tree-optimization/104941: Actually assign the conversion result
Commit Message
Assign the result of fold_convert to offset.
gcc/ChangeLog:
PR tree-optimization/104941
* tree-object-size.cc (size_for_offset): Assign result of
fold_convert to OFFSET.
gcc/testsuite/ChangeLog:
PR tree-optimization/104941
* gcc.dg/builtin-dynamic-object-size-0.c (S1, S2): New structs.
(test_alloc_nested_structs, g): New functions.
(main): Call test_alloc_nested_structs.
Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>
---
Testing:
- x86_64 bootstrap build and check
- i686 build and check
.../gcc.dg/builtin-dynamic-object-size-0.c | 34 +++++++++++++++++++
gcc/tree-object-size.cc | 2 +-
2 files changed, 35 insertions(+), 1 deletion(-)
Comments
On Wed, Mar 16, 2022 at 08:24:24PM +0530, Siddhesh Poyarekar wrote:
> Assign the result of fold_convert to offset.
>
> gcc/ChangeLog:
>
> PR tree-optimization/104941
> * tree-object-size.cc (size_for_offset): Assign result of
> fold_convert to OFFSET.
>
> gcc/testsuite/ChangeLog:
>
> PR tree-optimization/104941
> * gcc.dg/builtin-dynamic-object-size-0.c (S1, S2): New structs.
> (test_alloc_nested_structs, g): New functions.
> (main): Call test_alloc_nested_structs.
>
> Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>
> --- a/gcc/tree-object-size.cc
> +++ b/gcc/tree-object-size.cc
> @@ -372,7 +372,7 @@ size_for_offset (tree sz, tree offset, tree wholesize = NULL_TREE)
>
> /* Safe to convert now, since a valid net offset should be non-negative. */
> if (!types_compatible_p (TREE_TYPE (offset), sizetype))
> - fold_convert (sizetype, offset);
> + offset = fold_convert (sizetype, offset);
>
> if (TREE_CODE (offset) == INTEGER_CST)
> {
I think the types_compatible_p call is too heavy, you want to check if
emitting the fold_convert to sizetype is unnecessary, which is
if (!useless_type_conversion_p (sizetype, TREE_TYPE (offset)))
offset = fold_convert (sizetype, offset);
types_compatible_p is that the conversion is useless in both directions.
Ok for trunk with that change.
Jakub
@@ -323,6 +323,34 @@ test_substring (size_t sz, size_t off)
return __builtin_dynamic_object_size (&str[off], 0);
}
+struct S2
+{
+ char arr[7];
+};
+
+struct S1
+{
+ int pad;
+ struct S2 s2;
+};
+
+static long
+g (struct S1 *s1)
+{
+ struct S2 *s2 = &s1->s2;
+ return __builtin_dynamic_object_size (s2->arr, 0);
+}
+
+long
+__attribute__ ((noinline))
+test_alloc_nested_structs (int x)
+{
+ struct S1 *s1 = __builtin_malloc (x);
+ return g (s1);
+}
+
+/* POINTER_PLUS expressions. */
+
size_t
__attribute__ ((noinline))
test_substring_ptrplus (size_t sz, size_t off)
@@ -342,6 +370,8 @@ test_substring_ptrplus2 (size_t sz, size_t off, size_t off2)
return __builtin_dynamic_object_size (ptr + off2, 0);
}
+/* Function parameters. */
+
size_t
__attribute__ ((access (__read_write__, 1, 2)))
__attribute__ ((noinline))
@@ -382,6 +412,8 @@ test_parmsz_unknown (void *obj, void *unknown, size_t sz, int cond)
return __builtin_dynamic_object_size (cond ? obj : unknown, 0);
}
+/* Loops. */
+
size_t
__attribute__ ((noinline))
__attribute__ ((access (__read_write__, 1, 2)))
@@ -491,6 +523,8 @@ main (int argc, char **argv)
FAIL ();
if (test_dynarray_cond (1) != 8)
FAIL ();
+ if (test_alloc_nested_structs (42) != 42 - sizeof (int))
+ FAIL ();
if (test_deploop (128, 4) != 128)
FAIL ();
if (test_deploop (128, 129) != 32)
@@ -372,7 +372,7 @@ size_for_offset (tree sz, tree offset, tree wholesize = NULL_TREE)
/* Safe to convert now, since a valid net offset should be non-negative. */
if (!types_compatible_p (TREE_TYPE (offset), sizetype))
- fold_convert (sizetype, offset);
+ offset = fold_convert (sizetype, offset);
if (TREE_CODE (offset) == INTEGER_CST)
{