[cmake] Remove i686 target that is duplicate to i386

Authored by mgorny on Aug 27 2017, 12:44 AM.


[cmake] Remove i686 target that is duplicate to i386

Remove the explicit i686 target that is completely duplicate to
the i386 target, with the latter being used more commonly.

  1. The runtime built for i686 will be identical to the one built for


  1. Supporting both -i386 and -i686 suffixes causes unnecessary confusion

on the clang end which has to expect either of them.

  1. The checks are based on wrong assumption that i686 is defined for

all newer x86 CPUs. In fact, it is only declared when -march=i686 is
explicitly used. It is not available when a more specific (or newer)
-march is used.

Curious enough, if CFLAGS contain -march=i686, the runtime will be built
both for i386 and i686. For any other value, only i386 variant will be

Differential Revision: https://reviews.llvm.org/D26764

llvm-svn: 311842