[PATCH 2/3] toolchain/gcc: replace revert with upstream fix

Ilya Lipnitskiy ilya.lipnitskiy at gmail.com
Tue Dec 7 17:28:22 PST 2021


This will make upgrade to v11.3.0 easier and follows upstream more
closely.

Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy at gmail.com>
---
 ...leanup-range-of-address-calculations.patch | 160 ------------------
 ...ld_using_range-range_of_address-PR10.patch | 114 +++++++++++++
 2 files changed, 114 insertions(+), 160 deletions(-)
 delete mode 100644 toolchain/gcc/patches/11.2.0/001-Revert-Cleanup-range-of-address-calculations.patch
 create mode 100644 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-Revert-Cleanup-range-of-address-calculations.patch b/toolchain/gcc/patches/11.2.0/001-Revert-Cleanup-range-of-address-calculations.patch
deleted file mode 100644
index a97e061d6b64..000000000000
--- a/toolchain/gcc/patches/11.2.0/001-Revert-Cleanup-range-of-address-calculations.patch
+++ /dev/null
@@ -1,160 +0,0 @@
-From: Felix Fietkau <nbd at 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);
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 000000000000..71bbfe5a1df1
--- /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 at 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 at 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;
++}
-- 
2.34.1




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