[AArch64] Add some uxtw peephole tests. NFC

Author: davemgreen

llvm/test/CodeGen/AArch64/peephole-sxtw.mir

@@ -95,3 +95,57 @@ body:             |
     B %bb.2
 
 ...
+---
+name: removeUxtw
+tracksRegLiveness: true
+body: |
+  bb.0.entry:
+    liveins: $x0
+    ; CHECK-LABEL: name: removeUxtw
+    ; CHECK: liveins: $x0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:gpr32 = COPY [[COPY]].sub_32
+    ; CHECK-NEXT: [[ORRWrr:%[0-9]+]]:gpr32 = ORRWrr $wzr, [[COPY1]]
+    ; CHECK-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gpr64 = SUBREG_TO_REG 0, [[ORRWrr]], %subreg.sub_32
+    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:gpr32sp = COPY [[SUBREG_TO_REG]].sub_32
+    ; CHECK-NEXT: [[ADDWri:%[0-9]+]]:gpr32sp = ADDWri [[COPY2]], 1, 0
+    ; CHECK-NEXT: $w0 = COPY [[ADDWri]]
+    ; CHECK-NEXT: RET_ReallyLR implicit $w0
+    %0:gpr64 = COPY $x0
+    %1:gpr32 = COPY %0.sub_32
+    %2:gpr32 = ORRWrr $wzr, %1
+    %3:gpr64 = SUBREG_TO_REG 0, %2, %subreg.sub_32
+    %4:gpr32sp = COPY %3.sub_32
+    %5:gpr32sp = ADDWri %4, 1, 0
+    $w0 = COPY %5
+    RET_ReallyLR implicit $w0
+...
+---
+name: extraUseOrr
+tracksRegLiveness: true
+body: |
+  bb.0.entry:
+    liveins: $x0
+    ; CHECK-LABEL: name: extraUseOrr
+    ; CHECK: liveins: $x0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:gpr32 = COPY [[COPY]].sub_32
+    ; CHECK-NEXT: [[ORRWrr:%[0-9]+]]:gpr32 = ORRWrr $wzr, [[COPY1]]
+    ; CHECK-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gpr64 = SUBREG_TO_REG 0, [[ORRWrr]], %subreg.sub_32
+    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:gpr32sp = COPY [[SUBREG_TO_REG]].sub_32
+    ; CHECK-NEXT: [[ADDWri:%[0-9]+]]:gpr32sp = ADDWri [[COPY2]], 1, 0
+    ; CHECK-NEXT: $w0 = COPY [[ADDWri]]
+    ; CHECK-NEXT: $w1 = COPY [[ORRWrr]]
+    ; CHECK-NEXT: RET_ReallyLR implicit $w0
+    %0:gpr64 = COPY $x0
+    %1:gpr32 = COPY %0.sub_32
+    %2:gpr32 = ORRWrr $wzr, %1
+    %3:gpr64 = SUBREG_TO_REG 0, %2, %subreg.sub_32
+    %4:gpr32sp = COPY %3.sub_32
+    %5:gpr32sp = ADDWri %4, 1, 0
+    $w0 = COPY %5
+    $w1 = COPY %2
+    RET_ReallyLR implicit $w0
+...