Hello,
This patch - third of series - fixes vrp to handle bitwise one-bit
precision typed operations.
And it introduces a second - limitted to non-switch-statement range - vrp pass.
Bootstrapped and regression tested for all standard-languages (plus
Ada and Obj-C++) on host x86_64-pc-linux-gnu.
Ok for apply?
Regards,
Kai
ChangeLog
2011-07-07 Kai Tietz <kti...@redhat.com>
* tree-vrp.c (in_second_pass): New static variable.
(extract_range_from_binary_expr): Add handling for
BIT_IOR_EXPR, BIT_AND_EXPR, and BIT_NOT_EXPR.
(register_edge_assert_for_1): Add handling for 1-bit
BIT_IOR_EXPR and BIT_NOT_EXPR.
(register_edge_assert_for): Add handling for 1-bit
BIT_IOR_EXPR.
(ssa_name_get_inner_ssa_name_p): New helper function.
(ssa_name_get_cast_to_p): New helper function.
(simplify_truth_ops_using_ranges): Handle prefixed
cast instruction for result, and add support for one
bit precision BIT_IOR_EXPR, BIT_AND_EXPR, BIT_XOR_EXPR,
, and BIT_NOT_EXPR.
(simplify_stmt_using_ranges): Add handling for one bit
precision BIT_IOR_EXPR, BIT_AND_EXPR, BIT_XOR_EXPR,
and BIT_NOT_EXPR.
(vrp_finalize): Do substitute and fold pass a second
time for vrp_stmt and preserve switch-edge simplification
on second run.
(simplify_switch_using_ranges): Preserve rerun of function
in second pass.
Index: gcc-head/gcc/tree-vrp.c
===================================================================
--- gcc-head.orig/gcc/tree-vrp.c
+++ gcc-head/gcc/tree-vrp.c
@@ -74,6 +74,9 @@ struct value_range_d
typedef struct value_range_d value_range_t;
+/* This flag indicates that we are doing a second pass of VRP. */
+static bool in_second_pass = false;
+
/* Set of SSA names found live during the RPO traversal of the function
for still active basic-blocks. */
static sbitmap *live;
@@ -2232,6 +2235,7 @@ extract_range_from_binary_expr (value_ra
some cases. */
if (code != BIT_AND_EXPR
&& code != TRUTH_AND_EXPR
+ && code != BIT_IOR_EXPR
&& code != TRUTH_OR_EXPR
&& code != TRUNC_DIV_EXPR
&& code != FLOOR_DIV_EXPR
@@ -2291,6 +2295,8 @@ extract_range_from_binary_expr (value_ra
else
set_value_range_to_varying (vr);
}
+ else if (code == BIT_IOR_EXPR)
+ set_value_range_to_varying (vr);
else
gcc_unreachable ();
@@ -2300,11 +2306,13 @@ extract_range_from_binary_expr (value_ra
/* For integer ranges, apply the operation to each end of the
range and see what we end up with. */
if (code == TRUTH_AND_EXPR
- || code == TRUTH_OR_EXPR)
+ || code == TRUTH_OR_EXPR
+ || ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR)
+ && TYPE_PRECISION (TREE_TYPE (op1)) == 1))
{
/* If one of the operands is zero, we know that the whole
expression evaluates zero. */
- if (code == TRUTH_AND_EXPR
+ if ((code == TRUTH_AND_EXPR || code == BIT_AND_EXPR)
&& ((vr0.type == VR_RANGE
&& integer_zerop (vr0.min)
&& integer_zerop (vr0.max))
@@ -2317,7 +2325,7 @@ extract_range_from_binary_expr (value_ra
}
/* If one of the operands is one, we know that the whole
expression evaluates one. */
- else if (code == TRUTH_OR_EXPR
+ else if ((code == TRUTH_OR_EXPR || code == BIT_IOR_EXPR)
&& ((vr0.type == VR_RANGE
&& integer_onep (vr0.min)
&& integer_onep (vr0.max))
@@ -2809,7 +2817,7 @@ extract_range_from_unary_expr (value_ran
cannot easily determine a resulting range. */
if (code == FIX_TRUNC_EXPR
|| code == FLOAT_EXPR
- || code == BIT_NOT_EXPR
+ || (code == BIT_NOT_EXPR && TYPE_PRECISION (type) != 1)
|| code == CONJ_EXPR)
{
/* We can still do constant propagation here. */
@@ -3976,7 +3984,9 @@ build_assert_expr_for (tree cond, tree v
tree a = build2 (ASSERT_EXPR, TREE_TYPE (v), v, cond);
assertion = gimple_build_assign (n, a);
}
- else if (TREE_CODE (cond) == TRUTH_NOT_EXPR)
+ else if (TREE_CODE (cond) == TRUTH_NOT_EXPR
+ || (TREE_CODE (cond) == BIT_NOT_EXPR
+ && TYPE_PRECISION (TREE_TYPE (cond)) == 1))
{
/* Given !V, build the assignment N = false. */
tree op0 = TREE_OPERAND (cond, 0);
@@ -4531,7 +4541,9 @@ register_edge_assert_for_1 (tree op, enu
retval |= register_edge_assert_for_1 (gimple_assign_rhs2 (op_def),
code, e, bsi);
}
- else if (gimple_assign_rhs_code (op_def) == TRUTH_NOT_EXPR)
+ else if (gimple_assign_rhs_code (op_def) == TRUTH_NOT_EXPR
+ || (gimple_assign_rhs_code (op_def) == BIT_NOT_EXPR
+ && TYPE_PRECISION (TREE_TYPE (op)) == 1))
{
/* Recurse, flipping CODE. */
code = invert_tree_comparison (code, false);
@@ -4617,6 +4629,9 @@ register_edge_assert_for (tree name, edg
if (is_gimple_assign (def_stmt)
&& (gimple_assign_rhs_code (def_stmt) == TRUTH_OR_EXPR
+ || (gimple_assign_rhs_code (def_stmt) == BIT_IOR_EXPR
+ && INTEGRAL_TYPE_P (TREE_TYPE (name))
+ && TYPE_PRECISION (TREE_TYPE (name)) == 1)
/* For BIT_IOR_EXPR only if NAME == 0 both operands have
necessarily zero value. */
|| (comp_code == EQ_EXPR
@@ -6747,19 +6762,96 @@ varying:
return SSA_PROP_VARYING;
}
+/* Returns operand1 of ssa-name with SSA_NAME as code, Otherwise it
+ returns NULL_TREE. */
+static tree
+ssa_name_get_inner_ssa_name_p (tree op)
+{
+ gimple stmt;
+
+ if (TREE_CODE (op) != SSA_NAME
+ || !is_gimple_assign (SSA_NAME_DEF_STMT (op)))
+ return NULL_TREE;
+ stmt = SSA_NAME_DEF_STMT (op);
+ if (gimple_assign_rhs_code (stmt) != SSA_NAME)
+ return NULL_TREE;
+ return gimple_assign_rhs1 (stmt);
+}
+
+/* Returns operand of cast operation, if OP is a type-conversion. Otherwise
+ return NULL_TREE. */
+static tree
+ssa_name_get_cast_to_p (tree op)
+{
+ gimple stmt;
+
+ if (TREE_CODE (op) != SSA_NAME
+ || !is_gimple_assign (SSA_NAME_DEF_STMT (op)))
+ return NULL_TREE;
+ stmt = SSA_NAME_DEF_STMT (op);
+ if (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt)))
+ return NULL_TREE;
+ return gimple_assign_rhs1 (stmt);
+}
+
/* 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);
+ gimple stmt2 = stmt;
tree val = NULL;
- tree op0, op1;
+ tree op0, op1, cop0, cop1;
value_range_t *vr;
bool sop = false;
bool need_conversion;
+ location_t loc = gimple_location (stmt);
op0 = gimple_assign_rhs1 (stmt);
+ op1 = NULL_TREE;
+
+ /* Handle cases with prefixed type-cast. */
+ if (CONVERT_EXPR_CODE_P (rhs_code)
+ && INTEGRAL_TYPE_P (TREE_TYPE (op0))
+ && TREE_CODE (op0) == SSA_NAME
+ && is_gimple_assign (SSA_NAME_DEF_STMT (op0))
+ && INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_lhs (stmt))))
+ {
+ stmt2 = SSA_NAME_DEF_STMT (op0);
+ op0 = gimple_assign_rhs1 (stmt2);
+ if (!INTEGRAL_TYPE_P (TREE_TYPE (op0)))
+ return false;
+ rhs_code = gimple_assign_rhs_code (stmt2);
+ if (rhs_code != BIT_NOT_EXPR && rhs_code != TRUTH_NOT_EXPR
+ && rhs_code != TRUTH_AND_EXPR && rhs_code != BIT_AND_EXPR
+ && rhs_code != TRUTH_OR_EXPR && rhs_code != BIT_IOR_EXPR
+ && rhs_code != TRUTH_XOR_EXPR && rhs_code != BIT_XOR_EXPR
+ && rhs_code != NE_EXPR && rhs_code != EQ_EXPR)
+ return false;
+ if (rhs_code == BIT_AND_EXPR || rhs_code == BIT_IOR_EXPR
+ || rhs_code == BIT_XOR_EXPR || rhs_code == TRUTH_AND_EXPR
+ || rhs_code == TRUTH_OR_EXPR || rhs_code == TRUTH_XOR_EXPR
+ || rhs_code == NE_EXPR || rhs_code == EQ_EXPR)
+ op1 = gimple_assign_rhs2 (stmt2);
+ if (gimple_has_location (stmt2))
+ loc = gimple_location (stmt2);
+ }
+ else if (CONVERT_EXPR_CODE_P (rhs_code))
+ return false;
+ else if (rhs_code == BIT_AND_EXPR || rhs_code == BIT_IOR_EXPR
+ || rhs_code == BIT_XOR_EXPR || rhs_code == TRUTH_AND_EXPR
+ || rhs_code == TRUTH_OR_EXPR || rhs_code == TRUTH_XOR_EXPR
+ || rhs_code == NE_EXPR || rhs_code == EQ_EXPR)
+ op1 = gimple_assign_rhs2 (stmt);
+
+ /* ~X is only equivalent of !X, if type-precision is one and X has
+ an integral type. */
+ if (rhs_code == BIT_NOT_EXPR
+ && (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
+ || TYPE_PRECISION (TREE_TYPE (op0)) != 1))
+ return false;
+
if (TYPE_PRECISION (TREE_TYPE (op0)) != 1)
{
if (TREE_CODE (op0) != SSA_NAME)
@@ -6775,22 +6867,100 @@ simplify_truth_ops_using_ranges (gimple_
return false;
}
- if (rhs_code == TRUTH_NOT_EXPR)
+ if (op1 && TREE_CODE (op1) != INTEGER_CST
+ && 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;
+ }
+
+ need_conversion =
+ !useless_type_conversion_p (TREE_TYPE (gimple_assign_lhs (stmt)),
+ TREE_TYPE (op0));
+
+ /* As comparisons X != 0 getting folded by prior pass to (bool) X,
+ but X == 0 might be not folded for none boolean type of X
+ to (bool) (X ^ 1).
+ So for bitwise-binary operations we have three cases to handle:
+ a) ((bool) X) op ((bool) Y)
+ b) ((bool) X) op (Y == 0) OR (X == 0) op ((bool) Y)
+ c) (X == 0) op (Y == 0)
+ The later two cases can't be handled for now, as vr tables
+ would need to be adjusted. */
+ if (need_conversion
+ && (rhs_code == BIT_XOR_EXPR
+ || rhs_code == BIT_AND_EXPR
+ || rhs_code == BIT_IOR_EXPR)
+ && TREE_CODE (op1) == SSA_NAME && TREE_CODE (op0) == SSA_NAME)
+ {
+ cop0 = ssa_name_get_cast_to_p (op0);
+ cop1 = ssa_name_get_cast_to_p (op1);
+ if (!cop0 || !cop1)
+ /* We would need an new statment for cases b and c, and we can't
+ due vr table, so bail out. */
+ return false;
+
+ if (!INTEGRAL_TYPE_P (TREE_TYPE (cop0))
+ || !types_compatible_p (TREE_TYPE (cop0), TREE_TYPE (cop1)))
+ return false;
+ need_conversion =
+ !useless_type_conversion_p (TREE_TYPE (gimple_assign_lhs (stmt)),
+ TREE_TYPE (cop0));
+ if (need_conversion)
+ return false;
+ op0 = cop0;
+ op1 = cop1;
+
+ /* We need to re-check if value ranges for new operands
+ for 1-bit precision/range. */
+ 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 (op1 && 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;
+ }
+ }
+ else if (rhs_code == TRUTH_NOT_EXPR || rhs_code == BIT_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)
+ && rhs_code != TRUTH_XOR_EXPR
+ && rhs_code != BIT_XOR_EXPR)
return false;
if (!integer_zerop (op1)
@@ -6810,18 +6980,6 @@ simplify_truth_ops_using_ranges (gimple_
/* 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;
- }
}
}
@@ -6838,7 +6996,8 @@ simplify_truth_ops_using_ranges (gimple_
warning_at (location, OPT_Wstrict_overflow,
_("assuming signed overflow does not occur when "
"simplifying && or || to & or |"));
- else
+ else if (rhs_code != BIT_AND_EXPR && rhs_code != BIT_IOR_EXPR
+ && rhs_code != BIT_XOR_EXPR)
warning_at (location, OPT_Wstrict_overflow,
_("assuming signed overflow does not occur when "
"simplifying ==, != or ! to identity or ^"));
@@ -6859,16 +7018,21 @@ simplify_truth_ops_using_ranges (gimple_
case TRUTH_AND_EXPR:
rhs_code = BIT_AND_EXPR;
break;
+ case BIT_AND_EXPR:
+ break;
case TRUTH_OR_EXPR:
rhs_code = BIT_IOR_EXPR;
+ case BIT_IOR_EXPR:
break;
case TRUTH_XOR_EXPR:
+ case BIT_XOR_EXPR:
case NE_EXPR:
if (integer_zerop (op1))
{
gimple_assign_set_rhs_with_ops (gsi,
need_conversion ? NOP_EXPR : SSA_NAME,
op0, NULL);
+ gimple_set_location (stmt, loc);
update_stmt (gsi_stmt (*gsi));
return true;
}
@@ -6879,10 +7043,20 @@ simplify_truth_ops_using_ranges (gimple_
gcc_unreachable ();
}
+ /* We can't insert here new expression as otherwise
+ tracked vr tables getting out of bounds. */
if (need_conversion)
return false;
+ /* Reduce here SSA_NAME -> SSA_NAME. */
+ while ((cop0 = ssa_name_get_inner_ssa_name_p (op0)) != NULL_TREE)
+ op0 = cop0;
+
+ while ((cop1 = ssa_name_get_inner_ssa_name_p (op1)) != NULL_TREE)
+ op1 = cop1;
+
gimple_assign_set_rhs_with_ops (gsi, rhs_code, op0, op1);
+ gimple_set_location (stmt, loc);
update_stmt (gsi_stmt (*gsi));
return true;
}
@@ -7263,6 +7437,9 @@ simplify_switch_using_ranges (gimple stm
tree vec2;
switch_update su;
+ if (in_second_pass)
+ return false;
+
if (TREE_CODE (op) == SSA_NAME)
{
vr = get_value_range (op);
@@ -7390,6 +7567,7 @@ simplify_stmt_using_ranges (gimple_stmt_
{
case EQ_EXPR:
case NE_EXPR:
+ case BIT_NOT_EXPR:
case TRUTH_NOT_EXPR:
case TRUTH_AND_EXPR:
case TRUTH_OR_EXPR:
@@ -7425,13 +7603,21 @@ simplify_stmt_using_ranges (gimple_stmt_
if all the bits being cleared are already cleared or
all the bits being set are already set. */
if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
- return simplify_bit_ops_using_ranges (gsi, stmt);
+ {
+ if (simplify_truth_ops_using_ranges (gsi, stmt))
+ return true;
+ return simplify_bit_ops_using_ranges (gsi, stmt);
+ }
break;
CASE_CONVERT:
if (TREE_CODE (rhs1) == SSA_NAME
&& INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
- return simplify_conversion_using_ranges (stmt);
+ {
+ if (simplify_truth_ops_using_ranges (gsi, stmt))
+ return true;
+ return simplify_conversion_using_ranges (stmt);
+ }
break;
default:
@@ -7685,8 +7870,16 @@ vrp_finalize (void)
fprintf (dump_file, "\n");
}
+ /* We redo folding here one time for allowing to inspect more
+ complex reductions. */
+ substitute_and_fold (op_with_constant_singleton_value_range,
+ vrp_fold_stmt, false);
+ /* We need to mark this second pass to avoid re-entering of same
+ edges for switch statments. */
+ in_second_pass = true;
substitute_and_fold (op_with_constant_singleton_value_range,
vrp_fold_stmt, false);
+ in_second_pass = false;
if (warn_array_bounds)
check_all_array_refs ();
