advent: add 2020 day1 part1 solution (partial)

scu-dsp/advent/2020/day1/generate_input.py

@@ -0,0 +1,35 @@
+import random
+
+def has_2020_2(l):
+    length = len(l)
+    found = set()
+    for i in range(length):
+        for j in range(length):
+            if i == j:
+                continue
+            if l[i] + l[j] == 2020:
+                found.add(frozenset((i, j)))
+    return len(found) == 1
+
+def has_2020_3(l):
+    length = len(l)
+    found = set()
+    for i in range(length):
+        for j in range(length):
+            for k in range(length):
+                if i == j or k == i:
+                    continue
+                if l[i] + l[j] + l[k] == 2020:
+                    found.add(frozenset((i, j)))
+    return len(found) == 1
+
+def gen_random():
+    return [random.randint(100, 2500) for _ in range(64)]
+
+def find_input():
+    while True:
+        l = gen_random()
+        if has_2020_2(l) and has_2020_3(l):
+            return l
+
+print("\n".join(map(str, find_input())))

scu-dsp/advent/2020/day1/input.txt

@@ -0,0 +1,64 @@
+2425
+1176
+1549
+1178
+1758
+2293
+880
+1602
+871
+1423
+347
+2353
+1460
+2019
+1767
+2213
+1988
+193
+2434
+1862
+2176
+760
+1227
+1005
+1143
+2199
+2268
+927
+942
+240
+211
+1996
+1479
+1068
+1392
+1827
+2285
+1380
+1669
+1282
+2182
+2424
+1082
+1826
+344
+1584
+1741
+1614
+517
+907
+1091
+1755
+1921
+176
+1668
+2112
+1485
+944
+1771
+1105
+409
+1975
+2333
+2434

scu-dsp/advent/2020/day1/solution.asm

@@ -0,0 +1,70 @@
+        ;; input data: m0
+        ;; input data: m1
+        ;; input data: m2
+
+        ;; variables m3:
+        loop_0_ix = 0     ; decrementing counter
+        loop_1_start = 1
+
+        ;start = 0
+        start = 0 ; constant
+
+        ;; initialization
+        ;;   [X       ]   [Y       ]   [D1             ]
+                                       mov (start + 0),ct0
+
+        ;; initialize multiplier output to 2020
+                                       mov 63,ct3
+        mvi 2020,mc3                                       ; m3[63] used as temporary
+                                       mov 63,ct3
+                          mov m3,y     mov 1,rx
+        ;; initialize variables
+                                       mov loop_0_ix,ct3
+                                       mov (64 - start),mc3            ; loop_0_ix+
+                                       mov (start + 1),mc3 ; loop_1_start+
+
+        ;; outer loop init
+                                       mov loop_inner,top
+                                       mov (64 - start),lop          ; (LOP: 64)
+                                       mov 1,pl
+                                       mov loop_1_start,ct3
+solve_loop_0_top:
+        ;;   [X       ]   [Y       ]   [D1             ]
+        ;; calculate inner loop starting index
+        ;; P: 1 ; A: 64
+                          mov m3,a     mov m3,ct1          ; loop_1_start
+        ;; pre-decrement lop; effectively a jump to loop_inner
+        btm                                                ; (LOP: 63)
+        add                            mov all,mc3         ; loop_1_start+ (delay slot)
+
+loop_inner:
+             mov m0,p     mov m1,a
+        add  mov mul,p    mov alu,a
+        sub
+        jmp z,found
+        nop
+
+        btm
+        ;; increment ct1 (A discarded)
+             mov mc1,a                                    ; (delay slot)
+
+        ;; increment ct0 (A discarded)
+                          mov mc0,a
+
+loop_exit_test:
+        ;;   [X       ]   [Y       ]   [D1             ]
+                                       mov loop_0_ix,ct3
+                          mov m3,a     mov 1,pl           ; m3: loop_0_ix
+        sub               mov alu,a    mov all,mc3        ; m3: loop_0_ix+
+        jmp nz,solve_loop_0_top
+                                       mov all,lop        ; (delay slot)
+
+not_found:
+        jmp end
+        clr a                                             ; (delay slot)
+found:
+        ;;   [X       ]   [Y            ]   [D1             ]
+             mov m1,x     mov m0,y  clr a
+             mov mul,p
+        add               mov alu,a                       ; (delay slot)
+end:

scu-dsp/base10_to_bin.py

@@ -0,0 +1,20 @@
+import struct
+import sys
+
+input_file = sys.argv[1]
+output_file = sys.argv[2]
+
+with open(input_file, 'r') as f:
+    buf = f.read()
+
+def parse_input(buf):
+    lines = buf.strip().split('\n')
+    for line in lines:
+        if not line.strip():
+            yield 0
+        else:
+            yield int(line)
+
+with open(output_file, 'wb') as f:
+    for num in parse_input(buf):
+        f.write(struct.pack(">i", num))

scu-dsp/div10_vdp2.asm

@@ -14,7 +14,7 @@ base10_loop:
                                    mov 0,ct0
         mvi div10_unsigned,pc
         ;;   [X     ]   [Y     ]   [D1     ]
-                        mov mc0,y   mov 1,lop     ; mvi imm,pc delay slot (executed twice)
+                        mov mc0,y  mov 1,lop     ; mvi imm,pc delay slot (executed twice)
         ;; after function return:
                                    mov all,mc0   ; m0[1] (1234)
                                    mov all,pl    ; ??? why can't this happen in the next instruction?