diff options
Diffstat (limited to 'erts/emulator/utils/beam_makeops')
| -rwxr-xr-x | erts/emulator/utils/beam_makeops | 295 |
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 { |