llvm/llvm/test/CodeGen/ARM/misched-prevent-erase-history-of-subunits.mir

# RUN: llc -mtriple=thumbv7em-unknown-unknown -mcpu=cortex-m7 \
# RUN:    -sched-model-force-enable-intervals \
# RUN:    %s -run-pass=machine-scheduler -o - 2>&1 -debug | FileCheck %s
# REQUIRES: arm-registered-target, asserts

# NOTE: Without the bugfix introduced in this code, the test below
# would raise the assertion "A resource is being overwritten" from
# `ResourceSegments::add` when enforcing the use of resource intervals
# via -sched-model-force-enable-intervals with the scheduling model
# for -mcpu=cortex-m7.

# CHECK-LABEL: *** Final schedule for %bb.0 ***
# CHECK: SU(0):   %0:dpr = COPY $d0
# CHECK: SU(1):   %1:dpr = VABSD %0:dpr, 14, $noreg
# CHECK: SU(2):   %2:dpr = VLDRD %const.0, 0, 14, $noreg :: (load (s64) from constant-pool)
# CHECK: SU(4):   %3:rgpr = t2MOVi 0, 14, $noreg, $noreg
# CHECK: SU(3):   VCMPD %1:dpr, %2:dpr, 14, $noreg, implicit-def $fpscr_nzcv
# CHECK: SU(5):   $r0 = COPY %3:rgpr
---
name:            test
tracksRegLiveness: true
constants:
  - id:              0
    value:           double 0x7FF0000000000000
body:             |
  bb.0:
    liveins: $d0

    %0:dpr = COPY $d0
    %1:dpr = VABSD %0, 14 /* CC::al */, $noreg
    %2:dpr = VLDRD %const.0, 0, 14 /* CC::al */, $noreg :: (load (s64) from constant-pool)
    VCMPD %1, %2, 14 /* CC::al */, $noreg, implicit-def $fpscr_nzcv
    %4:rgpr = t2MOVi 0, 14 /* CC::al */, $noreg, $noreg
    $r0 = COPY %4
    tBX_RET 14 /* CC::al */, $noreg, implicit killed $r0

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