dfp-audit

name	dfp-audit
description	Scan the codebase for DFP (Decimal64) misuse — raw Java comparison operators used on DFP-encoded long values instead of Decimal64Utils helper methods. Run periodically to catch regressions.
context	fork
allowed-tools	["Read","Grep","Glob"]

DFP Misuse Audit

DFP encodes decimals as long with a special bit layout — raw Java operators (==, !=, <, >) produce silently wrong results on these values.

Exception: comparing against the null sentinel with ==/!= is correct and intentional:

if (price != TypeConstants.DECIMAL_NULL) { ... }  // OK
if (maxLoss != Decimal64Utils.NULL) { ... }        // OK

Scan

Run both greps (covers both operand orderings):

grep -rn -E "(==|!=|<=|>=|<|>)\s*Decimal64Utils\.(ZERO|ONE|TWO|NaN|POSITIVE_INFINITY|NEGATIVE_INFINITY|MAX_VALUE|MIN_VALUE)" --include="*.java" .

grep -rn -E "Decimal64Utils\.(ZERO|ONE|TWO|NaN|POSITIVE_INFINITY|NEGATIVE_INFINITY|MAX_VALUE|MIN_VALUE)\s*(==|!=|<=|>=|<|>)" --include="*.java" .

Filter out any hits involving NULL or DECIMAL_NULL — those are the sentinel exception above.

Fix

Wrong	Correct
x == Decimal64Utils.ZERO	Decimal64Utils.isZero(x)
x != Decimal64Utils.ZERO	Decimal64Utils.isNonZero(x)
x > Decimal64Utils.ZERO	Decimal64Utils.isPositive(x)
x < Decimal64Utils.ZERO	Decimal64Utils.isNegative(x)
x >= Decimal64Utils.ZERO	!Decimal64Utils.isNegative(x)
x <= Decimal64Utils.ZERO	!Decimal64Utils.isPositive(x)
x == y	Decimal64Utils.equals(x, y)
x < y	Decimal64Utils.isLess(x, y)
x > y	Decimal64Utils.isGreater(x, y)