On 06/27/2017 06:38 AM, Jakub Jelinek wrote:
On Tue, Jun 27, 2017 at 06:26:46AM -0400, Aldy Hernandez wrote:
How about this?
@@ -360,6 +363,22 @@ set_range_info (tree name, enum value_range_type
range_type,
}
}
+/* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name
+ NAME while making sure we don't store useless range info. */
+
+void
+set_range_info (tree name, enum value_range_type range_type,
+ const wide_int_ref &min, const wide_int_ref &max)
+{
+ /* A range of the entire domain is really no range at all. */
+ tree type = TREE_TYPE (name);
+ if (min == wi::min_value (TYPE_PRECISION (type), TYPE_SIGN (type))
+ && max == wi::max_value (TYPE_PRECISION (type), TYPE_SIGN (type)))
+ return;
+
+ set_range_info_raw (name, range_type, min, max);
+}
+
Won't this misbehave if we have a narrower range on some SSA_NAME and
call set_range_info to make it VARYING?
In that case (i.e. SSA_NAME_RANGE_INFO (name) != NULL), we should either
set_range_info_raw too (if nonzero_bits is not all ones) or clear
SSA_NAME_RANGE_INFO (otherwise).
Good point. Fixed.
/* Gets range information MIN, MAX and returns enum value_range_type
corresponding to tree ssa_name NAME. enum value_range_type returned
@@ -419,9 +438,13 @@ set_nonzero_bits (tree name, const wide_int_ref &mask)
{
gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name)));
if (SSA_NAME_RANGE_INFO (name) == NULL)
- set_range_info (name, VR_RANGE,
- TYPE_MIN_VALUE (TREE_TYPE (name)),
- TYPE_MAX_VALUE (TREE_TYPE (name)));
+ {
+ if (mask == -1)
+ return;
+ set_range_info_raw (name, VR_RANGE,
+ TYPE_MIN_VALUE (TREE_TYPE (name)),
+ TYPE_MAX_VALUE (TREE_TYPE (name)));
+ }
range_info_def *ri = SSA_NAME_RANGE_INFO (name);
ri->set_nonzero_bits (mask);
Similarly, if SSA_NAME_RANGE_INFO is previously non-NULL, but min/max
are VARYING and the new mask is -1, shouldn't we free it rather than
set it to the default?
Here, if SSA_NAME_RANGE_INFO is previously non-NULL then we proceed as
always-- just set the nonzero bits to whatever was specified (without
clearning SSA_NAME_RANGE_INFO). A mask of -1 and an SSA_NAME_RANGE_INFO
of non-NULL can coexist just fine.
How about this?
Aldy
gcc/
* tree-ssanames.c (set_range_info_raw): Abstract from ...
(set_range_info): ...here. Only call set_range_info_raw if domain
is useful.
(set_nonzero_bits): Call set_range_info_raw.
* tree-ssanames.h (set_range_info_raw): New.
gcc/testsuite/
* gcc.dg/Walloca-14.c: Adapt test to recognize new complaint of
unbounded use.
diff --git a/gcc/testsuite/gcc.dg/Walloca-14.c
b/gcc/testsuite/gcc.dg/Walloca-14.c
index 723dbe5..f3e3f57 100644
--- a/gcc/testsuite/gcc.dg/Walloca-14.c
+++ b/gcc/testsuite/gcc.dg/Walloca-14.c
@@ -9,5 +9,6 @@ g (int *p)
extern void f (void *);
void *q = __builtin_alloca (p); /* { dg-warning "passing argument 1" } */
+ /* { dg-warning "unbounded use of 'alloca'" "unbounded" { target *-*-* } 11
} */
f (q);
}
diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c
index 353c7b1..0053b01 100644
--- a/gcc/tree-ssanames.c
+++ b/gcc/tree-ssanames.c
@@ -320,11 +320,14 @@ make_ssa_name_fn (struct function *fn, tree var, gimple
*stmt,
return t;
}
-/* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name NAME. */
+/* Helper function for set_range_info.
+
+ Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name
+ NAME. */
void
-set_range_info (tree name, enum value_range_type range_type,
- const wide_int_ref &min, const wide_int_ref &max)
+set_range_info_raw (tree name, enum value_range_type range_type,
+ const wide_int_ref &min, const wide_int_ref &max)
{
gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name)));
gcc_assert (range_type == VR_RANGE || range_type == VR_ANTI_RANGE);
@@ -360,6 +363,34 @@ set_range_info (tree name, enum value_range_type
range_type,
}
}
+/* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name
+ NAME while making sure we don't store useless range info. */
+
+void
+set_range_info (tree name, enum value_range_type range_type,
+ const wide_int_ref &min, const wide_int_ref &max)
+{
+ gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name)));
+
+ /* A range of the entire domain is really no range at all. */
+ tree type = TREE_TYPE (name);
+ if (min == wi::min_value (TYPE_PRECISION (type), TYPE_SIGN (type))
+ && max == wi::max_value (TYPE_PRECISION (type), TYPE_SIGN (type)))
+ {
+ range_info_def *ri = SSA_NAME_RANGE_INFO (name);
+ if (ri == NULL)
+ return;
+ if (ri->get_nonzero_bits () == -1)
+ {
+ ggc_free (ri);
+ SSA_NAME_RANGE_INFO (name) = NULL;
+ return;
+ }
+ }
+
+ set_range_info_raw (name, range_type, min, max);
+}
+
/* Gets range information MIN, MAX and returns enum value_range_type
corresponding to tree ssa_name NAME. enum value_range_type returned
@@ -419,9 +450,13 @@ set_nonzero_bits (tree name, const wide_int_ref &mask)
{
gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name)));
if (SSA_NAME_RANGE_INFO (name) == NULL)
- set_range_info (name, VR_RANGE,
- TYPE_MIN_VALUE (TREE_TYPE (name)),
- TYPE_MAX_VALUE (TREE_TYPE (name)));
+ {
+ if (mask == -1)
+ return;
+ set_range_info_raw (name, VR_RANGE,
+ TYPE_MIN_VALUE (TREE_TYPE (name)),
+ TYPE_MAX_VALUE (TREE_TYPE (name)));
+ }
range_info_def *ri = SSA_NAME_RANGE_INFO (name);
ri->set_nonzero_bits (mask);
}
diff --git a/gcc/tree-ssanames.h b/gcc/tree-ssanames.h
index 9a18394..f7e032f 100644
--- a/gcc/tree-ssanames.h
+++ b/gcc/tree-ssanames.h
@@ -69,6 +69,9 @@ struct GTY ((variable_size)) range_info_def {
/* Sets the value range to SSA. */
extern void set_range_info (tree, enum value_range_type, const wide_int_ref &,
const wide_int_ref &);
+extern void set_range_info_raw (tree, enum value_range_type,
+ const wide_int_ref &,
+ const wide_int_ref &);
/* Gets the value range from SSA. */
extern enum value_range_type get_range_info (const_tree, wide_int *,
wide_int *);
