[gcc r13-5988] Simplify "1 - bool_val" to "bool_val ^ 1"

[Andrew Pinski]

https://gcc.gnu.org/g:a42ed1d9181d21d5cb02f131f641c0cf375eca9d

commit r13-5988-ga42ed1d9181d21d5cb02f131f641c0cf375eca9d
Author: Andrew Pinski <apinski@marvell.com>
Date:   Tue Jan 31 05:03:21 2023 +0000

    Simplify "1 - bool_val" to "bool_val ^ 1"
    
    For bool values, it is easier to deal with
    xor 1 rather than having 1 - a. This is because
    we are more likely to simplify the xor further in many
    cases.
    
    This is a special case for (MASK - b) where MASK
    is a powerof2 - 1 and b <= MASK but only for bool
    ranges ([0,1]) as that is the main case where the
    difference comes into play.
    
    Note this is enabled for gimple folding only
    as the ranges are only know while doing gimple
    folding and cfun is not always set when fold is called.
    
    OK? Bootstrapped and tested on x86_64-linux-gnu with no
    regressions.
    
    gcc/ChangeLog:
    
            PR tree-optimization/108355
            PR tree-optimization/96921
            * match.pd: Add pattern for "1 - bool_val".
    
    gcc/testsuite/ChangeLog:
    
            PR tree-optimization/108355
            PR tree-optimization/96921
            * gcc.dg/tree-ssa/bool-minus-1.c: New test.
            * gcc.dg/tree-ssa/bool-minus-2.c: New test.
            * gcc.dg/tree-ssa/pr108354-1.c: New test.

Diff:
---
 gcc/match.pd                                 | 13 +++++++++++
 gcc/testsuite/gcc.dg/tree-ssa/bool-minus-1.c | 11 ++++++++++
 gcc/testsuite/gcc.dg/tree-ssa/bool-minus-2.c | 33 ++++++++++++++++++++++++++++
 gcc/testsuite/gcc.dg/tree-ssa/pr108354-1.c   | 26 ++++++++++++++++++++++
 4 files changed, 83 insertions(+)

diff --git a/gcc/match.pd b/gcc/match.pd
index 821630d1d49..e7b700349a6 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1732,6 +1732,19 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
  (if (!FIXED_POINT_TYPE_P (type))
  (plus @0 (negate @1))))
 
+#if GIMPLE
+/* 1 - a is a ^ 1 if a had a bool range. */
+/* This is only enabled for gimple as sometimes
+   cfun is not set for the function which contains
+   the SSA_NAME (e.g. while IPA passes are happening,
+   fold might be called).  */
+(simplify
+ (minus integer_onep@0 SSA_NAME@1)
+  (if (INTEGRAL_TYPE_P (type)
+       && ssa_name_has_boolean_range (@1))
+   (bit_xor @1 @0)))
+#endif
+
 /* Other simplifications of negation (c.f. fold_negate_expr_1).  */
 (simplify
  (negate (mult:c@0 @1 negate_expr_p@2))
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/bool-minus-1.c b/gcc/testsuite/gcc.dg/tree-ssa/bool-minus-1.c
new file mode 100644
index 00000000000..e434ff9507a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/bool-minus-1.c
@@ -0,0 +1,11 @@
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+_Bool
+foo (_Bool a)
+{
+  int c = 1 - a;
+  return c;
+}
+
+/* { dg-final { scan-tree-dump-times "1 - " 0 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "~a" 1 "optimized" } } */
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/bool-minus-2.c b/gcc/testsuite/gcc.dg/tree-ssa/bool-minus-2.c
new file mode 100644
index 00000000000..b77d36c1d3c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/bool-minus-2.c
@@ -0,0 +1,33 @@
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+_Bool
+foo (_Bool a, _Bool b)
+{
+  int c = 1 - a;
+  int d = 1 - b;
+  int e = c & d;
+  return 1 - e;
+}
+
+_Bool
+bar (_Bool a, _Bool b)
+{
+  int c = 1 - a;
+  int d = 1 - b;
+  _Bool e = c & d;
+  return 1 - e;
+}
+
+_Bool
+baz (_Bool a, _Bool b)
+{
+  _Bool c = 1 - a;
+  _Bool d = 1 - b;
+  _Bool e = c & d;
+  return 1 - e;
+}
+
+/* { dg-final { scan-tree-dump-times "1 - " 0 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "~a" 0 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "~b" 0 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "a_\[0-9\]+.D. \\\| b_\[0-9\]+.D." 3 "optimized" } } */
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr108354-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr108354-1.c
new file mode 100644
index 00000000000..60d1dbc281e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr108354-1.c
@@ -0,0 +1,26 @@
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+int b;
+int *c;
+int e;
+static int *f = &e;
+int g;
+void foo();
+short(a)(short h, short i) { return h - i; }
+int(d)(int h) { return h == 83647 ? 0 : -h; }
+int main() {
+  short j;
+  int *k = &e, *l = &b;
+  *f = 0 == c;
+  j = a(0 != 2, *k);
+  if (d(j ^ (0 == l || *k)) != *k)
+    ;
+  else
+    foo();
+  c = &g;
+}
+
+/* { dg-final { scan-tree-dump-times " 1 - " 0 "optimized" } } */
+/* There should be no calls to foo. */
+/* { dg-final { scan-tree-dump-times "foo " 0 "optimized" } } */
+