Credits should go to Wolf0. This optimization is done based on his optimized miner https://github.com/wolf9466/wolf-m7m-cpuminer, by further abstraction of the gmp computation according to his prior work, as well as a few other improvements have been carried out. Anyone who can achieve further optimization and boost the speed, please release the code accordingly.
The above miner is slightly different from that on which prior windows compilation is based; so the speed might be different (not much expected). I will get another set of compilation for Windows.
The following is the miner with "-e" option in order to adjust CPU usage.
I made a test of Wolf's miner on Windows 7 64 My CPU is i5 i7 windows build give me best performance of windows builds linux virtual machine on same PC give me another 10%