llvm/test/CodeGen/RISCV/MachineSink-implicit-x0.mir

# RUN: llc -mtriple=riscv32 %s -run-pass=machine-sink -o - | FileCheck %s
# RUN: llc -mtriple=riscv32 %s -passes=machine-sink -o - | FileCheck %s

# Verify that sinking of '%20:gpr = LUI 1, implicit $x0' is not inhibited by
# the implicit use of '$x0'.
# Register '$x0' is a 'MRI->isConstantPhysReg()' on RISCV and such uses should
# not inhibit sinking transformation even though they are livein to the block
# they are to be sunk into (inhibit under such conditions should only happen
# for defines).

---
name:            f
tracksRegLiveness: true
body:             |
  ; CHECK-LABEL: bb.1:
  ; CHECK-NEXT:   successors: %bb.3(0x80000000)
  ; CHECK-NEXT:   liveins: $x0
  ; CHECK-NEXT: {{  $}}
  ; CHECK-NEXT:   [[LUI:%[0-9]+]]:gpr = LUI 1, implicit $x0
  bb.0:
    liveins: $x10
    %10:gpr = COPY $x10
    %20:gpr = LUI 1, implicit $x0
    BEQ %10, %10, %bb.2
    PseudoBR %bb.1
  bb.1:
    liveins: $x0
    %30:gpr = ADDI %20, 5
    PseudoBR %bb.3
  bb.2:
    PseudoBR %bb.3
  bb.3:
    PseudoRET
...