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authorIlya Lipnitskiy <ilya.lipnitskiy@gmail.com>2021-12-07 17:28:22 -0800
committerHauke Mehrtens <hauke@hauke-m.de>2021-12-17 15:10:22 +0100
commit0dca1060fd48d261f4ffead6efebd16170014ee3 (patch)
tree9ce064938663fd19567a751b4d7da76df6a9af12 /toolchain/gcc/patches/11.2.0/001-v11.3.0-ranger-Fix-up-fold_using_range-range_of_address-PR10.patch
parent475b366a5bddac851296a528ff86d5dcb5f12a96 (diff)
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toolchain/gcc: replace revert with upstream fix
This will make upgrade to v11.3.0 easier and follows upstream more closely. Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Diffstat (limited to 'toolchain/gcc/patches/11.2.0/001-v11.3.0-ranger-Fix-up-fold_using_range-range_of_address-PR10.patch')
-rw-r--r--toolchain/gcc/patches/11.2.0/001-v11.3.0-ranger-Fix-up-fold_using_range-range_of_address-PR10.patch114
1 files changed, 114 insertions, 0 deletions
diff --git a/toolchain/gcc/patches/11.2.0/001-v11.3.0-ranger-Fix-up-fold_using_range-range_of_address-PR10.patch b/toolchain/gcc/patches/11.2.0/001-v11.3.0-ranger-Fix-up-fold_using_range-range_of_address-PR10.patch
new file mode 100644
index 0000000000..71bbfe5a1d
--- /dev/null
+++ b/toolchain/gcc/patches/11.2.0/001-v11.3.0-ranger-Fix-up-fold_using_range-range_of_address-PR10.patch
@@ -0,0 +1,114 @@
+From a6219e8e0719b14f474b0dcaa7bde2f4e57474f9 Mon Sep 17 00:00:00 2001
+From: Jakub Jelinek <jakub@redhat.com>
+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 <jakub@redhat.com>
+
+ 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;
++}