|
|
@@ -1,114 +0,0 @@
|
|
|
-From a6219e8e0719b14f474b0dcaa7bde2f4e57474f9 Mon Sep 17 00:00:00 2001
|
|
|
-From: Jakub Jelinek <[email protected]>
|
|
|
-Date: Wed, 17 Nov 2021 13:45:53 +0100
|
|
|
-Subject: [PATCH] ranger: Fix up fold_using_range::range_of_address [PR103255]
|
|
|
-
|
|
|
-If on &base->member the offset isn't constant or isn't zero and
|
|
|
--fdelete-null-pointer-checks and not -fwrapv-pointer and base has a range
|
|
|
-that doesn't include NULL, we return the range of the base.
|
|
|
-Usually it isn't a big deal, because for most pointers we just use
|
|
|
-varying, range_zero and range_nonzero ranges and nothing beyond that,
|
|
|
-but if a pointer is initialized from a constant, we actually track the
|
|
|
-exact range and in that case this causes miscompilation.
|
|
|
-As discussed on IRC, I think doing something like:
|
|
|
- offset_int off2;
|
|
|
- if (off_cst && off.is_constant (&off2))
|
|
|
- {
|
|
|
- tree cst = wide_int_to_tree (sizetype, off2 / BITS_PER_UNIT);
|
|
|
- // adjust range r with POINTER_PLUS_EXPR cst
|
|
|
- if (!range_includes_zero_p (&r))
|
|
|
- return true;
|
|
|
- }
|
|
|
- // Fallback
|
|
|
- r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt)));
|
|
|
- return true;
|
|
|
-could work, given that most of the pointer ranges are just the simple ones
|
|
|
-perhaps it is too much for little benefit.
|
|
|
-
|
|
|
-2021-11-17 Jakub Jelinek <[email protected]>
|
|
|
-
|
|
|
- PR tree-optimization/103255
|
|
|
- * gimple-range.cc (fold_using_range::range_of_address): Return
|
|
|
- range_nonzero rather than unadjusted base's range. Formatting fixes.
|
|
|
-
|
|
|
- * gcc.c-torture/execute/pr103255.c: New test.
|
|
|
-
|
|
|
-(cherry picked from commit c39cb6bf835ca12e590eaa6f90222e51be207c50)
|
|
|
----
|
|
|
- gcc/gimple-range.cc | 16 +++++---
|
|
|
- .../gcc.c-torture/execute/pr103255.c | 41 +++++++++++++++++++
|
|
|
- 2 files changed, 52 insertions(+), 5 deletions(-)
|
|
|
- create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr103255.c
|
|
|
-
|
|
|
---- a/gcc/gimple-range.cc
|
|
|
-+++ b/gcc/gimple-range.cc
|
|
|
-@@ -491,14 +491,20 @@ gimple_ranger::range_of_address (irange
|
|
|
- }
|
|
|
- /* If &X->a is equal to X, the range of X is the result. */
|
|
|
- if (off_cst && known_eq (off, 0))
|
|
|
-- return true;
|
|
|
-+ return true;
|
|
|
- else if (flag_delete_null_pointer_checks
|
|
|
- && !TYPE_OVERFLOW_WRAPS (TREE_TYPE (expr)))
|
|
|
- {
|
|
|
-- /* For -fdelete-null-pointer-checks -fno-wrapv-pointer we don't
|
|
|
-- allow going from non-NULL pointer to NULL. */
|
|
|
-- if(!range_includes_zero_p (&r))
|
|
|
-- return true;
|
|
|
-+ /* For -fdelete-null-pointer-checks -fno-wrapv-pointer we don't
|
|
|
-+ allow going from non-NULL pointer to NULL. */
|
|
|
-+ if (!range_includes_zero_p (&r))
|
|
|
-+ {
|
|
|
-+ /* We could here instead adjust r by off >> LOG2_BITS_PER_UNIT
|
|
|
-+ using POINTER_PLUS_EXPR if off_cst and just fall back to
|
|
|
-+ this. */
|
|
|
-+ r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt)));
|
|
|
-+ return true;
|
|
|
-+ }
|
|
|
- }
|
|
|
- /* If MEM_REF has a "positive" offset, consider it non-NULL
|
|
|
- always, for -fdelete-null-pointer-checks also "negative"
|
|
|
---- /dev/null
|
|
|
-+++ b/gcc/testsuite/gcc.c-torture/execute/pr103255.c
|
|
|
-@@ -0,0 +1,41 @@
|
|
|
-+/* PR tree-optimization/103255 */
|
|
|
-+
|
|
|
-+struct H
|
|
|
-+{
|
|
|
-+ unsigned a;
|
|
|
-+ unsigned b;
|
|
|
-+ unsigned c;
|
|
|
-+};
|
|
|
-+
|
|
|
-+#if __SIZEOF_POINTER__ >= 4
|
|
|
-+#define ADDR 0x400000
|
|
|
-+#else
|
|
|
-+#define ADDR 0x4000
|
|
|
-+#endif
|
|
|
-+#define OFF 0x20
|
|
|
-+
|
|
|
-+int
|
|
|
-+main ()
|
|
|
-+{
|
|
|
-+ struct H *h = 0;
|
|
|
-+ unsigned long o;
|
|
|
-+ volatile int t = 1;
|
|
|
-+
|
|
|
-+ for (o = OFF; o <= OFF; o += 0x1000)
|
|
|
-+ {
|
|
|
-+ struct H *u;
|
|
|
-+ u = (struct H *) (ADDR + o);
|
|
|
-+ if (t)
|
|
|
-+ {
|
|
|
-+ h = u;
|
|
|
-+ break;
|
|
|
-+ }
|
|
|
-+ }
|
|
|
-+
|
|
|
-+ if (h == 0)
|
|
|
-+ return 0;
|
|
|
-+ unsigned *tt = &h->b;
|
|
|
-+ if ((__SIZE_TYPE__) tt != (ADDR + OFF + __builtin_offsetof (struct H, b)))
|
|
|
-+ __builtin_abort ();
|
|
|
-+ return 0;
|
|
|
-+}
|