> Found this while cleaning up x86_32 code for removal.
> 
> In our current code there is a block added by 
> [JDK-8076373](https://bugs.openjdk.org/browse/JDK-8076373):
> https://github.com/openjdk/jdk/blob/3b21a298c29d88720f6bfb2dc1f3305b6a3db307/src/hotspot/share/compiler/compileBroker.cpp#L1451-L1473
> 
> Ostensibly, that block is for x86_32 handling of signalling NaNs -- x87 FPU 
> has a peculiarity with them. See other funky bugs we seen with it: 
> [JDK-8285985](https://bugs.openjdk.org/browse/JDK-8285985), 
> [JDK-8293991](https://bugs.openjdk.org/browse/JDK-8293991).
> 
> But the way current block is coded, it is enabled for X86 wholesale, which 
> also means x86_64! In fact, it is likely even worse on x86_64, because the 
> related "fast" entries are generated only for x86_32:
> https://github.com/openjdk/jdk/blob/3b21a298c29d88720f6bfb2dc1f3305b6a3db307/src/hotspot/share/interpreter/templateInterpreterGenerator.cpp#L493-L502
> 
> This can be solved by checking `IA32` instead of `X86`. This block would be 
> gone completely once we remove x86_32 port. Meanwhile, we can make it right 
> by x86_64, and make eventual x86_32 removal less confusing. This issue seems 
> to only affect the compilation of native methods, while most of the hot code 
> is riding on compiler intrinsics. I'll put performance data in comments.
> 
> Additional testing:
>  - [x] Linux x86_64 server fastdebug, `all`

Aleksey Shipilev has updated the pull request incrementally with one additional 
commit since the last revision:

  Disable IR tests on IA32

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/22446/files
  - new: https://git.openjdk.org/jdk/pull/22446/files/e24b0060..51cb1660

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22446&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22446&range=01-02

  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/22446.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22446/head:pull/22446

PR: https://git.openjdk.org/jdk/pull/22446

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