CR for RFR 8140779

Berg, Michael C michael.c.berg at
Sat Oct 31 04:06:32 UTC 2015

Vladimir, Igor: I have uploaded the latest source at


-----Original Message-----
From: Vladimir Kozlov [mailto:vladimir.kozlov at] 
Sent: Friday, October 30, 2015 1:16 AM
To: hotspot-compiler-dev at; Berg, Michael C
Subject: Re: CR for RFR 8140779

match_rule_supported() already calls has_match_rule(opcode) so don't call it in match_rule_supported_vector().

Otherwise very nice cleanup. Thank you.

Igor, please, use RBT on x86 to execute a lot of tests.


On 10/30/15 3:06 AM, Berg, Michael C wrote:
> Hi Folks,
> I would like to contribute AVX 512 changes for bug fixes and 
> performance issues. I need two reviewers to examine this patch and comment as needed:
> Bug-id:
> webrev:
> Debugging on Evex machines, a number of issues were uncovered which 
> could not be addressed via emulation. These changes include a unified 
> approach with call frames for Evex and pre Evex targets, performance 
> changes for 32 bit Evex performance, general improvements to all x86 
> targets for reduction patterns, encoding changes for correctness, 
> changes that reduce register pressure for generated code, CPUID 
> additions for additional state control, vector length guards on 
> instructions which only partially support Evex on some targets. Also 
> included are the addition of a state object which is atomic to each 
> instruction emit and which is programmed with specific target 
> information. There is a reduction of x86 assembler interfaces from 20 
> to 4. Code which manages the legacy code path for instructions which 
> do not have Evex support is also included which must manage upper bank 
> resources of registers while avoiding complication in the register 
> allocator which would bloat code.
> Please consider this a high priority review for target system usage.
> Thanks,
> Michael

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