re PR tree-optimization/77988 (ICE on valid code at -Os and above on…

re PR tree-optimization/77988 (ICE on valid code at -Os and above on x86_64-linux-gnu: verify_gimple failed)

2016-10-17  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/77988
	* tree-vrp.c (remove_range_assertions): Use replace_uses_by.

	* gcc.dg/torture/pr77988.c: New testcase.

From-SVN: r241242

gcc/ChangeLog

+2016-10-17  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/77988
+	* tree-vrp.c (remove_range_assertions): Use replace_uses_by.
+
 2016-10-17  Marek Polacek  <polacek@redhat.com>
 
 	* Makefile.in (C_COMMON_OBJS): Add c-family/c-attribs.o.

gcc/testsuite/ChangeLog

+2016-10-17  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/77988
+	* gcc.dg/torture/pr77988.c: New testcase.
+
 2016-10-17  Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>
 
 	* gcc.dg/pr71636-1.c: New test-case.

gcc/testsuite/gcc.dg/torture/pr77988.c

+/* { dg-do compile } */
+
+static int a = 2;
+int b[1], c, d;
+
+int main ()
+{ 
+  int e = a, *f = &b[0];
+  if (d)
+    for (e = 0; e < 1; e++)
+      ;
+  if (e)
+    {
+L1:
+      if (b < f)
+	__builtin_abort ();
+      if (*f)
+	c++;
+      return 0;
+    }
+  f = 0;
+  goto L1;
+  return 0;
+}

gcc/tree-vrp.c

@@ -6882,7 +6882,6 @@ remove_range_assertions (void)
     for (si = gsi_after_labels (bb), is_unreachable = -1; !gsi_end_p (si);)
       {
 	gimple *stmt = gsi_stmt (si);
-	gimple *use_stmt;
 
 	if (is_gimple_assign (stmt)
 	    && gimple_assign_rhs_code (stmt) == ASSERT_EXPR)
@@ -6890,8 +6889,6 @@ remove_range_assertions (void)
 	    tree lhs = gimple_assign_lhs (stmt);
 	    tree rhs = gimple_assign_rhs1 (stmt);
 	    tree var;
-	    use_operand_p use_p;
-	    imm_use_iterator iter;
 
 	    var = ASSERT_EXPR_VAR (rhs);
 
@@ -6927,12 +6924,7 @@ remove_range_assertions (void)
 	      }
 
 	    /* Propagate the RHS into every use of the LHS.  */
-	    FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
-	      {
-		FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
-		  SET_USE (use_p, var);
-		update_stmt (use_stmt);
-	      }
+	    replace_uses_by (lhs, var);
 
 	    /* And finally, remove the copy, it is not needed.  */
 	    gsi_remove (&si, true);