Revert: [RTL ifcvt] Transform (X == CST) ? -CST : Y into (X == CST) ? -X : Y…

Revert: [RTL ifcvt] Transform (X == CST) ? -CST : Y into (X == CST) ? -X : Y when conditional negation is available

	Revert
	2016-09-30  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

	* ifcvt.c (noce_try_avoid_const_materialization): New function.
	(noce_process_if_block): Use it.

	* gcc.target/aarch64/ifcvt_avoid_const_materialization_1.c: New test.

From-SVN: r240708

gcc/ChangeLog

+2016-10-03  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	Revert
+	2016-09-30  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* ifcvt.c (noce_try_avoid_const_materialization): New function.
+	(noce_process_if_block): Use it.
+
 2016-10-03  Bernd Edlinger  <bernd.edlinger@hotmail.de>
 
 	* doc/invoke.texi: Update -Wint-in-bool-context.

gcc/ifcvt.c

@@ -1313,84 +1313,6 @@ noce_try_inverse_constants (struct noce_if_info *if_info)
   return false;
 }
 
-/* Try to avoid materializing a constant if we know it's in one of the
-   registers.  For example:
-   (X == CST) ? -CST : Y --> (X == CST) ? -X : Y.
-   Do this only if conditional negation is available.
-   Similar for bitwise NOT.  */
-
-static bool
-noce_try_avoid_const_materialization (struct noce_if_info *if_info)
-{
-  if (!noce_simple_bbs (if_info))
-    return false;
-
-  rtx cond = if_info->cond;
-  rtx a = if_info->a;
-  rtx b = if_info->b;
-  rtx_code code = GET_CODE (cond);
-  machine_mode mode = GET_MODE (if_info->x);
-
-  if (!(code == EQ || code == NE)
-      || !REG_P (XEXP (cond, 0))
-      || !REG_P (if_info->x)
-      || GET_MODE (XEXP (cond, 0)) != mode
-      || !CONST_INT_P (XEXP (cond, 1)))
-    return false;
-
-  rtx cst = XEXP (cond, 1);
-  if (cst == CONST0_RTX (mode))
-    return false;
-
-  rtx non_cst = XEXP (cond, 0);
-  rtx eq_side = code == EQ ? b : a;
-  if (!CONST_INT_P (eq_side))
-    return false;
-
-  HOST_WIDE_INT cstval = INTVAL (cst);
-  HOST_WIDE_INT eq_side_val = INTVAL (eq_side);
-
-  rtx_code op_code;
-  if (eq_side_val == ~cstval)
-    op_code = NOT;
-  else if (eq_side_val != HOST_WIDE_INT_MIN && (cstval == -eq_side_val))
-    op_code = NEG;
-  else
-    return false;
-
-  /* By the rules of the negcc/notcc optabs must happen when the COND is true,
-     in this case when register in COND is equal to CST so always set the
-     comparison to EQ.  */
-  if (code == NE)
-    {
-      a = non_cst;
-      cond = gen_rtx_fmt_ee (EQ, GET_MODE (cond), non_cst, cst);
-    }
-  else
-    b = non_cst;
-
-  start_sequence ();
-  rtx target
-    = emit_conditional_neg_or_complement (if_info->x, op_code, mode,
-					   cond, a, b);
-  if (!target)
-    {
-      end_sequence ();
-      return false;
-    }
-
-  if (target != if_info->x)
-    noce_emit_move_insn (if_info->x, target);
-
-  rtx_insn *seq = end_ifcvt_sequence (if_info);
-  if (!seq)
-    return false;
-
-   emit_insn_before_setloc (seq, if_info->jump,
-			     INSN_LOCATION (if_info->insn_a));
-  if_info->transform_name = "noce_try_avoid_const_materialization";
-  return true;
-}
 
 /* Convert "if (test) x = a; else x = b", for A and B constant.
    Also allow A = y + c1, B = y + c2, with a common y between A
@@ -3684,8 +3606,6 @@ noce_process_if_block (struct noce_if_info *if_info)
     goto success;
   if (noce_try_inverse_constants (if_info))
     goto success;
-  if (noce_try_avoid_const_materialization (if_info))
-    goto success;
   if (!targetm.have_conditional_execution ()
       && noce_try_store_flag_constants (if_info))
     goto success;

gcc/testsuite/ChangeLog

+2016-10-03  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	Revert
+	2016-09-30  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* gcc.target/aarch64/ifcvt_avoid_const_materialization_1.c: New test.
+
 2016-10-03  Marek Polacek  <polacek@redhat.com>
 
 	* g++.dg/cpp0x/nullptr37.C: New test.

gcc/testsuite/gcc.target/aarch64/ifcvt_avoid_const_materialization_1.c

-/* { dg-do compile } */
-/* { dg-options "-O2" } */
-
-/* Check that we avoid moving the immediate into a register
-   if comparison has shown that the inverse or negated form is
-   already in one of the registers.  */
-
-int
-foo (int a, int b)
-{
-  return a == 5 ? -5 : b;
-}
-
-int
-bar (int a, int b)
-{
-  return a != 5 ? b : ~5;
-}
-
-/* { dg-final { scan-assembler-not "mov\\tw\[0-9\]+" } } */
-/* { dg-final { scan-assembler-times "csneg\\tw\[0-9\]+" 1 } } */
-/* { dg-final { scan-assembler-times "csinv\\tw\[0-9\]+" 1 } } */