FAILURE MAP
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FA-90261 / Bytecode virtual machines / Open access

Switch dispatch: table offsets added to the aligned operand address · case 01

Matching cases land a few bytes past their intended targets.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Case offsets are added to the padded operand position instead of the opcode address.

VERIFIED REPAIR

Add every switch offset to the address of the switch opcode.

Unsuccessful approach: Treating the offset as absolute ignores the switch location entirely.

Case contract

code is a method's bytes; at addr is tableswitch (0xAA) or lookupswitch (0xAB). After the opcode, 0-3 padding bytes align the next byte to a multiple of 4 from the method start; then big-endian signed 32-bit words: default, and either low, high and high-low+1 offsets, or npairs followed by sorted (match, offset) pairs. Branch offsets are relative to the switch opcode address. Return the target address, or ["VerifyError", reason] for low > high, negative npairs, keys not strictly increasing, another opcode, or truncated operands.

Why this case matters

Switch opcodes combine alignment, signed decoding and relative targets in one instruction.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(code, addr, key):
    def s32(p):
        v = (code[p] << 24) | (code[p + 1] << 16) | (code[p + 2] << 8) | code[p + 3]
        return v - (1 << 32) if v & 0x80000000 else v
    def dispatch():
        op = code[addr]
        p = addr + 1
        p += (4 - p % 4) % 4
        default = s32(p)
        if op == 0xAA:
            low, high = s32(p + 4), s32(p + 8)
            if low > high:
                return ['VerifyError', 'low>high']
            if low <= key <= high:
                return p + s32(p + 12 + 4 * (key - low))
            return addr + default
        if op == 0xAB:
            npairs = s32(p + 4)
            if npairs < 0:
                return ['VerifyError', 'npairs']
            pairs = [(s32(p + 8 + 8 * i), s32(p + 12 + 8 * i)) for i in range(npairs)]
            if any(pairs[i][0] >= pairs[i + 1][0] for i in range(npairs - 1)):
                return ['VerifyError', 'unsorted']
            lo, hi = 0, npairs - 1
            while lo <= hi:
                mid = (lo + hi) // 2
                if pairs[mid][0] == key:
                    return addr + pairs[mid][1]
                if pairs[mid][0] < key:
                    lo = mid + 1
                else:
                    hi = mid - 1
            return addr + default
        return ['VerifyError', 'opcode']
    try:
        return dispatch()
    except IndexError:
        return ['VerifyError', 'truncated']
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    7,
    0),
   47),
  ('tableswitch hit at the high bound',
   ([0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    1,
    1),
   51),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    2,
    -2),
   22),
  ('tableswitch miss takes the backward default',
   ([0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    1,
    5),
   -7),
  ('lookupswitch hit with negative offset',
   ([0,
     171,
     0,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    1,
    100),
   -3),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    7,
    3),
   19),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 171, 0, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177], 1, 1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 170, 0, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 1, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    11,
    0),
   51),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    2,
    1),
   52),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    3,
    -2),
   23),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    2,
    5),
   -6),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     171,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    2,
    100),
   -2),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    11,
    3),
   23),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 171, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177], 2, 1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 170, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 2, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    15,
    0),
   55),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    3,
    1),
   53),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     0,
     170,
     0,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    4,
    -2),
   24),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    3,
    5),
   -5),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    3,
    100),
   -1),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    15,
    3),
   27),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 0, 171, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177], 3, 1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 0, 170, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 3, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    19,
    0),
   59),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     0,
     0,
     170,
     0,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    4,
    1),
   54),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     0,
     0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    5,
    -2),
   25),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     0,
     0,
     170,
     0,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    4,
    5),
   -4),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     36,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    4,
    100),
   0),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     36,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    19,
    3),
   31),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 0, 0, 171, 0, 0, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177],
    4,
    1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 0, 0, 170, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 4, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    23,
    0),
   63),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     0,
     0,
     0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    5,
    1),
   55),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     0,
     0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    6,
    -2),
   26),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     0,
     0,
     0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    5,
    5),
   -3),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     37,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    5,
    100),
   1),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     37,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    23,
    3),
   35),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 0, 0, 0, 171, 0, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177],
    5,
    1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 0, 0, 0, 170, 0, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 5, 3),
   ['VerifyError', 'low>high'])]]
for label, args, expected in cases[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression: tableswitch hit with aligned operands4847Failed
tableswitch hit at the high bound5451Failed
tableswitch hit at the low bound2422Failed
tableswitch miss takes the backward default-7-7Passed
lookupswitch hit with negative offset-3-3Passed
lookupswitch miss1919Passed
lookupswitch with duplicate keys is rejected['VerifyError', 'unsorted']['VerifyError', 'unsorted']Passed
control: low greater than high['VerifyError', 'low>high']['VerifyError', 'low>high']Passed

SHA-256 / 4287d6740b345d29b5200a144903a0ddbef8eeb86166ebbc82fda1a4eb52776b

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(code, addr, key):
    def s32(p):
        v = (code[p] << 24) | (code[p + 1] << 16) | (code[p + 2] << 8) | code[p + 3]
        return v - (1 << 32) if v & 0x80000000 else v
    def dispatch():
        op = code[addr]
        p = addr + 1
        p += (4 - p % 4) % 4
        default = s32(p)
        if op == 0xAA:
            low, high = s32(p + 4), s32(p + 8)
            if low > high:
                return ['VerifyError', 'low>high']
            if low <= key <= high:
                return s32(p + 12 + 4 * (key - low))
            return addr + default
        if op == 0xAB:
            npairs = s32(p + 4)
            if npairs < 0:
                return ['VerifyError', 'npairs']
            pairs = [(s32(p + 8 + 8 * i), s32(p + 12 + 8 * i)) for i in range(npairs)]
            if any(pairs[i][0] >= pairs[i + 1][0] for i in range(npairs - 1)):
                return ['VerifyError', 'unsorted']
            lo, hi = 0, npairs - 1
            while lo <= hi:
                mid = (lo + hi) // 2
                if pairs[mid][0] == key:
                    return addr + pairs[mid][1]
                if pairs[mid][0] < key:
                    lo = mid + 1
                else:
                    hi = mid - 1
            return addr + default
        return ['VerifyError', 'opcode']
    try:
        return dispatch()
    except IndexError:
        return ['VerifyError', 'truncated']
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    7,
    0),
   47),
  ('tableswitch hit at the high bound',
   ([0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    1,
    1),
   51),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    2,
    -2),
   22),
  ('tableswitch miss takes the backward default',
   ([0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    1,
    5),
   -7),
  ('lookupswitch hit with negative offset',
   ([0,
     171,
     0,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    1,
    100),
   -3),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    7,
    3),
   19),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 171, 0, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177], 1, 1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 170, 0, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 1, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    11,
    0),
   51),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    2,
    1),
   52),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    3,
    -2),
   23),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    2,
    5),
   -6),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     171,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    2,
    100),
   -2),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    11,
    3),
   23),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 171, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177], 2, 1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 170, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 2, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    15,
    0),
   55),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    3,
    1),
   53),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     0,
     170,
     0,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    4,
    -2),
   24),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    3,
    5),
   -5),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    3,
    100),
   -1),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    15,
    3),
   27),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 0, 171, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177], 3, 1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 0, 170, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 3, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    19,
    0),
   59),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     0,
     0,
     170,
     0,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    4,
    1),
   54),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     0,
     0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    5,
    -2),
   25),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     0,
     0,
     170,
     0,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    4,
    5),
   -4),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     36,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    4,
    100),
   0),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     36,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    19,
    3),
   31),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 0, 0, 171, 0, 0, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177],
    4,
    1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 0, 0, 170, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 4, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    23,
    0),
   63),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     0,
     0,
     0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    5,
    1),
   55),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     0,
     0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    6,
    -2),
   26),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     0,
     0,
     0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    5,
    5),
   -3),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     37,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    5,
    100),
   1),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     37,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    23,
    3),
   35),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 0, 0, 0, 171, 0, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177],
    5,
    1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 0, 0, 0, 170, 0, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 5, 3),
   ['VerifyError', 'low>high'])]]
for label, args, expected in cases[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression: tableswitch hit with aligned operands4047Failed
tableswitch hit at the high bound5051Failed
tableswitch hit at the low bound2022Failed
tableswitch miss takes the backward default-7-7Passed
lookupswitch hit with negative offset-3-3Passed
lookupswitch miss1919Passed
lookupswitch with duplicate keys is rejected['VerifyError', 'unsorted']['VerifyError', 'unsorted']Passed
control: low greater than high['VerifyError', 'low>high']['VerifyError', 'low>high']Passed

SHA-256 / d71b9b17f986b457f90df39b08e229e9d4e2facfef2372aed115ac023f96bef5

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(code, addr, key):
    def s32(p):
        v = (code[p] << 24) | (code[p + 1] << 16) | (code[p + 2] << 8) | code[p + 3]
        return v - (1 << 32) if v & 0x80000000 else v
    def dispatch():
        op = code[addr]
        p = addr + 1
        p += (4 - p % 4) % 4
        default = s32(p)
        if op == 0xAA:
            low, high = s32(p + 4), s32(p + 8)
            if low > high:
                return ['VerifyError', 'low>high']
            if low <= key <= high:
                return addr + s32(p + 12 + 4 * (key - low))
            return addr + default
        if op == 0xAB:
            npairs = s32(p + 4)
            if npairs < 0:
                return ['VerifyError', 'npairs']
            pairs = [(s32(p + 8 + 8 * i), s32(p + 12 + 8 * i)) for i in range(npairs)]
            if any(pairs[i][0] >= pairs[i + 1][0] for i in range(npairs - 1)):
                return ['VerifyError', 'unsorted']
            lo, hi = 0, npairs - 1
            while lo <= hi:
                mid = (lo + hi) // 2
                if pairs[mid][0] == key:
                    return addr + pairs[mid][1]
                if pairs[mid][0] < key:
                    lo = mid + 1
                else:
                    hi = mid - 1
            return addr + default
        return ['VerifyError', 'opcode']
    try:
        return dispatch()
    except IndexError:
        return ['VerifyError', 'truncated']
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    7,
    0),
   47),
  ('tableswitch hit at the high bound',
   ([0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    1,
    1),
   51),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    2,
    -2),
   22),
  ('tableswitch miss takes the backward default',
   ([0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     31,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    1,
    5),
   -7),
  ('lookupswitch hit with negative offset',
   ([0,
     171,
     0,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    1,
    100),
   -3),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    7,
    3),
   19),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 171, 0, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177], 1, 1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 170, 0, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 1, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    11,
    0),
   51),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    2,
    1),
   52),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    3,
    -2),
   23),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     32,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    2,
    5),
   -6),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     171,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    2,
    100),
   -2),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    11,
    3),
   23),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 171, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177], 2, 1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 170, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 2, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    15,
    0),
   55),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    3,
    1),
   53),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     0,
     170,
     0,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    4,
    -2),
   24),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     33,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    3,
    5),
   -5),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    3,
    100),
   -1),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    15,
    3),
   27),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 0, 171, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177], 3, 1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 0, 170, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 3, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    19,
    0),
   59),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     0,
     0,
     170,
     0,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    4,
    1),
   54),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     0,
     0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    5,
    -2),
   25),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     0,
     0,
     170,
     0,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     34,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    4,
    5),
   -4),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     36,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    4,
    100),
   0),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     36,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    19,
    3),
   31),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 0, 0, 171, 0, 0, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177],
    4,
    1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 0, 0, 170, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 4, 3),
   ['VerifyError', 'low>high'])],
 [('regression: tableswitch hit with aligned operands',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     170,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    23,
    0),
   63),
  ('tableswitch hit at the high bound',
   ([0,
     0,
     0,
     0,
     0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    5,
    1),
   55),
  ('tableswitch hit at the low bound',
   ([0,
     0,
     0,
     0,
     0,
     0,
     170,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    6,
    -2),
   26),
  ('tableswitch miss takes the backward default',
   ([0,
     0,
     0,
     0,
     0,
     170,
     0,
     0,
     255,
     255,
     255,
     248,
     255,
     255,
     255,
     254,
     0,
     0,
     0,
     1,
     0,
     0,
     0,
     20,
     0,
     0,
     0,
     35,
     0,
     0,
     0,
     40,
     0,
     0,
     0,
     50,
     177],
    5,
    5),
   -3),
  ('lookupswitch hit with negative offset',
   ([0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     37,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    5,
    100),
   1),
  ('lookupswitch miss',
   ([0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     171,
     0,
     0,
     0,
     12,
     0,
     0,
     0,
     4,
     255,
     255,
     255,
     251,
     0,
     0,
     0,
     16,
     0,
     0,
     0,
     0,
     0,
     0,
     0,
     24,
     0,
     0,
     0,
     7,
     0,
     0,
     0,
     37,
     0,
     0,
     0,
     100,
     255,
     255,
     255,
     252,
     177],
    23,
    3),
   35),
  ('lookupswitch with duplicate keys is rejected',
   ([0, 0, 0, 0, 0, 171, 0, 0, 0, 0, 0, 12, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 12, 177],
    5,
    1),
   ['VerifyError', 'unsorted']),
  ('control: low greater than high',
   ([0, 0, 0, 0, 0, 170, 0, 0, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 2, 177], 5, 3),
   ['VerifyError', 'low>high'])]]
for label, args, expected in cases[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression: tableswitch hit with aligned operands4747Passed
tableswitch hit at the high bound5151Passed
tableswitch hit at the low bound2222Passed
tableswitch miss takes the backward default-7-7Passed
lookupswitch hit with negative offset-3-3Passed
lookupswitch miss1919Passed
lookupswitch with duplicate keys is rejected['VerifyError', 'unsorted']['VerifyError', 'unsorted']Passed
control: low greater than high['VerifyError', 'low>high']['VerifyError', 'low>high']Passed

SHA-256 / 3ca024a5f888ea848ccc327ce22beb22587cd787a9c9b40136729a35b25f744f

Verification & scope

A deterministic, bounded teaching model of one bytecode virtual machine mechanism with a stipulated instruction encoding; it is not a production VM and claims no conformance to any real specification. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:51:25.082427+00:00.

Case digest / bbf95f8bfa73fc3d42e815763cc6204e949b7c610272334d6e794367885dc9f7