Re: [boost] [config] RFC PR 82

Subject: Re: [boost] [config] RFC PR 82
From: Joel FALCOU (joel.falcou_at_[hidden])
Date: 2015-12-02 08:39:32

On 02/12/2015 13:11, Andrey Semashev wrote:
> I see. I tried this locally with gcc and it succeeded, but apparently I
> used bitwise_cast in a context that allowed runtime execution, although
> the compiled code was still using a constant. In a purely constant
> expression it indeed fails to compile. Good to know.

boost::simd::bitwise_cast do uese memcpy. Be aware that sme cmpielrs 
liek ICC are extremely OCD about aliasign and  generate bogus code in 
those UB. We tried to removed all those tricks in Boost.SIMD in favor of 
well defined behavior. We didn't encountered much issues in terms of 
performances.

BUT we do have a special code for MSVC to use devious code instead.

My 2 cts.