Add abs_and_normal_FAC1

STATUS.md

@@ -210,6 +210,7 @@ Floating point mathematical routines - not official, but well known and broadly
 | `$B862`   | `add_align_exponents`  | DONE     |                                                    |
 | `$B867`   | `add_MEM_FAC1`         | DONE     |                                                    |
 | `$B86A`   | `add_FAC2_FAC1`        | DONE     |                                                    |
+| `$B8D2`   | `abs_and_normal_FAC`   | DONE     | From the Microsoft BASIC, original name: FADFLT    |
 | `$B8FE`   | `normal_FAC1`          | DONE     |                                                    |
 | `$B947`   | `inv_FAC1_mantissa`    | DONE     | From the Microsoft BASIC, original name: NEGFAC    |
 | `$B96F`   | `inc_FAC1`             | DONE     | From the Microsoft BASIC, original name: INCFAC    |

src/basic/math/b8d2.abs_and_normal.s

@@ -0,0 +1,22 @@
+;; #LAYOUT# STD *       #TAKE
+;; #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
+;; #LAYOUT# *   BASIC_0 #TAKE
+;; #LAYOUT# *   *       #IGNORE
+
+; This file is under the MIT license, it contains code released by Microsoft Corporation.
+; See LICENSE for more information.
+
+; Math package - abs and noramlize FAC1
+;
+; Input:
+; CF - Sign of number
+;
+; This is verified to be identical to the original Microsoft implementation where it was named FADFLT.
+;
+
+abs_and_normal_FAC1:
+
+    bcs normal_FAC1             ; If CF set only normalize
+    jsr inv_FAC1
+    
+    ; Fallthrough to normal_FAC1

tools/similarity.c

@@ -20,10 +20,11 @@ int matches[MAX_SIZE];
 
 int phase_mask[MAX_SIZE+MAX_SIZE];
 
-#define NUM_CHUNKS 7
+#define NUM_CHUNKS 8
 // Pairs of start, end memory addresses of known exact similarity with the open source Microsoft BASIC
 unsigned short microsoft_basic_chunks[NUM_CHUNKS * 2] = {
     0xB849, 0xB84F,
+    0xB8D2, 0xB8D5,
     0xB947, 0xB97D,
     0xB983, 0xB9BB,
     0xBBA2, 0xBC1A,