ssa_names);
- sbitmap_zero (found_in_subgraph);
-
- blocks_visited = sbitmap_alloc (last_basic_block);
- sbitmap_zero (blocks_visited);
-
need_assert_for = BITMAP_ALLOC (NULL);
asserts_for = XCNEWVEC (assert_locus_t, num_ssa_names);
calculate_dominance_info (CDI_DOMINATORS);
- update_ssa_p = false;
- FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
- if (find_assert_locations (e->dest))
- update_ssa_p = true;
-
- if (update_ssa_p)
+ if (find_assert_locations ())
{
process_assert_insertions ();
update_ssa (TODO_update_ssa_no_phi);
dump_function_to_file (current_function_decl, dump_file, dump_flags);
}
- sbitmap_free (found_in_subgraph);
free (asserts_for);
BITMAP_FREE (need_assert_for);
}
IGNORE_OFF_BY_ONE is true if the ARRAY_REF is inside a ADDR_EXPR. */
static void
-check_array_ref (tree ref, const location_t *location, bool ignore_off_by_one)
+check_array_ref (location_t location, tree ref, bool ignore_off_by_one)
{
value_range_t* vr = NULL;
tree low_sub, 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", location);
+ warning_at (location, OPT_Warray_bounds,
+ "array subscript is outside array bounds");
TREE_NO_WARNING (ref) = 1;
}
}
0),
up_sub)))
{
- warning (OPT_Warray_bounds, "%Harray subscript is above array bounds",
- location);
+ warning_at (location, OPT_Warray_bounds,
+ "array subscript is above array bounds");
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",
- location);
+ warning_at (location, OPT_Warray_bounds,
+ "array subscript is below array bounds");
TREE_NO_WARNING (ref) = 1;
}
}
address of an ARRAY_REF, and call check_array_ref on it. */
static void
-search_for_addr_array(tree t, const location_t *location)
+search_for_addr_array (tree t, location_t location)
{
while (TREE_CODE (t) == SSA_NAME)
{
if (gimple_code (g) != GIMPLE_ASSIGN)
return;
- if (get_gimple_rhs_class (gimple_assign_rhs_code (g)) !=
- GIMPLE_SINGLE_RHS)
+ if (get_gimple_rhs_class (gimple_assign_rhs_code (g))
+ != GIMPLE_SINGLE_RHS)
return;
t = gimple_assign_rhs1 (g);
do
{
if (TREE_CODE (t) == ARRAY_REF)
- check_array_ref (t, location, true /*ignore_off_by_one*/);
+ check_array_ref (location, t, true /*ignore_off_by_one*/);
- t = TREE_OPERAND(t,0);
+ t = TREE_OPERAND (t, 0);
}
while (handled_component_p (t));
}
{
tree t = *tp;
struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
- const location_t *location = (const location_t *) wi->info;
+ location_t location;
+
+ if (EXPR_HAS_LOCATION (t))
+ location = EXPR_LOCATION (t);
+ else
+ {
+ location_t *locp = (location_t *) wi->info;
+ location = *locp;
+ }
*walk_subtree = TRUE;
if (TREE_CODE (t) == ARRAY_REF)
- check_array_ref (t, location, false /*ignore_off_by_one*/);
+ check_array_ref (location, t, false /*ignore_off_by_one*/);
if (TREE_CODE (t) == INDIRECT_REF
|| (TREE_CODE (t) == RETURN_EXPR && TREE_OPERAND (t, 0)))
/* Skip bb's that are clearly unreachable. */
if (single_pred_p (bb))
{
- basic_block pred_bb = EDGE_PRED (bb, 0)->src;
+ int i;
+ bool reachable = true;
+ edge e2;
+ edge e = EDGE_PRED (bb, 0);
+ basic_block pred_bb = e->src;
gimple ls = NULL;
+ for (i = 0; VEC_iterate (edge, to_remove_edges, i, e2); ++i)
+ if (e == e2)
+ {
+ reachable = false;
+ break;
+ }
+
+ if (!reachable)
+ continue;
+
if (!gsi_end_p (gsi_last_bb (pred_bb)))
ls = gsi_stmt (gsi_last_bb (pred_bb));
for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
{
gimple stmt = gsi_stmt (si);
- const location_t *location = gimple_location_ptr (stmt);
struct walk_stmt_info wi;
if (!gimple_has_location (stmt))
continue;
for (i = 0; i < n; i++)
{
tree arg = gimple_call_arg (stmt, i);
- search_for_addr_array (arg, location);
+ search_for_addr_array (arg, gimple_location (stmt));
}
}
else
{
memset (&wi, 0, sizeof (wi));
- wi.info = CONST_CAST (void *, (const void *) location);
+ wi.info = CONST_CAST (void *, (const void *)
+ gimple_location_ptr (stmt));
walk_gimple_op (gsi_stmt (si),
check_array_bounds,
else
gsi_next (&si);
}
-
- sbitmap_free (blocks_visited);
}
&& ((is_gimple_call (stmt)
&& gimple_call_fndecl (stmt) != NULL_TREE
&& DECL_IS_BUILTIN (gimple_call_fndecl (stmt)))
- || ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS)))
+ || !gimple_vuse (stmt)))
return true;
}
else if (gimple_code (stmt) == GIMPLE_COND
{
gimple stmt = gsi_stmt (si);
- if (!stmt_interesting_for_vrp (stmt))
+ /* If the statement is a control insn, then we do not
+ want to avoid simulating the statement once. Failure
+ to do so means that those edges will never get added. */
+ if (stmt_ends_bb_p (stmt))
+ prop_set_simulate_again (stmt, true);
+ else if (!stmt_interesting_for_vrp (stmt))
{
ssa_op_iter i;
tree def;
prop_set_simulate_again (stmt, false);
}
else
- {
- prop_set_simulate_again (stmt, true);
- }
+ prop_set_simulate_again (stmt, true);
}
}
}
return NULL_TREE;
}
+/* Helper function for vrp_evaluate_conditional_warnv. */
+
+static tree
+vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code code,
+ tree op0, tree op1,
+ bool * strict_overflow_p)
+{
+ value_range_t *vr0, *vr1;
+
+ vr0 = (TREE_CODE (op0) == SSA_NAME) ? get_value_range (op0) : NULL;
+ vr1 = (TREE_CODE (op1) == SSA_NAME) ? get_value_range (op1) : NULL;
+
+ if (vr0 && vr1)
+ return compare_ranges (code, vr0, vr1, strict_overflow_p);
+ else if (vr0 && vr1 == NULL)
+ return compare_range_with_value (code, vr0, op1, strict_overflow_p);
+ else if (vr0 == NULL && vr1)
+ return (compare_range_with_value
+ (swap_tree_comparison (code), vr1, op0, strict_overflow_p));
+ return NULL;
+}
+
/* Helper function for vrp_evaluate_conditional_warnv. */
static tree
vrp_evaluate_conditional_warnv_with_ops (enum tree_code code, tree op0,
tree op1, bool use_equiv_p,
- bool *strict_overflow_p)
+ bool *strict_overflow_p, bool *only_ranges)
{
+ tree ret;
+ if (only_ranges)
+ *only_ranges = true;
+
/* We only deal with integral and pointer types. */
if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
&& !POINTER_TYPE_P (TREE_TYPE (op0)))
if (use_equiv_p)
{
+ if (only_ranges
+ && (ret = vrp_evaluate_conditional_warnv_with_ops_using_ranges
+ (code, op0, op1, strict_overflow_p)))
+ return ret;
+ *only_ranges = false;
if (TREE_CODE (op0) == SSA_NAME && TREE_CODE (op1) == SSA_NAME)
return compare_names (code, op0, op1, strict_overflow_p);
else if (TREE_CODE (op0) == SSA_NAME)
(swap_tree_comparison (code), op1, op0, strict_overflow_p));
}
else
- {
- value_range_t *vr0, *vr1;
-
- vr0 = (TREE_CODE (op0) == SSA_NAME) ? get_value_range (op0) : NULL;
- vr1 = (TREE_CODE (op1) == SSA_NAME) ? get_value_range (op1) : NULL;
-
- if (vr0 && vr1)
- return compare_ranges (code, vr0, vr1, strict_overflow_p);
- else if (vr0 && vr1 == NULL)
- return compare_range_with_value (code, vr0, op1, strict_overflow_p);
- else if (vr0 == NULL && vr1)
- return (compare_range_with_value
- (swap_tree_comparison (code), vr1, op0, strict_overflow_p));
- }
+ return vrp_evaluate_conditional_warnv_with_ops_using_ranges (code, op0, op1,
+ strict_overflow_p);
return NULL_TREE;
}
based on undefined signed overflow, issue a warning if
appropriate. */
-tree
+static tree
vrp_evaluate_conditional (enum tree_code code, tree op0, tree op1, gimple stmt)
{
bool sop;
tree ret;
+ bool only_ranges;
+
+ /* Some passes and foldings leak constants with overflow flag set
+ into the IL. Avoid doing wrong things with these and bail out. */
+ if ((TREE_CODE (op0) == INTEGER_CST
+ && TREE_OVERFLOW (op0))
+ || (TREE_CODE (op1) == INTEGER_CST
+ && TREE_OVERFLOW (op1)))
+ return NULL_TREE;
sop = false;
- ret = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, true, &sop);
+ ret = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, true, &sop,
+ &only_ranges);
if (ret && sop)
{
location = input_location;
else
location = gimple_location (stmt);
- warning (OPT_Wstrict_overflow, "%H%s", &location, warnmsg);
+ warning_at (location, OPT_Wstrict_overflow, "%s", warnmsg);
}
}
if (warn_type_limits
- && ret
+ && ret && only_ranges
&& TREE_CODE_CLASS (code) == tcc_comparison
&& TREE_CODE (op0) == SSA_NAME)
{
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 type = TREE_TYPE (op0);
value_range_t *vr0 = get_value_range (op0);
&& 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 location;
if (!gimple_has_location (stmt))
else
location = gimple_location (stmt);
- warning (OPT_Wtype_limits, "%H%s", &location, warnmsg);
+ warning_at (location, OPT_Wtype_limits,
+ integer_zerop (ret)
+ ? G_("comparison always false "
+ "due to limited range of data type")
+ : G_("comparison always true "
+ "due to limited range of data type"));
}
}
val = vrp_evaluate_conditional_warnv_with_ops (gimple_cond_code (stmt),
gimple_cond_lhs (stmt),
gimple_cond_rhs (stmt),
- false, &sop);
+ false, &sop, NULL);
if (val)
{
if (!sop)
If there is a CASE_LABEL for VAL, its index is placed in IDX and true is
returned.
- If there is no CASE_LABEL for VAL and the is one that is larger than VAL,
+ If there is no CASE_LABEL for VAL and there is one that is larger than VAL,
it is placed in IDX and false is returned.
If VAL is larger than any CASE_LABEL, n is placed on IDX and false is
fprintf (dump_file, "\n");
}
- if (is_gimple_assign (stmt) || is_gimple_call (stmt))
+ if (!stmt_interesting_for_vrp (stmt))
+ gcc_assert (stmt_ends_bb_p (stmt));
+ else if (is_gimple_assign (stmt) || is_gimple_call (stmt))
{
/* In general, assignments with virtual operands are not useful
for deriving ranges, with the obvious exception of calls to
if ((is_gimple_call (stmt)
&& gimple_call_fndecl (stmt) != NULL_TREE
&& DECL_IS_BUILTIN (gimple_call_fndecl (stmt)))
- || ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
+ || !gimple_vuse (stmt))
return vrp_visit_assignment_or_call (stmt, output_p);
}
else if (gimple_code (stmt) == GIMPLE_COND)
minimums. */
if (cmp_min > 0 || cmp_min < 0)
{
- /* If we will end up with a (-INF, +INF) range, set it
- to VARYING. */
- if (vrp_val_is_max (vr_result.max))
+ /* If we will end up with a (-INF, +INF) range, set it to
+ VARYING. Same if the previous max value was invalid for
+ the type and we'd end up with vr_result.min > vr_result.max. */
+ if (vrp_val_is_max (vr_result.max)
+ || compare_values (TYPE_MIN_VALUE (TREE_TYPE (vr_result.min)),
+ vr_result.max) > 0)
goto varying;
if (!needs_overflow_infinity (TREE_TYPE (vr_result.min))
the previous one, go all the way to +INF. */
if (cmp_max < 0 || cmp_max > 0)
{
- /* If we will end up with a (-INF, +INF) range, set it
- to VARYING. */
- if (vrp_val_is_min (vr_result.min))
+ /* If we will end up with a (-INF, +INF) range, set it to
+ VARYING. Same if the previous min value was invalid for
+ the type and we'd end up with vr_result.max < vr_result.min. */
+ if (vrp_val_is_min (vr_result.min)
+ || compare_values (TYPE_MAX_VALUE (TREE_TYPE (vr_result.max)),
+ vr_result.min) < 0)
goto varying;
if (!needs_overflow_infinity (TREE_TYPE (vr_result.max))
return SSA_PROP_VARYING;
}
+/* Simplify boolean operations if the source is known
+ to be already a boolean. */
+static bool
+simplify_truth_ops_using_ranges (gimple_stmt_iterator *gsi, gimple stmt)
+{
+ enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
+ tree val = NULL;
+ tree op0, op1;
+ value_range_t *vr;
+ bool sop = false;
+ bool need_conversion;
+
+ op0 = gimple_assign_rhs1 (stmt);
+ if (TYPE_PRECISION (TREE_TYPE (op0)) != 1)
+ {
+ if (TREE_CODE (op0) != SSA_NAME)
+ return false;
+ vr = get_value_range (op0);
+
+ val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, &sop);
+ if (!val || !integer_onep (val))
+ return false;
+
+ val = compare_range_with_value (LE_EXPR, vr, integer_one_node, &sop);
+ if (!val || !integer_onep (val))
+ return false;
+ }
+
+ if (rhs_code == TRUTH_NOT_EXPR)
+ {
+ rhs_code = NE_EXPR;
+ op1 = build_int_cst (TREE_TYPE (op0), 1);
+ }
+ else
+ {
+ op1 = gimple_assign_rhs2 (stmt);
+
+ /* Reduce number of cases to handle. */
+ if (is_gimple_min_invariant (op1))
+ {
+ /* Exclude anything that should have been already folded. */
+ if (rhs_code != EQ_EXPR
+ && rhs_code != NE_EXPR
+ && rhs_code != TRUTH_XOR_EXPR)
+ return false;
+
+ if (!integer_zerop (op1)
+ && !integer_onep (op1)
+ && !integer_all_onesp (op1))
+ return false;
+
+ /* Limit the number of cases we have to consider. */
+ if (rhs_code == EQ_EXPR)
+ {
+ rhs_code = NE_EXPR;
+ op1 = fold_unary (TRUTH_NOT_EXPR, TREE_TYPE (op1), op1);
+ }
+ }
+ else
+ {
+ /* Punt on A == B as there is no BIT_XNOR_EXPR. */
+ if (rhs_code == EQ_EXPR)
+ return false;
+
+ if (TYPE_PRECISION (TREE_TYPE (op1)) != 1)
+ {
+ vr = get_value_range (op1);
+ val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, &sop);
+ if (!val || !integer_onep (val))
+ return false;
+
+ val = compare_range_with_value (LE_EXPR, vr, integer_one_node, &sop);
+ if (!val || !integer_onep (val))
+ return false;
+ }
+ }
+ }
+
+ if (sop && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC))
+ {
+ location_t location;
+
+ if (!gimple_has_location (stmt))
+ location = input_location;
+ else
+ location = gimple_location (stmt);
+
+ if (rhs_code == TRUTH_AND_EXPR || rhs_code == TRUTH_OR_EXPR)
+ warning_at (location, OPT_Wstrict_overflow,
+ _("assuming signed overflow does not occur when "
+ "simplifying && or || to & or |"));
+ else
+ warning_at (location, OPT_Wstrict_overflow,
+ _("assuming signed overflow does not occur when "
+ "simplifying ==, != or ! to identity or ^"));
+ }
+
+ need_conversion =
+ !useless_type_conversion_p (TREE_TYPE (gimple_assign_lhs (stmt)),
+ TREE_TYPE (op0));
+
+ /* Make sure to not sign-extend -1 as a boolean value. */
+ if (need_conversion
+ && !TYPE_UNSIGNED (TREE_TYPE (op0))
+ && TYPE_PRECISION (TREE_TYPE (op0)) == 1)
+ return false;
+
+ switch (rhs_code)
+ {
+ case TRUTH_AND_EXPR:
+ rhs_code = BIT_AND_EXPR;
+ break;
+ case TRUTH_OR_EXPR:
+ rhs_code = BIT_IOR_EXPR;
+ break;
+ case TRUTH_XOR_EXPR:
+ case NE_EXPR:
+ if (integer_zerop (op1))
+ {
+ gimple_assign_set_rhs_with_ops (gsi,
+ need_conversion ? NOP_EXPR : SSA_NAME,
+ op0, NULL);
+ update_stmt (gsi_stmt (*gsi));
+ return true;
+ }
+
+ rhs_code = BIT_XOR_EXPR;
+ break;
+ default:
+ gcc_unreachable ();
+ }
+
+ if (need_conversion)
+ return false;
+
+ gimple_assign_set_rhs_with_ops (gsi, rhs_code, op0, op1);
+ update_stmt (gsi_stmt (*gsi));
+ return true;
+}
+
/* Simplify a division or modulo operator to a right shift or
bitwise and if the first operand is unsigned or is greater
than zero and the second operand is an exact power of two. */
-static void
+static bool
simplify_div_or_mod_using_ranges (gimple stmt)
{
enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
location = input_location;
else
location = gimple_location (stmt);
- warning (OPT_Wstrict_overflow,
- ("%Hassuming signed overflow does not occur when "
- "simplifying / or %% to >> or &"),
- &location);
+ warning_at (location, OPT_Wstrict_overflow,
+ "assuming signed overflow does not occur when "
+ "simplifying %</%> or %<%%%> to %<>>%> or %<&%>");
}
}
}
update_stmt (stmt);
+ return true;
}
+
+ return false;
}
/* If the operand to an ABS_EXPR is >= 0, then eliminate the
ABS_EXPR. If the operand is <= 0, then simplify the
ABS_EXPR into a NEGATE_EXPR. */
-static void
+static bool
simplify_abs_using_ranges (gimple stmt)
{
tree val = NULL;
location = input_location;
else
location = gimple_location (stmt);
- warning (OPT_Wstrict_overflow,
- ("%Hassuming signed overflow does not occur when "
- "simplifying abs (X) to X or -X"),
- &location);
+ warning_at (location, OPT_Wstrict_overflow,
+ "assuming signed overflow does not occur when "
+ "simplifying %<abs (X)%> to %<X%> or %<-X%>");
}
gimple_assign_set_rhs1 (stmt, op);
else
gimple_assign_set_rhs_code (stmt, SSA_NAME);
update_stmt (stmt);
+ return true;
}
}
+
+ return false;
}
/* We are comparing trees OP0 and OP1 using COND_CODE. OP0 has
value range information we have for op0. */
if (min && max)
{
- if (compare_values (vr->min, min) == -1)
- min = min;
- else
+ if (compare_values (vr->min, min) == 1)
min = vr->min;
- if (compare_values (vr->max, max) == 1)
- max = max;
- else
+ if (compare_values (vr->max, max) == -1)
max = vr->max;
/* If the new min/max values have converged to a single value,
test if the range information indicates only one value can satisfy
the original conditional. */
-static void
+static bool
simplify_cond_using_ranges (gimple stmt)
{
tree op0 = gimple_cond_lhs (stmt);
print_gimple_stmt (dump_file, stmt, 0, 0);
fprintf (dump_file, "\n");
}
- return;
+ return true;
}
/* Try again after inverting the condition. We only deal
print_gimple_stmt (dump_file, stmt, 0, 0);
fprintf (dump_file, "\n");
}
- return;
+ return true;
}
}
}
+
+ return false;
}
/* Simplify a switch statement using the value range of the switch
argument. */
-static void
+static bool
simplify_switch_using_ranges (gimple stmt)
{
tree op = gimple_switch_index (stmt);
tree vec2;
switch_update su;
- if (TREE_CODE (op) != SSA_NAME)
- return;
+ if (TREE_CODE (op) == SSA_NAME)
+ {
+ vr = get_value_range (op);
- vr = get_value_range (op);
+ /* We can only handle integer ranges. */
+ if (vr->type != VR_RANGE
+ || symbolic_range_p (vr))
+ return false;
- /* We can only handle integer ranges. */
- if (vr->type != VR_RANGE
- || symbolic_range_p (vr))
- return;
+ /* Find case label for min/max of the value range. */
+ take_default = !find_case_label_range (stmt, vr->min, vr->max, &i, &j);
+ }
+ else if (TREE_CODE (op) == INTEGER_CST)
+ {
+ take_default = !find_case_label_index (stmt, 1, op, &i);
+ if (take_default)
+ {
+ i = 1;
+ j = 0;
+ }
+ else
+ {
+ j = i;
+ }
+ }
+ else
+ return false;
- /* Find case label for min/max of the value range. */
n = gimple_switch_num_labels (stmt);
- take_default = !find_case_label_range (stmt, vr->min, vr->max, &i, &j);
/* Bail out if this is just all edges taken. */
if (i == 1
&& j == n - 1
&& take_default)
- return;
+ return false;
/* Build a new vector of taken case labels. */
vec2 = make_tree_vec (j - i + 1 + (int)take_default);
su.stmt = stmt;
su.vec = vec2;
VEC_safe_push (switch_update, heap, to_update_switch_stmts, &su);
+ return false;
}
/* Simplify STMT using ranges if possible. */
-void
-simplify_stmt_using_ranges (gimple stmt)
+static bool
+simplify_stmt_using_ranges (gimple_stmt_iterator *gsi)
{
+ gimple stmt = gsi_stmt (*gsi);
if (is_gimple_assign (stmt))
{
enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
+ switch (rhs_code)
+ {
+ case EQ_EXPR:
+ case NE_EXPR:
+ case TRUTH_NOT_EXPR:
+ case TRUTH_AND_EXPR:
+ case TRUTH_OR_EXPR:
+ case TRUTH_XOR_EXPR:
+ /* Transform EQ_EXPR, NE_EXPR, TRUTH_NOT_EXPR into BIT_XOR_EXPR
+ or identity if the RHS is zero or one, and the LHS are known
+ to be boolean values. Transform all TRUTH_*_EXPR into
+ BIT_*_EXPR if both arguments are known to be boolean values. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt))))
+ return simplify_truth_ops_using_ranges (gsi, stmt);
+ break;
+
/* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
and BIT_AND_EXPR respectively if the first operand is greater
than zero and the second operand is an exact power of two. */
- if ((rhs_code == TRUNC_DIV_EXPR || rhs_code == TRUNC_MOD_EXPR)
- && INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt)))
- && integer_pow2p (gimple_assign_rhs2 (stmt)))
- simplify_div_or_mod_using_ranges (stmt);
+ case TRUNC_DIV_EXPR:
+ case TRUNC_MOD_EXPR:
+ if (INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt)))
+ && integer_pow2p (gimple_assign_rhs2 (stmt)))
+ return simplify_div_or_mod_using_ranges (stmt);
+ break;
/* Transform ABS (X) into X or -X as appropriate. */
- if (rhs_code == ABS_EXPR
- && TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
- && INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt))))
- simplify_abs_using_ranges (stmt);
+ case ABS_EXPR:
+ if (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
+ && INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt))))
+ return simplify_abs_using_ranges (stmt);
+ break;
+
+ default:
+ break;
+ }
}
else if (gimple_code (stmt) == GIMPLE_COND)
- simplify_cond_using_ranges (stmt);
+ return simplify_cond_using_ranges (stmt);
else if (gimple_code (stmt) == GIMPLE_SWITCH)
- simplify_switch_using_ranges (stmt);
+ return simplify_switch_using_ranges (stmt);
+
+ return false;
+}
+
+/* If the statement pointed by SI has a predicate whose value can be
+ computed using the value range information computed by VRP, compute
+ its value and return true. Otherwise, return false. */
+
+static bool
+fold_predicate_in (gimple_stmt_iterator *si)
+{
+ bool assignment_p = false;
+ tree val;
+ gimple stmt = gsi_stmt (*si);
+
+ if (is_gimple_assign (stmt)
+ && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)) == tcc_comparison)
+ {
+ assignment_p = true;
+ val = vrp_evaluate_conditional (gimple_assign_rhs_code (stmt),
+ gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt),
+ stmt);
+ }
+ else if (gimple_code (stmt) == GIMPLE_COND)
+ val = vrp_evaluate_conditional (gimple_cond_code (stmt),
+ gimple_cond_lhs (stmt),
+ gimple_cond_rhs (stmt),
+ stmt);
+ else
+ return false;
+
+ if (val)
+ {
+ if (assignment_p)
+ val = fold_convert (gimple_expr_type (stmt), val);
+
+ if (dump_file)
+ {
+ fprintf (dump_file, "Folding predicate ");
+ print_gimple_expr (dump_file, stmt, 0, 0);
+ fprintf (dump_file, " to ");
+ print_generic_expr (dump_file, val, 0);
+ fprintf (dump_file, "\n");
+ }
+
+ if (is_gimple_assign (stmt))
+ gimple_assign_set_rhs_from_tree (si, val);
+ else
+ {
+ gcc_assert (gimple_code (stmt) == GIMPLE_COND);
+ if (integer_zerop (val))
+ gimple_cond_make_false (stmt);
+ else if (integer_onep (val))
+ gimple_cond_make_true (stmt);
+ else
+ gcc_unreachable ();
+ }
+
+ return true;
+ }
+
+ return false;
+}
+
+/* Callback for substitute_and_fold folding the stmt at *SI. */
+
+static bool
+vrp_fold_stmt (gimple_stmt_iterator *si)
+{
+ if (fold_predicate_in (si))
+ return true;
+
+ return simplify_stmt_using_ranges (si);
}
/* Stack of dest,src equivalency pairs that need to be restored after
}
/* We may have ended with ranges that have exactly one value. Those
- values can be substituted as any other copy/const propagated
+ values can be substituted as any other const propagated
value using substitute_and_fold. */
single_val_range = XCNEWVEC (prop_value_t, num_ssa_names);
for (i = 0; i < num_ssa_names; i++)
if (vr_value[i]
&& vr_value[i]->type == VR_RANGE
- && vr_value[i]->min == vr_value[i]->max)
+ && vr_value[i]->min == vr_value[i]->max
+ && is_gimple_min_invariant (vr_value[i]->min))
{
single_val_range[i].value = vr_value[i]->min;
do_value_subst_p = true;
single_val_range = NULL;
}
- substitute_and_fold (single_val_range, true);
+ substitute_and_fold (single_val_range, vrp_fold_stmt);
if (warn_array_bounds)
check_all_array_refs ();
to_remove_edges = VEC_alloc (edge, heap, 10);
to_update_switch_stmts = VEC_alloc (switch_update, heap, 5);
+ threadedge_initialize_values ();
vrp_initialize ();
ssa_propagate (vrp_visit_stmt, vrp_visit_phi_node);
{
size_t j;
size_t n = TREE_VEC_LENGTH (su->vec);
+ tree label;
gimple_switch_set_num_labels (su->stmt, n);
for (j = 0; j < n; j++)
gimple_switch_set_label (su->stmt, j, TREE_VEC_ELT (su->vec, j));
+ /* As we may have replaced the default label with a regular one
+ make sure to make it a real default label again. This ensures
+ optimal expansion. */
+ label = gimple_switch_default_label (su->stmt);
+ CASE_LOW (label) = NULL_TREE;
+ CASE_HIGH (label) = NULL_TREE;
}
if (VEC_length (edge, to_remove_edges) > 0)
VEC_free (edge, heap, to_remove_edges);
VEC_free (switch_update, heap, to_update_switch_stmts);
+ threadedge_finalize_values ();
scev_finalize ();
loop_optimizer_finalize ();
NULL, /* next */
0, /* static_pass_number */
TV_TREE_VRP, /* tv_id */
- PROP_ssa | PROP_alias, /* properties_required */
+ PROP_ssa, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
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