2013-11-18 Richard Biener <rguenther@suse.de>

	Backport from mainline
	2013-10-21  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/58794
	* fold-const.c (operand_equal_p): Compare FIELD_DECL operand
	of COMPONENT_REFs with OEP_CONSTANT_ADDRESS_OF left in place.

	* c-c++-common/torture/pr58794-1.c: New testcase.
	* c-c++-common/torture/pr58794-2.c: Likewise.

	2013-10-21  Richard Biener  <rguenther@suse.de>

	PR middle-end/58742
	* fold-const.c (fold_binary_loc): Fold ((T) (X /[ex] C)) * C
	to (T) X for sign-changing conversions (or no conversion).

	* c-c++-common/fold-divmul-1.c: New testcase.

	2013-11-06  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/58653
	* tree-predcom.c (ref_at_iteration): Rewrite to generate
	a MEM_REF.
	(prepare_initializers_chain): Adjust.

	* gcc.dg/tree-ssa/predcom-6.c: New testcase.
	* gcc.dg/tree-ssa/predcom-7.c: Likewise.

	PR tree-optimization/59047
	* tree-predcom.c (ref_at_iteration): Handle bitfield accesses
	properly.

	* gcc.dg/torture/pr59047.c: New testcase.

	2013-10-15  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/58143
	* tree-ssa-loop-im.c (arith_code_with_undefined_signed_overflow):
	New function.
	(rewrite_to_defined_overflow): Likewise.
	(move_computations_dom_walker::before_dom): Rewrite stmts
	with undefined signed overflow that are not always executed
	into unsigned arithmetic.

	* gcc.dg/torture/pr58143-1.c: New testcase.
	* gcc.dg/torture/pr58143-2.c: Likewise.
	* gcc.dg/torture/pr58143-3.c: Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_8-branch@204965 138bc75d-0d04-0410-961f-82ee72b054a4

14 files changed, 423 insertions, 90 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e580b142333..d4ea6919fea 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,39 @@
+2013-11-18  Richard Biener  <rguenther@suse.de>
+
+	Backport from mainline
+	2013-10-21  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58794
+	* fold-const.c (operand_equal_p): Compare FIELD_DECL operand
+	of COMPONENT_REFs with OEP_CONSTANT_ADDRESS_OF left in place.
+
+	2013-10-21  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/58742
+	* fold-const.c (fold_binary_loc): Fold ((T) (X /[ex] C)) * C
+	to (T) X for sign-changing conversions (or no conversion).
+
+	2013-11-06  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58653
+	* tree-predcom.c (ref_at_iteration): Rewrite to generate
+	a MEM_REF.
+	(prepare_initializers_chain): Adjust.
+
+	PR tree-optimization/59047
+	* tree-predcom.c (ref_at_iteration): Handle bitfield accesses
+	properly.
+
+	2013-10-15  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58143
+	* tree-ssa-loop-im.c (arith_code_with_undefined_signed_overflow):
+	New function.
+	(rewrite_to_defined_overflow): Likewise.
+	(move_computations_dom_walker::before_dom): Rewrite stmts
+	with undefined signed overflow that are not always executed
+	into unsigned arithmetic.
+
 2013-11-14  Uros Bizjak  <ubizjak@gmail.com>
 
 	Backport from mainline
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 6dc8934f33b..f66642980bb 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -2664,10 +2664,11 @@ operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
 	case COMPONENT_REF:
 	  /* Handle operand 2 the same as for ARRAY_REF.  Operand 0
 	     may be NULL when we're called to compare MEM_EXPRs.  */
-	  if (!OP_SAME_WITH_NULL (0))
+	  if (!OP_SAME_WITH_NULL (0)
+	      || !OP_SAME (1))
 	    return 0;
 	  flags &= ~OEP_CONSTANT_ADDRESS_OF;
-	  return OP_SAME (1) && OP_SAME_WITH_NULL (2);
+	  return OP_SAME_WITH_NULL (2);
 
 	case BIT_FIELD_REF:
 	  if (!OP_SAME (0))
@@ -10927,6 +10928,13 @@ fold_binary_loc (location_t loc,
 				fold_build2_loc (loc, MULT_EXPR, type,
 					     build_int_cst (type, 2) , arg1));
 
+	  /* ((T) (X /[ex] C)) * C cancels out if the conversion is
+	     sign-changing only.  */
+	  if (TREE_CODE (arg1) == INTEGER_CST
+	      && TREE_CODE (arg0) == EXACT_DIV_EXPR
+	      && operand_equal_p (arg1, TREE_OPERAND (arg0, 1), 0))
+	    return fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
+
 	  strict_overflow_p = false;
 	  if (TREE_CODE (arg1) == INTEGER_CST
 	      && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f1a29349b0f..017b96f69d8 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,33 @@
+2013-11-18  Richard Biener  <rguenther@suse.de>
+
+	Backport from mainline
+	2013-10-21  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58794
+	* c-c++-common/torture/pr58794-1.c: New testcase.
+	* c-c++-common/torture/pr58794-2.c: Likewise.
+
+	2013-10-21  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/58742
+	* c-c++-common/fold-divmul-1.c: New testcase.
+
+	2013-11-06  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58653
+	* gcc.dg/tree-ssa/predcom-6.c: New testcase.
+	* gcc.dg/tree-ssa/predcom-7.c: Likewise.
+
+	PR tree-optimization/59047
+	* gcc.dg/torture/pr59047.c: New testcase.
+
+	2013-10-15  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58143
+	* gcc.dg/torture/pr58143-1.c: New testcase.
+	* gcc.dg/torture/pr58143-2.c: Likewise.
+	* gcc.dg/torture/pr58143-3.c: Likewise.
+
 2013-11-17  Janus Weil  <janus@gcc.gnu.org>
 
 	Backport from mainline
diff --git a/gcc/testsuite/c-c++-common/fold-divmul-1.c b/gcc/testsuite/c-c++-common/fold-divmul-1.c
new file mode 100644
index 00000000000..5c867923d2e
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/fold-divmul-1.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-fdump-tree-original" } */
+
+int *
+fx (int *b, int *e)
+{
+  return b + (e - b);
+}
+
+/* { dg-final { scan-tree-dump-not "/\\\[ex\\\]" "original" } } */
+/* { dg-final { cleanup-tree-dump "original" } } */
diff --git a/gcc/testsuite/c-c++-common/torture/pr58794-1.c b/gcc/testsuite/c-c++-common/torture/pr58794-1.c
new file mode 100644
index 00000000000..175629fec90
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/torture/pr58794-1.c
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+
+struct S0
+{
+  int f;
+};
+
+struct S1
+{
+  struct S0 f1;
+  volatile int f2;
+};
+
+struct S2
+{
+  struct S1 g;
+} a, b; 
+
+static int *c[1][2] = {{0, (int *)&a.g.f2}};
+static int d; 
+
+int
+main ()
+{
+  for (d = 0; d < 1; d++)
+    for (b.g.f1.f = 0; b.g.f1.f < 1; b.g.f1.f++)
+      *c[b.g.f1.f][d + 1] = 0;
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/torture/pr58794-2.c b/gcc/testsuite/c-c++-common/torture/pr58794-2.c
new file mode 100644
index 00000000000..767798806db
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/torture/pr58794-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+
+struct S 
+{
+  volatile int f;
+} a;
+
+unsigned int b;
+
+static int *c[1][2] = {{0, (int *)&a.f}};
+static unsigned int d;
+
+int 
+main ()
+{
+  for (; d < 1; d++)
+    for (; b < 1; b++)
+      *c[b][d + 1] = 0;
+
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/torture/pr58143-1.c b/gcc/testsuite/gcc.dg/torture/pr58143-1.c
new file mode 100644
index 00000000000..855515edb97
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr58143-1.c
@@ -0,0 +1,51 @@
+/* { dg-do run } */
+/* { dg-additional-options "-fstrict-overflow" } */
+
+extern void abort (void);
+
+int a, b, c, d, e, f, g, h = 1, i;
+
+int foo (int p)
+{
+  return p < 0 && a < - __INT_MAX__ - 1 - p ? 0 : 1;
+}
+
+int *bar ()
+{
+  int j; 
+  i = h ? 0 : 1 % h;
+  for (j = 0; j < 1; j++)
+    for (d = 0; d; d++)
+      for (e = 1; e;)
+	return 0;
+  return 0;
+}
+
+int baz ()
+{
+  for (; b >= 0; b--)
+    for (c = 1; c >= 0; c--)
+      {
+	int *k = &c;
+	for (;;)
+	  {
+	    for (f = 0; f < 1; f++)
+	      {
+		g = foo (*k);
+		bar ();
+	      }
+	    if (*k)
+	      break;
+	    return 0;
+	  }
+      }
+  return 0;
+}
+
+int main ()
+{
+  baz ();
+  if (b != 0)
+    abort ();
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/torture/pr58143-2.c b/gcc/testsuite/gcc.dg/torture/pr58143-2.c
new file mode 100644
index 00000000000..dd0dae1efe0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr58143-2.c
@@ -0,0 +1,34 @@
+/* { dg-do run } */
+/* { dg-additional-options "-fstrict-overflow" } */
+
+int a, b, d, e, f, *g, h, i;
+volatile int c;
+
+char foo (unsigned char p)
+{
+  return p + 1;
+}
+
+int bar () 
+{
+  for (h = 0; h < 3; h = foo (h))
+    {
+      c;
+      for (f = 0; f < 1; f++)
+	{
+	  i = a && 0 < -__INT_MAX__ - h ? 0 : 1;
+	  if (e)
+	    for (; d;)
+	      b = 0;
+	  else
+	    g = 0;
+	}
+    }
+  return 0;
+}
+
+int main ()
+{
+  bar ();
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/torture/pr58143-3.c b/gcc/testsuite/gcc.dg/torture/pr58143-3.c
new file mode 100644
index 00000000000..23ae9cd39ce
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr58143-3.c
@@ -0,0 +1,18 @@
+/* { dg-do run } */
+/* { dg-additional-options "-fstrict-overflow" } */
+
+int a, b, c, d, e;
+
+int
+main ()
+{
+  for (b = 4; b > -30; b--)
+    for (; c;)
+      for (;;)
+	{
+	  e = a > __INT_MAX__ - b;
+	  if (d)
+	    break;
+	}
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/torture/pr59047.c b/gcc/testsuite/gcc.dg/torture/pr59047.c
new file mode 100644
index 00000000000..fcedfcba870
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr59047.c
@@ -0,0 +1,39 @@
+/* { dg-do run } */
+
+extern void abort (void);
+
+struct
+{
+  int f0;
+  int f1:1;
+  int f2:2;
+} a = {0, 0, 1};
+
+int b, c, *d, e, f;
+
+int
+fn1 ()
+{
+  for (; b < 1; ++b)
+    {
+      for (e = 0; e < 1; e = 1)
+	{
+	  int **g = &d;
+	  *g = &c;
+	} 
+      *d = 0;
+      f = a.f1;
+      if (f)
+	return 0;
+    }
+  return 0;
+}
+
+int
+main ()
+{
+  fn1 ();
+  if (b != 1)
+    abort ();
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/predcom-6.c b/gcc/testsuite/gcc.dg/tree-ssa/predcom-6.c
new file mode 100644
index 00000000000..0af24381485
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/predcom-6.c
@@ -0,0 +1,14 @@
+/* { dg-do run } */
+/* { dg-options "-O3" } */
+
+int a, c, e[5][2]; 
+unsigned int d;
+
+int
+main ()
+{
+  for (d = 0; d < 2; d++)
+    if (a ? 0 : e[c + 3][d] & e[c + 4][d])
+      break;
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/predcom-7.c b/gcc/testsuite/gcc.dg/tree-ssa/predcom-7.c
new file mode 100644
index 00000000000..e7ae87ccc7a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/predcom-7.c
@@ -0,0 +1,18 @@
+/* { dg-do run } */
+/* { dg-options "-O3 -fdump-tree-pcom-details" } */
+
+int b, f, d[5][2];
+unsigned int c;
+
+int
+main ()
+{
+  for (c = 0; c < 2; c++)
+    if (d[b + 3][c] & d[b + 4][c])
+      if (f)
+	break;
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump "Executing predictive commoning" "pcom" } } */
+/* { dg-final { cleanup-tree-dump "pcom" } } */
diff --git a/gcc/tree-predcom.c b/gcc/tree-predcom.c
index dceea8cc89a..7bad2a29d1f 100644
--- a/gcc/tree-predcom.c
+++ b/gcc/tree-predcom.c
@@ -1323,90 +1323,43 @@ replace_ref_with (gimple stmt, tree new_tree, bool set, bool in_lhs)
   gsi_insert_after (&bsi, new_stmt, GSI_NEW_STMT);
 }
 
-/* Returns the reference to the address of REF in the ITER-th iteration of
-   LOOP, or NULL if we fail to determine it (ITER may be negative).  We
-   try to preserve the original shape of the reference (not rewrite it
-   as an indirect ref to the address), to make tree_could_trap_p in
-   prepare_initializers_chain return false more often.  */
-
-static tree
-ref_at_iteration (struct loop *loop, tree ref, int iter)
-{
-  tree idx, *idx_p, type, val, op0 = NULL_TREE, ret;
-  affine_iv iv;
-  bool ok;
-
-  if (handled_component_p (ref))
-    {
-      op0 = ref_at_iteration (loop, TREE_OPERAND (ref, 0), iter);
-      if (!op0)
-	return NULL_TREE;
-    }
-  else if (!INDIRECT_REF_P (ref)
-	   && TREE_CODE (ref) != MEM_REF)
-    return unshare_expr (ref);
-
-  if (TREE_CODE (ref) == MEM_REF)
-    {
-      ret = unshare_expr (ref);
-      idx = TREE_OPERAND (ref, 0);
-      idx_p = &TREE_OPERAND (ret, 0);
-    }
-  else if (TREE_CODE (ref) == COMPONENT_REF)
-    {
-      /* Check that the offset is loop invariant.  */
-      if (TREE_OPERAND (ref, 2)
-	  && !expr_invariant_in_loop_p (loop, TREE_OPERAND (ref, 2)))
-	return NULL_TREE;
-
-      return build3 (COMPONENT_REF, TREE_TYPE (ref), op0,
-		     unshare_expr (TREE_OPERAND (ref, 1)),
-		     unshare_expr (TREE_OPERAND (ref, 2)));
-    }
-  else if (TREE_CODE (ref) == ARRAY_REF)
-    {
-      /* Check that the lower bound and the step are loop invariant.  */
-      if (TREE_OPERAND (ref, 2)
-	  && !expr_invariant_in_loop_p (loop, TREE_OPERAND (ref, 2)))
-	return NULL_TREE;
-      if (TREE_OPERAND (ref, 3)
-	  && !expr_invariant_in_loop_p (loop, TREE_OPERAND (ref, 3)))
-	return NULL_TREE;
-
-      ret = build4 (ARRAY_REF, TREE_TYPE (ref), op0, NULL_TREE,
-		    unshare_expr (TREE_OPERAND (ref, 2)),
-		    unshare_expr (TREE_OPERAND (ref, 3)));
-      idx = TREE_OPERAND (ref, 1);
-      idx_p = &TREE_OPERAND (ret, 1);
-    }
-  else
-    return NULL_TREE;
-
-  ok = simple_iv (loop, loop, idx, &iv, true);
-  if (!ok)
-    return NULL_TREE;
-  iv.base = expand_simple_operations (iv.base);
-  if (integer_zerop (iv.step))
-    *idx_p = unshare_expr (iv.base);
+/* Returns a memory reference to DR in the ITER-th iteration of
+   the loop it was analyzed in.  Append init stmts to STMTS.  */
+
+static tree 
+ref_at_iteration (data_reference_p dr, int iter, gimple_seq *stmts)
+{
+  tree off = DR_OFFSET (dr);
+  tree coff = DR_INIT (dr);
+  if (iter == 0)
+    ;
+  else if (TREE_CODE (DR_STEP (dr)) == INTEGER_CST)
+    coff = size_binop (PLUS_EXPR, coff,
+		       size_binop (MULT_EXPR, DR_STEP (dr), ssize_int (iter)));
   else
-    {
-      type = TREE_TYPE (iv.base);
-      if (POINTER_TYPE_P (type))
-	{
-	  val = fold_build2 (MULT_EXPR, sizetype, iv.step,
-			     size_int (iter));
-	  val = fold_build_pointer_plus (iv.base, val);
-	}
-      else
-	{
-	  val = fold_build2 (MULT_EXPR, type, iv.step,
-			     build_int_cst_type (type, iter));
-	  val = fold_build2 (PLUS_EXPR, type, iv.base, val);
-	}
-      *idx_p = unshare_expr (val);
+    off = size_binop (PLUS_EXPR, off,
+		      size_binop (MULT_EXPR, DR_STEP (dr), ssize_int (iter)));
+  tree addr = fold_build_pointer_plus (DR_BASE_ADDRESS (dr), off);
+  addr = force_gimple_operand_1 (addr, stmts, is_gimple_mem_ref_addr,
+				 NULL_TREE);
+  tree alias_ptr = fold_convert (reference_alias_ptr_type (DR_REF (dr)), coff);
+  /* While data-ref analysis punts on bit offsets it still handles
+     bitfield accesses at byte boundaries.  Cope with that.  Note that
+     we cannot simply re-apply the outer COMPONENT_REF because the
+     byte-granular portion of it is already applied via DR_INIT and
+     DR_OFFSET, so simply build a BIT_FIELD_REF knowing that the bits
+     start at offset zero.  */
+  if (TREE_CODE (DR_REF (dr)) == COMPONENT_REF
+      && DECL_BIT_FIELD (TREE_OPERAND (DR_REF (dr), 1)))
+    {
+      tree field = TREE_OPERAND (DR_REF (dr), 1);
+      return build3 (BIT_FIELD_REF, TREE_TYPE (DR_REF (dr)),
+		     build2 (MEM_REF, DECL_BIT_FIELD_TYPE (field),
+			     addr, alias_ptr),
+		     DECL_SIZE (field), bitsize_zero_node);
     }
-
-  return ret;
+  else
+    return fold_build2 (MEM_REF, TREE_TYPE (DR_REF (dr)), addr, alias_ptr);
 }
 
 /* Get the initialization expression for the INDEX-th temporary variable
@@ -2365,14 +2318,10 @@ prepare_initializers_chain (struct loop *loop, chain_p chain)
       if (chain->inits[i] != NULL_TREE)
 	continue;
 
-      init = ref_at_iteration (loop, DR_REF (dr), (int) i - n);
-      if (!init)
-	return false;
-
+      init = ref_at_iteration (dr, (int) i - n, &stmts);
       if (!chain->all_always_accessed && tree_could_trap_p (init))
 	return false;
 
-      init = force_gimple_operand (init, &stmts, false, NULL_TREE);
       if (stmts)
 	gsi_insert_seq_on_edge_immediate (entry, stmts);
 
diff --git a/gcc/tree-ssa-loop-im.c b/gcc/tree-ssa-loop-im.c
index 78ad0733016..72ed570dc55 100644
--- a/gcc/tree-ssa-loop-im.c
+++ b/gcc/tree-ssa-loop-im.c
@@ -1190,6 +1190,67 @@ determine_invariantness (void)
   fini_walk_dominator_tree (&walk_data);
 }
 
+/* Return true if CODE is an operation that when operating on signed
+   integer types involves undefined behavior on overflow and the
+   operation can be expressed with unsigned arithmetic.  */
+
+static bool
+arith_code_with_undefined_signed_overflow (tree_code code)
+{
+  switch (code)
+    {
+    case PLUS_EXPR:
+    case MINUS_EXPR:
+    case MULT_EXPR:
+    case NEGATE_EXPR:
+    case POINTER_PLUS_EXPR:
+      return true;
+    default:
+      return false;
+    }
+}
+
+/* Rewrite STMT, an assignment with a signed integer or pointer arithmetic
+   operation that can be transformed to unsigned arithmetic by converting
+   its operand, carrying out the operation in the corresponding unsigned
+   type and converting the result back to the original type.
+
+   Returns a sequence of statements that replace STMT and also contain
+   a modified form of STMT itself.  */
+
+static gimple_seq
+rewrite_to_defined_overflow (gimple stmt)
+{
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    {
+      fprintf (dump_file, "rewriting stmt with undefined signed "
+	       "overflow ");
+      print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
+    }
+
+  tree lhs = gimple_assign_lhs (stmt);
+  tree type = unsigned_type_for (TREE_TYPE (lhs));
+  gimple_seq stmts = NULL;
+  for (unsigned i = 1; i < gimple_num_ops (stmt); ++i)
+    {
+      gimple_seq stmts2 = NULL;
+      gimple_set_op (stmt, i,
+		     force_gimple_operand (fold_convert (type,
+							 gimple_op (stmt, i)),
+					   &stmts2, true, NULL_TREE));
+      gimple_seq_add_seq (&stmts, stmts2);
+    }
+  gimple_assign_set_lhs (stmt, make_ssa_name (type, stmt));
+  if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR)
+    gimple_assign_set_rhs_code (stmt, PLUS_EXPR);
+  gimple_seq_add_stmt (&stmts, stmt);
+  gimple cvt = gimple_build_assign_with_ops
+      (NOP_EXPR, lhs, gimple_assign_lhs (stmt), NULL_TREE);
+  gimple_seq_add_stmt (&stmts, cvt);
+
+  return stmts;
+}
+
 /* Hoist the statements in basic block BB out of the loops prescribed by
    data stored in LIM_DATA structures associated with each statement.  Callback
    for walk_dominator_tree.  */
@@ -1321,7 +1382,21 @@ move_computations_stmt (struct dom_walk_data *dw_data,
 	    }
 	}
       gsi_remove (&bsi, false);
-      gsi_insert_on_edge (e, stmt);
+      /* In case this is a stmt that is not unconditionally executed
+         when the target loop header is executed and the stmt may
+	 invoke undefined integer or pointer overflow rewrite it to
+	 unsigned arithmetic.  */
+      if (is_gimple_assign (stmt)
+	  && INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_lhs (stmt)))
+	  && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (gimple_assign_lhs (stmt)))
+	  && arith_code_with_undefined_signed_overflow
+	       (gimple_assign_rhs_code (stmt))
+	  && (!ALWAYS_EXECUTED_IN (bb)
+	      || !(ALWAYS_EXECUTED_IN (bb) == level
+		   || flow_loop_nested_p (ALWAYS_EXECUTED_IN (bb), level))))
+	gsi_insert_seq_on_edge (e, rewrite_to_defined_overflow (stmt));
+      else
+	gsi_insert_on_edge (e, stmt);
     }
 }