Re: [Boost-bugs] [Boost C++ Libraries] #8509: SSE/AVX optimization and C++11 support

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #8509: SSE/AVX optimization and C++11 support
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-09-26 07:12:35

#8509: SSE/AVX optimization and C++11 support
-------------------------------+--------------------------
  Reporter:  andysem           |      Owner:  atompkins
      Type:  Patches           |     Status:  closed
 Milestone:  To Be Determined  |  Component:  uuid
   Version:  Boost 1.53.0      |   Severity:  Optimization
Resolution:  fixed             |   Keywords:
-------------------------------+--------------------------

Comment (by hajokirchhoff <mailinglists@…>):

 I'll try to reproduce it. I am using /O2 and "no whole program
 optimization". The problem is that the optimizer will usually produce code
 like this:
 {{{
 000000013F2110DA  movdqu      xmm0,xmmword ptr [rsp+48h]
 000000013F2110E0  movdqu      xmm1,xmmword ptr [rax+10h]
 000000013F2110E5  pcmpeqd     xmm1,xmm0
 000000013F2110E9  pmovmskb    eax,xmm1
 000000013F2110ED  cmp         eax,0FFFFh
 }}}
 It's only when the register xmm0 is already assigned a different variable
 that the optimizer will then produce the problematic opcode. I need to
 find a way to reproduce that specific scenario. The bug manifests itself
 in a 29MB binary of an application I am currently porting from VS2008 to
 VS2013 (and boost 1.55 to boost 1.56).

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/8509#comment:5>
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