FAILURE MAP
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FA-89521 / Instruction set emulation / Open access

Lower-or-same requires both borrow and equality · case 01

ls is false for strictly lower operands.

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

ROOT CAUSE

The ls predicate joins its two conditions with and.

VERIFIED REPAIR

ls is carry clear or zero set.

Unsuccessful approach: Testing carry set follows borrow-style semantics and flips the unsigned order.

Case contract

Input [cond]. Evaluate the condition for all 16 flag states, ordered as NZCV from 0000 to 1111 (N is the most significant), returning 1/0. eq Z; ne !Z; cs C; cc !C; mi N; pl !N; vs V; vc !V; hi C and !Z; ls !C or Z; ge N==V; lt N!=V; gt !Z and N==V; le Z or N!=V; al always. Carry here is set when an unsigned subtraction did not borrow.

Why this case matters

Predicated execution in ARM-style emulators depends on exact condition predicates; unsigned conditions are easily confused with ISAs where carry means borrow.

1 / The failure

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

N = 1
observations = []
def solve(*args):
    cond = args[0]
    res = []
    for bits in range(16):
        n_, z, c, v = bits >> 3 & 1, bits >> 2 & 1, bits >> 1 & 1, bits & 1
        table = {'eq': z == 1, 'ne': z == 0, 'cs': c == 1, 'cc': c == 0, 'mi': n_ == 1, 'pl': n_ == 0,
                 'vs': v == 1, 'vc': v == 0, 'hi': c == 1 and z == 0, 'ls': c == 0 and z == 1,
                 'ge': n_ == v, 'lt': n_ != v, 'gt': z == 0 and n_ == v, 'le': z == 1 or n_ != v, 'al': True}
        res.append(int(table[cond]))
    return res
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition eq over all flags', ['eq'], [0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1]), ('condition ne over all flags', ['ne'], [1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0]), ('condition cs over all flags', ['cs'], [0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition ne over all flags', ['ne'], [1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0]), ('condition cs over all flags', ['cs'], [0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1]), ('condition cc over all flags', ['cc'], [1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition cs over all flags', ['cs'], [0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1]), ('condition cc over all flags', ['cc'], [1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0]), ('condition mi over all flags', ['mi'], [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition cc over all flags', ['cc'], [1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0]), ('condition mi over all flags', ['mi'], [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]), ('condition pl over all flags', ['pl'], [1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition mi over all flags', ['mi'], [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]), ('condition pl over all flags', ['pl'], [1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0]), ('condition vs over all flags', ['vs'], [0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1])]]
for label, args, expected in fixtures[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
condition hi over all flags[0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0][0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]Passed
condition ls over all flags[0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0][1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]Failed
condition ge over all flags[1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1][1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]Passed
condition gt over all flags[1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0][1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]Passed
condition le over all flags[0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1][0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]Passed
condition eq over all flags[0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1][0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1]Passed
condition ne over all flags[1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0][1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0]Passed
condition cs over all flags[0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1][0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1]Passed

SHA-256 / 1057ed2612e1ac0834963b40ce3aed3f1ce17d9ff652f585c56d223228c8af9f

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(*args):
    cond = args[0]
    res = []
    for bits in range(16):
        n_, z, c, v = bits >> 3 & 1, bits >> 2 & 1, bits >> 1 & 1, bits & 1
        table = {'eq': z == 1, 'ne': z == 0, 'cs': c == 1, 'cc': c == 0, 'mi': n_ == 1, 'pl': n_ == 0,
                 'vs': v == 1, 'vc': v == 0, 'hi': c == 1 and z == 0, 'ls': c == 1 or z == 1,
                 'ge': n_ == v, 'lt': n_ != v, 'gt': z == 0 and n_ == v, 'le': z == 1 or n_ != v, 'al': True}
        res.append(int(table[cond]))
    return res
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition eq over all flags', ['eq'], [0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1]), ('condition ne over all flags', ['ne'], [1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0]), ('condition cs over all flags', ['cs'], [0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition ne over all flags', ['ne'], [1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0]), ('condition cs over all flags', ['cs'], [0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1]), ('condition cc over all flags', ['cc'], [1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition cs over all flags', ['cs'], [0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1]), ('condition cc over all flags', ['cc'], [1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0]), ('condition mi over all flags', ['mi'], [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition cc over all flags', ['cc'], [1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0]), ('condition mi over all flags', ['mi'], [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]), ('condition pl over all flags', ['pl'], [1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition mi over all flags', ['mi'], [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]), ('condition pl over all flags', ['pl'], [1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0]), ('condition vs over all flags', ['vs'], [0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1])]]
for label, args, expected in fixtures[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
condition hi over all flags[0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0][0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]Passed
condition ls over all flags[0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1][1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]Failed
condition ge over all flags[1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1][1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]Passed
condition gt over all flags[1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0][1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]Passed
condition le over all flags[0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1][0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]Passed
condition eq over all flags[0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1][0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1]Passed
condition ne over all flags[1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0][1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0]Passed
condition cs over all flags[0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1][0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1]Passed

SHA-256 / 832d7cd147bbea9b1fd21f0bbd56fac099a20761765474c0c325963b03087b35

3 / The verified repair

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

N = 1
observations = []
def solve(*args):
    cond = args[0]
    res = []
    for bits in range(16):
        n_, z, c, v = bits >> 3 & 1, bits >> 2 & 1, bits >> 1 & 1, bits & 1
        table = {'eq': z == 1, 'ne': z == 0, 'cs': c == 1, 'cc': c == 0, 'mi': n_ == 1, 'pl': n_ == 0,
                 'vs': v == 1, 'vc': v == 0, 'hi': c == 1 and z == 0, 'ls': c == 0 or z == 1,
                 'ge': n_ == v, 'lt': n_ != v, 'gt': z == 0 and n_ == v, 'le': z == 1 or n_ != v, 'al': True}
        res.append(int(table[cond]))
    return res
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition eq over all flags', ['eq'], [0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1]), ('condition ne over all flags', ['ne'], [1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0]), ('condition cs over all flags', ['cs'], [0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition ne over all flags', ['ne'], [1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0]), ('condition cs over all flags', ['cs'], [0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1]), ('condition cc over all flags', ['cc'], [1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition cs over all flags', ['cs'], [0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1]), ('condition cc over all flags', ['cc'], [1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0]), ('condition mi over all flags', ['mi'], [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition cc over all flags', ['cc'], [1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0]), ('condition mi over all flags', ['mi'], [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]), ('condition pl over all flags', ['pl'], [1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0])], [('condition hi over all flags', ['hi'], [0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]), ('condition ls over all flags', ['ls'], [1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]), ('condition ge over all flags', ['ge'], [1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]), ('condition gt over all flags', ['gt'], [1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]), ('condition le over all flags', ['le'], [0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]), ('condition mi over all flags', ['mi'], [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]), ('condition pl over all flags', ['pl'], [1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0]), ('condition vs over all flags', ['vs'], [0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1])]]
for label, args, expected in fixtures[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
condition hi over all flags[0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0][0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0]Passed
condition ls over all flags[1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1][1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1]Passed
condition ge over all flags[1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1][1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1]Passed
condition gt over all flags[1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0][1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0]Passed
condition le over all flags[0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1][0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1]Passed
condition eq over all flags[0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1][0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1]Passed
condition ne over all flags[1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0][1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0]Passed
condition cs over all flags[0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1][0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1]Passed

SHA-256 / b97ec3ad30db53d1ada33596162127663ab38d8d677e2d095c63e1c2a7c421e1

Verification & scope

A deterministic bounded teaching model of one emulator rule; the instruction semantics are a stipulated contract inspired by common ISAs and are not a claim of cycle-exact or architectural conformance. 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 2026-09-29T14:51:18.136907+00:00.

Case digest / 40d2d2b003721dc12433547707ec5e65c097631046c3492162cf3df5e26186d9