llvm/llvm/test/CodeGen/Hexagon/regalloc-coal-fullreg-undef.mir

# RUN: llc -march=hexagon -run-pass=register-coalescer -o - %s | FileCheck %s

# Make sure that the coalescer does not create a full definition with
# an undef flag on the destination. This used to happen when rematerializing
# a double register and coalescing a smaller reg into a subreg of it.

# CHECK-NOT: undef %[0-9]+:doubleregs = A2_tfrpi 1

---
name: fred
tracksRegLiveness: true
body: |

  bb.0:
    successors: %bb.1(0x80000000); %bb.1(200.00%)

    %18:doubleregs = A2_tfrpi 1
    %23:intregs = IMPLICIT_DEF
    %24:doubleregs = IMPLICIT_DEF

  bb.1:
    successors: %bb.1(0x80000000); %bb.1(200.00%)

    %1:doubleregs = COPY %24:doubleregs
    %0:intregs = COPY %23:intregs
    %13:intregs = COPY %18.isub_lo:doubleregs
    %13:intregs = S2_asl_i_r_or %13:intregs, %0:intregs, 1
    %15:intregs = S2_extractu %0:intregs, 1, 31
    undef %17.isub_lo:doubleregs = COPY %13:intregs
    %17.isub_hi:doubleregs = COPY %15:intregs
    %2:doubleregs = A2_addp %17:doubleregs, %1:doubleregs
    %3:intregs = A2_addi %0:intregs, -1
    %23:intregs = COPY %3:intregs
    %24:doubleregs = COPY %2:doubleregs
    J2_jump %bb.1, implicit-def dead $pc

...