RFR: 8342769: HotSpot Windows/gcc port is broken [v4]

[Andrew Haley]

On Wed, 20 Nov 2024 14:01:15 GMT, Julian Waters <jwaters at openjdk.org> wrote:

> 
> I'm not sure I understand - The fix in this Pull Request already uses SharedRuntime::fmod_winx64 (Or more accurately, it doesn't change the existing code that uses it, just makes the ifdef check more accurate). I don't know if moving the implementation from sharedRuntimeRem.cpp to os_windows.cpp gives any benefit, and sharedRuntimeRem.cpp is already under os/windows. I might have misunderstood you earlier, but it sounded as if you were proposing to implement frem and drem in assembly for ARM64 like what is already done for x86

I got horribly confused.

I thought about custome asm, but there's little point in doing so because `fmod` is always going to require repeated division and subtraction, so it's going to be slow.


What you're doing in this patch looks correct as far as it goes, but `amd64`and `x64` in the comments in `sharedRuntime.[ch]pp` is wrong. Please find and fix those to make it clear we need this function on on AArch64 too. The name of the function `SharedRuntime::fmod_winx64` is at least misleading if not wrong. Maybe `SharedRuntime::fmod_win64`?

My apologies for the confusion.

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PR Comment: https://git.openjdk.org/jdk/pull/21627#issuecomment-2489086948