toolchain/gcc: replace revert with upstream fix

[openwrt/staging/chunkeey.git] / toolchain / gcc / patches / 11.2.0 / 001-v11.3.0-ranger-Fix-up-fold_using_range-range_of_address-PR10.patch

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 (file)
index 0000000..71bbfe5
--- /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;
++}