trying to optimize the exit_handler

gistfile1.txt

diff --git a/src/Perl6/Metamodel/BOOTSTRAP.nqp b/src/Perl6/Metamodel/BOOTSTRAP.nqp
index 5176e0c..e80b938 100644
--- a/src/Perl6/Metamodel/BOOTSTRAP.nqp
+++ b/src/Perl6/Metamodel/BOOTSTRAP.nqp
@@ -3236,23 +3236,17 @@ nqp::sethllconfig('perl6', nqp::hash(
         $result
     },
     'exit_handler', -> $coderef, $resultish {
-        my %phasers :=
-          nqp::getattr(nqp::getcodeobj($coderef),Block,'$!phasers');
-        unless nqp::isnull(%phasers) || nqp::p6inpre() {
-            my @leaves := nqp::atkey(%phasers, '!LEAVE-ORDER');
-            my @posts  := nqp::atkey(%phasers, 'POST');
-            my @exceptions;
-            unless nqp::isnull(@leaves) {
-                my @keeps  := nqp::atkey(%phasers, 'KEEP');
-                my @undos  := nqp::atkey(%phasers, 'UNDO');
-                my int $n := nqp::elems(@leaves);
-
-                # only have a single LEAVEish phaser, so no frills needed
-                if nqp::isnull(@keeps)
-                  && nqp::isnull(@undos)
-                  && nqp::isnull(@posts)
-                  && $n == 1
-                {
+        unless nqp::p6inpre() {
+            my %phasers :=
+              nqp::getattr(nqp::getcodeobj($coderef),Block,'$!phasers');
+            my @leaves := nqp::atkey(%phasers,'!LEAVE-ORDER');
+
+            # fast path: only the one LEAVE phaser
+            if nqp::elems(%phasers) == 1 
+              && nqp::not_i(nqp::isnull(@leaves))
+              && nqp::elems(@leaves) == 1 {
+                unless nqp::isnull(@leaves) {  # dummy if for extra scope
+                unless nqp::isnull(@leaves) {  # dummy if for extra scope
 #?if jvm
                     nqp::decont(nqp::atpos(@leaves,0))();
 #?endif
@@ -3262,71 +3256,78 @@ nqp::sethllconfig('perl6', nqp::hash(
 #?endif
                     # don't bother to CATCH, there can only be one exception
                 }
+                }
+            }
 
-                # slow path here
-                else {
-                    my int $i := -1;
-                    my int $run;
-                    my $phaser;
-                    while ++$i < $n {
-                        $phaser := nqp::decont(nqp::atpos(@leaves, $i));
-                        $run := 1;
-                        unless nqp::isnull(@keeps) {
-                            for @keeps {
-                                if nqp::eqaddr(nqp::decont($_),$phaser) {
-                                    $run := !nqp::isnull($resultish) &&
-                                             nqp::isconcrete($resultish) &&
-                                             $resultish.defined;
-                                    last;
-                                }
+            # slow path if we have any leaves
+            elsif nqp::not_i(nqp::isnull(@leaves)) {
+                my @exceptions;
+                my @keeps  := nqp::atkey(%phasers, 'KEEP');
+                my @undos  := nqp::atkey(%phasers, 'UNDO');
+                my int $n := nqp::elems(@leaves);
+
+                my int $i := -1;
+                my int $run;
+                my $phaser;
+                while ++$i < $n {
+                    $phaser := nqp::decont(nqp::atpos(@leaves, $i));
+                    $run := 1;
+                    unless nqp::isnull(@keeps) {
+                        for @keeps {
+                            if nqp::decont($_) =:= $phaser {
+                                $run := !nqp::isnull($resultish) &&
+                                         nqp::isconcrete($resultish) &&
+                                         $resultish.defined;
+                                last;
                             }
                         }
-                        unless nqp::isnull(@undos) {
-                            for @undos {
-                                if nqp::eqaddr(nqp::decont($_),$phaser) {
-                                    $run := nqp::isnull($resultish) ||
-                                            !nqp::isconcrete($resultish) ||
-                                            !$resultish.defined;
-                                    last;
-                                }
+                    }
+                    unless nqp::isnull(@undos) {
+                        for @undos {
+                            if nqp::decont($_) =:= $phaser {
+                                $run := nqp::isnull($resultish) ||
+                                        !nqp::isconcrete($resultish) ||
+                                        !$resultish.defined;
+                                last;
                             }
                         }
-                        if $run {
+                    }
+                    if $run {
 #?if jvm
-                            $phaser();
+                        $phaser();
 #?endif
 #?if moar
-                            nqp::p6capturelexwhere($phaser.clone())();
+                        nqp::p6capturelexwhere($phaser.clone())();
 #?endif
-                            CATCH { nqp::push(@exceptions, $_) }
-                        }
+                        CATCH { nqp::push(@exceptions, $_) }
                     }
                 }
-            }
 
-            unless nqp::isnull(@posts) {
-                my $value := nqp::ifnull($resultish,Mu);
-                my int $n := nqp::elems(@posts);
-                my int $i := -1;
-                while ++$i < $n {
+                my @posts  := nqp::atkey(%phasers, 'POST');
+                unless nqp::isnull(@posts) {
+                    my $value := nqp::ifnull($resultish,Mu);
+                    my int $n := nqp::elems(@posts);
+                    my int $i := -1;
+                    while ++$i < $n {
 #?if jvm
-                    nqp::atpos(@posts, $i)($value));
+                        nqp::atpos(@posts, $i)($value));
 #?endif
 #?if moar
-                    nqp::p6capturelexwhere(nqp::atpos(@posts,$i).clone)($value);
+                        nqp::p6capturelexwhere(nqp::atpos(@posts,$i).clone)($value);
 #?endif
-                    CATCH { nqp::push(@exceptions, $_); last; }
+                        CATCH { nqp::push(@exceptions, $_); last; }
+                    }
                 }
-            }
 
-            if @exceptions {
-                if nqp::elems(@exceptions) > 1 {
-                    my %ex := nqp::gethllsym('perl6', 'P6EX');
-                    if !nqp::isnull(%ex) && nqp::existskey(%ex, 'X::PhaserExceptions') {
-                        nqp::atkey(%ex, 'X::PhaserExceptions')(@exceptions);
+                if @exceptions {
+                    if nqp::elems(@exceptions) > 1 {
+                        my %ex := nqp::gethllsym('perl6', 'P6EX');
+                        if !nqp::isnull(%ex) && nqp::existskey(%ex, 'X::PhaserExceptions') {
+                            nqp::atkey(%ex, 'X::PhaserExceptions')(@exceptions);
+                        }
                     }
+                    nqp::rethrow(@exceptions[0]);
                 }
-                nqp::rethrow(@exceptions[0]);
             }
         }
     },