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JVM int32 opcodes: irem follows the divisor sign · case 04

Remainders of negative dividends come out positive (-10 % 3 gives 2).

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

Each op is [name, a, b] over 32-bit two's complement ints: iadd/imul wrap; idiv truncates toward zero and MIN_VALUE / -1 wraps to MIN_VALUE; irem has the sign of the dividend; ishl/ishr/iushr use only the low five bits of the shift count, iushr shifts in zeros; ineg wraps. Division by zero yields "ArithmeticException", an unknown op "VerifyError".

Why this case matters

Bytecode integer opcodes must reproduce fixed-width semantics that host-language integers do not.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
irem takes the sign of the dividend	`[2, -1]`	`[-1, 2]`	Failed

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