match.pd (swapped_tcc_comparison): New operator list.

2015-05-26  Marc Glisse  <marc.glisse@inria.fr>

	* match.pd (swapped_tcc_comparison): New operator list.
	(-A CMP -B): New simplification.
	* fold-const.c (fold_comparison): Remove corresponding code.

From-SVN: r223689

gcc/ChangeLog

+2015-05-26  Marc Glisse  <marc.glisse@inria.fr>
+
+	* match.pd (swapped_tcc_comparison): New operator list.
+	(-A CMP -B): New simplification.
+	* fold-const.c (fold_comparison): Remove corresponding code.
+
 2015-05-26  Richard Sandiford  <richard.sandiford@arm.com>
 
 	* caller-save.c (init_caller_save): Base temporary register numbers

gcc/fold-const.c

@@ -9183,24 +9183,11 @@ fold_comparison (location_t loc, enum tree_code code, tree type,
 			    fold_convert_loc (loc, newtype, targ0),
 			    fold_convert_loc (loc, newtype, targ1));
 
-      /* (-a) CMP (-b) -> b CMP a  */
-      if (TREE_CODE (arg0) == NEGATE_EXPR
-	  && TREE_CODE (arg1) == NEGATE_EXPR)
-	return fold_build2_loc (loc, code, type, TREE_OPERAND (arg1, 0),
-			    TREE_OPERAND (arg0, 0));
-
       if (TREE_CODE (arg1) == REAL_CST)
 	{
 	  REAL_VALUE_TYPE cst;
 	  cst = TREE_REAL_CST (arg1);
 
-	  /* (-a) CMP CST -> a swap(CMP) (-CST)  */
-	  if (TREE_CODE (arg0) == NEGATE_EXPR)
-	    return fold_build2_loc (loc, swap_tree_comparison (code), type,
-				TREE_OPERAND (arg0, 0),
-				build_real (TREE_TYPE (arg1),
-					    real_value_negate (&cst)));
-
 	  /* IEEE doesn't distinguish +0 and -0 in comparisons.  */
 	  /* a CMP (-0) -> a CMP 0  */
 	  if (REAL_VALUE_MINUS_ZERO (cst))

gcc/match.pd

@@ -38,6 +38,8 @@ along with GCC; see the file COPYING3.  If not see
   ge   gt   ne eq lt   le   ordered   unordered ge   gt   le   lt   ltgt uneq)
 (define_operator_list inverted_tcc_comparison_with_nans
   unge ungt ne eq unlt unle ordered   unordered ge   gt   le   lt   ltgt uneq)
+(define_operator_list swapped_tcc_comparison
+  gt   ge   eq ne le   lt   unordered ordered   ungt unge unlt unle uneq ltgt)
 
 
 /* Simplifications of operations with one constant operand and
@@ -980,6 +982,24 @@ along with GCC; see the file COPYING3.  If not see
  (bit_and:c (ordered @0 @0) (ordered:c@2 @0 @1))
  @2)
 
+/* -A CMP -B -> B CMP A.  */
+(for cmp (tcc_comparison)
+     scmp (swapped_tcc_comparison)
+ (simplify
+  (cmp (negate @0) (negate @1))
+  (if (FLOAT_TYPE_P (TREE_TYPE (@0))
+       || (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
+	   && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))))
+   (scmp @0 @1)))
+ (simplify
+  (cmp (negate @0) CONSTANT_CLASS_P@1)
+  (if (FLOAT_TYPE_P (TREE_TYPE (@0))
+       || (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
+	   && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))))
+   (with { tree tem = fold_unary (NEGATE_EXPR, TREE_TYPE (@0), @1); }
+    (if (tem && !TREE_OVERFLOW (tem))
+     (scmp @0 { tem; }))))))
+
 /* Simplification of math builtins.  */
 
 (define_operator_list LOG BUILT_IN_LOGF BUILT_IN_LOG BUILT_IN_LOGL)