+++ /dev/null
-From: Felix Fietkau <nbd@nbd.name>
-Date: Tue, 16 Nov 2021 10:39:51 +0100
-Subject: [PATCH] Revert "Cleanup range of address calculations."
-
-This reverts commit 47923622c663ffad8b14aa93706183290d4f6791.
-This commit is causing issues with offset of struct members.
-
-https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103255
----
- delete mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr78655.c
-
---- a/gcc/gimple-range.cc
-+++ b/gcc/gimple-range.cc
-@@ -431,9 +431,8 @@ gimple_ranger::range_of_range_op (irange
- m_cache.register_dependency (lhs, op2);
- }
-
-- if (gimple_code (s) == GIMPLE_ASSIGN
-- && gimple_assign_rhs_code (s) == ADDR_EXPR)
-- return range_of_address (r, s);
-+ if (range_of_non_trivial_assignment (r, s))
-+ return true;
-
- if (range_of_expr (range1, op1, s))
- {
-@@ -447,84 +446,48 @@ gimple_ranger::range_of_range_op (irange
- return true;
- }
-
--// Calculate the range of an assignment containing an ADDR_EXPR.
-+// Calculate the range of a non-trivial assignment. That is, is one
-+// inolving arithmetic on an SSA name (for example, an ADDR_EXPR).
- // Return the range in R.
--// If a range cannot be calculated, set it to VARYING and return true.
-+//
-+// If a range cannot be calculated, return false.
-
- bool
--gimple_ranger::range_of_address (irange &r, gimple *stmt)
-+gimple_ranger::range_of_non_trivial_assignment (irange &r, gimple *stmt)
- {
-- gcc_checking_assert (gimple_code (stmt) == GIMPLE_ASSIGN);
-- gcc_checking_assert (gimple_assign_rhs_code (stmt) == ADDR_EXPR);
-+ if (gimple_code (stmt) != GIMPLE_ASSIGN)
-+ return false;
-
-- bool strict_overflow_p;
-- tree expr = gimple_assign_rhs1 (stmt);
-- poly_int64 bitsize, bitpos;
-- tree offset;
-- machine_mode mode;
-- int unsignedp, reversep, volatilep;
-- tree base = get_inner_reference (TREE_OPERAND (expr, 0), &bitsize,
-- &bitpos, &offset, &mode, &unsignedp,
-- &reversep, &volatilep);
--
--
-- if (base != NULL_TREE
-- && TREE_CODE (base) == MEM_REF
-- && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
-+ tree base = gimple_range_base_of_assignment (stmt);
-+ if (base)
- {
-- tree ssa = TREE_OPERAND (base, 0);
-- gcc_checking_assert (irange::supports_type_p (TREE_TYPE (ssa)));
-- range_of_expr (r, ssa, stmt);
-- range_cast (r, TREE_TYPE (gimple_assign_rhs1 (stmt)));
--
-- poly_offset_int off = 0;
-- bool off_cst = false;
-- if (offset == NULL_TREE || TREE_CODE (offset) == INTEGER_CST)
-+ if (TREE_CODE (base) == MEM_REF)
- {
-- off = mem_ref_offset (base);
-- if (offset)
-- off += poly_offset_int::from (wi::to_poly_wide (offset),
-- SIGNED);
-- off <<= LOG2_BITS_PER_UNIT;
-- off += bitpos;
-- off_cst = true;
-+ if (TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
-+ {
-+ int_range_max range1;
-+ tree ssa = TREE_OPERAND (base, 0);
-+ if (range_of_expr (range1, ssa, stmt))
-+ {
-+ tree type = TREE_TYPE (ssa);
-+ range_operator *op = range_op_handler (POINTER_PLUS_EXPR,
-+ type);
-+ int_range<2> offset (TREE_OPERAND (base, 1),
-+ TREE_OPERAND (base, 1));
-+ op->fold_range (r, type, range1, offset);
-+ return true;
-+ }
-+ }
-+ return false;
- }
-- /* If &X->a is equal to X, the range of X is the result. */
-- if (off_cst && known_eq (off, 0))
-- 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;
-- }
-- /* If MEM_REF has a "positive" offset, consider it non-NULL
-- always, for -fdelete-null-pointer-checks also "negative"
-- ones. Punt for unknown offsets (e.g. variable ones). */
-- if (!TYPE_OVERFLOW_WRAPS (TREE_TYPE (expr))
-- && off_cst
-- && known_ne (off, 0)
-- && (flag_delete_null_pointer_checks || known_gt (off, 0)))
-+ if (gimple_assign_rhs_code (stmt) == ADDR_EXPR)
- {
-+ // Handle "= &a" and return non-zero.
- r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt)));
- return true;
- }
-- r = int_range<2> (TREE_TYPE (gimple_assign_rhs1 (stmt)));
-- return true;
-- }
--
-- // Handle "= &a".
-- if (tree_single_nonzero_warnv_p (expr, &strict_overflow_p))
-- {
-- r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt)));
-- return true;
- }
--
-- // Otherwise return varying.
-- r = int_range<2> (TREE_TYPE (gimple_assign_rhs1 (stmt)));
-- return true;
-+ return false;
- }
-
- // Calculate a range for phi statement S and return it in R.
---- a/gcc/gimple-range.h
-+++ b/gcc/gimple-range.h
-@@ -62,7 +62,7 @@ protected:
- ranger_cache m_cache;
- private:
- bool range_of_phi (irange &r, gphi *phi);
-- bool range_of_address (irange &r, gimple *s);
-+ bool range_of_non_trivial_assignment (irange &r, gimple *s);
- bool range_of_builtin_call (irange &r, gcall *call);
- bool range_with_loop_info (irange &r, tree name);
- void range_of_ssa_name_with_loop_info (irange &, tree, class loop *,
---- a/gcc/range-op.cc
-+++ b/gcc/range-op.cc
-@@ -3447,7 +3447,6 @@ pointer_table::pointer_table ()
- set (GT_EXPR, op_gt);
- set (GE_EXPR, op_ge);
- set (SSA_NAME, op_identity);
-- set (INTEGER_CST, op_integer_cst);
- set (ADDR_EXPR, op_addr);
- set (NOP_EXPR, op_convert);
- set (CONVERT_EXPR, op_convert);
--- /dev/null
+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;
++}
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