RFR: 8261397: Try Catch Method Failing to Work When Dividing An Integer By 0 [v3]

[Gerard Ziemski]

On Thu, 18 Feb 2021 16:28:38 GMT, Gerard Ziemski <gziemski at openjdk.org> wrote:

> > The workaround itself seems okay as far as it goes but what happens if native code triggers a real FPE_FLTINV that we will now treat as "div by zero"?
> 
> Excellent question. According to https://en.wikipedia.org/wiki/IEEE_754 invalid operation is `mathematically undefined, e.g., the square root of a negative number. By default, returns qNaN.` I will test this scenario out and report back...

According to the **man pages** for `log()` function:

`log(x), log2(x), and log10(x) return a NaN and raise the "invalid" floating-point exception for x < 0.`

and the **man pages** for `sqrt()` function:

`sqrt(x) returns a NaN and generates a domain error for x < 0`

but what I see in our signal handler is a signal of type `FPE_FLTDIV` returned **not** `FPE_FLTINV` for `sqrt(-1.0)` and `log(-1.0)`

I can't seem to be able to get `FPE_FLTINV` at all - it's seems that it's unused natively on `macOS x86_64` so we are good I think.

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PR: https://git.openjdk.java.net/jdk/pull/2615