1. If a double FP constant must be put into a constant pool, but it can be

1. If a double FP constant must be put into a constant pool, but it can be
   precisely represented as a float, put it into the constant pool as a
   float.
2. Use the cbw/cwd/cdq instructions instead of an explicit SAR for signed
   division.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19291 91177308-0d34-0410-b5e6-96231b3b80d8