diff options
| -rwxr-xr-x | erts/emulator/utils/beam_makeops | 57 |
1 files changed, 53 insertions, 4 deletions
diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops index b5187dd676..f1fa71fd9e 100755 --- a/erts/emulator/utils/beam_makeops +++ b/erts/emulator/utils/beam_makeops @@ -1304,7 +1304,8 @@ sub tr_gen { foreach $ref (@g) { my($line, $orig_transform, $from_ref, $to_ref) = @$ref; - my $so_far = tr_gen_from($line, @$from_ref); + my $used_ref = used_vars($from_ref, $to_ref); + my $so_far = tr_gen_from($line, $used_ref, @$from_ref); tr_gen_to($line, $orig_transform, $so_far, @$to_ref); } @@ -1342,8 +1343,48 @@ 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($line, @tr) = @_; + my($line,$used_ref,@tr) = @_; my(%var) = (); my(%var_type); my($var_num) = 0; @@ -1353,6 +1394,7 @@ sub tr_gen_from { my(@fix_pred_funcs); my($op, $ref); # Loop variables. my $where = "left side of transformation in line $line: "; + my %var_used = %$used_ref; foreach $ref (@tr) { my($name, $arity, @ops) = @$ref; @@ -1387,6 +1429,7 @@ sub tr_gen_from { $min_window++; foreach $op (@ops) { my($var, $type, $type_val, $cond, $val) = @$op; + my $ignored_var = "$var (ignored)"; if ($type ne '' && $type ne '*') { # @@ -1394,6 +1437,7 @@ sub tr_gen_from { # their own built-in type test and don't need to # be guarded with a type test instruction. # + $ignored_var = ''; unless ($cond eq 'is_bif' or $cond eq 'is_not_bif' or $cond eq 'is_func') { @@ -1415,22 +1459,27 @@ sub tr_gen_from { if ($cond eq 'is_func') { my($m, $f, $a) = split(/:/, $val); + $ignored_var = ''; push(@code, &make_op('', "$cond", "am_$m", "am_$f", $a)); } elsif ($cond ne '') { + $ignored_var = ''; push(@code, &make_op('', "$cond", $val)); } if ($var ne '') { if (defined $var{$var}) { + $ignored_var = ''; push(@code, &make_op($var, 'is_same_var', $var{$var})); } elsif ($type eq '*') { # # Reserve a hole for a 'rest_args' instruction. # + $ignored_var = ''; push(@fix_rest_args, scalar(@code)); push(@code, $var); - } else { + } elsif ($var_used{$var}) { + $ignored_var = ''; $var_type{$var} = 'scalar'; $var{$var} = $var_num; $var_num++; @@ -1443,7 +1492,7 @@ sub tr_gen_from { my $var = $ref->[1][1]; push(@code, make_op($comment, 'set_var_next_arg', $var)); } else { - push(@code, &make_op('', 'next_arg')); + push(@code, &make_op($ignored_var, 'next_arg')); } } # Remove redundant 'next_arg' instructions before 'next_instr'. |