Supported CPUs

Boost no longer supports the 80386 target CPU, the minimum x86 32-bit target is i486. The 80386 target was not properly supported by Boost.SmartPtr and Boost.Atomic (as well as the libraries that used them internally) even before this release. Some Boost libraries may have higher requirements on the minimum target CPU (like Boost.Log for example), see the respective library documentation for details.

Also by default, when building Boost for x86 32-bit targets it will compile for i686 (Pentium Pro) and later CPUs. This can be changed by specifying the instruction-set property in b2 or bjam command line, for example:

b2 variant=release architecture=x86 instruction-set=i486 stage

Possible values for the instruction-set are:

Target for the host CPU: native

Generic x86 CPUs: i486 , i586 , i686

Intel CPUs: pentium , pentium-mmx , pentiumpro , pentium2 , pentium3 , pentium3m , pentium-m , pentium4 , pentium4m , prescott , nocona , core2 , corei7 , corei7-avx , core-avx-i , conroe , conroe-xe , conroe-l , allendale , merom , merom-xe , kentsfield , kentsfield-xe , penryn , wolfdale , yorksfield , nehalem , sandy-bridge , ivy-bridge , haswell , atom

AMD CPUs: k6 , k6-2 , k6-3 , athlon , athlon-tbird , athlon-4 , athlon-xp , athlon-mp , k8 , opteron , athlon64 , athlon-fx , k8-sse3 , opteron-sse3 , athlon64-sse3 , amdfam10 , barcelona , bdver1 , bdver2 , bdver3 , btver1 , btver2

VIA CPUs: c3 , c3-2

IDT CPUs: winchip-c6 , winchip2

Note that not all these values may be supported by a particular compiler.