[15] RFR (S): 8242491: C2: assert(v2->bottom_type() == vt) failed: mismatch when creating MacroLogicV

[Viswanathan, Sandhya]

Hi Vladimir,

Your change looks good to me.

Best Regards,
Sandhya

-----Original Message-----
From: hotspot-compiler-dev <hotspot-compiler-dev-bounces at openjdk.java.net> On Behalf Of Vladimir Ivanov
Sent: Friday, April 10, 2020 7:07 AM
To: hotspot compiler <hotspot-compiler-dev at openjdk.java.net>
Subject: [15] RFR (S): 8242491: C2: assert(v2->bottom_type() == vt) failed: mismatch when creating MacroLogicV

http://cr.openjdk.java.net/~vlivanov/8242491/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8242491

Asserts on input types for MacroLogicV are too strong.
SuperWord pass can mix vectors of distinct subword types (byte and boolean or short and char).

Though it's possible to explicitly check for such particular cases, the fix relaxes the assert even more and only verifies that inputs are of the same size (in bytes), so bitwise reinterpretation of vector values is safe.

Testing: hs-precheckin-comp,hs-tier1,hs-tier2

Thanks!

Best regards,
Vladimir Ivanov