[PATCH] D109963: [AArch64] Split bitmask immediate of bitwise AND operation

Tue Sep 21 06:46:18 PDT 2021

jaykang10 added inline comments.

================
Comment at: llvm/test/CodeGen/AArch64/arm64-ccmp.ll:374
+; CHECK-NEXT:    and x8, x8, #0x3f
+; CHECK-NEXT:    and x8, x8, #0xffffffffffffffdf
 ; CHECK-NEXT:    ccmp x8, #0, #4, ls
----------------
jaykang10 wrote:
> jaykang10 wrote:
> > efriedma wrote:
> > > This looks wrong?
> > um... I think it is correct.
> > ```
> > mov x9, #31
> > movk x9, #48, lsl #32
> > ==>
> > (48 << 32) | 31 = 31
> > ```
> > ```
> > and x8, x8, #0x3f
> > and x8, x8, #0xffffffffffffffdf
> > ==>
> > 0xffffffffffffffdf & 0x3f = 31
> > ```
> Sorry, I made a mistake. x register is 64 bit... Let me fix it.
I have fixed it with new patch.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D109963/new/

https://reviews.llvm.org/D109963