Provide add and sub for IEEE quad. From GuanHong Liu.

Differential Revision: http://reviews.llvm.org/D2798


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@211312 91177308-0d34-0410-b5e6-96231b3b80d8
Provide mul for IEEE quad. From GuanHong Liu.

Differential Revision: http://reviews.llvm.org/D2799


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@211313 91177308-0d34-0410-b5e6-96231b3b80d8