re PR tree-optimization/66422 (-Warray-bounds false positive with -O3)

2015-06-08  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/66422
	* tree-ssa-loop-ivcanon.c (remove_exits_and_undefined_stmts): Split
	block after inserted gcc_unreachable.

	* gcc.dg/Warray-bounds-16.c: New testcase.

From-SVN: r224235

gcc/ChangeLog

+2015-06-08  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/66422
+	* tree-ssa-loop-ivcanon.c (remove_exits_and_undefined_stmts): Split
+	block after inserted gcc_unreachable.
+
 2015-06-08  Nick Clifton  <nickc@redhat.com>
 
 	* config/rx/rx.c (rx_function_value): Do not promote vector types.

gcc/testsuite/ChangeLog

 2015-06-08  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/66422
+	* gcc.dg/Warray-bounds-16.c: New testcase.
+
+2015-06-08  Richard Biener  <rguenther@suse.de>
+
 	* gcc.dg/vect/slp-perm-10.c: New testcase.
 	* gcc.dg/vect/slp-23.c: Adjust.
 	* gcc.dg/torture/pr53366-2.c: Also verify cross-iteration

gcc/testsuite/gcc.dg/Warray-bounds-16.c

+/* { dg-do compile } */
+/* { dg-options "-O3 -Warray-bounds" } */
+
+typedef struct foo {
+    unsigned char foo_size;
+    int buf[4];
+    const char* bar;
+} foo;
+
+const foo *get_foo(int index);
+
+static int foo_loop(const foo *myfoo) {
+    int i;
+    if (myfoo->foo_size < 3)
+        return 0;
+    for (i = 0; i < myfoo->foo_size; i++) {
+        if (myfoo->buf[i] != 1) /* { dg-bogus "above array bounds" } */
+            return 0;
+    }
+
+    return 1;
+}
+
+static int run_foo(void) {
+    int i;
+    for (i = 0; i < 1; i++) {
+        const foo *myfoo = get_foo(i);
+        if (foo_loop(myfoo))
+            return 0;
+    }
+    return -1;
+}
+
+typedef struct hack {
+    int (*func)(void);
+} hack;
+
+hack myhack = {
+    .func = run_foo,
+};

gcc/tree-ssa-loop-ivcanon.c

@@ -520,9 +520,9 @@ remove_exits_and_undefined_stmts (struct loop *loop, unsigned int npeeled)
 	  gimple_stmt_iterator gsi = gsi_for_stmt (elt->stmt);
 	  gcall *stmt = gimple_build_call
 	      (builtin_decl_implicit (BUILT_IN_UNREACHABLE), 0);
-
 	  gimple_set_location (stmt, gimple_location (elt->stmt));
 	  gsi_insert_before (&gsi, stmt, GSI_NEW_STMT);
+	  split_block (gimple_bb (stmt), stmt);
 	  changed = true;
 	  if (dump_file && (dump_flags & TDF_DETAILS))
 	    {