Re: Fold more boolean expressions

["MCC CS" <mcccs at gmx dot com>]

Now that it has got enough reviews and there's
been no comments for a week, I believe
now it's time for us to install it on trunk.
The patch is the same as previous, but rebased
on current trunk.

Could you please push it for me? If there's anything
I can do to help, just tell me.

2018-09-30 MCC CS <deswurstes@users.noreply.github.com>

gcc/
PR tree-optimization/87261
* match.pd: Add boolean optimizations,
fix whitespace.

2018-09-30 MCC CS <deswurstes@users.noreply.github.com>

gcc/testsuite/
PR tree-optimization/87261
* gcc.dg/pr87261.c: New test.

Index: gcc/match.pd
===================================================================
--- gcc/match.pd	(revision 264725)
+++ gcc/match.pd	(working copy)
@@ -92,7 +92,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
   IFN_FMA IFN_FMS IFN_FNMA IFN_FNMS)
 (define_operator_list COND_TERNARY
   IFN_COND_FMA IFN_COND_FMS IFN_COND_FNMA IFN_COND_FNMS)
-    
+
 /* As opposed to convert?, this still creates a single pattern, so
    it is not a suitable replacement for convert? in all cases.  */
 (match (nop_convert @0)
@@ -106,7 +106,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
       && tree_nop_conversion_p (TREE_TYPE (type), TREE_TYPE (TREE_TYPE (@0))))))
 /* This one has to be last, or it shadows the others.  */
 (match (nop_convert @0)
- @0) 
+ @0)
 
 /* Transform likes of (char) ABS_EXPR <(int) x> into (char) ABSU_EXPR <x>
    ABSU_EXPR returns unsigned absolute value of the operand and the operand
@@ -285,7 +285,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
      And not for _Fract types where we can't build 1.  */
   (if (!integer_zerop (@0) && !ALL_FRACT_MODE_P (TYPE_MODE (type)))
    { build_one_cst (type); }))
- /* X / abs (X) is X < 0 ? -1 : 1.  */ 
+ /* X / abs (X) is X < 0 ? -1 : 1.  */
  (simplify
    (div:C @0 (abs @0))
    (if (INTEGRAL_TYPE_P (type)
@@ -929,6 +929,31 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
   (bitop:c @0 (bit_not (bitop:cs @0 @1)))
   (bitop @0 (bit_not @1))))
 
+/* (~x & y) | ~(x | y) -> ~x */
+(simplify
+ (bit_ior:c (bit_and:c (bit_not@2 @0) @1) (bit_not (bit_ior:c @0 @1)))
+ @2)
+
+/* (x | y) ^ (x | ~y) -> ~x */
+(simplify
+ (bit_xor:c (bit_ior:c @0 @1) (bit_ior:c @0 (bit_not @1)))
+ (bit_not @0))
+
+/* (x & y) | ~(x | y) -> ~(x ^ y) */
+(simplify
+ (bit_ior:c (bit_and:cs @0 @1) (bit_not:s (bit_ior:s @0 @1)))
+ (bit_not (bit_xor @0 @1)))
+
+/* (~x | y) ^ (x ^ y) -> x | ~y */
+(simplify
+ (bit_xor:c (bit_ior:cs (bit_not @0) @1) (bit_xor:s @0 @1))
+ (bit_ior @0 (bit_not @1)))
+
+/* (x ^ y) | ~(x | y) -> ~(x & y) */
+(simplify
+ (bit_ior:c (bit_xor:cs @0 @1) (bit_not:s (bit_ior:s @0 @1)))
+ (bit_not (bit_and @0 @1)))
+
 /* (x | y) & ~x -> y & ~x */
 /* (x & y) | ~x -> y | ~x */
 (for bitop (bit_and bit_ior)
@@ -1139,7 +1164,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
   (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
        && tree_nop_conversion_p (type, TREE_TYPE (@1)))
    (mult (convert @0) (convert (negate @1)))))
- 
+
 /* -(A + B) -> (-B) - A.  */
 (simplify
  (negate (plus:c @0 negate_expr_p@1))
@@ -3099,7 +3124,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
     (if (tree_int_cst_sgn (@1) < 0)
      (scmp @0 @2)
      (cmp @0 @2))))))
- 
+
 /* Simplify comparison of something with itself.  For IEEE
    floating-point, we can only do some of these simplifications.  */
 (for cmp (eq ge le)
@@ -3170,11 +3195,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
         }
       tree newtype
         = (TYPE_PRECISION (TREE_TYPE (@0)) > TYPE_PRECISION (type1)
-	   ? TREE_TYPE (@0) : type1); 
+	   ? TREE_TYPE (@0) : type1);
     }
     (if (TYPE_PRECISION (TREE_TYPE (@2)) > TYPE_PRECISION (newtype))
      (cmp (convert:newtype @0) (convert:newtype @1))))))
- 
+
  (simplify
   (cmp @0 REAL_CST@1)
   /* IEEE doesn't distinguish +0 and -0 in comparisons.  */
@@ -3422,7 +3447,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 	    (FTYPE) N == CST -> 0
 	    (FTYPE) N != CST -> 1.  */
 	(if (cmp == EQ_EXPR || cmp == NE_EXPR)
-	 { constant_boolean_node (cmp == NE_EXPR, type); }) 
+	 { constant_boolean_node (cmp == NE_EXPR, type); })
 	/* Otherwise replace with sensible integer constant.  */
 	(with
 	 {
@@ -3666,7 +3691,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
  (simplify
   (cmp (bit_and@2 @0 integer_pow2p@1) @1)
   (icmp @2 { build_zero_cst (TREE_TYPE (@0)); })))
- 
+
 /* If we have (A & C) != 0 ? D : 0 where C and D are powers of 2,
    convert this into a shift followed by ANDing with D.  */
 (simplify
@@ -3886,7 +3911,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
         (if (cmp == LE_EXPR)
 	 (ge (convert:st @0) { build_zero_cst (st); })
 	 (lt (convert:st @0) { build_zero_cst (st); }))))))))))
- 
+
 (for cmp (unordered ordered unlt unle ungt unge uneq ltgt)
  /* If the second operand is NaN, the result is constant.  */
  (simplify
@@ -4540,7 +4565,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
   (if (wi::to_wide (@1) == -1)
    (rdiv { build_real (type, dconst1); } @0))))
 
-/* Narrowing of arithmetic and logical operations. 
+/* Narrowing of arithmetic and logical operations.
 
    These are conceptually similar to the transformations performed for
    the C/C++ front-ends by shorten_binary_op and shorten_compare.  Long
@@ -4612,7 +4637,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
      (convert (bit_and (op (convert:utype @0) (convert:utype @1))
 	       (convert:utype @4))))))))
 
-/* Transform (@0 < @1 and @0 < @2) to use min, 
+/* Transform (@0 < @1 and @0 < @2) to use min,
    (@0 > @1 and @0 > @2) to use max */
 (for logic (bit_and bit_and bit_and bit_and bit_ior bit_ior bit_ior bit_ior)
      op    (lt      le      gt      ge      lt      le      gt      ge     )
Index: gcc/testsuite/gcc.dg/pr87261.c
===================================================================
--- gcc/testsuite/gcc.dg/pr87261.c	(nonexistent)
+++ gcc/testsuite/gcc.dg/pr87261.c	(working copy)
@@ -0,0 +1,35 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-original" } */
+
+int f1 (int a, int b)
+{
+ return ~(a|b)|(~a&b);
+}
+
+int f2 (int a, int b)
+{
+ return (a|b)^(a|~b);
+}
+
+/* { dg-final { scan-tree-dump-times "return \\~a;" 2 "original" } } */
+
+int f3 (int a, int b)
+{
+ return ~(a|b)|(a&b);
+}
+
+/* { dg-final { scan-tree-dump "return \\~\\(a \\^ b\\);" "original" } } */
+
+int f4 (int a, int b)
+{
+ return a^b^(~a|b);
+}
+
+/* { dg-final { scan-tree-dump "return \\~b \\| a;" "original" } } */
+
+int f5 (int a, int b)
+{
+ return (a^b)|~(a|b);
+}
+
+/* { dg-final { scan-tree-dump "return \\~\\(a \\& b\\);" "original" } } */