re PR rtl-optimization/19579 (-march=i686 generates a bogus program for x86*)

	PR rtl-optimization/19579
	* ifcvt.c (noce_try_cmove_arith): If emitting instructions to set up
	both A and B, see if they don't clobber registers the other expr uses.

	* gcc.c-torture/execute/20050124-1.c: New test.

From-SVN: r94234

gcc/ChangeLog

+2005-01-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/19579
+	* ifcvt.c (noce_try_cmove_arith): If emitting instructions to set up
+	both A and B, see if they don't clobber registers the other expr uses.
+
 2005-01-25  J"orn Rennecke <joern.rennecke@st.com>
 
 	* real.c (do_add): Initialize signalling and canonical members.

gcc/ifcvt.c

@@ -1229,6 +1229,7 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
   rtx a = if_info->a;
   rtx b = if_info->b;
   rtx x = if_info->x;
+  rtx orig_a, orig_b;
   rtx insn_a, insn_b;
   rtx tmp, target;
   int is_mem = 0;
@@ -1304,6 +1305,9 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
 
   start_sequence ();
 
+  orig_a = a;
+  orig_b = b;
+
   /* If either operand is complex, load it into a register first.
      The best way to do this is to copy the original insn.  In this
      way we preserve any clobbers etc that the insn may have had.
@@ -1335,7 +1339,7 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
     }
   if (! general_operand (b, GET_MODE (b)))
     {
-      rtx set;
+      rtx set, last;
 
       if (no_new_pseudos)
 	goto end_seq_and_fail;
@@ -1343,9 +1347,7 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
       if (is_mem)
 	{
           tmp = gen_reg_rtx (GET_MODE (b));
-	  tmp = emit_insn (gen_rtx_SET (VOIDmode,
-				  	tmp,
-					b));
+	  tmp = gen_rtx_SET (VOIDmode, tmp, b);
 	}
       else if (! insn_b)
 	goto end_seq_and_fail;
@@ -1355,8 +1357,22 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
 	  tmp = copy_rtx (insn_b);
 	  set = single_set (tmp);
 	  SET_DEST (set) = b;
-	  tmp = emit_insn (PATTERN (tmp));
+	  tmp = PATTERN (tmp);
+	}
+
+      /* If insn to set up A clobbers any registers B depends on, try to
+	 swap insn that sets up A with the one that sets up B.  If even
+	 that doesn't help, punt.  */
+      last = get_last_insn ();
+      if (last && modified_in_p (orig_b, last))
+	{
+	  tmp = emit_insn_before (tmp, get_insns ());
+	  if (modified_in_p (orig_a, tmp))
+	    goto end_seq_and_fail;
 	}
+      else
+	tmp = emit_insn (tmp);
+
       if (recog_memoized (tmp) < 0)
 	goto end_seq_and_fail;
     }

gcc/testsuite/ChangeLog

+2005-01-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/19579
+	* gcc.c-torture/execute/20050124-1.c: New test.
+
 2005-01-18  Jan Hubicka  <jh@suse.cz>
 
 	PR tree-optimize/19337

gcc/testsuite/gcc.c-torture/execute/20050124-1.c

+/* PR rtl-optimization/19579 */
+
+extern void abort (void);
+
+int
+foo (int i, int j)
+{
+  int k = i + 1;
+
+  if (j)
+    {
+      if (k > 0)
+	k++;
+      else if (k < 0)
+	k--;
+    }
+
+  return k;
+}
+
+int
+main (void)
+{
+  if (foo (-2, 0) != -1)
+    abort ();
+  if (foo (-1, 0) != 0)
+    abort ();
+  if (foo (0, 0) != 1)
+    abort ();
+  if (foo (1, 0) != 2)
+    abort ();
+  if (foo (-2, 1) != -2)
+    abort ();
+  if (foo (-1, 1) != 0)
+    abort ();
+  if (foo (0, 1) != 2)
+    abort ();
+  if (foo (1, 1) != 3)
+    abort ();
+  return 0;
+}