Tim Armstrong has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/10243 )

Change subject: IMPALA-6882: prevent instr. hoist from CpuInfo::IsSupported()
......................................................................


Patch Set 2:

(2 comments)

http://gerrit.cloudera.org:8080/#/c/10243/2/be/src/util/bit-util-test.cc
File be/src/util/bit-util-test.cc:

http://gerrit.cloudera.org:8080/#/c/10243/2/be/src/util/bit-util-test.cc@314
PS2, Line 314:     __asm__ __volatile__("ud2" : "=a"(result): "mr"(arg): "cc");
> Were you able to demonstrate a crash with this? Can you use EXPECT_DEATH fr
It definitely crashes if the instruction is executed, it isn't hoisted out of 
the branch even without __volatile__. I wasn't able to find a valid instruction 
that crashed that gcc would hoist.


http://gerrit.cloudera.org:8080/#/c/10243/2/be/src/util/bit-util-test.cc@325
PS2, Line 325:   CpuInfo::TempDisable disable_sssse3(CpuInfo::SSSE3);
> CpuInfo flag duplicated in above. Might want to make this a parameter to Cp
Done



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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I9ec51bdfcb9455c93ff69827929a59fcccb81b80
Gerrit-Change-Number: 10243
Gerrit-PatchSet: 2
Gerrit-Owner: Tim Armstrong <[email protected]>
Gerrit-Reviewer: Jim Apple <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
Gerrit-Comment-Date: Tue, 01 May 2018 17:19:47 +0000
Gerrit-HasComments: Yes

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