         HEX: 391c0cb3 HEX: 4ed8aa4a HEX: 5b9cca4f HEX: 682e6ff3
         HEX: 748f82ee HEX: 78a5636f HEX: 84c87814 HEX: 8cc70208
         HEX: 90befffa HEX: a4506ceb HEX: bef9a3f7 HEX: c67178f2
-    } ;
+    }
 
 : s0-256 ( x -- x' )
-    [ -7 bitroll-32 ] keep
-    [ -18 bitroll-32 ] keep
-    -3 shift bitxor bitxor ; inline
+    [
+        [ -7 bitroll-32 ]
+        [ -18 bitroll-32 ]
+        [ -3 shift ] tri
+    ] [ bitxor ] reduce-outputs ; inline
 
 : s1-256 ( x -- x' )
-    [ -17 bitroll-32 ] keep
-    [ -19 bitroll-32 ] keep
-    -10 shift bitxor bitxor ; inline
+    [
+        [ -17 bitroll-32 ]
+        [ -19 bitroll-32 ]
+        [ -10 shift ] tri
+    ] [ bitxor ] reduce-outputs ; inline
 
 : process-M-256 ( seq n -- )
     [ 16 - swap nth ] 2keep

! See http://factorcode.org/license.txt for BSD license.
USING: kernel splitting grouping math sequences namespaces make
io.binary math.bitwise checksums checksums.common
sbufs strings ;
IN: checksums.sha2

<PRIVATE

SYMBOLS: vars M K H S0 S1 process-M word-size block-size ;

CONSTANT: a 0
CONSTANT: b 1

CONSTANT: g 6
CONSTANT: h 7

CONSTANT: initial-H-256
    {
        HEX: 6a09e667 HEX: bb67ae85 HEX: 3c6ef372 HEX: a54ff53a
        HEX: 510e527f HEX: 9b05688c HEX: 1f83d9ab HEX: 5be0cd19
    }

CONSTANT: K-256
    {
        HEX: 428a2f98 HEX: 71374491 HEX: b5c0fbcf HEX: e9b5dba5
        HEX: 3956c25b HEX: 59f111f1 HEX: 923f82a4 HEX: ab1c5ed5
