diff --git a/llvm/include/llvm/Transforms/Utils/LoopPeel.h b/llvm/include/llvm/Transforms/Utils/LoopPeel.h index dd59a9c766e45..49dbc9aa1f2a9 100644 --- a/llvm/include/llvm/Transforms/Utils/LoopPeel.h +++ b/llvm/include/llvm/Transforms/Utils/LoopPeel.h @@ -44,7 +44,8 @@ gatherPeelingPreferences(Loop *L, ScalarEvolution &SE, void computePeelCount(Loop *L, unsigned LoopSize, TargetTransformInfo::PeelingPreferences &PP, unsigned TripCount, DominatorTree &DT, - ScalarEvolution &SE, AssumptionCache *AC = nullptr, + ScalarEvolution &SE, const TargetTransformInfo &TTI, + AssumptionCache *AC = nullptr, unsigned Threshold = UINT_MAX); } // end namespace llvm diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp index 0b9fee5727c6f..afa7abfea419e 100644 --- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp +++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp @@ -1014,7 +1014,7 @@ bool llvm::computeUnrollCount( } // 5th priority is loop peeling. - computePeelCount(L, LoopSize, PP, TripCount, DT, SE, AC, UP.Threshold); + computePeelCount(L, LoopSize, PP, TripCount, DT, SE, TTI, AC, UP.Threshold); if (PP.PeelCount) { UP.Runtime = false; UP.Count = 1; diff --git a/llvm/lib/Transforms/Utils/LoopPeel.cpp b/llvm/lib/Transforms/Utils/LoopPeel.cpp index f348d24ec24fb..e1dc052837f7f 100644 --- a/llvm/lib/Transforms/Utils/LoopPeel.cpp +++ b/llvm/lib/Transforms/Utils/LoopPeel.cpp @@ -38,6 +38,7 @@ #include "llvm/Transforms/Utils/Cloning.h" #include "llvm/Transforms/Utils/LoopSimplify.h" #include "llvm/Transforms/Utils/LoopUtils.h" +#include "llvm/Transforms/Utils/ScalarEvolutionExpander.h" #include "llvm/Transforms/Utils/ValueMapper.h" #include #include @@ -330,11 +331,7 @@ static unsigned peelToTurnInvariantLoadsDerefencebale(Loop &L, bool llvm::canPeelLastIteration(const Loop &L, ScalarEvolution &SE) { const SCEV *BTC = SE.getBackedgeTakenCount(&L); - // The loop must execute at least 2 iterations to guarantee that peeled - // iteration executes. - // TODO: Add checks during codegen. - if (isa(BTC) || - !SE.isKnownPredicate(CmpInst::ICMP_UGT, BTC, SE.getZero(BTC->getType()))) + if (isa(BTC)) return false; // Check if the exit condition of the loop can be adjusted by the peeling @@ -364,12 +361,18 @@ bool llvm::canPeelLastIteration(const Loop &L, ScalarEvolution &SE) { /// is known at the second-to-last. static bool shouldPeelLastIteration(Loop &L, CmpPredicate Pred, const SCEVAddRecExpr *LeftAR, - const SCEV *RightSCEV, - ScalarEvolution &SE) { + const SCEV *RightSCEV, ScalarEvolution &SE, + const TargetTransformInfo &TTI) { if (!canPeelLastIteration(L, SE)) return false; const SCEV *BTC = SE.getBackedgeTakenCount(&L); + SCEVExpander Expander(SE, L.getHeader()->getDataLayout(), "loop-peel"); + if (!SE.isKnownNonZero(BTC) && + Expander.isHighCostExpansion(BTC, &L, SCEVCheapExpansionBudget, &TTI, + L.getLoopPredecessor()->getTerminator())) + return false; + const SCEV *ValAtLastIter = LeftAR->evaluateAtIteration(BTC, SE); const SCEV *ValAtSecondToLastIter = LeftAR->evaluateAtIteration( SE.getMinusSCEV(BTC, SE.getOne(BTC->getType())), SE); @@ -391,7 +394,8 @@ static bool shouldPeelLastIteration(Loop &L, CmpPredicate Pred, // .. // } static std::pair -countToEliminateCompares(Loop &L, unsigned MaxPeelCount, ScalarEvolution &SE) { +countToEliminateCompares(Loop &L, unsigned MaxPeelCount, ScalarEvolution &SE, + const TargetTransformInfo &TTI) { assert(L.isLoopSimplifyForm() && "Loop needs to be in loop simplify form"); unsigned DesiredPeelCount = 0; unsigned DesiredPeelCountLast = 0; @@ -479,7 +483,7 @@ countToEliminateCompares(Loop &L, unsigned MaxPeelCount, ScalarEvolution &SE) { const SCEV *Step = LeftAR->getStepRecurrence(SE); if (!PeelWhilePredicateIsKnown(NewPeelCount, IterVal, RightSCEV, Step, Pred)) { - if (shouldPeelLastIteration(L, Pred, LeftAR, RightSCEV, SE)) + if (shouldPeelLastIteration(L, Pred, LeftAR, RightSCEV, SE, TTI)) DesiredPeelCountLast = 1; return; } @@ -593,8 +597,8 @@ static bool violatesLegacyMultiExitLoopCheck(Loop *L) { void llvm::computePeelCount(Loop *L, unsigned LoopSize, TargetTransformInfo::PeelingPreferences &PP, unsigned TripCount, DominatorTree &DT, - ScalarEvolution &SE, AssumptionCache *AC, - unsigned Threshold) { + ScalarEvolution &SE, const TargetTransformInfo &TTI, + AssumptionCache *AC, unsigned Threshold) { assert(LoopSize > 0 && "Zero loop size is not allowed!"); // Save the PP.PeelCount value set by the target in // TTI.getPeelingPreferences or by the flag -unroll-peel-count. @@ -656,7 +660,7 @@ void llvm::computePeelCount(Loop *L, unsigned LoopSize, } const auto &[CountToEliminateCmps, CountToEliminateCmpsLast] = - countToEliminateCompares(*L, MaxPeelCount, SE); + countToEliminateCompares(*L, MaxPeelCount, SE, TTI); DesiredPeelCount = std::max(DesiredPeelCount, CountToEliminateCmps); if (DesiredPeelCount == 0) @@ -822,7 +826,7 @@ static void initBranchWeights(DenseMap &WeightInfos, /// instructions in the last peeled-off iteration. static void cloneLoopBlocks( Loop *L, unsigned IterNumber, bool PeelLast, BasicBlock *InsertTop, - BasicBlock *InsertBot, + BasicBlock *InsertBot, BasicBlock *OrigPreHeader, SmallVectorImpl> &ExitEdges, SmallVectorImpl &NewBlocks, LoopBlocksDFS &LoopBlocks, ValueToValueMapTy &VMap, ValueToValueMapTy &LVMap, DominatorTree *DT, @@ -914,12 +918,22 @@ static void cloneLoopBlocks( // loop iteration. Since this copy is no longer part of the loop, we // resolve this statically: if (PeelLast) { - // For the last iteration, we use the value from the latch of the original - // loop directly. + // For the last iteration, we introduce new phis for each header phi in + // InsertTop, using the incoming value from the preheader for the original + // preheader (when skipping the main loop) and the incoming value from the + // latch for the latch (when continuing from the main loop). + IRBuilder<> B(InsertTop->getTerminator()); for (BasicBlock::iterator I = Header->begin(); isa(I); ++I) { PHINode *NewPHI = cast(VMap[&*I]); - VMap[&*I] = NewPHI->getIncomingValueForBlock(Latch); + PHINode *PN = B.CreatePHI(NewPHI->getType(), 2); NewPHI->eraseFromParent(); + if (OrigPreHeader) + PN->addIncoming(cast(&*I)->getIncomingValueForBlock(PreHeader), + OrigPreHeader); + + PN->addIncoming(cast(&*I)->getIncomingValueForBlock(Latch), + Latch); + VMap[&*I] = PN; } } else { // For the first iteration, we use the value from the preheader directly. @@ -1053,7 +1067,7 @@ bool llvm::peelLoop(Loop *L, unsigned PeelCount, bool PeelLast, LoopInfo *LI, // Set up all the necessary basic blocks. BasicBlock *InsertTop; BasicBlock *InsertBot; - BasicBlock *NewPreHeader; + BasicBlock *NewPreHeader = nullptr; DenseMap ExitValues; if (PeelLast) { // It is convenient to split the single exit block from the latch the @@ -1084,11 +1098,34 @@ bool llvm::peelLoop(Loop *L, unsigned PeelCount, bool PeelLast, LoopInfo *LI, for (PHINode &P : Exit->phis()) ExitValues[&P] = P.getIncomingValueForBlock(Latch); + const SCEV *BTC = SE->getBackedgeTakenCount(L); + InsertTop = SplitEdge(Latch, Exit, &DT, LI); InsertBot = SplitBlock(InsertTop, InsertTop->getTerminator(), &DT, LI); InsertTop->setName(Exit->getName() + ".peel.begin"); InsertBot->setName(Exit->getName() + ".peel.next"); + NewPreHeader = nullptr; + + // If the original loop may only execute a single iteration we need to + // insert a trip count check and skip the original loop with the last + // iteration peeled off if necessary. + if (!SE->isKnownNonZero(BTC)) { + NewPreHeader = SplitEdge(PreHeader, Header, &DT, LI); + SCEVExpander Expander(*SE, Latch->getDataLayout(), "loop-peel"); + + BranchInst *PreHeaderBR = cast(PreHeader->getTerminator()); + Value *BTCValue = + Expander.expandCodeFor(BTC, BTC->getType(), PreHeaderBR); + IRBuilder<> B(PreHeaderBR); + Value *Cond = + B.CreateICmpNE(BTCValue, ConstantInt::get(BTCValue->getType(), 0)); + B.CreateCondBr(Cond, NewPreHeader, InsertTop); + PreHeaderBR->eraseFromParent(); + + // PreHeader now dominates InsertTop. + DT.changeImmediateDominator(InsertTop, PreHeader); + } } else { // It is convenient to split the preheader into 3 parts - two blocks to // anchor the peeled copy of the loop body, and a new preheader for the @@ -1162,8 +1199,9 @@ bool llvm::peelLoop(Loop *L, unsigned PeelCount, bool PeelLast, LoopInfo *LI, for (unsigned Iter = 0; Iter < PeelCount; ++Iter) { SmallVector NewBlocks; - cloneLoopBlocks(L, Iter, PeelLast, InsertTop, InsertBot, ExitEdges, - NewBlocks, LoopBlocks, VMap, LVMap, &DT, LI, + cloneLoopBlocks(L, Iter, PeelLast, InsertTop, InsertBot, + NewPreHeader ? PreHeader : nullptr, ExitEdges, NewBlocks, + LoopBlocks, VMap, LVMap, &DT, LI, LoopLocalNoAliasDeclScopes, *SE); // Remap to use values from the current iteration instead of the @@ -1216,9 +1254,11 @@ bool llvm::peelLoop(Loop *L, unsigned PeelCount, bool PeelLast, LoopInfo *LI, if (PeelLast) { // Now adjust users of the original exit values by replacing them with the - // exit value from the peeled iteration. - for (const auto &[P, E] : ExitValues) + // exit value from the peeled iteration and remove them. + for (const auto &[P, E] : ExitValues) { P->replaceAllUsesWith(isa(E) ? E : &*VMap.lookup(E)); + P->eraseFromParent(); + } formLCSSA(*L, DT, LI, SE); } else { // Now adjust the phi nodes in the loop header to get their initial values diff --git a/llvm/test/Transforms/LoopUnroll/peel-last-iteration-expansion-cost.ll b/llvm/test/Transforms/LoopUnroll/peel-last-iteration-expansion-cost.ll index 342c70170fef3..f3910f9bfc399 100644 --- a/llvm/test/Transforms/LoopUnroll/peel-last-iteration-expansion-cost.ll +++ b/llvm/test/Transforms/LoopUnroll/peel-last-iteration-expansion-cost.ll @@ -25,17 +25,41 @@ define i32 @test_expansion_cost_2(i32 %start, i32 %end) { ; BUDGET3-SAME: i32 [[START:%.*]], i32 [[END:%.*]]) { ; BUDGET3-NEXT: [[ENTRY:.*]]: ; BUDGET3-NEXT: [[SUB:%.*]] = add i32 [[END]], -1 +; BUDGET3-NEXT: [[TMP0:%.*]] = sub i32 [[SUB]], [[START]] +; BUDGET3-NEXT: [[TMP1:%.*]] = icmp ne i32 [[TMP0]], 0 +; BUDGET3-NEXT: br i1 [[TMP1]], label %[[ENTRY_SPLIT:.*]], label %[[EXIT_PEEL_BEGIN:.*]] +; BUDGET3: [[ENTRY_SPLIT]]: ; BUDGET3-NEXT: br label %[[LOOP_HEADER:.*]] ; BUDGET3: [[LOOP_HEADER]]: -; BUDGET3-NEXT: [[TMP3:%.*]] = phi i32 [ [[START]], %[[ENTRY]] ], [ [[IV_NEXT_PEEL:%.*]], %[[LOOP_LATCH:.*]] ] -; BUDGET3-NEXT: [[C_PEEL:%.*]] = icmp eq i32 [[TMP3]], [[SUB]] -; BUDGET3-NEXT: br i1 [[C_PEEL]], label %[[THEN:.*]], label %[[LOOP_LATCH]] +; BUDGET3-NEXT: [[IV:%.*]] = phi i32 [ [[START]], %[[ENTRY_SPLIT]] ], [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ] +; BUDGET3-NEXT: [[C:%.*]] = icmp eq i32 [[IV]], [[SUB]] +; BUDGET3-NEXT: br i1 [[C]], label %[[THEN:.*]], label %[[LOOP_LATCH]] ; BUDGET3: [[THEN]]: ; BUDGET3-NEXT: br label %[[LOOP_LATCH]] ; BUDGET3: [[LOOP_LATCH]]: -; BUDGET3-NEXT: [[IV_NEXT_PEEL]] = add nsw i32 [[TMP3]], 1 +; BUDGET3-NEXT: [[IV_NEXT]] = add nsw i32 [[IV]], 1 +; BUDGET3-NEXT: [[TMP2:%.*]] = sub i32 [[END]], 1 +; BUDGET3-NEXT: [[EC:%.*]] = icmp eq i32 [[IV_NEXT]], [[TMP2]] +; BUDGET3-NEXT: br i1 [[EC]], label %[[EXIT_PEEL_BEGIN_LOOPEXIT:.*]], label %[[LOOP_HEADER]], !llvm.loop [[LOOP0:![0-9]+]] +; BUDGET3: [[EXIT_PEEL_BEGIN_LOOPEXIT]]: +; BUDGET3-NEXT: [[DOTPH:%.*]] = phi i32 [ [[IV_NEXT]], %[[LOOP_LATCH]] ] +; BUDGET3-NEXT: br label %[[EXIT_PEEL_BEGIN]] +; BUDGET3: [[EXIT_PEEL_BEGIN]]: +; BUDGET3-NEXT: [[TMP3:%.*]] = phi i32 [ [[START]], %[[ENTRY]] ], [ [[DOTPH]], %[[EXIT_PEEL_BEGIN_LOOPEXIT]] ] +; BUDGET3-NEXT: br label %[[LOOP_HEADER_PEEL:.*]] +; BUDGET3: [[LOOP_HEADER_PEEL]]: +; BUDGET3-NEXT: [[C_PEEL:%.*]] = icmp eq i32 [[TMP3]], [[SUB]] +; BUDGET3-NEXT: br i1 [[C_PEEL]], label %[[THEN_PEEL:.*]], label %[[LOOP_LATCH_PEEL:.*]] +; BUDGET3: [[THEN_PEEL]]: +; BUDGET3-NEXT: br label %[[LOOP_LATCH_PEEL]] +; BUDGET3: [[LOOP_LATCH_PEEL]]: +; BUDGET3-NEXT: [[IV_NEXT_PEEL:%.*]] = add nsw i32 [[TMP3]], 1 ; BUDGET3-NEXT: [[EC_PEEL:%.*]] = icmp eq i32 [[IV_NEXT_PEEL]], [[END]] -; BUDGET3-NEXT: br i1 [[EC_PEEL]], label %[[EXIT:.*]], label %[[LOOP_HEADER]] +; BUDGET3-NEXT: br i1 [[EC_PEEL]], label %[[EXIT_PEEL_NEXT:.*]], label %[[EXIT_PEEL_NEXT]] +; BUDGET3: [[EXIT_PEEL_NEXT]]: +; BUDGET3-NEXT: br label %[[LOOP_HEADER_PEEL_NEXT:.*]] +; BUDGET3: [[LOOP_HEADER_PEEL_NEXT]]: +; BUDGET3-NEXT: br label %[[EXIT:.*]] ; BUDGET3: [[EXIT]]: ; BUDGET3-NEXT: ret i32 0 ; @@ -59,3 +83,7 @@ loop.latch: exit: ret i32 0 } +;. +; BUDGET3: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]]} +; BUDGET3: [[META1]] = !{!"llvm.loop.peeled.count", i32 1} +;. diff --git a/llvm/test/Transforms/LoopUnroll/peel-last-iteration-with-constant-trip-count.ll b/llvm/test/Transforms/LoopUnroll/peel-last-iteration-with-constant-trip-count.ll index f1290069bda0c..5c9b2fa6a9d60 100644 --- a/llvm/test/Transforms/LoopUnroll/peel-last-iteration-with-constant-trip-count.ll +++ b/llvm/test/Transforms/LoopUnroll/peel-last-iteration-with-constant-trip-count.ll @@ -13,7 +13,6 @@ define i64 @peel_single_block_loop_iv_step_1() { ; CHECK-NEXT: br i1 [[EC1]], label %[[LOOP]], label %[[EXIT_PEEL_BEGIN:.*]], !llvm.loop [[LOOP0:![0-9]+]] ; CHECK: [[EXIT_PEEL_BEGIN]]: ; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[IV_NEXT1]], %[[LOOP]] ] -; CHECK-NEXT: [[IV_LCSSA:%.*]] = phi i64 [ [[IV1]], %[[LOOP]] ] ; CHECK-NEXT: br label %[[LOOP_PEEL:.*]] ; CHECK: [[LOOP_PEEL]]: ; CHECK-NEXT: [[CMP18_NOT:%.*]] = icmp eq i64 [[IV]], 63 @@ -92,7 +91,6 @@ define i64 @peel_single_block_loop_iv_step_1_eq_pred() { ; CHECK-NEXT: br i1 [[CMP_PEEL]], label %[[EXIT_PEEL_BEGIN:.*]], label %[[LOOP]], !llvm.loop [[LOOP2:![0-9]+]] ; CHECK: [[EXIT_PEEL_BEGIN]]: ; CHECK-NEXT: [[IV_NEXT_LCSSA:%.*]] = phi i64 [ [[IV_LCSSA]], %[[LOOP]] ] -; CHECK-NEXT: [[IV_LCSSA1:%.*]] = phi i64 [ [[IV]], %[[LOOP]] ] ; CHECK-NEXT: br label %[[LOOP_PEEL:.*]] ; CHECK: [[LOOP_PEEL]]: ; CHECK-NEXT: [[CMP_PEEL1:%.*]] = icmp eq i64 [[IV_NEXT_LCSSA]], 63 @@ -171,7 +169,6 @@ define i64 @peel_single_block_loop_iv_step_1_nested_loop() { ; CHECK-NEXT: br i1 [[EC]], label %[[LOOP]], label %[[OUTER_LATCH_PEEL_BEGIN:.*]], !llvm.loop [[LOOP3:![0-9]+]] ; CHECK: [[OUTER_LATCH_PEEL_BEGIN]]: ; CHECK-NEXT: [[IV_NEXT_LCSSA:%.*]] = phi i64 [ [[IV_NEXT]], %[[LOOP]] ] -; CHECK-NEXT: [[IV_LCSSA:%.*]] = phi i64 [ [[IV]], %[[LOOP]] ] ; CHECK-NEXT: br label %[[LOOP_PEEL:.*]] ; CHECK: [[LOOP_PEEL]]: ; CHECK-NEXT: [[CMP_PEEL:%.*]] = icmp eq i64 [[IV_NEXT_LCSSA]], 63 @@ -237,7 +234,6 @@ define i64 @peel_multi_block_loop_iv_step_1() { ; CHECK-NEXT: br i1 [[EC]], label %[[LOOP]], label %[[EXIT_PEEL_BEGIN:.*]], !llvm.loop [[LOOP4:![0-9]+]] ; CHECK: [[EXIT_PEEL_BEGIN]]: ; CHECK-NEXT: [[IV_NEXT_LCSSA:%.*]] = phi i64 [ [[IV_NEXT]], %[[LATCH]] ] -; CHECK-NEXT: [[IV_LCSSA:%.*]] = phi i64 [ [[IV]], %[[LATCH]] ] ; CHECK-NEXT: br label %[[LOOP_PEEL:.*]] ; CHECK: [[LOOP_PEEL]]: ; CHECK-NEXT: [[CMP_PEEL:%.*]] = icmp eq i64 [[IV_NEXT_LCSSA]], 63 @@ -365,7 +361,6 @@ define i64 @peel_single_block_loop_iv_step_1_btc_1() { ; CHECK-NEXT: br i1 false, label %[[LOOP]], label %[[EXIT_PEEL_BEGIN:.*]], !llvm.loop [[LOOP5:![0-9]+]] ; CHECK: [[EXIT_PEEL_BEGIN]]: ; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[IV_NEXT1]], %[[LOOP]] ] -; CHECK-NEXT: [[IV_LCSSA:%.*]] = phi i64 [ [[IV1]], %[[LOOP]] ] ; CHECK-NEXT: br label %[[LOOP_PEEL:.*]] ; CHECK: [[LOOP_PEEL]]: ; CHECK-NEXT: [[CMP:%.*]] = icmp eq i64 [[IV]], 1 @@ -483,9 +478,8 @@ define i32 @peel_loop_with_branch_and_phi_uses(ptr %x, i1 %c) { ; CHECK-NEXT: [[EC1:%.*]] = icmp ne i32 [[IV_NEXT1]], 99 ; CHECK-NEXT: br i1 [[EC1]], label %[[LOOP_HEADER]], label %[[LOOPEXIT_PEEL_BEGIN:.*]], !llvm.loop [[LOOP6:![0-9]+]] ; CHECK: [[LOOPEXIT_PEEL_BEGIN]]: -; CHECK-NEXT: [[RED:%.*]] = phi i32 [ [[ADD1]], %[[LOOP_LATCH]] ] ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_NEXT1]], %[[LOOP_LATCH]] ] -; CHECK-NEXT: [[ADD_LCSSA:%.*]] = phi i32 [ [[ADD1]], %[[LOOP_LATCH]] ] +; CHECK-NEXT: [[RED:%.*]] = phi i32 [ [[ADD1]], %[[LOOP_LATCH]] ] ; CHECK-NEXT: br label %[[LOOP_HEADER_PEEL:.*]] ; CHECK: [[LOOP_HEADER_PEEL]]: ; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i32 [[IV]], 99 diff --git a/llvm/test/Transforms/LoopUnroll/peel-last-iteration-with-variable-trip-count.ll b/llvm/test/Transforms/LoopUnroll/peel-last-iteration-with-variable-trip-count.ll index 75f3674732f35..a8712e04d43c1 100644 --- a/llvm/test/Transforms/LoopUnroll/peel-last-iteration-with-variable-trip-count.ll +++ b/llvm/test/Transforms/LoopUnroll/peel-last-iteration-with-variable-trip-count.ll @@ -9,18 +9,36 @@ define i32 @peel_last_with_trip_count_check_lcssa_phi(i32 %n) { ; CHECK-SAME: i32 [[N:%.*]]) { ; CHECK-NEXT: [[ENTRY:.*]]: ; CHECK-NEXT: [[SUB:%.*]] = add i32 [[N]], -1 +; CHECK-NEXT: [[TMP0:%.*]] = icmp ne i32 [[SUB]], 0 +; CHECK-NEXT: br i1 [[TMP0]], label %[[ENTRY_SPLIT:.*]], label %[[EXIT_PEEL_BEGIN:.*]] +; CHECK: [[ENTRY_SPLIT]]: ; CHECK-NEXT: br label %[[LOOP:.*]] ; CHECK: [[LOOP]]: -; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ] +; CHECK-NEXT: [[IV1:%.*]] = phi i32 [ 0, %[[ENTRY_SPLIT]] ], [ [[IV_NEXT1:%.*]], %[[LOOP]] ] +; CHECK-NEXT: call void @foo(i32 2) +; CHECK-NEXT: [[IV_NEXT1]] = add nuw i32 [[IV1]], 1 +; CHECK-NEXT: [[TMP1:%.*]] = sub i32 [[N]], 1 +; CHECK-NEXT: [[EC1:%.*]] = icmp ne i32 [[IV_NEXT1]], [[TMP1]] +; CHECK-NEXT: br i1 [[EC1]], label %[[LOOP]], label %[[EXIT_PEEL_BEGIN_LOOPEXIT:.*]], !llvm.loop [[LOOP0:![0-9]+]] +; CHECK: [[EXIT_PEEL_BEGIN_LOOPEXIT]]: +; CHECK-NEXT: [[DOTPH:%.*]] = phi i32 [ [[IV_NEXT1]], %[[LOOP]] ] +; CHECK-NEXT: br label %[[EXIT_PEEL_BEGIN]] +; CHECK: [[EXIT_PEEL_BEGIN]]: +; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[DOTPH]], %[[EXIT_PEEL_BEGIN_LOOPEXIT]] ] +; CHECK-NEXT: br label %[[LOOP_PEEL:.*]] +; CHECK: [[LOOP_PEEL]]: ; CHECK-NEXT: [[C:%.*]] = icmp eq i32 [[IV]], [[SUB]] ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[C]], i32 1, i32 2 ; CHECK-NEXT: call void @foo(i32 [[SEL]]) -; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], 1 +; CHECK-NEXT: [[IV_NEXT:%.*]] = add i32 [[IV]], 1 ; CHECK-NEXT: [[EC:%.*]] = icmp ne i32 [[IV_NEXT]], [[N]] -; CHECK-NEXT: br i1 [[EC]], label %[[LOOP]], label %[[EXIT:.*]] +; CHECK-NEXT: br i1 [[EC]], label %[[EXIT_PEEL_NEXT:.*]], label %[[EXIT_PEEL_NEXT]] +; CHECK: [[EXIT_PEEL_NEXT]]: +; CHECK-NEXT: br label %[[LOOP_PEEL_NEXT:.*]] +; CHECK: [[LOOP_PEEL_NEXT]]: +; CHECK-NEXT: br label %[[EXIT:.*]] ; CHECK: [[EXIT]]: -; CHECK-NEXT: [[SEL_LCSSA:%.*]] = phi i32 [ [[SEL]], %[[LOOP]] ] -; CHECK-NEXT: ret i32 [[SEL_LCSSA]] +; CHECK-NEXT: ret i32 [[SEL]] ; entry: %sub = add i32 %n, -1 @@ -160,21 +178,44 @@ define void @peel_last_with_trip_count_check_nested_loop(i32 %n) { ; CHECK-NEXT: [[ENTRY:.*:]] ; CHECK-NEXT: [[SUB:%.*]] = add i32 [[N]], -1 ; CHECK-NEXT: br label %[[OUTER_HEADER:.*]] -; CHECK: [[OUTER_HEADER_LOOPEXIT:.*]]: +; CHECK: [[OUTER_HEADER_LOOPEXIT_PEEL_BEGIN_LOOPEXIT:.*]]: +; CHECK-NEXT: [[DOTPH:%.*]] = phi i32 [ [[IV_NEXT1:%.*]], %[[INNER_LATCH:.*]] ] +; CHECK-NEXT: br label %[[OUTER_HEADER_LOOPEXIT_PEEL_BEGIN:.*]] +; CHECK: [[OUTER_HEADER_LOOPEXIT_PEEL_BEGIN]]: +; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, %[[OUTER_HEADER]] ], [ [[DOTPH]], %[[OUTER_HEADER_LOOPEXIT_PEEL_BEGIN_LOOPEXIT]] ] +; CHECK-NEXT: br label %[[INNER_HEADER_PEEL:.*]] +; CHECK: [[INNER_HEADER_PEEL]]: +; CHECK-NEXT: [[C:%.*]] = icmp eq i32 [[IV]], [[SUB]] +; CHECK-NEXT: br i1 [[C]], label %[[INNER_LATCH_PEEL:.*]], label %[[THEN_PEEL:.*]] +; CHECK: [[THEN_PEEL]]: +; CHECK-NEXT: call void @foo(i32 1) +; CHECK-NEXT: br label %[[INNER_LATCH_PEEL]] +; CHECK: [[INNER_LATCH_PEEL]]: +; CHECK-NEXT: [[IV_NEXT:%.*]] = add i32 [[IV]], 1 +; CHECK-NEXT: [[EXITCOND_NOT:%.*]] = icmp eq i32 [[IV_NEXT]], [[N]] +; CHECK-NEXT: br i1 [[EXITCOND_NOT]], label %[[OUTER_HEADER_LOOPEXIT_PEEL_NEXT:.*]], label %[[OUTER_HEADER_LOOPEXIT_PEEL_NEXT]] +; CHECK: [[OUTER_HEADER_LOOPEXIT_PEEL_NEXT]]: +; CHECK-NEXT: br label %[[INNER_HEADER_PEEL_NEXT:.*]] +; CHECK: [[INNER_HEADER_PEEL_NEXT]]: +; CHECK-NEXT: br label %[[OUTER_HEADER_LOOPEXIT:.*]] +; CHECK: [[OUTER_HEADER_LOOPEXIT]]: ; CHECK-NEXT: br label %[[OUTER_HEADER]] ; CHECK: [[OUTER_HEADER]]: +; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i32 [[SUB]], 0 +; CHECK-NEXT: br i1 [[TMP1]], label %[[OUTER_HEADER_SPLIT:.*]], label %[[OUTER_HEADER_LOOPEXIT_PEEL_BEGIN]] +; CHECK: [[OUTER_HEADER_SPLIT]]: ; CHECK-NEXT: br label %[[INNER_HEADER:.*]] ; CHECK: [[INNER_HEADER]]: -; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, %[[OUTER_HEADER]] ], [ [[IV_NEXT:%.*]], %[[INNER_LATCH:.*]] ] -; CHECK-NEXT: [[C:%.*]] = icmp eq i32 [[IV]], [[SUB]] -; CHECK-NEXT: br i1 [[C]], label %[[INNER_LATCH]], label %[[THEN:.*]] +; CHECK-NEXT: [[IV1:%.*]] = phi i32 [ 0, %[[OUTER_HEADER_SPLIT]] ], [ [[IV_NEXT1]], %[[INNER_LATCH]] ] +; CHECK-NEXT: br i1 false, label %[[INNER_LATCH]], label %[[THEN:.*]] ; CHECK: [[THEN]]: ; CHECK-NEXT: call void @foo(i32 1) ; CHECK-NEXT: br label %[[INNER_LATCH]] ; CHECK: [[INNER_LATCH]]: -; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], 1 -; CHECK-NEXT: [[EXITCOND_NOT:%.*]] = icmp eq i32 [[IV_NEXT]], [[N]] -; CHECK-NEXT: br i1 [[EXITCOND_NOT]], label %[[OUTER_HEADER_LOOPEXIT]], label %[[INNER_HEADER]] +; CHECK-NEXT: [[IV_NEXT1]] = add nuw i32 [[IV1]], 1 +; CHECK-NEXT: [[TMP2:%.*]] = sub i32 [[N]], 1 +; CHECK-NEXT: [[EXITCOND_NOT1:%.*]] = icmp eq i32 [[IV_NEXT1]], [[TMP2]] +; CHECK-NEXT: br i1 [[EXITCOND_NOT1]], label %[[OUTER_HEADER_LOOPEXIT_PEEL_BEGIN_LOOPEXIT]], label %[[INNER_HEADER]], !llvm.loop [[LOOP2:![0-9]+]] ; entry: %sub = add i32 %n, -1 @@ -197,3 +238,8 @@ inner.latch: %exitcond.not = icmp eq i32 %iv.next, %n br i1 %exitcond.not, label %outer.header, label %inner.header } +;. +; CHECK: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]]} +; CHECK: [[META1]] = !{!"llvm.loop.peeled.count", i32 1} +; CHECK: [[LOOP2]] = distinct !{[[LOOP2]], [[META1]]} +;. diff --git a/llvm/test/Transforms/LoopUnroll/unroll-and-peel-last-iteration.ll b/llvm/test/Transforms/LoopUnroll/unroll-and-peel-last-iteration.ll index f57fb2d9b7057..7d38c18d10667 100644 --- a/llvm/test/Transforms/LoopUnroll/unroll-and-peel-last-iteration.ll +++ b/llvm/test/Transforms/LoopUnroll/unroll-and-peel-last-iteration.ll @@ -20,7 +20,6 @@ define i32 @peel_last_iter_of_outer_lcssa_phi_with_constant_after_unrolling_inne ; CHECK-NEXT: br i1 [[EC]], label %[[EXIT_PEEL_BEGIN:.*]], label %[[OUTER_HEADER]], !llvm.loop [[LOOP0:![0-9]+]] ; CHECK: [[EXIT_PEEL_BEGIN]]: ; CHECK-NEXT: [[IV_NEXT_LCSSA:%.*]] = phi i16 [ [[IV_NEXT]], %[[INNER_LATCH]] ] -; CHECK-NEXT: [[DOTLCSSA_LCSSA:%.*]] = phi i32 [ 1, %[[INNER_LATCH]] ] ; CHECK-NEXT: br label %[[OUTER_HEADER_PEEL:.*]] ; CHECK: [[OUTER_HEADER_PEEL]]: ; CHECK-NEXT: [[TMP0:%.*]] = icmp eq i16 [[IV_NEXT_LCSSA]], 999