[PATCH 4.8] PR66306 Fix reload problem with commutative operands

[Andreas Krebbel]

Hi,

this fixes a reload problem with match_dup's on commutative operands.

Bootstrapped and regtested on x86-64, ppc64, and s390x.

Ok?

Bye,

-Andreas-

2015-06-11  Andreas Krebbel  <kreb...@linux.vnet.ibm.com>

        PR rtl-optimization/66306
        * reload.c (find_reloads): Swap the match_dup info for
        commutative operands.

2015-06-11  Andreas Krebbel  <kreb...@linux.vnet.ibm.com>

        PR rtl-optimization/66306
        * gcc.target/s390/pr66306.c: New test.

diff --git a/gcc/reload.c b/gcc/reload.c
index 2546c1b..48ad99c 100644
--- a/gcc/reload.c
+++ b/gcc/reload.c
@@ -3924,6 +3924,12 @@ find_reloads (rtx insn, int replace, int ind_levels, int 
live_known,
        = *recog_data.operand_loc[commutative + 1];
       *recog_data.operand_loc[commutative + 1] = tem;
 
+      for (i = 0; i < recog_data.n_dups; i++)
+       if (recog_data.dup_num[i] == commutative
+           || recog_data.dup_num[i] == commutative + 1)
+         *recog_data.dup_loc[i]
+           = recog_data.operand[(int) recog_data.dup_num[i]];
+
       for (i = 0; i < n_reloads; i++)
        {
          if (rld[i].opnum == commutative)
diff --git a/gcc/testsuite/gcc.target/s390/pr66306.c 
b/gcc/testsuite/gcc.target/s390/pr66306.c
new file mode 100644
index 0000000..73903cb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/s390/pr66306.c
@@ -0,0 +1,26 @@
+/* This caused an ICE on s390x due to a reload bug handling
+   commutative constraints.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O1" } */
+
+struct line_map
+{
+  unsigned start_location;
+  unsigned ordinary;
+};
+unsigned
+linemap_resolve_location (struct line_map **loc_map);
+
+unsigned
+linemap_position_for_loc_and_offset (unsigned h, unsigned loc)
+{
+  struct line_map *map = 0;
+  linemap_resolve_location (&map);
+
+  if (map->ordinary <= loc + map->start_location + map->ordinary)
+    __builtin_abort ();
+
+  if (h >= loc + map->start_location)
+    __builtin_abort ();
+}