max(INT_MIN, x) -> x

2016-04-21  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* match.pd (min(int_max, x), max(int_min, x)): New transformations.

gcc/testsuite/
	* gcc.dg/tree-ssa/minmax-1.c: New testcase.

From-SVN: r235323

gcc/ChangeLog

+2016-04-21  Marc Glisse  <marc.glisse@inria.fr>
+
+	* match.pd (min(int_max, x), max(int_min, x)): New transformations.
+
 2016-04-20  Jan Hubicka  <jh@suse.cz>
 
 	* ipa-inline.c (can_inline_edge_p): Pass caller info to

gcc/match.pd

@@ -1192,16 +1192,26 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
  @1)
 (simplify
  (min @0 @1)
- (if (INTEGRAL_TYPE_P (type)
-      && TYPE_MIN_VALUE (type)
-      && operand_equal_p (@1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
-  @1))
+ (switch
+  (if (INTEGRAL_TYPE_P (type)
+       && TYPE_MIN_VALUE (type)
+       && operand_equal_p (@1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
+   @1)
+  (if (INTEGRAL_TYPE_P (type)
+       && TYPE_MAX_VALUE (type)
+       && operand_equal_p (@1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
+   @0)))
 (simplify
  (max @0 @1)
- (if (INTEGRAL_TYPE_P (type)
-      && TYPE_MAX_VALUE (type)
-      && operand_equal_p (@1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
-  @1))
+ (switch
+  (if (INTEGRAL_TYPE_P (type)
+       && TYPE_MAX_VALUE (type)
+       && operand_equal_p (@1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
+   @1)
+  (if (INTEGRAL_TYPE_P (type)
+       && TYPE_MIN_VALUE (type)
+       && operand_equal_p (@1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
+   @0)))
 (for minmax (FMIN FMAX)
  /* If either argument is NaN, return the other one.  Avoid the
     transformation if we get (and honor) a signalling NaN.  */

gcc/testsuite/ChangeLog

+2016-04-21  Marc Glisse  <marc.glisse@inria.fr>
+
+	* gcc.dg/tree-ssa/minmax-1.c: New testcase.
+
 2016-04-20  Jan Hubicka  <jh@suse.cz>
 
 	PR ipa/70018

gcc/testsuite/gcc.dg/tree-ssa/minmax-1.c

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+static int min(int a,int b){return (a<b)?a:b;}
+static int max(int a,int b){return (a<b)?b:a;}
+int f(int x){return max(x,-__INT_MAX__-1);}
+int g(int x){return min(x,__INT_MAX__);}
+
+/* { dg-final { scan-tree-dump-times "return x_\[0-9\]+.D.;" 2 "optimized" } } */