From d2a1bee2d44d9293aeb2666a856e5c0292f06f19 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Mon, 11 Jan 2010 21:02:33 +0000 Subject: [PATCH] Avoid adding PHI arguments for a predecessor that has gone away when a BRCOND was constant folded. This fixes PR5980. llvm-svn: 93184 --- .../CodeGen/SelectionDAG/SelectionDAGISel.cpp | 33 ++++--- .../CodeGen/X86/2010-01-11-ExtraPHIArg.ll | 97 +++++++++++++++++++ 2 files changed, 116 insertions(+), 14 deletions(-) create mode 100644 llvm/test/CodeGen/X86/2010-01-11-ExtraPHIArg.ll diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp index edcd91e8deda..e3c3862a4d15 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp @@ -1017,8 +1017,7 @@ SelectionDAGISel::FinishBasicBlock() { for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size(); j != ej; ++j) { MachineBasicBlock* cBB = SDB->BitTestCases[i].Cases[j].ThisBB; - if (cBB->succ_end() != - std::find(cBB->succ_begin(),cBB->succ_end(), PHIBB)) { + if (cBB->isSuccessor(PHIBB)) { PHI->addOperand(MachineOperand::CreateReg(SDB->PHINodesToUpdate[pi].second, false)); PHI->addOperand(MachineOperand::CreateMBB(cBB)); @@ -1067,7 +1066,7 @@ SelectionDAGISel::FinishBasicBlock() { (MachineOperand::CreateMBB(SDB->JTCases[i].first.HeaderBB)); } // JT BB. Just iterate over successors here - if (BB->succ_end() != std::find(BB->succ_begin(),BB->succ_end(), PHIBB)) { + if (BB->isSuccessor(PHIBB)) { PHI->addOperand (MachineOperand::CreateReg(SDB->PHINodesToUpdate[pi].second, false)); PHI->addOperand(MachineOperand::CreateMBB(BB)); @@ -1113,17 +1112,23 @@ SelectionDAGISel::FinishBasicBlock() { SDB->EdgeMapping.find(BB); if (EI != SDB->EdgeMapping.end()) ThisBB = EI->second; - for (MachineBasicBlock::iterator Phi = BB->begin(); - Phi != BB->end() && Phi->getOpcode() == TargetInstrInfo::PHI; ++Phi){ - // This value for this PHI node is recorded in PHINodesToUpdate, get it. - for (unsigned pn = 0; ; ++pn) { - assert(pn != SDB->PHINodesToUpdate.size() && - "Didn't find PHI entry!"); - if (SDB->PHINodesToUpdate[pn].first == Phi) { - Phi->addOperand(MachineOperand::CreateReg(SDB->PHINodesToUpdate[pn]. - second, false)); - Phi->addOperand(MachineOperand::CreateMBB(ThisBB)); - break; + + // BB may have been removed from the CFG if a branch was constant folded. + if (ThisBB->isSuccessor(BB)) { + for (MachineBasicBlock::iterator Phi = BB->begin(); + Phi != BB->end() && Phi->getOpcode() == TargetInstrInfo::PHI; + ++Phi) { + // This value for this PHI node is recorded in PHINodesToUpdate. + for (unsigned pn = 0; ; ++pn) { + assert(pn != SDB->PHINodesToUpdate.size() && + "Didn't find PHI entry!"); + if (SDB->PHINodesToUpdate[pn].first == Phi) { + Phi->addOperand(MachineOperand:: + CreateReg(SDB->PHINodesToUpdate[pn].second, + false)); + Phi->addOperand(MachineOperand::CreateMBB(ThisBB)); + break; + } } } } diff --git a/llvm/test/CodeGen/X86/2010-01-11-ExtraPHIArg.ll b/llvm/test/CodeGen/X86/2010-01-11-ExtraPHIArg.ll new file mode 100644 index 000000000000..db98eef30e1e --- /dev/null +++ b/llvm/test/CodeGen/X86/2010-01-11-ExtraPHIArg.ll @@ -0,0 +1,97 @@ +; RUN: llc -verify-machineinstrs < %s +; +; The lowering of a switch combined with constand folding would leave spurious extra arguments on a PHI instruction. +; +target triple = "x86_64-apple-darwin10" + +define void @foo() { + br label %cond_true813.i + +cond_true813.i: ; preds = %0 + br i1 false, label %cond_true818.i, label %cond_next1146.i + +cond_true818.i: ; preds = %cond_true813.i + br i1 false, label %recog_memoized.exit52, label %cond_next1146.i + +recog_memoized.exit52: ; preds = %cond_true818.i + switch i32 0, label %bb886.i.preheader [ + i32 0, label %bb907.i + i32 44, label %bb866.i + i32 103, label %bb874.i + i32 114, label %bb874.i + ] + +bb857.i: ; preds = %bb886.i, %bb866.i + %tmp862.i494.24 = phi i8* [ null, %bb866.i ], [ %tmp862.i494.26, %bb886.i ] ; [#uses=1] + switch i32 0, label %bb886.i.preheader [ + i32 0, label %bb907.i + i32 44, label %bb866.i + i32 103, label %bb874.i + i32 114, label %bb874.i + ] + +bb866.i.loopexit: ; preds = %bb874.i + br label %bb866.i + +bb866.i.loopexit31: ; preds = %cond_true903.i + br label %bb866.i + +bb866.i: ; preds = %bb866.i.loopexit31, %bb866.i.loopexit, %bb857.i, %recog_memoized.exit52 + br i1 false, label %bb907.i, label %bb857.i + +bb874.i.preheader.loopexit: ; preds = %cond_true903.i, %cond_true903.i + ret void + +bb874.i: ; preds = %bb857.i, %bb857.i, %recog_memoized.exit52, %recog_memoized.exit52 + switch i32 0, label %bb886.i.preheader.loopexit [ + i32 0, label %bb907.i + i32 44, label %bb866.i.loopexit + i32 103, label %bb874.i.backedge + i32 114, label %bb874.i.backedge + ] + +bb874.i.backedge: ; preds = %bb874.i, %bb874.i + ret void + +bb886.i.preheader.loopexit: ; preds = %bb874.i + ret void + +bb886.i.preheader: ; preds = %bb857.i, %recog_memoized.exit52 + %tmp862.i494.26 = phi i8* [ undef, %recog_memoized.exit52 ], [ %tmp862.i494.24, %bb857.i ] ; [#uses=1] + br label %bb886.i + +bb886.i: ; preds = %cond_true903.i, %bb886.i.preheader + br i1 false, label %bb857.i, label %cond_true903.i + +cond_true903.i: ; preds = %bb886.i + switch i32 0, label %bb886.i [ + i32 0, label %bb907.i + i32 44, label %bb866.i.loopexit31 + i32 103, label %bb874.i.preheader.loopexit + i32 114, label %bb874.i.preheader.loopexit + ] + +bb907.i: ; preds = %cond_true903.i, %bb874.i, %bb866.i, %bb857.i, %recog_memoized.exit52 + br i1 false, label %cond_next1146.i, label %cond_true910.i + +cond_true910.i: ; preds = %bb907.i + ret void + +cond_next1146.i: ; preds = %bb907.i, %cond_true818.i, %cond_true813.i + ret void + +bb2060.i: ; No predecessors! + br i1 false, label %cond_true2064.i, label %bb2067.i + +cond_true2064.i: ; preds = %bb2060.i + unreachable + +bb2067.i: ; preds = %bb2060.i + ret void + +cond_next3473: ; No predecessors! + ret void + +cond_next3521: ; No predecessors! + ret void +}