[PATCH] [AArch64] Refines the Cortex-A57 Machine Model

[Jiangning Liu]

Hi Dave,

The new version shows good potential, I think.

	spec.cpu2000.ref.300_twolf     -4.44%
	spec.cpu2000.ref.175_vpr        -2.58%
	spec.cpu2000.ref.255_vortex   -1.39%
	spec.cpu2000.ref.254_gap       1.40%
	spec.cpu2000.ref.183_equake  2.88%

Thanks,
-Jiangning

http://reviews.llvm.org/D5372