diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 0bd68b5e2d4..52414f7729e 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -3462,11 +3462,35 @@ operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
 	}
 
     case tcc_declaration:
-      /* Consider __builtin_sqrt equal to sqrt.  */
-      return (TREE_CODE (arg0) == FUNCTION_DECL
-	      && fndecl_built_in_p (arg0) && fndecl_built_in_p (arg1)
-	      && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
-	      && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
+      switch (TREE_CODE (arg0))
+	{
+	case FUNCTION_DECL:
+	  /* Consider __builtin_sqrt equal to sqrt.  */
+	  return (fndecl_built_in_p (arg0) && fndecl_built_in_p (arg1)
+		  && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
+		  && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
+	case FIELD_DECL:
+	  {
+	    tree fo0 = DECL_FIELD_OFFSET (arg0);
+	    tree fo1 = DECL_FIELD_OFFSET (arg1);
+	    if (fo0 != NULL && fo1 != NULL
+		&& !operand_equal_p (fo0, fo1, OEP_ONLY_CONST))
+	      return false;
+	    else if (fo0 != fo1)
+	      return false;
+
+	    tree fbo0 = DECL_FIELD_BIT_OFFSET (arg0);
+	    tree fbo1 = DECL_FIELD_BIT_OFFSET (arg1);
+	    if (fbo0 != NULL && fbo1 != NULL
+		&& !operand_equal_p (fbo0, fbo1, OEP_ONLY_CONST))
+	      return false;
+	    else if (fbo0 != fbo1)
+	      return false;
+	    return true;
+	  }
+	default:
+	  return false;
+	}
 
     case tcc_exceptional:
       if (TREE_CODE (arg0) == CONSTRUCTOR)
diff --git a/gcc/testsuite/gcc.dg/torture/pr70740.c b/gcc/testsuite/gcc.dg/pr70740.c
similarity index 77%
rename from gcc/testsuite/gcc.dg/torture/pr70740.c
rename to gcc/testsuite/gcc.dg/pr70740.c
index 5bf8e4adc91..186da1b2637 100644
--- a/gcc/testsuite/gcc.dg/torture/pr70740.c
+++ b/gcc/testsuite/gcc.dg/pr70740.c
@@ -1,4 +1,5 @@
 /* { dg-do compile } */
+/* { dg-options "-O2" } */
 
 extern int foo (void);
 extern void *memcpy (void *, const void *, __SIZE_TYPE__);
@@ -32,7 +33,7 @@ baz ()
     e = c.a3;
   else
     e = c.a1;
-  memcpy (d.a, e, 6);
+  memcpy (d.a, e, 6); /* { dg-warning "reading 5 bytes from a region of size 0" } */
   f = bar ();
   memcpy (d.a, f, 1);
 }
diff --git a/gcc/testsuite/gcc.dg/vect/vect-35-big-array.c b/gcc/testsuite/gcc.dg/vect/vect-35-big-array.c
index ca57a10f714..fa356c2c4a2 100644
--- a/gcc/testsuite/gcc.dg/vect/vect-35-big-array.c
+++ b/gcc/testsuite/gcc.dg/vect/vect-35-big-array.c
@@ -47,5 +47,4 @@ int main (void)
 }
 
 
-/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect"  { xfail { ia64-*-* sparc*-*-* } } } } */
-/* { dg-final { scan-tree-dump "can't determine dependence between" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 2 loops" 1 "vect"  { xfail { ia64-*-* sparc*-*-* } } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-35.c b/gcc/testsuite/gcc.dg/vect/vect-35.c
index 76fe32d68ad..3023c8c714f 100644
--- a/gcc/testsuite/gcc.dg/vect/vect-35.c
+++ b/gcc/testsuite/gcc.dg/vect/vect-35.c
@@ -47,5 +47,4 @@ int main (void)
 } 
 
 
-/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect"  { xfail { ia64-*-* sparc*-*-* } } } } */
-/* { dg-final { scan-tree-dump "can't determine dependence between" "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 2 loops" 1 "vect"  { xfail { ia64-*-* sparc*-*-* } } } } */
diff --git a/gcc/testsuite/gfortran.dg/vect/vect-8.f90 b/gcc/testsuite/gfortran.dg/vect/vect-8.f90
index e26cdf95e51..f83f0d0aa27 100644
--- a/gcc/testsuite/gfortran.dg/vect/vect-8.f90
+++ b/gcc/testsuite/gfortran.dg/vect/vect-8.f90
@@ -704,5 +704,5 @@ CALL track('KERNEL  ')
 RETURN
 END SUBROUTINE kernel
 
-! { dg-final { scan-tree-dump-times "vectorized 22 loops" 1 "vect" { target vect_intdouble_cvt } } }
+! { dg-final { scan-tree-dump-times "vectorized 23 loops" 1 "vect" { target vect_intdouble_cvt } } }
 ! { dg-final { scan-tree-dump-times "vectorized 17 loops" 1 "vect" { target { ! vect_intdouble_cvt } } } }
diff --git a/gcc/tree.c b/gcc/tree.c
index efa49e99d65..91ebc9eddc4 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -7887,6 +7887,10 @@ add_expr (const_tree t, inchash::hash &hstate, unsigned int flags)
     case IDENTIFIER_NODE:
       hstate.add_object (IDENTIFIER_HASH_VALUE (t));
       return;
+    case FIELD_DECL:
+      inchash::add_expr (DECL_FIELD_OFFSET (t), hstate, flags);
+      inchash::add_expr (DECL_FIELD_BIT_OFFSET (t), hstate, flags);
+      return;
     case FUNCTION_DECL:
       /* When referring to a built-in FUNCTION_DECL, use the __builtin__ form.
 	 Otherwise nodes that compare equal according to operand_equal_p might