Commit 22a64d4a authored by Jessica Paquette's avatar Jessica Paquette
Browse files

[MachineOutliner][AArch64] Ensure LR is live-in when inserting reg-save calls 

Similar to other code which handles creating the function frame.

If LR isn't live-in to the block that we're inserting the call into, we'll get
a MachineVerifier error.
parent eae44c8a

llvm/lib/Target/AArch64/AArch64InstrInfo.cpp

+5 −1
Original line number Diff line number Diff line
@@ -7350,7 +7350,11 @@ MachineBasicBlock::iterator AArch64InstrInfo::insertOutlinedCall( 
    unsigned Reg = findRegisterToSaveLRTo(C);

    assert(Reg != 0 && "No callee-saved register available?");



    // Save and restore LR from that register.

    // LR has to be a live in so that we can save it.

    if (!MBB.isLiveIn(AArch64::LR))

      MBB.addLiveIn(AArch64::LR);



    // Save and restore LR from Reg.

    Save = BuildMI(MF, DebugLoc(), get(AArch64::ORRXrs), Reg)

               .addReg(AArch64::XZR)

               .addReg(AArch64::LR)

llvm/test/CodeGen/AArch64/machine-outliner-create-lr-livein.mir

0 → 100644
+50 −0
Original line number Diff line number Diff line 
# RUN: llc -mtriple=aarch64-apple-darwin -run-pass=machine-outliner -verify-machineinstrs %s -o - | FileCheck %s

# In bb.4,  we save + restore LR using a register. We need LR to be live-in to

# the block to prevent MachineVerifier errors.



name:            lr_not_live_in

tracksRegLiveness: true

fixedStack:

machineFunctionInfo:

  hasRedZone:      false

body:             |

  bb.0:

    $x9 = ORRXri $xzr, 1

  bb.1:

    liveins: $w9

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 2

  bb.2:

    liveins: $w9

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 2

  bb.3:

    liveins: $w9

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 2

  bb.4:

    liveins: $w9

    ; CHECK-LABEL: bb.4

    ; CHECK: liveins: $w9, $lr

    ; CHECK: BL

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 1

    $w9 = ORRWri $wzr, 2

  bb.5:

    liveins: $w9, $lr

    RET undef $lr