From 71d5a2540a98c81f5bcaeb48805e0e2881f530ef Mon Sep 17 00:00:00 2001 From: Dimitry Andric Date: Sun, 16 Apr 2017 16:01:22 +0000 Subject: Vendor import of llvm trunk r300422: https://llvm.org/svn/llvm-project/llvm/trunk@300422 --- lib/CodeGen/MachineBasicBlock.cpp | 57 ++++++++++++++++++++++++++++++--------- 1 file changed, 44 insertions(+), 13 deletions(-) (limited to 'lib/CodeGen/MachineBasicBlock.cpp') diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp index 3869f976854d0..06112723497b0 100644 --- a/lib/CodeGen/MachineBasicBlock.cpp +++ b/lib/CodeGen/MachineBasicBlock.cpp @@ -23,6 +23,7 @@ #include "llvm/CodeGen/SlotIndexes.h" #include "llvm/IR/BasicBlock.h" #include "llvm/IR/DataLayout.h" +#include "llvm/IR/DebugInfoMetadata.h" #include "llvm/IR/ModuleSlotTracker.h" #include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCContext.h" @@ -148,8 +149,11 @@ MachineBasicBlock::iterator MachineBasicBlock::getFirstNonPHI() { MachineBasicBlock::iterator MachineBasicBlock::SkipPHIsAndLabels(MachineBasicBlock::iterator I) { + const TargetInstrInfo *TII = getParent()->getSubtarget().getInstrInfo(); + iterator E = end(); - while (I != E && (I->isPHI() || I->isPosition())) + while (I != E && (I->isPHI() || I->isPosition() || + TII->isBasicBlockPrologue(*I))) ++I; // FIXME: This needs to change if we wish to bundle labels // inside the bundle. @@ -160,8 +164,11 @@ MachineBasicBlock::SkipPHIsAndLabels(MachineBasicBlock::iterator I) { MachineBasicBlock::iterator MachineBasicBlock::SkipPHIsLabelsAndDebug(MachineBasicBlock::iterator I) { + const TargetInstrInfo *TII = getParent()->getSubtarget().getInstrInfo(); + iterator E = end(); - while (I != E && (I->isPHI() || I->isPosition() || I->isDebugValue())) + while (I != E && (I->isPHI() || I->isPosition() || I->isDebugValue() || + TII->isBasicBlockPrologue(*I))) ++I; // FIXME: This needs to change if we wish to bundle labels / dbg_values // inside the bundle. @@ -225,7 +232,7 @@ StringRef MachineBasicBlock::getName() const { if (const BasicBlock *LBB = getBasicBlock()) return LBB->getName(); else - return "(null)"; + return StringRef("", 0); } /// Return a hopefully unique identifier for this block. @@ -417,7 +424,7 @@ void MachineBasicBlock::updateTerminator() { MachineBasicBlock *TBB = nullptr, *FBB = nullptr; SmallVector Cond; - DebugLoc DL; // FIXME: this is nowhere + DebugLoc DL = findBranchDebugLoc(); bool B = TII->analyzeBranch(*this, TBB, FBB, Cond); (void) B; assert(!B && "UpdateTerminators requires analyzable predecessors!"); @@ -485,7 +492,7 @@ void MachineBasicBlock::updateTerminator() { // FIXME: This does not seem like a reasonable pattern to support, but it // has been seen in the wild coming out of degenerate ARM test cases. TII->removeBranch(*this); - + // Finally update the unconditional successor to be reached via a branch if // it would not be reached by fallthrough. if (!isLayoutSuccessor(TBB)) @@ -681,16 +688,16 @@ bool MachineBasicBlock::isLayoutSuccessor(const MachineBasicBlock *MBB) const { return std::next(I) == MachineFunction::const_iterator(MBB); } -bool MachineBasicBlock::canFallThrough() { +MachineBasicBlock *MachineBasicBlock::getFallThrough() { MachineFunction::iterator Fallthrough = getIterator(); ++Fallthrough; // If FallthroughBlock is off the end of the function, it can't fall through. if (Fallthrough == getParent()->end()) - return false; + return nullptr; // If FallthroughBlock isn't a successor, no fallthrough is possible. if (!isSuccessor(&*Fallthrough)) - return false; + return nullptr; // Analyze the branches, if any, at the end of the block. MachineBasicBlock *TBB = nullptr, *FBB = nullptr; @@ -702,25 +709,31 @@ bool MachineBasicBlock::canFallThrough() { // is possible. The isPredicated check is needed because this code can be // called during IfConversion, where an instruction which is normally a // Barrier is predicated and thus no longer an actual control barrier. - return empty() || !back().isBarrier() || TII->isPredicated(back()); + return (empty() || !back().isBarrier() || TII->isPredicated(back())) + ? &*Fallthrough + : nullptr; } // If there is no branch, control always falls through. - if (!TBB) return true; + if (!TBB) return &*Fallthrough; // If there is some explicit branch to the fallthrough block, it can obviously // reach, even though the branch should get folded to fall through implicitly. if (MachineFunction::iterator(TBB) == Fallthrough || MachineFunction::iterator(FBB) == Fallthrough) - return true; + return &*Fallthrough; // If it's an unconditional branch to some block not the fall through, it // doesn't fall through. - if (Cond.empty()) return false; + if (Cond.empty()) return nullptr; // Otherwise, if it is conditional and has no explicit false block, it falls // through. - return FBB == nullptr; + return (FBB == nullptr) ? &*Fallthrough : nullptr; +} + +bool MachineBasicBlock::canFallThrough() { + return getFallThrough() != nullptr; } MachineBasicBlock *MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, @@ -1144,6 +1157,24 @@ MachineBasicBlock::findDebugLoc(instr_iterator MBBI) { return {}; } +/// Find and return the merged DebugLoc of the branch instructions of the block. +/// Return UnknownLoc if there is none. +DebugLoc +MachineBasicBlock::findBranchDebugLoc() { + DebugLoc DL; + auto TI = getFirstTerminator(); + while (TI != end() && !TI->isBranch()) + ++TI; + + if (TI != end()) { + DL = TI->getDebugLoc(); + for (++TI ; TI != end() ; ++TI) + if (TI->isBranch()) + DL = DILocation::getMergedLocation(DL, TI->getDebugLoc()); + } + return DL; +} + /// Return probability of the edge from this block to MBB. BranchProbability MachineBasicBlock::getSuccProbability(const_succ_iterator Succ) const { -- cgit v1.2.3