RFR: 8292628: x86: Improve handling of constants in trigonometric stubs [v2]

[Aleksey Shipilev]

On Thu, 18 Aug 2022 21:07:43 GMT, Vladimir Ivanov <vlivanov at openjdk.org> wrote:

>> Improve how constants are handled in trigonometric stubs on x86. 
>> In particular, extract shared constants into a separate file and 
>> encapsulate them in MacroAssembler.
>> 
>> Also, some minor cleanups included. 
>> 
>> Testing:
>>  - [x] hs-tier1 - hs-tier4
>>  - [x] x86_32 build
>
> Vladimir Ivanov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   StubRoutines cleanup

Looks okay with some nits.

src/hotspot/cpu/x86/macroAssembler_x86_constants.cpp line 251:

> 249: 
> 250: ATTRIBUTE_ALIGNED(16) juint _PI4X3[] = {
> 251:     0x54443000UL, 0xbfe921fbUL, 0x3b39a000UL, 0x3d373dcbUL, 0xe0e68948UL, 0xba845c06UL

While at it, maybe we should stick to one style for these tables. The large table above has five columns, so maybe wrap this and following table like that too?

src/hotspot/cpu/x86/macroAssembler_x86_exp.cpp line 206:

> 204:   movdqu(xmm6, ExternalAddress(SHIFTER));  // 0x00000000UL, 0x43380000UL, 0x00000000UL, 0x43380000UL
> 205:   movdqu(xmm2, ExternalAddress(16 + cv));    // 0xfefa0000UL, 0x3f862e42UL, 0xfefa0000UL, 0x3f862e42UL
> 206:   movdqu(xmm3, ExternalAddress(32 + cv));    // 0xbc9e3b3aUL, 0x3d1cf79aUL, 0xbc9e3b3aUL, 0x3d1cf79aUL

If you are flipping `+` operands near the changes, maybe flip these too?

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

Marked as reviewed by shade (Reviewer).

PR: https://git.openjdk.org/jdk/pull/9923