Index: compare-elim.c
===================================================================
--- compare-elim.c	(revision 184067)
+++ compare-elim.c	(working copy)
@@ -297,11 +297,36 @@ find_comparisons_in_bb (struct dom_walk_data *data
       src = conforming_compare (insn);
       if (src)
 	{
+	  enum machine_mode src_mode = GET_MODE (src);
+
 	  /* Eliminate a compare that's redundant with the previous.  */
 	  if (last_cmp_valid
 	      && rtx_equal_p (last_cmp->in_a, XEXP (src, 0))
 	      && rtx_equal_p (last_cmp->in_b, XEXP (src, 1)))
 	    {
+	      rtx flags, x;
+	      enum machine_mode new_mode
+		= targetm.cc_modes_compatible (last_cmp->orig_mode, src_mode);
+
+	      /* New mode is incompatible with the previous compare mode.  */
+	      if (new_mode == VOIDmode)
+		continue;
+
+	      if (new_mode != last_cmp->orig_mode)
+		{
+		  flags = gen_rtx_REG (src_mode, targetm.flags_regnum);
+
+		  /* Generate new comparison for substitution.  */
+		  x = gen_rtx_COMPARE (new_mode, XEXP (src, 0), XEXP (src, 1));
+		  x = gen_rtx_SET (VOIDmode, flags, x);
+
+		  if (!validate_change (last_cmp->insn,
+					&PATTERN (last_cmp->insn), x, false))
+		    continue;
+
+		  last_cmp->orig_mode = new_mode;
+		}
+
 	      delete_insn (insn);
 	      continue;
 	    }
@@ -311,7 +336,7 @@ find_comparisons_in_bb (struct dom_walk_data *data
 	  last_cmp->prev_clobber = last_clobber;
 	  last_cmp->in_a = XEXP (src, 0);
 	  last_cmp->in_b = XEXP (src, 1);
-	  last_cmp->orig_mode = GET_MODE (SET_DEST (single_set (insn)));
+	  last_cmp->orig_mode = src_mode;
 	  VEC_safe_push (comparison_struct_p, heap, all_compares, last_cmp);
 
 	  /* It's unusual, but be prepared for comparison patterns that
Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c	(revision 184067)
+++ config/i386/i386.c	(working copy)
@@ -17778,6 +17778,11 @@ ix86_cc_modes_compatible (enum machine_mode m1, en
       || (m1 == CCGOCmode && m2 == CCGCmode))
     return CCGCmode;
 
+  if (m1 == CCZmode && (m2 == CCGCmode || m2 == CCGOCmode))
+    return m2;
+  else if (m2 == CCZmode && (m1 == CCGCmode || m1 == CCGOCmode))
+    return m1;
+
   switch (m1)
     {
     default:
@@ -38685,6 +38690,9 @@ ix86_autovectorize_vector_sizes (void)
 #undef TARGET_EXPAND_TO_RTL_HOOK
 #define TARGET_EXPAND_TO_RTL_HOOK ix86_maybe_switch_abi
 
+#undef TARGET_FLAGS_REGNUM
+#define TARGET_FLAGS_REGNUM FLAGS_REG
+
 #undef TARGET_LEGITIMATE_ADDRESS_P
 #define TARGET_LEGITIMATE_ADDRESS_P ix86_legitimate_address_p