[PATCH] D16203: [AArch64] Add pass to remove redundant copy after RA

[Jun Bum Lim via llvm-commits]

junbuml added a comment.

By placing this pass before the control flow opt, we could remove basic blocks which contain only MOV zero. 
E.g., we convert :

    cbz     x8, BB1
    ldr     w8, [x8,#4]
    b       BB2 
  BB1:  
    mov     w8, wzr
  BB2:  
    cmp     w22, w8

into

    cbz     x8, BB1 
    ldr     w8, [x8,#4]
  BB1:
    cmp     w22, w8

This transformation happens in almost all spec2006 benchmarks.


http://reviews.llvm.org/D16203