[llvm] [NVPTX] cleanup & canonicalize `mov` (PR #129344)

[Artem Belevich via llvm-commits]

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@@ -1068,12 +1068,11 @@ define i16 @acq_rel_sys_i16(ptr %addr, i16 %cmp, i16 %new) {
 ; SM30-NEXT:  // %bb.2: // %partword.cmpxchg.failure
 ; SM30-NEXT:    // in Loop: Header=BB8_1 Depth=1
 ; SM30-NEXT:    and.b32 %r8, %r7, %r2;
-; SM30-NEXT:    setp.ne.s32 %p2, %r19, %r8;
-; SM30-NEXT:    mov.u32 %r19, %r8;
-; SM30-NEXT:    @%p2 bra $L__BB8_1;
-; SM30-NEXT:  $L__BB8_3: // %partword.cmpxchg.end
-; SM30-NEXT:    membar.sys;
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Artem-B wrote:

Where did all the membar/fence instructions go? Is that expected?

https://github.com/llvm/llvm-project/pull/129344