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-rwxr-xr-xerts/emulator/utils/beam_makeops295
1 files changed, 193 insertions, 102 deletions
diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops
index f805e7cc64..2e7073a8f0 100755
--- a/erts/emulator/utils/beam_makeops
+++ b/erts/emulator/utils/beam_makeops
@@ -113,7 +113,6 @@ my @if_line;
#
my $te_max_vars = 0; # Max number of variables ever needed.
my %gen_transform;
-my %min_window;
my %match_engine_ops; # All opcodes for the match engine.
my %gen_transform_offset;
my @transformations;
@@ -382,7 +381,6 @@ while (<>) {
$gen_arity{$name} = $arity;
$gen_to_spec{"$name/$arity"} = undef;
$num_specific{"$name/$arity"} = 0;
- $min_window{"$name/$arity"} = 255;
$obsolete[$op_num] = defined $obsolete;
} else { # Unnumbered generic operation.
push(@unnumbered_generic, [$name, $arity]);
@@ -440,7 +438,6 @@ $num_file_opcodes = @gen_opname;
$gen_arity{$name} = $arity;
$gen_to_spec{"$name/$arity"} = undef;
$num_specific{"$name/$arity"} = 0;
- $min_window{"$name/$arity"} = 255;
}
}
@@ -607,7 +604,7 @@ sub emulator_output {
$is_transformed{$name,$arity} or
error("instruction $key has no specific instruction");
$spec_op = -1 unless defined $spec_op;
- &init_item($name, $arity, $spec_op, $num_specific, $tr, $min_window{$key});
+ &init_item($name, $arity, $spec_op, $num_specific, $tr);
}
}
print "};\n";
@@ -1405,8 +1402,7 @@ sub tr_gen {
foreach $ref (@g) {
my($line, $orig_transform, $from_ref, $to_ref) = @$ref;
- my $used_ref = used_vars($from_ref, $to_ref);
- my $so_far = tr_gen_from($line, $used_ref, @$from_ref);
+ my $so_far = tr_gen_from($line, @$from_ref);
tr_gen_to($line, $orig_transform, $so_far, @$to_ref);
}
@@ -1457,58 +1453,14 @@ sub tr_gen {
print "};\n\n";
}
-sub used_vars {
- my($from_ref,$to_ref) = @_;
- my %used;
- my %seen;
-
- foreach my $ref (@$from_ref) {
- my($name,$arity,@ops) = @$ref;
- if ($name =~ /^[.]/) {
- foreach my $var (@ops) {
- $used{$var} = 1;
- }
- } else {
- # Any variable that is used at least twice on the
- # left-hand side is used. (E.g. "move R R".)
- foreach my $op (@ops) {
- my($var, $type, $type_val) = @$op;
- next if $var eq '';
- $used{$var} = 1 if $seen{$var};
- $seen{$var} = 1;
- }
- }
- }
-
- foreach my $ref (@$to_ref) {
- my($name, $arity, @ops) = @$ref;
- if ($name =~ /^[.]/) {
- foreach my $var (@ops) {
- $used{$var} = 1;
- }
- } else {
- foreach my $op (@ops) {
- my($var, $type, $type_val) = @$op;
- next if $var eq '';
- $used{$var} = 1;
- }
- }
- }
- \%used;
-}
-
sub tr_gen_from {
- my($line,$used_ref,@tr) = @_;
+ my($line,@tr) = @_;
my(%var) = ();
my(%var_type);
my($var_num) = 0;
my(@code);
- my($min_window) = 0;
- my(@fix_rest_args);
- my(@fix_pred_funcs);
my($op, $ref); # Loop variables.
my $where = "left side of transformation in line $line: ";
- my %var_used = %$used_ref;
my $may_fail = 0;
my $is_first = 1;
@@ -1530,8 +1482,20 @@ sub tr_gen_from {
my $var;
my(@args);
- push(@fix_pred_funcs, scalar(@code));
- push(@code, [$name, @ops]);
+ foreach $var (@ops) {
+ error($where, "variable '$var' unbound")
+ unless defined $var{$var};
+ if ($var_type{$var} eq 'scalar') {
+ push(@args, "var[$var{$var}]");
+ } else {
+ push(@args, "rest_args");
+ }
+ }
+ my $pi = tr_next_index(\@pred_table, \%pred_table, $name, @args);
+ my $op = make_op("$name()", 'pred', $pi);
+ my @slots = grep(/^\d+/, map { $var{$_} } @ops);
+ op_slot_usage($op, @slots);
+ push(@code, $op);
next;
}
@@ -1544,7 +1508,6 @@ sub tr_gen_from {
$opnum = $gen_opnum{$name,$arity};
push(@code, make_op("$name/$arity", 'next_instr', $opnum));
- $min_window++;
foreach $op (@ops) {
my($var, $type, $type_val, $cond, $val) = @$op;
my $ignored_var = "$var (ignored)";
@@ -1593,15 +1556,21 @@ sub tr_gen_from {
if (defined $var{$var}) {
$ignored_var = '';
$may_fail = 1;
- push(@code, &make_op($var, 'is_same_var', $var{$var}));
+ my $op = make_op($var, 'is_same_var', $var{$var});
+ op_slot_usage($op, $var{$var});
+ push(@code, $op);
} elsif ($type eq '*') {
- #
- # Reserve a hole for a 'rest_args' instruction.
- #
+ foreach my $type (values %var_type) {
+ error("only one use of a '*' variable is " .
+ "allowed on the left hand side of " .
+ "a transformation")
+ if $type eq 'array';
+ }
$ignored_var = '';
- push(@fix_rest_args, scalar(@code));
- push(@code, $var);
- } elsif ($var_used{$var}) {
+ $var{$var} = 'unnumbered';
+ $var_type{$var} = 'array';
+ push(@code, make_op($var, 'rest_args'));
+ } else {
$ignored_var = '';
$var_type{$var} = 'scalar';
$var{$var} = $var_num;
@@ -1629,46 +1598,14 @@ sub tr_gen_from {
#
push(@code, make_op($may_fail ? '' : 'always reached', 'commit'));
- #
- # If there is an rest_args instruction, we must insert its correct
- # variable number (higher than any other).
- #
- my $index;
- &error("only one use of a '*' variable is allowed on the left hand side of a transformation")
- if @fix_rest_args > 1;
- foreach $index (@fix_rest_args) {
- my $var = $code[$index];
- $var{$var} = $var_num++;
- $var_type{$var} = 'array';
- splice(@code, $index, 1, &make_op($var, 'rest_args', $var{$var}));
- }
-
- foreach $index (@fix_pred_funcs) {
- my($name, @ops) = @{$code[$index]};
- my(@args);
- my $var;
-
- foreach $var (@ops) {
- &error($where, "variable '$var' unbound")
- unless defined $var{$var};
- if ($var_type{$var} eq 'scalar') {
- push(@args, "var[$var{$var}]");
- } else {
- push(@args, "var+$var{$var}");
- }
- }
- my $pi = tr_next_index(\@pred_table, \%pred_table, $name, @args);
- splice(@code, $index, 1, make_op("$name()", 'pred', $pi));
- }
-
$te_max_vars = $var_num
if $te_max_vars < $var_num;
- [$min_window, \%var, \%var_type, \@code];
+ [\%var, \%var_type, \@code];
}
sub tr_gen_to {
my($line, $orig_transform, $so_far, @tr) = @_;
- my($min_window, $var_ref, $var_type_ref, $code_ref) = @$so_far;
+ my($var_ref, $var_type_ref, $code_ref) = @$so_far;
my(%var) = %$var_ref;
my(%var_type) = %$var_type_ref;
my(@code) = @$code_ref;
@@ -1697,13 +1634,16 @@ sub tr_gen_to {
if ($var_type{$var} eq 'scalar') {
push(@args, "var[$var{$var}]");
} else {
- push(@args, "var+$var{$var}");
+ push(@args, "rest_args");
}
}
pop(@code); # Get rid of 'commit' instruction
my $index = tr_next_index(\@call_table, \%call_table,
$name, @args);
- push(@code, make_op("$name()", 'call_end', $index));
+ my $op = make_op("$name()", 'call_end', $index);
+ my @slots = grep(/^\d+/, map { $var{$_} } @ops);
+ op_slot_usage($op, @slots);
+ push(@code, $op);
last;
}
@@ -1725,11 +1665,13 @@ sub tr_gen_to {
my($var, $type, $type_val) = @$op;
if ($type eq '*') {
- push(@code, make_op($var, 'store_rest_args', $var{$var}));
+ push(@code, make_op($var, 'store_rest_args'));
} elsif ($var ne '') {
&error($where, "variable '$var' unbound")
unless defined $var{$var};
- push(@code, &make_op($var, 'store_var_next_arg', $var{$var}));
+ my $op = make_op($var, 'store_var_next_arg', $var{$var});
+ op_slot_usage($op, $var{$var});
+ push(@code, $op);
} elsif ($type ne '') {
push(@code, &make_op('', 'store_type', "TAG_$type"));
if ($type_val) {
@@ -1744,6 +1686,10 @@ sub tr_gen_to {
push(@code, make_op('', 'end'))
unless is_instr($code[$#code], 'call_end');
+ tr_maybe_keep(\@code);
+ tr_maybe_rename(\@code);
+ tr_remove_unused(\@code);
+
#
# Chain together all codes segments having the same first operation.
#
@@ -1752,8 +1698,6 @@ sub tr_gen_to {
my($dummy, $arity);
($dummy, $op, $arity) = @$first;
my($comment) = "\n/*\n * Line $line:\n * $orig_transform\n */\n\n";
- $min_window{$key} = $min_window
- if $min_window{$key} > $min_window;
my $prev_last;
$prev_last = pop(@{$gen_transform{$key}})
@@ -1771,6 +1715,148 @@ sub tr_gen_to {
push(@{$gen_transform{$key}}, @code),
}
+sub tr_maybe_keep {
+ my($ref) = @_;
+ my @last_instr;
+ my $pos;
+ my $reused_instr;
+
+ for (my $i = 0; $i < @$ref; $i++) {
+ my $instr = $$ref[$i];
+ my($size, $instr_ref, $comment) = @$instr;
+ my($op, @args) = @$instr_ref;
+ if ($op eq 'next_instr') {
+ @last_instr = ($args[0]);
+ } elsif ($op eq 'set_var_next_arg') {
+ push @last_instr, $args[0];
+ } elsif ($op eq 'next_arg') {
+ push @last_instr, 'ignored';
+ } elsif ($op eq 'new_instr') {
+ unless (defined $pos) {
+ # 'new_instr' immediately after 'commit'.
+ $reused_instr = $args[0];
+ return unless shift(@last_instr) == $reused_instr;
+ $pos = $i - 1;
+ } else {
+ # Second 'new_instr' after 'commit'. The instructions
+ # from $pos up to and including $i - 1 rebuilds the
+ # existing instruction exactly.
+ my $name = $gen_opname[$reused_instr];
+ my $arity = $gen_arity[$reused_instr];
+ my $reuse = make_op("$name/$arity", 'keep');
+ splice @$ref, $pos, $i-$pos, ($reuse);
+ return;
+ }
+ } elsif ($op eq 'store_var_next_arg') {
+ return unless shift(@last_instr) eq $args[0];
+ } elsif (defined $pos) {
+ return;
+ }
+ }
+}
+
+sub tr_maybe_rename {
+ my($ref) = @_;
+ my $s = 'left';
+ my $a = 0;
+ my $num_args = 0;
+ my $new_instr;
+ my $first;
+ my $i;
+
+ for ($i = 1; $i < @$ref; $i++) {
+ my $instr = $$ref[$i];
+ my($size, $instr_ref, $comment) = @$instr;
+ my($op, @args) = @$instr_ref;
+
+ if ($s eq 'left') {
+ if ($op eq 'set_var_next_arg') {
+ if ($num_args == $a and $args[0] == $a) {
+ $num_args++;
+ }
+ $a++;
+ } elsif ($op eq 'next_arg') {
+ $a++;
+ } elsif ($op eq 'commit') {
+ $a = 0;
+ $first = $i;
+ $s = 'committed';
+ } elsif ($op eq 'next_instr') {
+ return;
+ }
+ } elsif ($s eq 'committed') {
+ if ($op eq 'new_instr') {
+ $new_instr = $args[0];
+ $a = 0;
+ $s = 'right';
+ } else {
+ return;
+ }
+ } elsif ($s eq 'right') {
+ if ($op eq 'store_var_next_arg' && $args[0] == $a) {
+ $a++;
+ } elsif ($op eq 'end' && $a <= $num_args) {
+ my $name = $gen_opname[$new_instr];
+ my $arity = $gen_arity[$new_instr];
+ my $new_op = make_op("$name/$arity", 'rename', $new_instr);
+ splice @$ref, $first, $i-$first+1, ($new_op);
+ return;
+ } else {
+ return;
+ }
+ }
+ }
+}
+
+sub tr_remove_unused {
+ my($ref) = @_;
+ my %used;
+
+ # Collect all used variables.
+ for my $instr (@$ref) {
+ my $uref = $$instr[3];
+ for my $slot (@$uref) {
+ $used{$slot} = 1;
+ }
+ }
+
+ # Replace 'set_var_next_arg' with 'next_arg' if the variable
+ # is never used.
+ for my $instr (@$ref) {
+ my($size, $instr_ref, $comment) = @$instr;
+ my($op, @args) = @$instr_ref;
+ if ($op eq 'set_var_next_arg') {
+ my $var = $args[0];
+ next if $used{$var};
+ $instr = make_op("$comment (ignored)", 'next_arg');
+ }
+ }
+
+ # Delete a sequence of 'next_arg' instructions when they are
+ # redundant before instructions such as 'commit'.
+ my @opcode;
+ my %ending = (call_end => 1,
+ commit => 1,
+ next_instr => 1,
+ pred => 1,
+ rename => 1,
+ keep => 1);
+ for (my $i = 0; $i < @$ref; $i++) {
+ my $instr = $$ref[$i];
+ my($size, $instr_ref, $comment) = @$instr;
+ my($opcode) = @$instr_ref;
+
+ if ($ending{$opcode}) {
+ my $first = $i;
+ $first-- while $first > 0 and $opcode[$first-1] eq 'next_arg';
+ my $n = $i - $first;
+ splice @$ref, $first, $n;
+ $i -= $n;
+ }
+ $opcode[$i] = $opcode;
+ }
+}
+
sub tr_code_len {
my($sum) = 0;
my($ref);
@@ -1783,7 +1869,12 @@ sub tr_code_len {
sub make_op {
my($comment, @op) = @_;
- [scalar(@op), [@op], $comment];
+ [scalar(@op), [@op], $comment, []];
+}
+
+sub op_slot_usage {
+ my($op_ref, @slots) = @_;
+ $$op_ref[3] = \@slots;
}
sub is_instr {