diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 59c92b3c6866..f57f4a8e2810 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -1019,12 +1019,27 @@ static bool IsBetterFallthrough(MachineBasicBlock *MBB1, return MBB2I->isCall() && !MBB1I->isCall(); } +/// getBranchDebugLoc - Find and return, if any, the DebugLoc of the branch +/// instructions on the block. Always use the DebugLoc of the first +/// branching instruction found unless its absent, in which case use the +/// DebugLoc of the second if present. +static DebugLoc getBranchDebugLoc(MachineBasicBlock &MBB) { + MachineBasicBlock::iterator I = MBB.end(); + if (I == MBB.begin()) + return DebugLoc(); + --I; + while (I->isDebugValue() && I != MBB.begin()) + --I; + if (I->isBranch()) + return I->getDebugLoc(); + return DebugLoc(); +} + /// OptimizeBlock - Analyze and optimize control flow related to the specified /// block. This is never called on the entry block. bool BranchFolder::OptimizeBlock(MachineBasicBlock *MBB) { bool MadeChange = false; MachineFunction &MF = *MBB->getParent(); - DebugLoc dl; // FIXME: this is nowhere ReoptimizeBlock: MachineFunction::iterator FallThrough = MBB; @@ -1073,6 +1088,7 @@ ReoptimizeBlock: // destination, remove the branch, replacing it with an unconditional one or // a fall-through. if (PriorTBB && PriorTBB == PriorFBB) { + DebugLoc dl = getBranchDebugLoc(PrevBB); TII->RemoveBranch(PrevBB); PriorCond.clear(); if (PriorTBB != MBB) @@ -1130,6 +1146,7 @@ ReoptimizeBlock: // If the prior block branches somewhere else on the condition and here if // the condition is false, remove the uncond second branch. if (PriorFBB == MBB) { + DebugLoc dl = getBranchDebugLoc(PrevBB); TII->RemoveBranch(PrevBB); TII->InsertBranch(PrevBB, PriorTBB, 0, PriorCond, dl); MadeChange = true; @@ -1143,6 +1160,7 @@ ReoptimizeBlock: if (PriorTBB == MBB) { SmallVector NewPriorCond(PriorCond); if (!TII->ReverseBranchCondition(NewPriorCond)) { + DebugLoc dl = getBranchDebugLoc(PrevBB); TII->RemoveBranch(PrevBB); TII->InsertBranch(PrevBB, PriorFBB, 0, NewPriorCond, dl); MadeChange = true; @@ -1180,6 +1198,7 @@ ReoptimizeBlock: DEBUG(dbgs() << "\nMoving MBB: " << *MBB << "To make fallthrough to: " << *PriorTBB << "\n"); + DebugLoc dl = getBranchDebugLoc(PrevBB); TII->RemoveBranch(PrevBB); TII->InsertBranch(PrevBB, MBB, 0, NewPriorCond, dl); @@ -1209,6 +1228,7 @@ ReoptimizeBlock: if (CurTBB && CurFBB && CurFBB == MBB && CurTBB != MBB) { SmallVector NewCond(CurCond); if (!TII->ReverseBranchCondition(NewCond)) { + DebugLoc dl = getBranchDebugLoc(*MBB); TII->RemoveBranch(*MBB); TII->InsertBranch(*MBB, CurFBB, CurTBB, NewCond, dl); MadeChange = true; @@ -1222,6 +1242,7 @@ ReoptimizeBlock: if (CurTBB && CurCond.empty() && CurFBB == 0 && IsBranchOnlyBlock(MBB) && CurTBB != MBB && !MBB->hasAddressTaken()) { + DebugLoc dl = getBranchDebugLoc(*MBB); // This block may contain just an unconditional branch. Because there can // be 'non-branch terminators' in the block, try removing the branch and // then seeing if the block is empty. @@ -1264,8 +1285,9 @@ ReoptimizeBlock: assert(PriorFBB == 0 && "Machine CFG out of date!"); PriorFBB = MBB; } + DebugLoc pdl = getBranchDebugLoc(PrevBB); TII->RemoveBranch(PrevBB); - TII->InsertBranch(PrevBB, PriorTBB, PriorFBB, PriorCond, dl); + TII->InsertBranch(PrevBB, PriorTBB, PriorFBB, PriorCond, pdl); } // Iterate through all the predecessors, revectoring each in-turn. @@ -1289,9 +1311,10 @@ ReoptimizeBlock: bool NewCurUnAnalyzable = TII->AnalyzeBranch(*PMBB, NewCurTBB, NewCurFBB, NewCurCond, true); if (!NewCurUnAnalyzable && NewCurTBB && NewCurTBB == NewCurFBB) { + DebugLoc pdl = getBranchDebugLoc(*PMBB); TII->RemoveBranch(*PMBB); NewCurCond.clear(); - TII->InsertBranch(*PMBB, NewCurTBB, 0, NewCurCond, dl); + TII->InsertBranch(*PMBB, NewCurTBB, 0, NewCurCond, pdl); MadeChange = true; ++NumBranchOpts; PMBB->CorrectExtraCFGEdges(NewCurTBB, 0, false); @@ -1351,7 +1374,7 @@ ReoptimizeBlock: if (CurFallsThru) { MachineBasicBlock *NextBB = llvm::next(MachineFunction::iterator(MBB)); CurCond.clear(); - TII->InsertBranch(*MBB, NextBB, 0, CurCond, dl); + TII->InsertBranch(*MBB, NextBB, 0, CurCond, DebugLoc()); } MBB->moveAfter(PredBB); MadeChange = true;