From de4fe231392165c7566081fb3f86aee4f6a4e0d6 Mon Sep 17 00:00:00 2001 From: Bob Wilson Date: Sat, 26 Jun 2010 17:47:06 +0000 Subject: [PATCH] Revert my if-conversion cleanup since it caused a bunch of nightly test regressions. --- Reverse-merging r106939 into '.': U test/CodeGen/Thumb2/thumb2-ifcvt3.ll U lib/CodeGen/IfConversion.cpp git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106951 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/IfConversion.cpp | 70 +++++++++++++--------------- test/CodeGen/Thumb2/thumb2-ifcvt3.ll | 2 +- 2 files changed, 34 insertions(+), 38 deletions(-) diff --git a/lib/CodeGen/IfConversion.cpp b/lib/CodeGen/IfConversion.cpp index 7237c041219..51fea7f94e5 100644 --- a/lib/CodeGen/IfConversion.cpp +++ b/lib/CodeGen/IfConversion.cpp @@ -186,7 +186,7 @@ namespace { SmallVectorImpl &Cond, SmallSet &Redefs, bool IgnoreBr = false); - void MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI, bool AddEdges = true); + void MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI); bool MeetIfcvtSizeLimit(MachineBasicBlock &BB, unsigned Size) const { return Size > 0 && TII->isProfitableToIfCvt(BB, Size); @@ -1036,10 +1036,6 @@ bool IfConverter::IfConvertSimple(BBInfo &BBI, IfcvtKind Kind) { IterIfcvt = false; } - // RemoveExtraEdges won't work if the block has an unanalyzable branch, - // which is typically the case for IfConvertSimple, so explicitly remove - // CvtBBI as a successor. - BBI.BB->removeSuccessor(CvtBBI->BB); RemoveExtraEdges(BBI); // Update block info. BB can be iteratively if-converted. @@ -1102,7 +1098,8 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) { InitPredRedefs(NextBBI->BB, Redefs, TRI); bool HasEarlyExit = CvtBBI->FalseBB != NULL; - if (CvtBBI->BB->pred_size() > 1) { + bool DupBB = CvtBBI->BB->pred_size() > 1; + if (DupBB) { BBI.NonPredSize -= TII->RemoveBranch(*BBI.BB); // Copy instructions in the true block, predicate them, and add them to // the entry block. @@ -1114,7 +1111,7 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) { // Now merge the entry of the triangle with the true block. BBI.NonPredSize -= TII->RemoveBranch(*BBI.BB); - MergeBlocks(BBI, *CvtBBI, false); + MergeBlocks(BBI, *CvtBBI); } // If 'true' block has a 'false' successor, add an exit branch to it. @@ -1187,9 +1184,9 @@ bool IfConverter::IfConvertDiamond(BBInfo &BBI, IfcvtKind Kind, return false; } - // Put the predicated instructions from the 'true' block before the - // instructions from the 'false' block, unless the true block would clobber - // the predicate, in which case, do the opposite. + // Merge the 'true' and 'false' blocks by copying the instructions + // from the 'false' block to the 'true' block. That is, unless the true + // block would clobber the predicate, in that case, do the opposite. BBInfo *BBI1 = &TrueBBI; BBInfo *BBI2 = &FalseBBI; SmallVector RevCond(BBI.BrCond.begin(), BBI.BrCond.end()); @@ -1279,8 +1276,8 @@ bool IfConverter::IfConvertDiamond(BBInfo &BBI, IfcvtKind Kind, PredicateBlock(*BBI2, DI2, *Cond2, Redefs); // Merge the true block into the entry of the diamond. - MergeBlocks(BBI, *BBI1, TailBB == 0); - MergeBlocks(BBI, *BBI2, TailBB == 0); + MergeBlocks(BBI, *BBI1); + MergeBlocks(BBI, *BBI2); // If the if-converted block falls through or unconditionally branches into // the tail block, and the tail block does not have other predecessors, then @@ -1289,20 +1286,15 @@ bool IfConverter::IfConvertDiamond(BBInfo &BBI, IfcvtKind Kind, if (TailBB) { BBInfo TailBBI = BBAnalysis[TailBB->getNumber()]; if (TailBB->pred_size() == 1 && !TailBBI.HasFallThrough) { + BBI.NonPredSize -= TII->RemoveBranch(*BBI.BB); MergeBlocks(BBI, TailBBI); TailBBI.IsDone = true; } else { - BBI.BB->addSuccessor(TailBB); InsertUncondBranch(BBI.BB, TailBB, TII); BBI.HasFallThrough = false; } } - // RemoveExtraEdges won't work if the block has an unanalyzable branch, - // which can happen here if TailBB is unanalyzable and is merged, so - // explicitly remove BBI1 and BBI2 as successors. - BBI.BB->removeSuccessor(BBI1->BB); - BBI.BB->removeSuccessor(BBI2->BB); RemoveExtraEdges(BBI); // Update block info. @@ -1375,19 +1367,17 @@ void IfConverter::CopyAndPredicateBlock(BBInfo &ToBBI, BBInfo &FromBBI, UpdatePredRedefs(MI, Redefs, TRI, true); } - if (!IgnoreBr) { - std::vector Succs(FromBBI.BB->succ_begin(), - FromBBI.BB->succ_end()); - MachineBasicBlock *NBB = getNextBlock(FromBBI.BB); - MachineBasicBlock *FallThrough = FromBBI.HasFallThrough ? NBB : NULL; + std::vector Succs(FromBBI.BB->succ_begin(), + FromBBI.BB->succ_end()); + MachineBasicBlock *NBB = getNextBlock(FromBBI.BB); + MachineBasicBlock *FallThrough = FromBBI.HasFallThrough ? NBB : NULL; - for (unsigned i = 0, e = Succs.size(); i != e; ++i) { - MachineBasicBlock *Succ = Succs[i]; - // Fallthrough edge can't be transferred. - if (Succ == FallThrough) - continue; - ToBBI.BB->addSuccessor(Succ); - } + for (unsigned i = 0, e = Succs.size(); i != e; ++i) { + MachineBasicBlock *Succ = Succs[i]; + // Fallthrough edge can't be transferred. + if (Succ == FallThrough) + continue; + ToBBI.BB->addSuccessor(Succ); } std::copy(FromBBI.Predicate.begin(), FromBBI.Predicate.end(), @@ -1401,14 +1391,21 @@ void IfConverter::CopyAndPredicateBlock(BBInfo &ToBBI, BBInfo &FromBBI, } /// MergeBlocks - Move all instructions from FromBB to the end of ToBB. -/// This will leave FromBB as an empty block, so remove all of its -/// successor edges except for the fall-through edge. If AddEdges is true, -/// i.e., when FromBBI's branch is being moved, add those successor edges to -/// ToBBI. -void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI, bool AddEdges) { +/// +void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI) { ToBBI.BB->splice(ToBBI.BB->end(), FromBBI.BB, FromBBI.BB->begin(), FromBBI.BB->end()); + // Redirect all branches to FromBB to ToBB. + std::vector Preds(FromBBI.BB->pred_begin(), + FromBBI.BB->pred_end()); + for (unsigned i = 0, e = Preds.size(); i != e; ++i) { + MachineBasicBlock *Pred = Preds[i]; + if (Pred == ToBBI.BB) + continue; + Pred->ReplaceUsesOfBlockWith(FromBBI.BB, ToBBI.BB); + } + std::vector Succs(FromBBI.BB->succ_begin(), FromBBI.BB->succ_end()); MachineBasicBlock *NBB = getNextBlock(FromBBI.BB); @@ -1420,8 +1417,7 @@ void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI, bool AddEdges) { if (Succ == FallThrough) continue; FromBBI.BB->removeSuccessor(Succ); - if (AddEdges) - ToBBI.BB->addSuccessor(Succ); + ToBBI.BB->addSuccessor(Succ); } // Now FromBBI always falls through to the next block! diff --git a/test/CodeGen/Thumb2/thumb2-ifcvt3.ll b/test/CodeGen/Thumb2/thumb2-ifcvt3.ll index cc2ef140d11..e465c00eae9 100644 --- a/test/CodeGen/Thumb2/thumb2-ifcvt3.ll +++ b/test/CodeGen/Thumb2/thumb2-ifcvt3.ll @@ -23,7 +23,7 @@ bb52: ; preds = %newFuncRoot ; CHECK: movne ; CHECK: moveq ; CHECK: pop -; CHECK-NEXT: @ BB#1: +; CHECK-NEXT: LBB0_1: %0 = load i64* @posed, align 4 ; [#uses=3] %1 = sub i64 %0, %.reload78 ; [#uses=1] %2 = ashr i64 %1, 1 ; [#uses=3]