Jim Apple has posted comments on this change.

Change subject: Allow compiler to use SSE3 and SSSE3 instructions.
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Patch Set 1:

> Compiling with SSE enabled, I don't feel confident that we'll
 > actually get to the CpuInfo::VerifyCpuRequirements() check before
 > executing an SSE3 instruction. Is there some way we can test this
 > or compile the appropriate functions/module without enabling SSE3.

I doubt that we can manually prevent this instruction from showing up before we 
check for it. Global variable constructors are permitted to run before main() 
starts.

We can ask GCC to run the check as soon as possible, but other functions may 
make the same request and be competing:

https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Attributes.html#C_002b_002b-Attributes

It would be hard to compile certain modules without -msse3 and -mssse3, not 
only due to the cmake surgery, but also because we don't know which modules 
will have globals that could run before the check.

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Gerrit-MessageType: comment
Gerrit-Change-Id: Ib045e00b5aa71cc6ef16dbda160bfdc7b765158a
Gerrit-PatchSet: 1
Gerrit-Project: Impala
Gerrit-Branch: cdh5-trunk
Gerrit-Owner: Jim Apple <[email protected]>
Gerrit-Reviewer: Dan Hecht <[email protected]>
Gerrit-Reviewer: Jim Apple <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
Gerrit-HasComments: No

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