added a runtime switch to use 32-bit indices in for_each when the data range permits using difference_type for loop indices is considerably more expensive on 64-bit platforms and almost never necessary
added a runtime switch to use 32-bit indices in for_each when the data range permits
using difference_type for loop indices is considerably more expensive on 64-bit platforms and almost never necessary

--HG--
extra : convert_revision : svn%3A83215879-3e5a-4751-8c9d-778f44bb06a5/trunk%40611

mohamed-ali/thrust,thvasilo/thrust,egaburov/thrust,thrust/thrust,jaredhoberock/thrust,GrimDerp/thrust,Ricardo666666/thrust,xiongzhanblake/thrust,thrust/thrust,raygit/thrust,sarvex/thrust,xiongzhanblake/thrust_src,xiongzhanblake/thrust,jaredhoberock/thrust,zeryx/thrust,GrimDerp/thrust,jaredhoberock/thrust,andrewcorrigan/thrust-multi-permutation-iterator,sdalton1/thrust,arnabgho/thrust,jaredhoberock/thrust,marksantos/thrust,egaburov/thrust,mohamed-ali/thrust,dachziegel/thrust,raygit/thrust,zhenglaizhang/thrust,GrimDerp/thrust,zeryx/thrust,Ricardo666666/thrust,jaredhoberock/thrust,xiongzhanblake/thrust_src,thrust/thrust,thrust/thrust,raygit/thrust,marksantos/thrust,arnabgho/thrust,marksantos/thrust,sdalton1/thrust,xiongzhanblake/thrust,zhenglaizhang/thrust,xiongzhanblake/thrust_src,dachziegel/thrust,egaburov/thrust,zeryx/thrust,andrewcorrigan/thrust-multi-permutation-iterator,sarvex/thrust,dachziegel/thrust,thvasilo/thrust,andrewcorrigan/thrust-multi-permutation-iterator,mohamed-ali/thrust,arnabgho/thrust,Ricardo666666/thrust,sdalton1/thrust,thvasilo/thrust,zhenglaizhang/thrust,thrust/thrust,sarvex/thrust