RFR: 8255368: Math.exp() gives wrong result for large values on x86 32-bit platforms [v6]

[Vladimir Kozlov]

On Fri, 13 Nov 2020 17:53:16 GMT, Xubo Zhang <github.com+58006833+xbzhang99 at openjdk.org> wrote:

>> Math.exp(10000) produces 0 instead of positive infinity on x86 32-bit platform. The reason was for some jmp instructions, it used jge instead of jae. Also changed movdqu to movsd as it was supposed to load a 64-bit number
>
> Xubo Zhang has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision:
> 
>   Fixed the bug in 32-bit build, exp generates 0 when the exponent is too large

Changes requested by kvn (Reviewer).

src/hotspot/cpu/x86/macroAssembler_x86_exp.cpp line 496:

> 494:   movl(Address(rsp, 64), tmp);
> 495:   lea(tmp, ExternalAddress(static_const_table));
> 496:   movsd(xmm0, Address(rsp, 128));

Can you explain this change?

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PR: https://git.openjdk.java.net/jdk/pull/894