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defpackage bigint2 :
import core
import verse
import firrtl/ir-utils
;============ Big Int Library =============
;------------ Helper Functions ------------
val word-size = 32
defn as-digit (c: Char) -> Int :
index-of("0123456789abcdef", c) as Int
defn num-words (b:BigInt) :
val n = length(d(b))
if num-bits(b) > n * word-size :
error("Number of bits greater than size of BigInt")
n
defn to-hex (b:BigInt) -> String :
defn as-hex (i: Int) -> String :
val str = "0123456789abcdef"
substring(str,i,i + 1)
var str = "h"
val len = num-bits(b)
for i in 0 to len by 4 do :
val pos = len - 4 - i
val digit = (d(b)[pos / 32] >> (pos % 32)) & 15
val hex = as-hex(digit)
if str == "h" and hex == "0" and (i + 4 < len) : false
else : str = string-join([str hex])
string-join([ '\"' str '\"'])
defn to-bin (b:BigInt) -> String :
string-join $ generate<Char> :
defn* loop (pos:Int) :
if (pos >= 0) :
yield(if (d(b)[pos / 32] >> (pos % 32))&1 == 1: '1' else: '0')
loop(pos - 1)
loop(num-bits(b) - 1)
;------------ Library ----------------
public defstruct BigInt :
d : Array<Int>
num-bits : Int
public defmethod to-string (b:BigInt) : to-hex(b)
public defmethod print (o:OutputStream, b:BigInt) :
print(o, to-string(b))
public defn BigIntEmpty (num-bits:Int) -> BigInt :
val num-words = (num-bits + word-size - 1) / word-size
val d = Array<Int>(num-words)
BigInt(d,num-bits)
public defn BigIntLit (data:Int) -> BigInt :
BigIntLit(data,req-num-bits(data))
public defn BigIntLit (data:Int, num-bits:Int) -> BigInt :
val b = BigIntEmpty(num-bits)
d(b)[0] = data
b
public defn BigIntLit (data:String) -> BigInt :
val base = data[0]
val shamt = if base == 'b': 1 else if base == 'h': 4 else: 2
val digits = substring(data, 1)
val num-bits = length(digits) * shamt
BigIntLit(digits,shamt,num-bits)
public defn BigIntLit (digits:String, shamt:Int, num-bits:Int) -> BigInt :
val lit = BigIntEmpty(num-bits)
;; println-all(["BASE " base " SHAMT " shamt " DIGITS " digits])
for i in 0 to num-words(lit) do :
d(lit)[i] = 0
for i in 0 to length(digits) do :
val off = (length(digits) - 1 - i) * shamt
val wi = off / word-size
val bi = off % word-size
d(lit)[wi] = d(lit)[wi] | (as-digit(digits[i]) << bi)
;; println-all(["OFF " off " wi " wi " bi " bi " lit[wi] " lit[wi] " => " lit])
;; println-all(["RES = " lit])
lit
;------------------- Library API -----------------
public defn bits (b:BigInt, high:Int, low:Int) -> BigInt : b
public defn bit (b:BigInt, index:Int) -> BigInt : b
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