test/CodeGen/Hexagon/two-addr-tied-subregs.mir

# RUN: llc -march hexagon -run-pass livevars -run-pass twoaddressinstruction  -verify-machineinstrs -o - %s | FileCheck %s


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---
name:            test1
tracksRegLiveness: true
body:             |
  bb.0.entry:
    liveins: $d0

    %0:doubleregs = COPY killed $d0
    %1:intregs = S2_lsr_i_r_acc %0.isub_lo, %0.isub_lo, 16

...

# Verify that both uses if %0.isub_lo are replaced here.
# (we used to get %1:intregs = S2_lsr_i_r_acc %1, %1.isub_lo, 16)
#
# CHECK-LABEL: name:            test1
# CHECK:  bb.0.entry:
# CHECK:      %0:doubleregs = COPY killed $d0
# CHECK-NEXT: %1:intregs = COPY killed %0.isub_lo
# CHECK-NEXT: %1:intregs = S2_lsr_i_r_acc %1, %1, 16


###############################################################################

---
name:            test2
tracksRegLiveness: true
body:             |
  bb.0.entry:
    liveins: $d0

    %0:doubleregs = COPY killed $d0
    %1:intregs = S2_lsr_i_r_acc %0.isub_lo, %0.isub_hi, 16

...

# Verify that the use of %0.isub_hi isn't replaced here.
# (we used to get %1:intregs = S2_lsr_i_r_acc %1, %1.isub_hi, 16)
#
# We also used to get an incorrect "killed" for %0 in the second COPY.
# So we verify that we do not get machine verifier complaints here.
# An improvement could be to get a "killed" attribute on the last
# use of %0.isub_hi, but we do not need it for the IR to be valid.
#
# CHECK-LABEL: name:            test2
# CHECK:  bb.0.entry:
# CHECK:      %0:doubleregs = COPY killed $d0
# CHECK-NEXT: %1:intregs = COPY %0.isub_lo
# CHECK-NEXT: %1:intregs = S2_lsr_i_r_acc %1, %0.isub_hi, 16

###############################################################################