match.pd (max:c @0 (plus@2 @0 INTEGER_CST@1)): New Pattern.

2016-12-22  Andrew Pinski  <apinski@cavium.com>
	    Naveen H.S <Naveen.Hurugalawadi@cavium.com>

gcc
        * match.pd (max:c @0 (plus@2 @0 INTEGER_CST@1)): New Pattern.
	(min:c @0 (plus@2 @0 INTEGER_CST@1)) : New Pattern.
gcc/testsuite
	* gcc.dg/max.c: New Testcase.
	* gcc.dg/min.c: New Testcase.

From-SVN: r243838

gcc/ChangeLog

+2016-12-22  Andrew Pinski  <apinski@cavium.com>
+
+        * match.pd (max:c @0 (plus@2 @0 INTEGER_CST@1)): New Pattern.
+	(min:c @0 (plus@2 @0 INTEGER_CST@1)) : New Pattern.
+
 2016-12-20  James Greenhalgh  <james.greenhalghj@arm.com>
 
 	* common.opt (excess_precision): Tag as SetByCombined.

gcc/match.pd

@@ -1373,6 +1373,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
        && operand_equal_p (@1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
    @0)))
 
+/* max (a, a + CST) -> a + CST where CST is positive.  */
+/* max (a, a + CST) -> a where CST is negative.  */
+(simplify
+ (max:c @0 (plus@2 @0 INTEGER_CST@1))
+  (if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
+   (if (tree_int_cst_sgn (@1) > 0)
+    @2
+    @0)))
+
+/* min (a, a + CST) -> a where CST is positive.  */
+/* min (a, a + CST) -> a + CST where CST is negative. */
+(simplify
+ (min:c @0 (plus@2 @0 INTEGER_CST@1))
+  (if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
+   (if (tree_int_cst_sgn (@1) > 0)
+    @0
+    @2)))
+
 /* (convert (minmax ((convert (x) c)))) -> minmax (x c) if x is promoted
    and the outer convert demotes the expression back to x's type.  */
 (for minmax (min max)

gcc/testsuite/ChangeLog

+2016-12-22  Naveen H.S  <Naveen.Hurugalawadi@cavium.com>
+
+	* gcc.dg/max.c: New Testcase.
+	* gcc.dg/min.c: New Testcase.
+
 2016-12-21  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/77767

gcc/testsuite/gcc.dg/max.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+static inline int
+max (int a, int b)
+{
+  return a < b ? b : a;
+}
+
+int
+test_00 (int a)
+{
+  return max (a, a + 8);
+}
+
+int
+test_01 (int a)
+{
+  return max (a, a - 8);
+}
+
+/* { dg-final { scan-tree-dump-not "MAX_EXPR" "optimized" } } */

gcc/testsuite/gcc.dg/min.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+static inline int
+min (int a, int b)
+{
+  return a < b ? a : b;
+}
+
+int
+test_00 (int a)
+{
+  return min (a, a + 8);
+}
+
+int
+test_01 (int a)
+{
+  return min (a, a - 8);
+}
+
+/* { dg-final { scan-tree-dump-not "MIN_EXPR" "optimized" } } */