Index: llvm/lib/CodeGen/TypePromotion.cpp
===================================================================
--- llvm/lib/CodeGen/TypePromotion.cpp
+++ llvm/lib/CodeGen/TypePromotion.cpp
@@ -868,6 +868,8 @@
       continue;
     }
 
+    if (isa<PHINode>(V))
+      continue;
     if (Sinks.count(cast<Instruction>(V)))
       continue;
     ++ToPromote;
Index: llvm/test/CodeGen/AArch64/atomic-ops.ll
===================================================================
--- llvm/test/CodeGen/AArch64/atomic-ops.ll
+++ llvm/test/CodeGen/AArch64/atomic-ops.ll
@@ -979,24 +979,23 @@
 ; INLINE_ATOMICS-LABEL: test_atomic_cmpxchg_i8:
 ; INLINE_ATOMICS:       // %bb.0:
 ; INLINE_ATOMICS-NEXT:    // kill: def $w1 killed $w1 def $x1
-; INLINE_ATOMICS-NEXT:    and w8, w0, #0xff
 ; INLINE_ATOMICS-NEXT:    adrp x9, var8
 ; INLINE_ATOMICS-NEXT:    add x9, x9, :lo12:var8
 ; INLINE_ATOMICS-NEXT:  .LBB40_1: // %cmpxchg.start
 ; INLINE_ATOMICS-NEXT:    // =>This Inner Loop Header: Depth=1
-; INLINE_ATOMICS-NEXT:    ldaxrb w0, [x9]
-; INLINE_ATOMICS-NEXT:    cmp w0, w8
+; INLINE_ATOMICS-NEXT:    ldaxrb w8, [x9]
+; INLINE_ATOMICS-NEXT:    cmp w8, w0, uxtb
 ; INLINE_ATOMICS-NEXT:    b.ne .LBB40_4
 ; INLINE_ATOMICS-NEXT:  // %bb.2: // %cmpxchg.trystore
 ; INLINE_ATOMICS-NEXT:    // in Loop: Header=BB40_1 Depth=1
 ; INLINE_ATOMICS-NEXT:    stxrb w10, w1, [x9]
 ; INLINE_ATOMICS-NEXT:    cbnz w10, .LBB40_1
 ; INLINE_ATOMICS-NEXT:  // %bb.3: // %cmpxchg.end
-; INLINE_ATOMICS-NEXT:    // kill: def $w0 killed $w0 killed $x0
+; INLINE_ATOMICS-NEXT:    mov w0, w8
 ; INLINE_ATOMICS-NEXT:    ret
 ; INLINE_ATOMICS-NEXT:  .LBB40_4: // %cmpxchg.nostore
 ; INLINE_ATOMICS-NEXT:    clrex
-; INLINE_ATOMICS-NEXT:    // kill: def $w0 killed $w0 killed $x0
+; INLINE_ATOMICS-NEXT:    mov w0, w8
 ; INLINE_ATOMICS-NEXT:    ret
 ;
 ; OUTLINE_ATOMICS-LABEL: test_atomic_cmpxchg_i8:
@@ -1016,24 +1015,23 @@
 ; INLINE_ATOMICS-LABEL: test_atomic_cmpxchg_i16:
 ; INLINE_ATOMICS:       // %bb.0:
 ; INLINE_ATOMICS-NEXT:    // kill: def $w1 killed $w1 def $x1
-; INLINE_ATOMICS-NEXT:    and w8, w0, #0xffff
 ; INLINE_ATOMICS-NEXT:    adrp x9, var16
 ; INLINE_ATOMICS-NEXT:    add x9, x9, :lo12:var16
 ; INLINE_ATOMICS-NEXT:  .LBB41_1: // %cmpxchg.start
 ; INLINE_ATOMICS-NEXT:    // =>This Inner Loop Header: Depth=1
-; INLINE_ATOMICS-NEXT:    ldaxrh w0, [x9]
-; INLINE_ATOMICS-NEXT:    cmp w0, w8
+; INLINE_ATOMICS-NEXT:    ldaxrh w8, [x9]
+; INLINE_ATOMICS-NEXT:    cmp w8, w0, uxth
 ; INLINE_ATOMICS-NEXT:    b.ne .LBB41_4
 ; INLINE_ATOMICS-NEXT:  // %bb.2: // %cmpxchg.trystore
 ; INLINE_ATOMICS-NEXT:    // in Loop: Header=BB41_1 Depth=1
 ; INLINE_ATOMICS-NEXT:    stlxrh w10, w1, [x9]
 ; INLINE_ATOMICS-NEXT:    cbnz w10, .LBB41_1
 ; INLINE_ATOMICS-NEXT:  // %bb.3: // %cmpxchg.end
-; INLINE_ATOMICS-NEXT:    // kill: def $w0 killed $w0 killed $x0
+; INLINE_ATOMICS-NEXT:    mov w0, w8
 ; INLINE_ATOMICS-NEXT:    ret
 ; INLINE_ATOMICS-NEXT:  .LBB41_4: // %cmpxchg.nostore
 ; INLINE_ATOMICS-NEXT:    clrex
-; INLINE_ATOMICS-NEXT:    // kill: def $w0 killed $w0 killed $x0
+; INLINE_ATOMICS-NEXT:    mov w0, w8
 ; INLINE_ATOMICS-NEXT:    ret
 ;
 ; OUTLINE_ATOMICS-LABEL: test_atomic_cmpxchg_i16:
Index: llvm/test/CodeGen/AArch64/cmpxchg-idioms.ll
===================================================================
--- llvm/test/CodeGen/AArch64/cmpxchg-idioms.ll
+++ llvm/test/CodeGen/AArch64/cmpxchg-idioms.ll
@@ -52,17 +52,16 @@
 define i1 @test_return_bool(i8* %value, i8 %oldValue, i8 %newValue) {
 ; CHECK-LABEL: test_return_bool:
 ; CHECK:       ; %bb.0:
-; CHECK-NEXT:    and w8, w1, #0xff
 ; CHECK-NEXT:    ; kill: def $w2 killed $w2 def $x2
 ; CHECK-NEXT:  LBB1_1: ; %cmpxchg.start
 ; CHECK-NEXT:    ; =>This Inner Loop Header: Depth=1
-; CHECK-NEXT:    ldaxrb w9, [x0]
-; CHECK-NEXT:    cmp w9, w8
+; CHECK-NEXT:    ldaxrb w8, [x0]
+; CHECK-NEXT:    cmp w8, w1, uxtb
 ; CHECK-NEXT:    b.ne LBB1_4
 ; CHECK-NEXT:  ; %bb.2: ; %cmpxchg.trystore
 ; CHECK-NEXT:    ; in Loop: Header=BB1_1 Depth=1
-; CHECK-NEXT:    stlxrb w9, w2, [x0]
-; CHECK-NEXT:    cbnz w9, LBB1_1
+; CHECK-NEXT:    stlxrb w8, w2, [x0]
+; CHECK-NEXT:    cbnz w8, LBB1_1
 ; CHECK-NEXT:  ; %bb.3:
 ; CHECK-NEXT:    mov w8, #1
 ; CHECK-NEXT:    eor w0, w8, #0x1
Index: llvm/test/CodeGen/AArch64/typepromotion-cost.ll
===================================================================
--- llvm/test/CodeGen/AArch64/typepromotion-cost.ll
+++ llvm/test/CodeGen/AArch64/typepromotion-cost.ll
@@ -15,7 +15,6 @@
 ; CHECK-NEXT:  .LBB0_3:
 ; CHECK-NEXT:    mov w9, #1
 ; CHECK-NEXT:  .LBB0_4: // %lor.end.sink.split
-; CHECK-NEXT:    and w8, w8, #0xffff
 ; CHECK-NEXT:    cmp w8, w9
 ; CHECK-NEXT:    cset w0, eq
 ; CHECK-NEXT:    ret