[ARM] Introduce test for PR121565 (NFC)

Author: antoniofrighetto

llvm/test/CodeGen/ARM/sink-store-pre-load-dependency.mir

@@ -0,0 +1,42 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -o - %s -mtriple=armv7-- -run-pass=machine-sink | FileCheck %s
+
+name: sink-store-load-dep
+tracksRegLiveness: true
+stack:
+  - { id: 0, type: default, size: 8, alignment: 8 }
+body: |
+  bb.0:
+    ; FIXME: This is a miscompilation.
+    ; CHECK-LABEL: name: sink-store-load-dep
+    ; CHECK:       bb.0:
+    ; CHECK:         [[LDRi12_:%[0-9]+]]:gpr = LDRi12 %stack.0, 0, 14 /* CC::al */, $noreg :: (load (s32))
+    ; CHECK-NEXT:    [[MOVi:%[0-9]+]]:gpr = MOVi 55296, 14 /* CC::al */, $noreg, $noreg
+    ; CHECK-NEXT:    [[MOVi1:%[0-9]+]]:gpr = MOVi 0, 14 /* CC::al */, $noreg, $noreg
+    ; CHECK-NEXT:    early-clobber %5:gpr = STRH_PRE [[MOVi:%[0-9]+]], [[LDRi12_:%[0-9]+]], [[MOVi1:%[0-9]+]], 0, 14 /* CC::al */, $noreg
+    ; CHECK-NEXT:    [[SUBri:%.*]]:gpr = SUBri [[LDRi12_:%[0-9]+]], 0, 14 /* CC::al */, $noreg, $noreg
+    ; CHECK:       bb.2:
+    ; CHECK-NEXT:    [[ADDri1:%[0-9]+]]:gpr = ADDri [[LDRi12_:%[0-9]+]], 0, 14 /* CC::al */, $noreg, $noreg
+    ; CHECK-NEXT:    [[LDRH:%[0-9]+]]:gpr = LDRH [[ADDri1:%[0-9]+]], $noreg, 0, 14 /* CC::al */, $noreg :: (load (s16))
+    ; CHECK-NEXT:    [[MOVi2:%[0-9]+]]:gpr = MOVi [[LDRH:%[0-9]+]], 14 /* CC::al */, $noreg, $noreg
+    %0:gpr = LDRi12 %stack.0, 0, 14, $noreg :: (load (s32))
+    %1:gpr = MOVi 55296, 14, $noreg, $noreg
+    %2:gpr = ADDri %0:gpr, 0, 14, $noreg, $noreg
+    %3:gpr = LDRH killed %2:gpr, $noreg, 0, 14, $noreg :: (load (s16))
+    %4:gpr = MOVi 0, 14, $noreg, $noreg
+    early-clobber %5:gpr = STRH_PRE %1:gpr, %0:gpr, %4:gpr, 0, 14, $noreg
+    %6:gpr = SUBri killed %0:gpr, 0, 14, $noreg, $noreg
+    CMPri %6:gpr, 0, 14, $noreg, implicit-def $cpsr
+    Bcc %bb.2, 3, $cpsr
+    B %bb.1
+
+  bb.1:
+    %8:gpr = MOVi 0, 14, $noreg, $noreg
+    $r0 = COPY %8:gpr
+    BX_RET 14, $noreg, implicit $r0
+
+  bb.2:
+    %9:gpr = MOVi %3:gpr, 14, $noreg, $noreg
+    $r0 = COPY %9:gpr
+    BX_RET 14, $noreg, implicit $r0
+...