[AArch64] Add PreTest for optimizing MOV to ORR

Author: ParkHanbum

llvm/test/CodeGen/AArch64/movimm-expand-ldst.mir

@@ -0,0 +1,35 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 4
+# RUN: llc -mtriple=aarch64 -verify-machineinstrs -run-pass=aarch64-expand-pseudo -run-pass=aarch64-ldst-opt -debug-only=aarch64-ldst-opt %s -o - | FileCheck %s
+---
+name: test_fold_repeating_constant_load
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $x0
+    ; CHECK-LABEL: name: test_fold_repeating_constant_load
+    ; CHECK: liveins: $x0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: renamable $x0 = MOVZXi 49370, 0
+    ; CHECK-NEXT: renamable $x0 = MOVKXi $x0, 320, 16
+    ; CHECK-NEXT: renamable $x0 = MOVKXi $x0, 49370, 32
+    ; CHECK-NEXT: renamable $x0 = MOVKXi $x0, 320, 48
+    ; CHECK-NEXT: RET undef $lr, implicit $x0
+    renamable $x0 = MOVi64imm 90284035103834330
+    RET_ReallyLR implicit $x0
+...
+---
+name: test_fold_repeating_constant_load_neg
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $x0
+    ; CHECK-LABEL: name: test_fold_repeating_constant_load_neg
+    ; CHECK: liveins: $x0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: renamable $x0 = MOVZXi 320, 0
+    ; CHECK-NEXT: renamable $x0 = MOVKXi $x0, 49370, 16
+    ; CHECK-NEXT: renamable $x0 = MOVKXi $x0, 320, 32
+    ; CHECK-NEXT: renamable $x0 = MOVKXi $x0, 49370, 48
+    ; CHECK-NEXT: RET undef $lr, implicit $x0
+    renamable $x0 = MOVi64imm -4550323095879417536
+    RET_ReallyLR implicit $x0