llvm/llvm/test/CodeGen/Hexagon/ifcvt-live-subreg.mir

# RUN: llc -march=hexagon -run-pass if-converter -o - %s | FileCheck %s
# Check that an implicit use is generated for a predicated instruction
# when a subregister of the redefined register is live.

# CHECK-LABEL: name: foo

# Verify the predicated block:
# CHECK-LABEL: bb.0:
# CHECK: liveins: $r0, $r1, $p0, $d8
# CHECK: $d8 = A2_combinew killed $r0, killed $r1
# CHECK: $d8 = L2_ploadrdf_io $p0, $r29, 0, implicit killed $d8
# CHECK: J2_jumprf killed $p0, $r31, implicit-def $pc, implicit-def $pc, implicit $d8

--- |
  define void @foo() {
    ret void
  }
...


---
name:            foo
alignment:       16
tracksRegLiveness: true
liveins:
  - { reg: '$r0' }
  - { reg: '$r1' }
  - { reg: '$p0' }
  - { reg: '$d8' }
body:             |
  bb.0:
    successors: %bb.1, %bb.2
    liveins: $r0, $r1, $p0, $d8
    $d8 = A2_combinew killed $r0, killed $r1
    J2_jumpf killed $p0, %bb.2, implicit-def $pc

  bb.1:
    liveins: $r17
    $r0 = A2_tfrsi 0
    $r1 = A2_tfrsi 0
    A2_nop ; non-predicable
    J2_jumpr killed $r31, implicit-def dead $pc, implicit killed $d0

  bb.2:
    ; Predicate this block.
    $d8 = L2_loadrd_io $r29, 0
    J2_jumpr killed $r31, implicit-def dead $pc, implicit killed $d8

...