.sub _main

	print "sha1(\"this is a test\") : "
	$S1 = _sha1("this is a test")
	print $S1
	print "\n"

	end
.end

#
# stuff below here is the real code
#

.sub _string_to_buffer
	.param string s

	.local pmc buffer

	new buffer, .PerlArray

	length $I0, s
	buffer = $I0

	$I1 = 0
_string_to_buffer_jump1:

	ord $I2, s, $I1
	buffer[$I1] = $I2

	$I1 = $I1 + 1
	if $I1 < $I0 goto _string_to_buffer_jump1

	.pcc_begin_return
	.return buffer
	.pcc_end_return
.end


.sub _sha1_str2blks_SHA1
	.param string str_in

	.local pmc str
	.local int nblk
	.local pmc blks

	str = _string_to_buffer(str_in)

	# $nblk = ((strlen($str) + 8) >> 6) + 1; 

	$I0 = str
	$I0 = $I0 + 8
	$I0 = $I0 >> 6
	$I0 = $I0 & 0xfff
	nblk = $I0 + 1


	# for($i=0; $i < $nblk * 16; $i++) $blks[$i] = 0; 

	new blks, .PerlArray

	$I0 = 0
	$I1 = nblk * 16

sha1_str2blks_SHA1_loop_1:

	blks[$I0] = 0

	$I0 = $I0 + 1
	if $I0 < $I1 goto sha1_str2blks_SHA1_loop_1


	# for($i=0; $i < strlen($str); $i++) { 
	# 	$blks[$i >> 2] |= ord(substr($str, $i, 1)) << (24 - ($i % 4) * 8); 
	# } 

	$I0 = 0

sha1_str2blks_SHA1_loop_2:

	$I1 = $I0 >> 2

	$I3 =  str[$I0]

	$I4 = $I0 % 4
	$I4 = $I4 * 8
	$I4 = 24 - $I4

	$I2 =  $I3 << $I4
	$I3 = blks[$I1]
	$I3 = $I3 | $I2
	blks[$I1] = $I3

	$I0 = $I0 + 1
	$I1 = str
	if $I0 < $I1 goto sha1_str2blks_SHA1_loop_2
	

	# $blks[$i >> 2] |= 0x80 << (24 - ($i % 4) * 8);

	$I1 = $I0 >> 2
	$I2 = $I0 % 4
	$I2 = $I2 * 8
	$I2 = 24 - $I2
	$I2 = 0x80 << $I2
	$I3 = blks[$I1]
	$I3 = $I3 | $I2
	blks[$I1] = $I3


	# $blks[$nblk * 16 - 1] = strlen($str) * 8; 

	$I0 = nblk * 16
	$I0 = $I0 - 1
	$I1 = str
	$I1 = $I1 * 8
	blks[$I0] = $I1

	# return $blks; 
	# this isn't needed - we're doing pass by ref. i hope :)

	.pcc_begin_return
	.return blks
	.pcc_end_return
.end

.sub _sha1_safe_add
	.param int x
	.param int y

	.local int lsw
	.local int msw

	# $lsw = ($x & 0xFFFF) + ($y & 0xFFFF); 

	$I0 = x & 0xFFFF
	$I1 = y & 0xFFFF
	lsw = $I0 + $I1


	# $msw = ($x >> 16) + ($y >> 16) + ($lsw >> 16); 

	$I0 = x >> 16
	$I1 = y >> 16
	$I2 = lsw >> 16
	msw = $I0 + $I1
	msw = msw + $I2


	# return ($msw << 16) | ($lsw & 0xFFFF); 

	$I1 = msw << 16
	$I2 = lsw & 0xFFFF
	$I0 = $I1 | $I2

	.pcc_begin_return
	.return $I0
	.pcc_end_return
.end

.sub _sha1_rol
	.param int numb
	.param int cnt

	# return ($num << $cnt) | sha1_zeroFill($num, 32 - $cnt); 

	$I1 = numb << cnt
	$I3 = 32 - cnt
	$I2 = _sha1_zeroFill(numb, $I3)

	$I0 = $I1 | $I2

	.pcc_begin_return
	.return $I0
	.pcc_end_return

.end

.sub _sha1_zeroFill
	.param int a
	.param int b

	.local string bin

	# $bin = decbin($a); 
	bin = _decbin(a)

	# if (strlen($bin) < $b) $bin = 0; 
	# else $bin = substr($bin, 0, strlen($bin) - $b); 

	length $I0, bin
	if $I0 < b goto _sha1_zeroFill_jump1
	goto _sha1_zeroFill_jump2

_sha1_zeroFill_jump1:
	bin = "0"
	goto _sha1_zeroFill_jump3

_sha1_zeroFill_jump2:
	length $I0, bin
	$I0 = $I0 - b
	substr bin, bin, 0, $I0
	goto _sha1_zeroFill_jump3

_sha1_zeroFill_jump3:


	# for ($i=0; $i < $b; $i++) { 
	#     $bin = "0".$bin; 
	# } 

	.local int i

	i = 0
	if i >= b goto _sha1_zeroFill_jump5
_sha1_zeroFill_jump4:

	concat bin, "0", bin

	i = i + 1
	if i < b goto _sha1_zeroFill_jump4

_sha1_zeroFill_jump5:

	# return bindec($bin); 

	$I0 = _bindec(bin)

	.pcc_begin_return
	.return $I0
	.pcc_end_return
	
.end

.sub _decbin
	.param int a

	$P0 = new Array
	$P0 = 1
	$P0[0] = a
 
	sprintf $S0, "%b", $P0

	length $I0, $S0

	if $I0 <= 32 goto _decbin_jump1

	$I0 = $I0 - 32

	substr $S0, $S0, $I0

_decbin_jump1:

	.pcc_begin_return
	.return $S0
	.pcc_end_return
.end

.sub _bindec
	.param string a

	# this is the result
	$I0 = 0

	# this is the loop var
	$I1 = 0

	# this is the str length
	length $I2, a

	ord $I5, "1"

_bindec_jump_1:

	# get character at this position
	$S0 = a[$I1]
	ord $I3, $S0

	if $I3 != $I5 goto _bindec_jump_2

	# we found a one - shift and add

	$I6 = $I2 - $I1
	$I6 = $I6 - 1
	$I4 = 0x0001 << $I6
	$I0 = $I0 + $I4

_bindec_jump_2:

	# loop
	$I1 = $I1 + 1
	if $I1 < $I2 goto _bindec_jump_1


	.pcc_begin_return
	.return $I0
	.pcc_end_return
.end

# function sha1_ft($t, $b, $c, $d) { 
.sub _sha1_ft
	.param int t
	.param int b
	.param int c
	.param int d

	# if($t < 20) return ($b & $c) | ((~$b) & $d); 

	if t >= 20 goto _sha1_ft_jump1

	$I1 = b & c
	$I2 = ~b
	$I2 = $I2 & d
	$I0 = $I1 | $I2

	.pcc_begin_return
	.return $I0
	.pcc_end_return

_sha1_ft_jump1:


	# if($t < 40) return $b ^ $c ^ $d; 

	if t >= 40 goto _sha1_ft_jump2

	bxor $I0, b, c
	bxor $I0, $I0, d

	.pcc_begin_return
	.return $I0
	.pcc_end_return

_sha1_ft_jump2:


	# if($t < 60) return ($b & $c) | ($b & $d) | ($c & $d); 

	if t >= 60 goto _sha1_ft_jump3

	$I1 = b & c
	$I2 = b & d
	$I3 = c & d

	$I0 = $I1 | $I2
	$I0 = $I0 | $I3

	.pcc_begin_return
	.return $I0
	.pcc_end_return

_sha1_ft_jump3:


	# return $b ^ $c ^ $d; 

	bxor $I0, b, c
	bxor $I0, $I0, d

	.pcc_begin_return
	.return $I0
	.pcc_end_return

.end

# function sha1_kt($t) { 
.sub _sha1_kt
	.param int t

	# if ($t < 20) return 1518500249;

	if t >= 20 goto _sha1_kt_jump1

	.pcc_begin_return
	.return 1518500249
	.pcc_end_return

_sha1_kt_jump1:


	# if ($t < 40) return 1859775393; 

	if t >= 40 goto _sha1_kt_jump2

	.pcc_begin_return
	.return  1859775393
	.pcc_end_return

_sha1_kt_jump2:


	# if ($t < 60) return -1894007588; 

	if t >= 60 goto _sha1_kt_jump3

	.pcc_begin_return
	.return -1894007588
	.pcc_end_return

_sha1_kt_jump3:


	# return -899497514; 

	.pcc_begin_return
	.return -899497514
	.pcc_end_return
.end
 

# function sha1($str) { 

.sub _sha1
	.param string str

	.local pmc x
	.local int a
	.local int b
	.local int c
	.local int d
	.local int e
	.local int sizeof_x
	.local int i
	.local int j
	.local int t

	.local int olda
	.local int oldb
	.local int oldc
	.local int oldd
	.local int olde

	# $x = sha1_str2blks_SHA1($str); 
	# $a =  1732584193; 
	# $b = -271733879; 
	# $c = -1732584194; 
	# $d =  271733878; 
	# $e = -1009589776; 

	x = _sha1_str2blks_SHA1(str)
	a = 1732584193
	b = -271733879
	c = -1732584194
	d = 271733878
	e = -1009589776

	# for($i = 0; $i < sizeof($x); $i += 16) { 

	sizeof_x = x
	i = 0
_sha1_jump1:


	# $olda = $a; 
	# $oldb = $b; 
	# $oldc = $c; 
	# $oldd = $d; 
	# $olde = $e; 

	olda = a
	oldb = b
	oldc = c
	oldd = d
	olde = e

	.local pmc w

	new w, .PerlArray
	w = 80


	# for($j = 0; $j < 80; $j++) { 

	j = 0
_sha1_jump2:


	# if($j < 16) $w[$j] = $x[$i + $j]; 
	# else $w[$j] = sha1_rol($w[$j - 3] ^ $w[$j - 8] ^ $w[$j - 14] ^ $w[$j - 16], 1); 

	if j < 16 goto _sha1_jump3

	$I0 = j - 16
	$I1 = j - 14
	$I2 = j - 8
	$I3 = j - 3

	# $w[$j] = sha1_rol($w[$I3] ^ $w[$I2] ^ $w[$I1] ^ $w[$I0], 1);

	$I7 = w[$I3]
	$I8 = w[$I2]
	$I9 = w[$I1]
	$I10 = w[$I0]

	bxor $I5, $I7, $I8
	bxor $I6, $I9, $I10
	bxor $I4, $I5, $I6
	$I0 = _sha1_rol($I4, 1)
	w[j] = $I0

	goto _sha1_jump4

_sha1_jump3:

	# $w[$j] = $x[$i + $j]

	$I0 = i + j
	$I0 = x[$I0]
	w[j] = $I0

_sha1_jump4:

	# $t = sha1_safe_add(sha1_safe_add(sha1_rol($a, 5), sha1_ft($j, $b, $c, $d)), sha1_safe_add(sha1_safe_add($e, $w[$j]), sha1_kt($j))); 

	$I0 = _sha1_kt(j)
	$I1 = _sha1_ft(j, b, c, d)
	$I2 = _sha1_rol(a, 5)
	$I3 = _sha1_safe_add($I2, $I1)
	$I4 = w[j]
	$I4 = _sha1_safe_add(e, $I4)
	$I5 = _sha1_safe_add($I4, $I0)
	t = _sha1_safe_add($I3, $I5)


	# $e = $d; 
	# $d = $c; 
	# $c = sha1_rol($b, 30); 
	# $b = $a; 
	# $a = $t;

	e = d
	d = c
	c = _sha1_rol(b, 30)
	b = a
	a = t

	# end of for j
	j = j + 1
	if j < 80 goto _sha1_jump2

	# $a = sha1_safe_add($a, $olda); 
	# $b = sha1_safe_add($b, $oldb); 
	# $c = sha1_safe_add($c, $oldc); 
	# $d = sha1_safe_add($d, $oldd); 
	# $e = sha1_safe_add($e, $olde); 

	a = _sha1_safe_add(a, olda)
	b = _sha1_safe_add(b, oldb)
	c = _sha1_safe_add(c, oldc)
	d = _sha1_safe_add(d, oldd)
	e = _sha1_safe_add(e, olde)


	# end of for i
	i = i + 16
	if i < sizeof_x goto _sha1_jump1


	# return sprintf("%08lx%08lx%08lx%08lx%08lx", $a, $b, $c, $d, $e);

	$P0 = new Array
	$P0 = 5
	$P0[0] = a
	$P0[1] = b
	$P0[2] = c
	$P0[3] = d
	$P0[4] = e

	sprintf $S0, "%08lx%08lx%08lx%08lx%08lx", $P0

	.pcc_begin_return
	.return $S0
	.pcc_end_return
.end