Re: [Boost-bugs] [Boost C++ Libraries] #9243: Subopimal bitwise or (with bytes)

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #9243: Subopimal bitwise or (with bytes)
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-10-12 09:52:22

#9243: Subopimal bitwise or (with bytes)
-------------------------------+----------------------------
  Reporter:  psiha             |      Owner:  johnmaddock
      Type:  Bugs              |     Status:  new
 Milestone:  To Be Determined  |  Component:  multiprecision
   Version:  Boost 1.54.0      |   Severity:  Optimization
Resolution:                    |   Keywords:
-------------------------------+----------------------------
Description changed by psiha:

Old description:

> I'd expect oring with a byte (or any integral builtin type smaller or
> equal in size to a static, unchecked, unsigned cpp_int) to produce a
> single instruction, yet it evaluates to a call to a fairly fat
> function...

New description:

 I'd expect oring with a byte (or any integral builtin type smaller or
 equal in size to a static, unchecked, unsigned cpp_int) to produce a
 single instruction, yet it evaluates to a call to a fairly fat function...

 ps. I'm doing
 number<> big_int;
 unsigned char const * p_data;
 while () { big_int |= *p_data++; big_int <<= 8; }

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Ticket URL: <https://svn.boost.org/trac/boost/ticket/9243#comment:1>
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