[PATCH][combine][1/2] Try to simplify before substituting

	* combine.c (combine_simplify_rtx): Move simplification step
	before various transformations/substitutions.

From-SVN: r225996

gcc/ChangeLog

+2015-07-20  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* combine.c (combine_simplify_rtx): Move simplification step
+	before various transformations/substitutions.
+
 2015-07-20  Mikhail Maltsev  <maltsevm@gmail.com>
 
 	* wide-int.h (struct binary_traits): Fix partial specialization syntax.

gcc/combine.c

@@ -5489,6 +5489,51 @@ combine_simplify_rtx (rtx x, machine_mode op0_mode, int in_dest,
       SUBST (XEXP (x, 1), temp);
     }
 
+  /* Try to fold this expression in case we have constants that weren't
+     present before.  */
+  temp = 0;
+  switch (GET_RTX_CLASS (code))
+    {
+    case RTX_UNARY:
+      if (op0_mode == VOIDmode)
+	op0_mode = GET_MODE (XEXP (x, 0));
+      temp = simplify_unary_operation (code, mode, XEXP (x, 0), op0_mode);
+      break;
+    case RTX_COMPARE:
+    case RTX_COMM_COMPARE:
+      {
+	machine_mode cmp_mode = GET_MODE (XEXP (x, 0));
+	if (cmp_mode == VOIDmode)
+	  {
+	    cmp_mode = GET_MODE (XEXP (x, 1));
+	    if (cmp_mode == VOIDmode)
+	      cmp_mode = op0_mode;
+	  }
+	temp = simplify_relational_operation (code, mode, cmp_mode,
+					      XEXP (x, 0), XEXP (x, 1));
+      }
+      break;
+    case RTX_COMM_ARITH:
+    case RTX_BIN_ARITH:
+      temp = simplify_binary_operation (code, mode, XEXP (x, 0), XEXP (x, 1));
+      break;
+    case RTX_BITFIELD_OPS:
+    case RTX_TERNARY:
+      temp = simplify_ternary_operation (code, mode, op0_mode, XEXP (x, 0),
+					 XEXP (x, 1), XEXP (x, 2));
+      break;
+    default:
+      break;
+    }
+
+  if (temp)
+    {
+      x = temp;
+      code = GET_CODE (temp);
+      op0_mode = VOIDmode;
+      mode = GET_MODE (temp);
+    }
+
   /* If this is a simple operation applied to an IF_THEN_ELSE, try
      applying it to the arms of the IF_THEN_ELSE.  This often simplifies
      things.  Check for cases where both arms are testing the same
@@ -5588,51 +5633,6 @@ combine_simplify_rtx (rtx x, machine_mode op0_mode, int in_dest,
 	}
     }
 
-  /* Try to fold this expression in case we have constants that weren't
-     present before.  */
-  temp = 0;
-  switch (GET_RTX_CLASS (code))
-    {
-    case RTX_UNARY:
-      if (op0_mode == VOIDmode)
-	op0_mode = GET_MODE (XEXP (x, 0));
-      temp = simplify_unary_operation (code, mode, XEXP (x, 0), op0_mode);
-      break;
-    case RTX_COMPARE:
-    case RTX_COMM_COMPARE:
-      {
-	machine_mode cmp_mode = GET_MODE (XEXP (x, 0));
-	if (cmp_mode == VOIDmode)
-	  {
-	    cmp_mode = GET_MODE (XEXP (x, 1));
-	    if (cmp_mode == VOIDmode)
-	      cmp_mode = op0_mode;
-	  }
-	temp = simplify_relational_operation (code, mode, cmp_mode,
-					      XEXP (x, 0), XEXP (x, 1));
-      }
-      break;
-    case RTX_COMM_ARITH:
-    case RTX_BIN_ARITH:
-      temp = simplify_binary_operation (code, mode, XEXP (x, 0), XEXP (x, 1));
-      break;
-    case RTX_BITFIELD_OPS:
-    case RTX_TERNARY:
-      temp = simplify_ternary_operation (code, mode, op0_mode, XEXP (x, 0),
-					 XEXP (x, 1), XEXP (x, 2));
-      break;
-    default:
-      break;
-    }
-
-  if (temp)
-    {
-      x = temp;
-      code = GET_CODE (temp);
-      op0_mode = VOIDmode;
-      mode = GET_MODE (temp);
-    }
-
   /* First see if we can apply the inverse distributive law.  */
   if (code == PLUS || code == MINUS
       || code == AND || code == IOR || code == XOR)