#! /usr/bin/perl

#
# trace 16/32 bit context switches and warn if we messed things up
#

use Getopt::Long;

$opt_verbose = 0;

GetOptions(
  'verbose|v' => \$opt_verbose
);

$ctx = 16;
$line = 0;

$err = 0;

while(<>) {
  chomp;

  $line++;

  $macro = 1 if /^\s*%macro/;
  $macro = 0 if /^\s*%endmacro/;

  s/\s*;.*$//;

  $_ = "" if $macro || /^\s*%endmacro/;

  push @line, [ $ctx, $_, $line ];

  $ctx_cnt{$ctx}++;

  if(!$macro) {
    if(/^\s*(\S+):/) {
      $label{$1}{ctx} = $ctx;
      $label{$1}{line} = $line;
    }

    $ctx = $2 if /^\s*(switch_to_)?bits\s+(16|32)\s*$/;
    $ctx = 32 if /^\s*pm_enter\s*$/;
    $ctx = 16 if /^\s*pm_leave\s*$/;
    $ctx = 32 if /^\s*gfx_enter\s*$/;
    $ctx = 16 if /^\s*gfx_leave\s*$/;
  }
}

$macro = 0;

for $l (@line) {
  $_ = $l->[1];

  if(/^\s*(\S+:)?\s*(call|j[a-z]+)(\s+far)?\s+(\S+)/) {
    $op = $2;
    $dst = $4;
    next if $dst eq '$';
    if($label{$dst}) {
      if($label{$dst}{ctx} != $l->[0]) {
        printf "%5d: wrong context (%d -> %d): %s\n", $l->[2], $l->[0], $label{$dst}{ctx}, $_;
        $err = 1;
      }
    }
    else {
      printf "%5d: no target: %s\n", $l->[2], $_ if $opt_verbose;
    }

    next;
  }

  if(/^\s*(\S+:)?\s*([rp]m32_call)\s+(\S+)/) {
    $op = $2;
    $dst = $3;

    ($c0, $c1) = $op eq 'pm32_call' ? (16, 32) : (32, 16);

    if($label{$dst}) {
      if($label{$dst}{ctx} != $c1 || $l->[0] != $c0) {
        printf "%5d: wrong context (%d -> %d): %s\n", $l->[2], $l->[0], $label{$dst}{ctx}, $_;
        $err = 1
      }
    }
    else {
      printf "%5d: no target: %s\n", $l->[2], $_ if $opt_verbose;
    }

    next;
  }


  if(/^\s*(\S+:)?\s*(pm_enter|pm_leave)\s*$/) {
    $op = $2;

    $c = $op eq 'pm_enter' ? 16 : 32;

    if($l->[0] != $c) {
      printf "%5d: wrong context (%d): %s\n", $l->[2], $l->[0], $_;
      $err = 1
    }

    next;
  }

}

for (sort keys %label) {
  if(/^prim_/ && $label{$_}{ctx} != 32) {
    printf "%s: wrong context (16)\n", $_;
    $err = 1;
  }
}

printf "  32 bit: %d (of %d)\n", $ctx_cnt{32}, scalar(@line);

exit $err;