commit 1e0dd52b909722e9387a34ef546fc308c68dac23
Author: Aldy Hernandez <aldyh@redhat.com>
Date: Fri Jun 29 20:12:36 2018 +0200
* tree-vrp.c (extract_range_from_unary_expr): Abstract ABS_EXPR
code...
(extract_range_from_abs_expr): ...here.
@@ -1,3 +1,9 @@
+2018-06-29 Aldy Hernandez <aldyh@redhat.com>
+
+ * tree-vrp.c (extract_range_from_unary_expr): Abstract ABS_EXPR
+ code...
+ (extract_range_from_abs_expr): ...here.
+
2018-06-29 Aldy Hernandez <aldyh@redhat.com>
* tree-vrp.c (extract_range_from_binary_expr_1): Abstract a lot of the
@@ -2365,6 +2365,85 @@ extract_range_from_binary_expr_1 (value_range *vr,
set_value_range (vr, type, min, max, NULL);
}
+/* Calculates the absolute value of a range and puts the result in VR.
+ VR0 is the input range. TYPE is the type of the resulting
+ range. */
+
+static void
+extract_range_from_abs_expr (value_range &vr, tree type, value_range &vr0)
+{
+ /* Pass through vr0 in the easy cases. */
+ if (TYPE_UNSIGNED (type)
+ || value_range_nonnegative_p (&vr0))
+ {
+ copy_value_range (&vr, &vr0);
+ return;
+ }
+
+ /* For the remaining varying or symbolic ranges we can't do anything
+ useful. */
+ if (vr0.type == VR_VARYING
+ || symbolic_range_p (&vr0))
+ {
+ set_value_range_to_varying (&vr);
+ return;
+ }
+
+ /* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a
+ useful range. */
+ if (!TYPE_OVERFLOW_UNDEFINED (type)
+ && ((vr0.type == VR_RANGE
+ && vrp_val_is_min (vr0.min))
+ || (vr0.type == VR_ANTI_RANGE
+ && !vrp_val_is_min (vr0.min))))
+ {
+ set_value_range_to_varying (&vr);
+ return;
+ }
+
+ /* ABS_EXPR may flip the range around, if the original range
+ included negative values. */
+ tree min, max;
+ if (!vrp_val_is_min (vr0.min))
+ min = fold_unary_to_constant (ABS_EXPR, type, vr0.min);
+ else
+ min = TYPE_MAX_VALUE (type);
+
+ if (!vrp_val_is_min (vr0.max))
+ max = fold_unary_to_constant (ABS_EXPR, type, vr0.max);
+ else
+ max = TYPE_MAX_VALUE (type);
+
+ int cmp = compare_values (min, max);
+ gcc_assert (vr0.type != VR_ANTI_RANGE);
+
+ /* If the range contains zero then we know that the minimum value in the
+ range will be zero. */
+ if (range_includes_zero_p (vr0.min, vr0.max) == 1)
+ {
+ if (cmp == 1)
+ max = min;
+ min = build_int_cst (type, 0);
+ }
+ else
+ {
+ /* If the range was reversed, swap MIN and MAX. */
+ if (cmp == 1)
+ std::swap (min, max);
+ }
+
+ cmp = compare_values (min, max);
+ if (cmp == -2 || cmp == 1)
+ {
+ /* If the new range has its limits swapped around (MIN > MAX),
+ then the operation caused one of them to wrap around, mark
+ the new range VARYING. */
+ set_value_range_to_varying (&vr);
+ }
+ else
+ set_value_range (&vr, vr0.type, min, max, NULL);
+}
+
/* Extract range information from a unary operation CODE based on
the range of its operand *VR0 with type OP0_TYPE with resulting type TYPE.
The resulting range is stored in *VR. */
@@ -2495,117 +2574,7 @@ extract_range_from_unary_expr (value_range *vr,
return;
}
else if (code == ABS_EXPR)
- {
- tree min, max;
- int cmp;
-
- /* Pass through vr0 in the easy cases. */
- if (TYPE_UNSIGNED (type)
- || value_range_nonnegative_p (&vr0))
- {
- copy_value_range (vr, &vr0);
- return;
- }
-
- /* For the remaining varying or symbolic ranges we can't do anything
- useful. */
- if (vr0.type == VR_VARYING
- || symbolic_range_p (&vr0))
- {
- set_value_range_to_varying (vr);
- return;
- }
-
- /* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a
- useful range. */
- if (!TYPE_OVERFLOW_UNDEFINED (type)
- && ((vr0.type == VR_RANGE
- && vrp_val_is_min (vr0.min))
- || (vr0.type == VR_ANTI_RANGE
- && !vrp_val_is_min (vr0.min))))
- {
- set_value_range_to_varying (vr);
- return;
- }
-
- /* ABS_EXPR may flip the range around, if the original range
- included negative values. */
- if (!vrp_val_is_min (vr0.min))
- min = fold_unary_to_constant (code, type, vr0.min);
- else
- min = TYPE_MAX_VALUE (type);
-
- if (!vrp_val_is_min (vr0.max))
- max = fold_unary_to_constant (code, type, vr0.max);
- else
- max = TYPE_MAX_VALUE (type);
-
- cmp = compare_values (min, max);
-
- /* If a VR_ANTI_RANGEs contains zero, then we have
- ~[-INF, min(MIN, MAX)]. */
- if (vr0.type == VR_ANTI_RANGE)
- {
- if (range_includes_zero_p (vr0.min, vr0.max) == 1)
- {
- /* Take the lower of the two values. */
- if (cmp != 1)
- max = min;
-
- /* Create ~[-INF, min (abs(MIN), abs(MAX))]
- 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. */
- if (TYPE_OVERFLOW_WRAPS (type))
- {
- tree type_min_value = TYPE_MIN_VALUE (type);
-
- min = (vr0.min != type_min_value
- ? int_const_binop (PLUS_EXPR, type_min_value,
- build_int_cst (TREE_TYPE (type_min_value), 1))
- : type_min_value);
- }
- else
- min = TYPE_MIN_VALUE (type);
- }
- else
- {
- /* All else has failed, so create the range [0, INF], even for
- flag_wrapv since TYPE_MIN_VALUE is in the original
- anti-range. */
- vr0.type = VR_RANGE;
- min = build_int_cst (type, 0);
- max = TYPE_MAX_VALUE (type);
- }
- }
-
- /* If the range contains zero then we know that the minimum value in the
- range will be zero. */
- else if (range_includes_zero_p (vr0.min, vr0.max) == 1)
- {
- if (cmp == 1)
- max = min;
- min = build_int_cst (type, 0);
- }
- else
- {
- /* If the range was reversed, swap MIN and MAX. */
- if (cmp == 1)
- std::swap (min, max);
- }
-
- cmp = compare_values (min, max);
- if (cmp == -2 || cmp == 1)
- {
- /* If the new range has its limits swapped around (MIN > MAX),
- then the operation caused one of them to wrap around, mark
- the new range VARYING. */
- set_value_range_to_varying (vr);
- }
- else
- set_value_range (vr, vr0.type, min, max, NULL);
- return;
- }
+ return extract_range_from_abs_expr (*vr, type, vr0);
/* For unhandled operations fall back to varying. */
set_value_range_to_varying (vr);