re PR rtl-optimization/51933 (wrong code due to -free)

	PR rtl-optimization/51933
	* ree.c (transform_ifelse): Return true right away if dstreg is
	already wider or equal to cand->mode.
	(enum ext_modified_kind, struct ext_modified, ext_state): New types.
	(make_defs_and_copies_lists): Remove defs_list and copies_list
	arguments, add state argument, just truncate state->work_list
	instead of always allocating and freeing the vector.  Assert that
	get_defs succeeds instead of returning 2.  Changed return type to
	bool.
	(merge_def_and_ext): Add state argument.  If SET_DEST doesn't
	have ext_src_mode, see if it has been modified already with the
	right kind of extension and has been extended before from the
	ext_src_mode.  If SET_DEST is already wider or equal to cand->mode,
	just return true.  Remember the original mode in state->modified
	array.
	(combine_reaching_defs): Add state argument.  Don't allocate and
	free here def_list, copied_list and vec vectors, instead just
	VEC_truncate the vectors in *state.  Don't handle outcome == 2
	here.
	(find_and_remove_re): Set DF_DEFER_INSN_RESCAN df flag.
	Add state variable, clear vectors in it, initialize state.modified
	if needed.  Free all the vectors at the end and state.modified too.
	Don't skip a candidate if the extension expression has been modified.

	* gcc.c-torture/execute/pr51933.c: New test.

From-SVN: r183416

gcc/ChangeLog

+2012-01-23  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/51933
+	* ree.c (transform_ifelse): Return true right away if dstreg is
+	already wider or equal to cand->mode.
+	(enum ext_modified_kind, struct ext_modified, ext_state): New types.
+	(make_defs_and_copies_lists): Remove defs_list and copies_list
+	arguments, add state argument, just truncate state->work_list
+	instead of always allocating and freeing the vector.  Assert that
+	get_defs succeeds instead of returning 2.  Changed return type to
+	bool.
+	(merge_def_and_ext): Add state argument.  If SET_DEST doesn't
+	have ext_src_mode, see if it has been modified already with the
+	right kind of extension and has been extended before from the
+	ext_src_mode.  If SET_DEST is already wider or equal to cand->mode,
+	just return true.  Remember the original mode in state->modified
+	array.
+	(combine_reaching_defs): Add state argument.  Don't allocate and
+	free here def_list, copied_list and vec vectors, instead just
+	VEC_truncate the vectors in *state.  Don't handle outcome == 2
+	here.
+	(find_and_remove_re): Set DF_DEFER_INSN_RESCAN df flag.
+	Add state variable, clear vectors in it, initialize state.modified
+	if needed.  Free all the vectors at the end and state.modified too.
+	Don't skip a candidate if the extension expression has been modified.
+
 2012-01-22  Douglas B Rupp  <rupp@gnat.com>
 
 	PR target/47096

gcc/testsuite/ChangeLog

+2012-01-23  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/51933
+	* gcc.c-torture/execute/pr51933.c: New test.
+
 2012-01-22  Douglas B Rupp  <rupp@gnat.com>
 
 	* gcc.dg/builtins-config.h (HAVE_C99_RUNTIME):

gcc/testsuite/gcc.c-torture/execute/pr51933.c

+/* PR rtl-optimization/51933 */
+
+static signed char v1;
+static unsigned char v2[256], v3[256];
+
+__attribute__((noclone, noinline)) void
+foo (void)
+{
+  asm volatile ("" : : "g" (&v1), "g" (&v2[0]), "g" (&v3[0]) : "memory");
+}
+
+__attribute__((noclone, noinline)) int
+bar (const int x, const unsigned short *y, char *z)
+{
+  int i;
+  unsigned short u;
+  if (!v1)
+    foo ();
+  for (i = 0; i < x; i++)
+    {
+      u = y[i];
+      z[i] = u < 0x0100 ? v2[u] : v3[u & 0xff];
+    }
+  z[x] = '\0';
+  return x;
+}
+
+int
+main (void)
+{
+  char buf[18];
+  unsigned short s[18];
+  unsigned char c[18] = "abcdefghijklmnopq";
+  int i;
+  for (i = 0; i < 256; i++)
+    {
+      v2[i] = i;
+      v3[i] = i + 1;
+    }
+  for (i = 0; i < 18; i++)
+    s[i] = c[i];
+  s[5] |= 0x600;
+  s[6] |= 0x500;
+  s[11] |= 0x2000;
+  s[15] |= 0x500;
+  foo ();
+  if (bar (17, s, buf) != 17
+      || __builtin_memcmp (buf, "abcdeghhijkmmnoqq", 18) != 0)
+    __builtin_abort ();
+  return 0;
+}