add xor, grep, flip, flop to boolean cxt detection

The code that detects whether certain ops (currently just PADHV and RV2HV)
are called in boolean context only recognises a few ops as providing
boolean context: NOT, OR, DOR, AND, COND_EXPR.

This commit expands this by adding GREPWHILE, FLIP, FLOP, XOR too (in the
case of XOR it only applies to the RHS arg - the LHS is not simple to
detect).

This means that in something like

    @AofH_nonempty = grep %$_, @AofH

the test for each hash being non-empty will now be done in boolean rather
than full scalar context, so may be faster.

Similarly (although less excitingly) these hash key counts are also
boolean now:

    %hash .. $other;
    $other .. %hash;
    $other xor %hash;

(I basically did a grep for 'SvTRUE' in pp*.c to see what other ops might
be imposing boolean context.)

Since this has been added to the general boolean context detection
mechanism, it will also apply for any future ops with are 'booleanised'.

1 files changed, 33 insertions, 1 deletions

diff --git a/t/perf/optree.t b/t/perf/optree.t
index 189cee081c..4aebb9eebe 100644
--- a/t/perf/optree.t
+++ b/t/perf/optree.t
@@ -13,7 +13,7 @@ BEGIN {
     @INC = '../lib';
 }
 
-plan 543;
+plan 711;
 
 use v5.10; # state
 use B qw(svref_2object
@@ -312,6 +312,38 @@ for my $ops (
         [ [1,9,1], [0,0,0,1], 'if ($x && %s) {$x} else {$y}'     ],
         [ [1,9,2], [0,0,0,1], 'unless ($x && %s) {$x}'           ],
 
+        # INNER XOR LHS
+
+            # LHS of XOR is currently too hard to detect as
+            # being in boolean context
+
+        # INNER XOR RHS
+
+        [ [1,1,1], [1],       '($x xor %s)'                      ],
+        [ [1,1,1], [0,1],     '!($x xor %s)'                     ],
+        [ [1,1,1], [0,1,1],   '$y || ($x xor %s)'                ],
+        [ [1,9,1], [0,0,1],   'if ($x xor %s) {$x}'              ],
+        [ [1,9,1], [0,0,1],   'if ($x xor %s) {$x} else {$y}'    ],
+        [ [1,9,1], [0,0,1],   'unless ($x xor %s) {$x}'          ],
+
+        # GREP
+
+        [ [1,1,1], [0,1,0],    'grep %s,1,2'                     ],
+        [ [1,1,1], [0,1,0,0],  'grep !%s,1,2'                    ],
+        [ [1,1,1], [0,1,0,0,1],'grep  $y || %s,1,2'              ],
+
+        # FLIP
+
+        [ [1,1,1], [0,0,0,0],      '%s..$x'                      ],
+        [ [1,1,1], [0,0,0,0,0],    '!%s..$x'                     ],
+        [ [1,1,1], [0,0,0,0,0,1],  '($y || %s)..$x'              ],
+
+        # FLOP
+
+        [ [1,1,1], [0,0,0,1],      '$x..%s'                      ],
+        [ [1,1,1], [0,0,0,1,0],    '$x..!%s'                     ],
+        [ [1,1,1], [0,0,0,1,0,1],  '$x..($y || %s)'              ],
+
     ) {
         my ($expects, $op_path, $code_fmt) = @$test;