MIPS64: Optimize simulator.

MIPS64: Optimize simulator.

Port 09f41681ef83fe9e9d79748e2a60f16b70d5934c

Original commit message:
The patch decreases the calls of huge switch instructions making the
DecodeType*() functions to work in one phase and optimizing
Instruction::InstructionType(). Speed gain in release full check is
about 33% (6:13 s -> 4:09 s) and in optdebug full test is about 50%
(12:29 -> 6:17)

BUG=

Committed: https://crrev.com/b89eec39a18b1c2600bc1cebd38d4c5f1a7c2e61
Cr-Commit-Position: refs/heads/master@{#30824}

[balazs.kilvady, 2015-09-17 17:00:26]

balazs.kilvady@imgtec.com changed reviewers:
+ akos.palfi@imgtec.com, paul.lind@imgtec.com

[paul.l..., 2015-09-17 18:07:24]

LGTM. Thanks, really nice perf improvement!

One nit, I built with that change, and it seems fine.

https://codereview.chromium.org/1356693002/diff/1/src/mips64/disasm-mips64.cc
File src/mips64/disasm-mips64.cc (right):

https://codereview.chromium.org/1356693002/diff/1/src/mips64/disasm-mips64.cc...
src/mips64/disasm-mips64.cc:1831: switch
(instr->InstructionType(Instruction::EXTRA)) {
Can we do Instruction::TypeChecks::EXTRA here? That is self-explanatory, whereas
omitting the enum name makes this confusing (to me anyway, and I already know
what it does :-)

[balazs.kilvady, 2015-09-17 18:30:17]

On 2015/09/17 18:07:24, paul.l... wrote:
> LGTM. Thanks, really nice perf improvement!
> 
> One nit, I built with that change, and it seems fine.
> 
> https://codereview.chromium.org/1356693002/diff/1/src/mips64/disasm-mips64.cc
> File src/mips64/disasm-mips64.cc (right):
> 
>
https://codereview.chromium.org/1356693002/diff/1/src/mips64/disasm-mips64.cc...
> src/mips64/disasm-mips64.cc:1831: switch
> (instr->InstructionType(Instruction::EXTRA)) {
> Can we do Instruction::TypeChecks::EXTRA here? That is self-explanatory,
whereas
> omitting the enum name makes this confusing (to me anyway, and I already know
> what it does :-)

Thanks for the quick LGTM. I will fix the nit and land it tomorrow if it
acceptable.

[balazs.kilvady, 2015-09-18 10:42:52]

https://codereview.chromium.org/1356693002/diff/1/src/mips64/disasm-mips64.cc
File src/mips64/disasm-mips64.cc (right):

https://codereview.chromium.org/1356693002/diff/1/src/mips64/disasm-mips64.cc...
src/mips64/disasm-mips64.cc:1831: switch
(instr->InstructionType(Instruction::EXTRA)) {
On 2015/09/17 18:07:24, paul.l... wrote:
> Can we do Instruction::TypeChecks::EXTRA here? That is self-explanatory,
whereas
> omitting the enum name makes this confusing (to me anyway, and I already know
> what it does :-)

Done.

[balazs.kilvady, 2015-09-18 10:43:44]

The CQ bit was checked by balazs.kilvady@imgtec.com

[balazs.kilvady, 2015-09-18 10:43:44]

The patchset sent to the CQ was uploaded after l-g-t-m from paul.lind@imgtec.com
Link to the patchset: https://codereview.chromium.org/1356693002/#ps20001
(title: "Fix nit.")

[commit-bot: I haz the power, 2015-09-18 10:43:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1356693002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1356693002/20001

[commit-bot: I haz the power, 2015-09-18 11:08:23]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-18 11:08:40]

Patchset 2 (id:??) landed as
https://crrev.com/b89eec39a18b1c2600bc1cebd38d4c5f1a7c2e61
Cr-Commit-Position: refs/heads/master@{#30824}