re PR target/64268 (bootstrap failure (ICE in wide_int_to_tree, at tree.c:1438)…

re PR target/64268 (bootstrap failure (ICE in wide_int_to_tree, at tree.c:1438) on powerpc in libgcc, stage2)

	PR target/64268
	* combine.c (try_combine): Immediately return if any of I0,I1,I2
	are the same insn.

From-SVN: r218971

gcc/ChangeLog

+2014-12-19  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	PR target/64268
+	* combine.c (try_combine): Immediately return if any of I0,I1,I2
+	are the same insn.
+
 2014-12-19  Alan Lawrence  <alan.lawrence@arm.com>
 
 	* config/aarch64/aarch64.c (<LOGICAL:optab>_one_cmpl<mode>3):

gcc/combine.c

@@ -2588,6 +2588,11 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
   rtx new_other_notes;
   int i;
 
+  /* Immediately return if any of I0,I1,I2 are the same insn (I3 can
+     never be).  */
+  if (i1 == i2 || i0 == i2 || (i0 && i0 == i1))
+    return 0;
+
   /* Only try four-insn combinations when there's high likelihood of
      success.  Look for simple insns, such as loads of constants or
      binary operations involving a constant.  */