[vector api] RFR: Fix AArch64 build failure and jtreg long64/double64 failures for AArch64 NEON

[Vladimir Ivanov]

On 22/10/2018 18:40, Yang Zhang (Arm Technology China) wrote:
> Hi,
> 
> I'm working on supporting vector api for aarch64 NEON.
> I have a patch which can fix AArch64 build failure and jtreg long64/double64 failures for AArch64 NEON. Could you please help to review this?
> 
> Webrev:
> http://cr.openjdk.java.net/~yzhang/vectorapi.bugfix/webrev.00/

src/hotspot/share/opto/library_call.cpp:
+#ifdef X86
    int bits = num_elem * BitsPerByte * type2aelembytes(bt);
    if (bits == 512 && !VM_Version::supports_avx512vlbwdq()) {
      return NULL;
    }
+#endif

That's ok as a temporary workaround, but shared code shouldn't access 
platform-specific API and VM_Version::supports_avx512vlbwdq() is 
x86-specific.

So far, platform-specific logic is hidden behind Matcher.

Jp, I see you added the problematic code [1]. Please, fix it.

Best regards,
Vladimir Ivanov

[1] http://hg.openjdk.java.net/panama/dev/rev/a6e1c1fd5e27