From 08056a49f10d411c010fa450f86732ff87f5cf49 Mon Sep 17 00:00:00 2001 From: Adam Nemet Date: Mon, 22 Jun 2015 22:59:40 +0000 Subject: [PATCH] [LoopDist] Improve variable names and comments in LoopVersioning class, NFC As with the previous patch, the goal is to turn the class into a general loop-versioning class. This patch removes any references to loop distribution. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240352 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LoopDistribute.cpp | 54 ++++++++++++---------- .../LoopDistribute/basic-with-memchecks.ll | 12 ++--- test/Transforms/LoopDistribute/outside-use.ll | 2 +- 3 files changed, 36 insertions(+), 32 deletions(-) diff --git a/lib/Transforms/Scalar/LoopDistribute.cpp b/lib/Transforms/Scalar/LoopDistribute.cpp index d21a7db48c5..0325d268c32 100644 --- a/lib/Transforms/Scalar/LoopDistribute.cpp +++ b/lib/Transforms/Scalar/LoopDistribute.cpp @@ -635,10 +635,11 @@ public: LoopVersioning(const LoopAccessInfo &LAI, Loop *L, LoopInfo *LI, DominatorTree *DT, const SmallVector *PtrToPartition = nullptr) - : OrigLoop(L), NonDistributedLoop(nullptr), + : VersionedLoop(L), NonVersionedLoop(nullptr), PtrToPartition(PtrToPartition), LAI(LAI), LI(LI), DT(DT) {} - /// \brief Returns true if we need memchecks to distribute the loop. + /// \brief Returns true if we need memchecks to disambiguate may-aliasing + /// accesses. bool needsRuntimeChecks() const { return LAI.getRuntimePointerCheck()->needsAnyChecking(PtrToPartition); } @@ -649,49 +650,51 @@ public: Instruction *FirstCheckInst; Instruction *MemRuntimeCheck; // Add the memcheck in the original preheader (this is empty initially). - BasicBlock *MemCheckBB = OrigLoop->getLoopPreheader(); + BasicBlock *MemCheckBB = VersionedLoop->getLoopPreheader(); std::tie(FirstCheckInst, MemRuntimeCheck) = LAI.addRuntimeCheck(MemCheckBB->getTerminator(), PtrToPartition); assert(MemRuntimeCheck && "called even though needsAnyChecking = false"); // Rename the block to make the IR more readable. - MemCheckBB->setName(OrigLoop->getHeader()->getName() + ".ldist.memcheck"); + MemCheckBB->setName(VersionedLoop->getHeader()->getName() + + ".lver.memcheck"); // Create empty preheader for the loop (and after cloning for the - // original/nondist loop). + // non-versioned loop). BasicBlock *PH = SplitBlock(MemCheckBB, MemCheckBB->getTerminator(), DT, LI); - PH->setName(OrigLoop->getHeader()->getName() + ".ph"); + PH->setName(VersionedLoop->getHeader()->getName() + ".ph"); // Clone the loop including the preheader. // // FIXME: This does not currently preserve SimplifyLoop because the exit // block is a join between the two loops. - SmallVector NonDistributedLoopBlocks; - NonDistributedLoop = - cloneLoopWithPreheader(PH, MemCheckBB, OrigLoop, VMap, ".ldist.nondist", - LI, DT, NonDistributedLoopBlocks); - remapInstructionsInLoop(NonDistributedLoopBlocks, VMap); + SmallVector NonVersionedLoopBlocks; + NonVersionedLoop = + cloneLoopWithPreheader(PH, MemCheckBB, VersionedLoop, VMap, + ".lver.orig", LI, DT, NonVersionedLoopBlocks); + remapInstructionsInLoop(NonVersionedLoopBlocks, VMap); // Insert the conditional branch based on the result of the memchecks. Instruction *OrigTerm = MemCheckBB->getTerminator(); - BranchInst::Create(NonDistributedLoop->getLoopPreheader(), - OrigLoop->getLoopPreheader(), MemRuntimeCheck, OrigTerm); + BranchInst::Create(NonVersionedLoop->getLoopPreheader(), + VersionedLoop->getLoopPreheader(), MemRuntimeCheck, + OrigTerm); OrigTerm->eraseFromParent(); // The loops merge in the original exit block. This is now dominated by the // memchecking block. - DT->changeImmediateDominator(OrigLoop->getExitBlock(), MemCheckBB); + DT->changeImmediateDominator(VersionedLoop->getExitBlock(), MemCheckBB); } /// \brief Adds the necessary PHI nodes for the versioned loops based on the /// loop-defined values used outside of the loop. void addPHINodes(const SmallVectorImpl &DefsUsedOutside) { - BasicBlock *PHIBlock = OrigLoop->getExitBlock(); + BasicBlock *PHIBlock = VersionedLoop->getExitBlock(); assert(PHIBlock && "No single successor to loop exit block"); for (auto *Inst : DefsUsedOutside) { - auto *NonDistInst = cast(VMap[Inst]); + auto *NonVersionedLoopInst = cast(VMap[Inst]); PHINode *PN; // First see if we have a single-operand PHI with the value defined by the @@ -704,24 +707,25 @@ public: } // If not create it. if (!PN) { - PN = PHINode::Create(Inst->getType(), 2, Inst->getName() + ".ldist", + PN = PHINode::Create(Inst->getType(), 2, Inst->getName() + ".lver", PHIBlock->begin()); for (auto *User : Inst->users()) - if (!OrigLoop->contains(cast(User)->getParent())) + if (!VersionedLoop->contains(cast(User)->getParent())) User->replaceUsesOfWith(Inst, PN); - PN->addIncoming(Inst, OrigLoop->getExitingBlock()); + PN->addIncoming(Inst, VersionedLoop->getExitingBlock()); } - // Add the new incoming value from the non-distributed loop. - PN->addIncoming(NonDistInst, NonDistributedLoop->getExitingBlock()); + // Add the new incoming value from the non-versioned loop. + PN->addIncoming(NonVersionedLoopInst, + NonVersionedLoop->getExitingBlock()); } } private: /// \brief The original loop. This becomes the "versioned" one, i.e. control /// goes if the memchecks all pass. - Loop *OrigLoop; + Loop *VersionedLoop; /// \brief The fall-back loop, i.e. if any of the memchecks fail. - Loop *NonDistributedLoop; + Loop *NonVersionedLoop; /// \brief For each memory pointer it contains the partitionId it is used in. /// If nullptr, no partitioning is used. @@ -730,8 +734,8 @@ private: /// If the pointer is used in multiple partitions the entry is set to -1. const SmallVector *PtrToPartition; - /// \brief This maps the instructions from OrigLoop to their counterpart in - /// NonDistributedLoop. + /// \brief This maps the instructions from VersionedLoop to their counterpart + /// in NonVersionedLoop. ValueToValueMapTy VMap; /// \brief Analyses used. diff --git a/test/Transforms/LoopDistribute/basic-with-memchecks.ll b/test/Transforms/LoopDistribute/basic-with-memchecks.ll index 4c1c1b82296..fde06d33c5a 100644 --- a/test/Transforms/LoopDistribute/basic-with-memchecks.ll +++ b/test/Transforms/LoopDistribute/basic-with-memchecks.ll @@ -35,7 +35,7 @@ entry: ; We have two compares for each array overlap check which is a total of 10 ; compares. ; -; CHECK: for.body.ldist.memcheck: +; CHECK: for.body.lver.memcheck: ; CHECK: = icmp ; CHECK: = icmp @@ -52,14 +52,14 @@ entry: ; CHECK: = icmp ; CHECK-NOT: = icmp -; CHECK: br i1 %memcheck.conflict, label %for.body.ph.ldist.nondist, label %for.body.ph.ldist1 +; CHECK: br i1 %memcheck.conflict, label %for.body.ph.lver.orig, label %for.body.ph.ldist1 ; The non-distributed loop that the memchecks fall back on. -; CHECK: for.body.ph.ldist.nondist: -; CHECK: br label %for.body.ldist.nondist -; CHECK: for.body.ldist.nondist: -; CHECK: br i1 %exitcond.ldist.nondist, label %for.end, label %for.body.ldist.nondist +; CHECK: for.body.ph.lver.orig: +; CHECK: br label %for.body.lver.orig +; CHECK: for.body.lver.orig: +; CHECK: br i1 %exitcond.lver.orig, label %for.end, label %for.body.lver.orig ; Verify the two distributed loops. diff --git a/test/Transforms/LoopDistribute/outside-use.ll b/test/Transforms/LoopDistribute/outside-use.ll index 546050d5b04..7a3fe1be067 100644 --- a/test/Transforms/LoopDistribute/outside-use.ll +++ b/test/Transforms/LoopDistribute/outside-use.ll @@ -37,7 +37,7 @@ entry: ; CHECK: for.body: ; CHECK: %sum_add = add nuw nsw i32 %sum, %loadC ; CHECK: for.end: -; CHECK: %sum_add.ldist = phi i32 [ %sum_add, %for.body ], [ %sum_add.ldist.nondist, %for.body.ldist.nondist ] +; CHECK: %sum_add.lver = phi i32 [ %sum_add, %for.body ], [ %sum_add.lver.orig, %for.body.lver.orig ] for.body: ; preds = %for.body, %entry %ind = phi i64 [ 0, %entry ], [ %add, %for.body ] -- 2.11.0