rtlanal.c (canonicalize_condition): Split out duplicated mode check.

gcc/
	* rtlanal.c (canonicalize_condition): Split out duplicated mode check.
	Handle XOR.

gcc/testsuite/
	* gcc.dg/unroll_1.c: Add -fenable-rtl-loop2.

From-SVN: r207076

gcc/ChangeLog

+2014-01-25  Richard Sandiford  <rdsandiford@googlemail.com>
+
+	* rtlanal.c (canonicalize_condition): Split out duplicated mode check.
+	Handle XOR.
+
 2014-01-25  Jakub Jelinek  <jakub@redhat.com>
 
 	* print-rtl.c (in_call_function_usage): New var.

gcc/rtlanal.c

@@ -5051,23 +5051,24 @@ canonicalize_condition (rtx insn, rtx cond, int reverse, rtx *earliest,
 
 	     ??? This mode check should perhaps look more like the mode check
 	     in simplify_comparison in combine.  */
-
-	  if ((GET_CODE (SET_SRC (set)) == COMPARE
-	       || (((code == NE
-		     || (code == LT
-			 && val_signbit_known_set_p (inner_mode,
-						     STORE_FLAG_VALUE))
+	  if (((GET_MODE_CLASS (mode) == MODE_CC)
+	       != (GET_MODE_CLASS (inner_mode) == MODE_CC))
+	      && mode != VOIDmode
+	      && inner_mode != VOIDmode)
+	    break;
+	  if (GET_CODE (SET_SRC (set)) == COMPARE
+	      || (((code == NE
+		    || (code == LT
+			&& val_signbit_known_set_p (inner_mode,
+						    STORE_FLAG_VALUE))
 #ifdef FLOAT_STORE_FLAG_VALUE
-		     || (code == LT
-			 && SCALAR_FLOAT_MODE_P (inner_mode)
-			 && (fsfv = FLOAT_STORE_FLAG_VALUE (inner_mode),
-			     REAL_VALUE_NEGATIVE (fsfv)))
+		    || (code == LT
+			&& SCALAR_FLOAT_MODE_P (inner_mode)
+			&& (fsfv = FLOAT_STORE_FLAG_VALUE (inner_mode),
+			    REAL_VALUE_NEGATIVE (fsfv)))
 #endif
-		     ))
-		   && COMPARISON_P (SET_SRC (set))))
-	      && (((GET_MODE_CLASS (mode) == MODE_CC)
-		   == (GET_MODE_CLASS (inner_mode) == MODE_CC))
-		  || mode == VOIDmode || inner_mode == VOIDmode))
+		    ))
+		  && COMPARISON_P (SET_SRC (set))))
 	    x = SET_SRC (set);
 	  else if (((code == EQ
 		     || (code == GE
@@ -5080,15 +5081,25 @@ canonicalize_condition (rtx insn, rtx cond, int reverse, rtx *earliest,
 			     REAL_VALUE_NEGATIVE (fsfv)))
 #endif
 		     ))
-		   && COMPARISON_P (SET_SRC (set))
-		   && (((GET_MODE_CLASS (mode) == MODE_CC)
-			== (GET_MODE_CLASS (inner_mode) == MODE_CC))
-		       || mode == VOIDmode || inner_mode == VOIDmode))
-
+		   && COMPARISON_P (SET_SRC (set)))
 	    {
 	      reverse_code = 1;
 	      x = SET_SRC (set);
 	    }
+	  else if ((code == EQ || code == NE)
+		   && GET_CODE (SET_SRC (set)) == XOR)
+	    /* Handle sequences like:
+
+	       (set op0 (xor X Y))
+	       ...(eq|ne op0 (const_int 0))...
+
+	       in which case:
+
+	       (eq op0 (const_int 0)) reduces to (eq X Y)
+	       (ne op0 (const_int 0)) reduces to (ne X Y)
+
+	       This is the form used by MIPS16, for example.  */
+	    x = SET_SRC (set);
 	  else
 	    break;
 	}

gcc/testsuite/ChangeLog

+2014-01-25  Richard Sandiford  <rdsandiford@googlemail.com>
+
+	* gcc.dg/unroll_1.c: Add -fenable-rtl-loop2.
+
 2014-01-25  Bernd Edlinger  <bernd.edlinger@hotmail.de>
 
 	* gcc.dg/vect/vect-nop-move.c (main): Check for vect runtime.

gcc/testsuite/gcc.dg/unroll_1.c

 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-rtl-loop2_unroll=stderr -fno-peel-loops -fno-tree-vrp -fdisable-tree-cunroll -fdisable-tree-cunrolli -fenable-rtl-loop2_unroll" } */
+/* { dg-options "-O2 -fdump-rtl-loop2_unroll=stderr -fno-peel-loops -fno-tree-vrp -fdisable-tree-cunroll -fdisable-tree-cunrolli -fenable-rtl-loop2 -fenable-rtl-loop2_unroll" } */
 
 unsigned a[100], b[100];
 inline void bar()