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#!/opt/bin/perl |
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|
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{ |
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package Coro::State; |
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|
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use common::sense; |
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|
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my @insn; |
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|
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$insn[0][1] = "\x0f\xb6"; # movzbl mem -> rax |
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$insn[0][2] = "\x0f\xb7"; # movzwl mem -> rax |
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$insn[0][4] = "\x8b"; # movl mem -> rax |
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$insn[1][1] = "\x88"; # movb al -> mem |
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$insn[1][2] = "\x66\x89"; # movw eax -> mem |
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$insn[1][4] = "\x89"; # movl rax -> mem |
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|
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my $modrm_abs = 0x05; |
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my $modrm_disp8 = 0x40; |
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my $modrm_disp32 = 0x80; |
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my $modrm_edx = 0x02; |
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|
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my @vars; |
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|
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my $mov = sub { |
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my ($size, $mod_rm, $store, $offset) = @_; |
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|
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if ($mod_rm == $modrm_abs) { |
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$offset = pack "V", $offset; |
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} else { |
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if ($offset < -128 || $offset > 127) { |
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$mod_rm |= $modrm_disp32; |
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$offset = pack "V", $offset; |
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} elsif ($offset) { |
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$mod_rm |= $modrm_disp8; |
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$offset = pack "c", $offset; |
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} else { |
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$offset = ""; |
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} |
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} |
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|
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my $insn = $insn[$store][$size] . (chr $mod_rm) . $offset; |
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|
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# some instructions have shorter sequences |
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|
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$insn =~ s/^\x8b\x05/\xa1/; |
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$insn =~ s/^\x88\x05/\xa2/; |
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$insn =~ s/^\x66\x89\x05/\x66\xa3/; |
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$insn =~ s/^\x89\x05/\xa3/; |
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|
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$insn |
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}; |
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|
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my $gencopy = sub { |
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my ($save) = shift; |
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|
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my $code = "\x8b\x54\x24\x04"; # mov 4(%esp),%edx |
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|
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my $curslot = 0; |
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|
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for (@vars) { |
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my ($addr, $asize, $slot, $ssize) = @$_; |
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|
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my $slotofs = $slot - $curslot; |
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|
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# the sort ensures that this condition and adjustment suffices |
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if ($slotofs > 127) { |
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my $adj = 256; |
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$code .= "\x81\xc2" . pack "V", $adj; # add imm32, %edi |
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$curslot += $adj; |
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$slotofs -= $adj; |
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} |
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|
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if ($save) { |
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$code .= $mov->($asize, $modrm_abs, 0, $addr); |
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$code .= $mov->($ssize, $modrm_edx, 1, $slotofs); |
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} else { |
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$code .= $mov->($ssize, $modrm_edx, 0, $slotofs); |
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$code .= $mov->($asize, $modrm_abs, 1, $addr); |
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} |
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} |
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|
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$code .= "\xc3"; # retl |
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|
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$code |
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}; |
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|
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sub _jit { |
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@vars = @_; |
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|
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# split 8-byte accesses into two 4-byte accesses |
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# not needed even for 64 bit perls, but you never know |
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for (@vars) { |
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if ($_->[1] == 8) { |
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die "Coro: FATAL - cannot handle size mismatch between 8 and $_->[3] byte slots.\n"; |
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|
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$_->[1] = |
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$_->[3] = 4; |
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|
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push @vars, |
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[$_->[0] + 4, 4, |
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$_->[1] + 4, 4]; |
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} |
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} |
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|
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# sort by slot offset, required by gencopy to work |
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@vars = sort { $a->[2] <=> $b->[2] } @vars; |
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|
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# we *could* combine adjacent vars, but this is not very common |
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|
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my $load = $gencopy->(0); |
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my $save = $gencopy->(1); |
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#open my $fh, ">dat"; syswrite $fh, $save; system "objdump -b binary -m i386 -D dat"; |
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#warn length $load; |
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#warn length $save; |
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|
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($load, $save) |
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} |
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} |
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