Math.exp() yields different results on 32 bit systems

[Andreas Ahlenstorf]

Hi!

According to a bug report at AdoptOpenJDK [1] Math.exp(10_000.0) yields different results on 32 bit systems than on 64 bit systems.

public class Test {
	public static void main(String[] args) {
		System.out.println(Math.exp(10_000.0));
	}
}

On 64 bit systems the code above prints Infinity. On 32 bit systems the result is 0.0. I think that's wrong, but I'm far from an expert in floating point arithmetics.

Affected versions:

* OpenJDK 9.0.1
* OpenJDK 11.0.8
* OpenJDK 15

Not affected:

* OpenJDK 8u265

We tested both with AdoptOpenJDK and Azul Zulu on Windows and Linux on x86 and x64. If we disable intrinsics (-XX:+UnlockDiagnosticVMOptions -XX:-UseLibmIntrinsic), Infinity is printed on x86 systems, too.

Is this expected behavior?

Best,
Andreas

[1] https://github.com/AdoptOpenJDK/openjdk-support/issues/182