diff --git a/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp b/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp index 4f66946ed89c..5283bb52ee47 100644 --- a/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp +++ b/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp @@ -26,6 +26,7 @@ #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/Statistic.h" #include "llvm/ADT/StringRef.h" +#include "llvm/CodeGen/LivePhysRegs.h" #include "llvm/CodeGen/MachineBasicBlock.h" #include "llvm/CodeGen/MachineConstantPool.h" #include "llvm/CodeGen/MachineFunction.h" @@ -357,9 +358,6 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &mf) { HasFarJump = false; bool GenerateTBB = isThumb2 || (isThumb1 && SynthesizeThumb1TBB); - // This pass invalidates liveness information when it splits basic blocks. - MF->getRegInfo().invalidateLiveness(); - // Renumber all of the machine basic blocks in the function, guaranteeing that // the numbers agree with the position of the block in the function. MF->RenumberBlocks(); @@ -880,6 +878,13 @@ void ARMConstantIslands::updateForInsertedWaterBlock(MachineBasicBlock *NewBB) { MachineBasicBlock *ARMConstantIslands::splitBlockBeforeInstr(MachineInstr *MI) { MachineBasicBlock *OrigBB = MI->getParent(); + // Collect liveness information at MI. + LivePhysRegs LRs(*MF->getSubtarget().getRegisterInfo()); + LRs.addLiveOuts(*OrigBB); + auto LivenessEnd = ++MachineBasicBlock::iterator(MI).getReverse(); + for (MachineInstr &LiveMI : make_range(OrigBB->rbegin(), LivenessEnd)) + LRs.stepBackward(LiveMI); + // Create a new MBB for the code after the OrigBB. MachineBasicBlock *NewBB = MF->CreateMachineBasicBlock(OrigBB->getBasicBlock()); @@ -908,6 +913,12 @@ MachineBasicBlock *ARMConstantIslands::splitBlockBeforeInstr(MachineInstr *MI) { // OrigBB branches to NewBB. OrigBB->addSuccessor(NewBB); + // Update live-in information in the new block. + MachineRegisterInfo &MRI = MF->getRegInfo(); + for (MCPhysReg L : LRs) + if (!MRI.isReserved(L)) + NewBB->addLiveIn(L); + // Update internal data structures to account for the newly inserted MBB. // This is almost the same as updateForInsertedWaterBlock, except that // the Water goes after OrigBB, not NewBB. @@ -2331,6 +2342,10 @@ adjustJTTargetBlockForward(MachineBasicBlock *BB, MachineBasicBlock *JTBB) { MachineFunction::iterator MBBI = ++JTBB->getIterator(); MF->insert(MBBI, NewBB); + // Copy live-in information to new block. + for (const MachineBasicBlock::RegisterMaskPair &RegMaskPair : BB->liveins()) + NewBB->addLiveIn(RegMaskPair); + // Add an unconditional branch from NewBB to BB. // There doesn't seem to be meaningful DebugInfo available; this doesn't // correspond directly to anything in the source. diff --git a/llvm/test/CodeGen/ARM/constant-island-movwt.mir b/llvm/test/CodeGen/ARM/constant-island-movwt.mir index f45013af36f1..12361c97c0db 100644 --- a/llvm/test/CodeGen/ARM/constant-island-movwt.mir +++ b/llvm/test/CodeGen/ARM/constant-island-movwt.mir @@ -898,5 +898,13 @@ body: | # CHECK-NEXT: CONSTPOOL_ENTRY 1, %const.0, 4 # CHECK-NEXT: {{^ $}} # CHECK-NEXT: bb.2.entry (align 1): +# CHECK-NEXT: liveins: $d13, $s27, $r10, $r9, $r8, $s26, $d12, $s25, $s24, +# CHECK-SAME: $d15, $s30, $s31, $d14, $s28, $s29, $lr, $r0, $d21, +# CHECK-SAME: $r3, $q10, $d20, $d17, $r2, $d25, $q11, $d22, $d23, +# CHECK-SAME: $r1, $q8, $d16, $s3, $q14, $d28, $d29, $d19, $s17, +# CHECK-SAME: $d8, $s16, $r6, $r7, $r4, $q12, $q9, $d18, $s0, $q15, +# CHECK-SAME: $d30, $d31, $r12, $s1, $d0, $d24, $s2, $d1, $q0, $s6, +# CHECK-SAME: $d3, $d2, $s4, $q1, $s7, $s5, $d9, $s18, $s19, $q4 +# CHECK-NEXT: {{^ $}} # CHECK-NEXT: $r5 = t2MOVi16 target-flags(arm-lo16) @.str.84, 14, $noreg # CHECK-NEXT: $r5 = t2MOVTi16 $r5, target-flags(arm-hi16) @.str.84, 14, $noreg