[llvm] r245402 - Revert "Fix PR24469 resulting from r245025 and re-enable dead store elimination across basicblocks."

Eric Christopher via llvm-commits llvm-commits at lists.llvm.org
Tue Aug 18 19:15:13 PDT 2015


Author: echristo
Date: Tue Aug 18 21:15:13 2015
New Revision: 245402

URL: http://llvm.org/viewvc/llvm-project?rev=245402&view=rev
Log:
Revert "Fix PR24469 resulting from r245025 and re-enable dead store elimination across basicblocks."

This is causing bootstrap problems, e.g.: http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/2960

This reverts r245195.

Removed:
    llvm/trunk/test/Transforms/DeadStoreElimination/cross_block_dse.ll
    llvm/trunk/test/Transforms/DeadStoreElimination/cross_block_dse_loop.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp?rev=245402&r1=245401&r2=245402&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp Tue Aug 18 21:15:13 2015
@@ -16,16 +16,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Scalar.h"
-#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/CaptureTracking.h"
-#include "llvm/Analysis/CFG.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
-#include "llvm/Analysis/PostDominators.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/Constants.h"
@@ -45,7 +42,6 @@ using namespace llvm;
 
 STATISTIC(NumRedundantStores, "Number of redundant stores deleted");
 STATISTIC(NumFastStores, "Number of stores deleted");
-STATISTIC(NumCrossBlockStores, "Number of cross block stores deleted");
 STATISTIC(NumFastOther , "Number of other instrs removed");
 
 namespace {
@@ -53,41 +49,12 @@ namespace {
     AliasAnalysis *AA;
     MemoryDependenceAnalysis *MD;
     DominatorTree *DT;
-    PostDominatorTree *PDT;
     const TargetLibraryInfo *TLI;
-    SmallVector<SmallVector<StoreInst *, 8>, 16> Candidates;
-    SetVector<StoreInst *> DeadStores;
-    SmallVector<std::pair<const BasicBlock *, const BasicBlock *>, 32>
-        BackEdges;
-    DenseSet<std::pair<const BasicBlock *, const BasicBlock *>> BackEdgesMap;
+
     static char ID; // Pass identification, replacement for typeid
-    DSE()
-        : FunctionPass(ID), AA(nullptr), MD(nullptr), DT(nullptr),
-          PDT(nullptr) {
+    DSE() : FunctionPass(ID), AA(nullptr), MD(nullptr), DT(nullptr) {
       initializeDSEPass(*PassRegistry::getPassRegistry());
     }
-    // Return all stores in a given BasicBlock.
-    SmallVector<StoreInst *, 8> getStores(BasicBlock *BB) {
-      SmallVector<StoreInst *, 8> VecStores;
-      for (auto &BI : *BB) {
-        if (StoreInst *SI = dyn_cast<StoreInst>(&BI))
-          VecStores.push_back(SI);
-      }
-      return VecStores;
-    }
-
-    // Get dfs in/out on the PDT and populate Candidates store list which
-    // is used to find potential dead stores for a given block
-    void populateCandidateStores(Function &F) {
-      for (auto &I : F) {
-        DomTreeNode *DTNode = PDT->getNode(&I);
-        if (!DTNode)
-          continue;
-        int DFSIn = DTNode->getDFSNumIn();
-        SmallVector<StoreInst *, 8> VecStores = getStores(&I);
-        Candidates[DFSIn] = VecStores;
-      }
-    }
 
     bool runOnFunction(Function &F) override {
       if (skipOptnoneFunction(F))
@@ -97,21 +64,7 @@ namespace {
       MD = &getAnalysis<MemoryDependenceAnalysis>();
       DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
       TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
-      PDT = &getAnalysis<PostDominatorTree>();
-      if (PDT->getRootNode()) {
-        int Count = PDT->getRootNode()->getDFSNumOut();
-        SmallVector<StoreInst *, 8> VecStores;
-        Candidates.resize(Count + 1);
-        Candidates.assign(Count + 1, VecStores);
-
-        // If we have more than 1 block try to populate candidate store.
-        if (Count > 1) {
-          populateCandidateStores(F);
-          FindFunctionBackedges(F, BackEdges);
-          for (auto I : BackEdges)
-            BackEdgesMap.insert(I);
-        }
-      }
+
       bool Changed = false;
       for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
         // Only check non-dead blocks.  Dead blocks may have strange pointer
@@ -130,24 +83,16 @@ namespace {
     void RemoveAccessedObjects(const MemoryLocation &LoadedLoc,
                                SmallSetVector<Value *, 16> &DeadStackObjects,
                                const DataLayout &DL);
-    void handleNonLocalStoreDeletion(StoreInst *SI, BasicBlock::iterator &BBI,
-                                     BasicBlock &CurBlock);
-    bool isSafeCandidateForDeletion(BasicBlock *SrcBlock, BasicBlock *SinkBlock,
-                                    StoreInst *SI);
-    void DeleteDeadInstruction(Instruction *I, MemoryDependenceAnalysis &MD,
-                               const TargetLibraryInfo &TLI,
-                               SmallSetVector<Value *, 16> *ValueSet = nullptr);
+
     void getAnalysisUsage(AnalysisUsage &AU) const override {
       AU.setPreservesCFG();
       AU.addRequired<DominatorTreeWrapperPass>();
       AU.addRequired<AliasAnalysis>();
       AU.addRequired<MemoryDependenceAnalysis>();
-      AU.addRequired<PostDominatorTree>();
       AU.addRequired<TargetLibraryInfoWrapperPass>();
       AU.addPreserved<AliasAnalysis>();
       AU.addPreserved<DominatorTreeWrapperPass>();
       AU.addPreserved<MemoryDependenceAnalysis>();
-      AU.addPreserved<PostDominatorTree>();
     }
   };
 }
@@ -157,7 +102,6 @@ INITIALIZE_PASS_BEGIN(DSE, "dse", "Dead
 INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(MemoryDependenceAnalysis)
-INITIALIZE_PASS_DEPENDENCY(PostDominatorTree)
 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
 INITIALIZE_PASS_END(DSE, "dse", "Dead Store Elimination", false, false)
 
@@ -167,6 +111,50 @@ FunctionPass *llvm::createDeadStoreElimi
 // Helper functions
 //===----------------------------------------------------------------------===//
 
+/// DeleteDeadInstruction - Delete this instruction.  Before we do, go through
+/// and zero out all the operands of this instruction.  If any of them become
+/// dead, delete them and the computation tree that feeds them.
+///
+/// If ValueSet is non-null, remove any deleted instructions from it as well.
+///
+static void DeleteDeadInstruction(Instruction *I,
+                               MemoryDependenceAnalysis &MD,
+                               const TargetLibraryInfo &TLI,
+                               SmallSetVector<Value*, 16> *ValueSet = nullptr) {
+  SmallVector<Instruction*, 32> NowDeadInsts;
+
+  NowDeadInsts.push_back(I);
+  --NumFastOther;
+
+  // Before we touch this instruction, remove it from memdep!
+  do {
+    Instruction *DeadInst = NowDeadInsts.pop_back_val();
+    ++NumFastOther;
+
+    // This instruction is dead, zap it, in stages.  Start by removing it from
+    // MemDep, which needs to know the operands and needs it to be in the
+    // function.
+    MD.removeInstruction(DeadInst);
+
+    for (unsigned op = 0, e = DeadInst->getNumOperands(); op != e; ++op) {
+      Value *Op = DeadInst->getOperand(op);
+      DeadInst->setOperand(op, nullptr);
+
+      // If this operand just became dead, add it to the NowDeadInsts list.
+      if (!Op->use_empty()) continue;
+
+      if (Instruction *OpI = dyn_cast<Instruction>(Op))
+        if (isInstructionTriviallyDead(OpI, &TLI))
+          NowDeadInsts.push_back(OpI);
+    }
+
+    DeadInst->eraseFromParent();
+
+    if (ValueSet) ValueSet->remove(DeadInst);
+  } while (!NowDeadInsts.empty());
+}
+
+
 /// hasMemoryWrite - Does this instruction write some memory?  This only returns
 /// true for things that we can analyze with other helpers below.
 static bool hasMemoryWrite(Instruction *I, const TargetLibraryInfo &TLI) {
@@ -539,15 +527,10 @@ bool DSE::runOnBasicBlock(BasicBlock &BB
 
     MemDepResult InstDep = MD->getDependency(Inst);
 
-    if (!InstDep.isDef() && !InstDep.isClobber() && !InstDep.isNonLocal())
+    // Ignore any store where we can't find a local dependence.
+    // FIXME: cross-block DSE would be fun. :)
+    if (!InstDep.isDef() && !InstDep.isClobber())
       continue;
-    if (InstDep.isNonLocal()) {
-      if (!PDT->getRootNode())
-        continue;
-      if (StoreInst *SI = dyn_cast<StoreInst>(Inst))
-        handleNonLocalStoreDeletion(SI, BBI, BB);
-      continue;
-    }
 
     // Figure out what location is being stored to.
     MemoryLocation Loc = getLocForWrite(Inst, *AA);
@@ -721,50 +704,6 @@ static void FindUnconditionalPreds(Small
   }
 }
 
-/// DeleteDeadInstruction - Delete this instruction.  Before we do, go through
-/// and zero out all the operands of this instruction.  If any of them become
-/// dead, delete them and the computation tree that feeds them.
-/// If ValueSet is non-null, remove any deleted instructions from it as well.
-void DSE::DeleteDeadInstruction(Instruction *I, MemoryDependenceAnalysis &MD,
-                                const TargetLibraryInfo &TLI,
-                                SmallSetVector<Value *, 16> *ValueSet) {
-  SmallVector<Instruction *, 32> NowDeadInsts;
-
-  NowDeadInsts.push_back(I);
-  --NumFastOther;
-
-  // Before we touch this instruction, remove it from memdep!
-  do {
-    Instruction *DeadInst = NowDeadInsts.pop_back_val();
-    ++NumFastOther;
-    if (StoreInst *SI = dyn_cast<StoreInst>(DeadInst))
-      DeadStores.insert(SI);
-
-    // This instruction is dead, zap it, in stages.  Start by removing it from
-    // MemDep, which needs to know the operands and needs it to be in the
-    // function.
-    MD.removeInstruction(DeadInst);
-
-    for (unsigned op = 0, e = DeadInst->getNumOperands(); op != e; ++op) {
-      Value *Op = DeadInst->getOperand(op);
-      DeadInst->setOperand(op, nullptr);
-
-      // If this operand just became dead, add it to the NowDeadInsts list.
-      if (!Op->use_empty())
-        continue;
-
-      if (Instruction *OpI = dyn_cast<Instruction>(Op))
-        if (isInstructionTriviallyDead(OpI, &TLI))
-          NowDeadInsts.push_back(OpI);
-    }
-
-    DeadInst->eraseFromParent();
-
-    if (ValueSet)
-      ValueSet->remove(DeadInst);
-  } while (!NowDeadInsts.empty());
-}
-
 /// HandleFree - Handle frees of entire structures whose dependency is a store
 /// to a field of that structure.
 bool DSE::HandleFree(CallInst *F) {
@@ -992,122 +931,3 @@ void DSE::RemoveAccessedObjects(const Me
     return !AA->isNoAlias(StackLoc, LoadedLoc);
   });
 }
-
-/// isSafeCandidateForDeletion- Check all paths from the SrcBlock till
-/// SinkBlock to see if Store 'SI' is safe to be remove.
-/// Returns true if the candidate store SI is safe to delete
-/// else returns false.
-bool DSE::isSafeCandidateForDeletion(BasicBlock *SrcBlock,
-                                     BasicBlock *SinkBlock, StoreInst *SI) {
-  SmallVector<BasicBlock *, 16> WorkList;
-  SmallPtrSet<BasicBlock *, 8> Visited;
-  BasicBlock::iterator BBI(SI);
-
-  // Check from the store till end of block and make sure we have no references
-  // to memory stored by this Store Instruction.
-  for (auto BI = ++BBI, BE = SrcBlock->end(); BI != BE; ++BI) {
-    Instruction *I = BI;
-    StoreInst *CSI = dyn_cast<StoreInst>(I);
-    if (CSI) {
-      AliasResult R =
-          AA->alias(MemoryLocation::get(SI), MemoryLocation::get(CSI));
-      if (R == MustAlias)
-        return true;
-    } else {
-      ModRefInfo Res = AA->getModRefInfo(I, MemoryLocation::get(SI));
-      if (Res != MRI_NoModRef)
-        return false;
-    }
-  }
-
-  // Add successors of the block to stack and start DFS.
-  for (succ_iterator I = succ_begin(SrcBlock), E = succ_end(SrcBlock); I != E;
-       ++I) {
-    if (!Visited.insert(*I).second)
-      continue;
-    // A path with backedge may not be safe. Conservatively mark
-    // this store unsafe.
-    if (BackEdgesMap.count(std::make_pair(SrcBlock, *I)))
-      return false;
-    WorkList.push_back(*I);
-  }
-
-  while (!WorkList.empty()) {
-    BasicBlock *B = WorkList.pop_back_val();
-    auto BI = B->begin();
-    auto BE = B->end();
-    for (; BI != BE; ++BI) {
-      Instruction *I = BI;
-      StoreInst *CSI = dyn_cast<StoreInst>(I);
-      if (CSI) {
-        AliasResult R =
-            AA->alias(MemoryLocation::get(SI), MemoryLocation::get(CSI));
-        if (R == MustAlias)
-          break;
-      } else {
-        ModRefInfo Res = AA->getModRefInfo(I, MemoryLocation::get(SI));
-        if (Res != MRI_NoModRef)
-          return false;
-      }
-    }
-
-    // If we reached the sink node or we found a block which has a stores that
-    // overwrites the candidate block we need not look at their successors.
-    if (B == SinkBlock || BI != BE)
-      continue;
-
-    for (succ_iterator I = succ_begin(B), E = succ_end(B); I != E; ++I) {
-      if (!Visited.insert(*I).second)
-        continue;
-      // A path with backedge may not be safe.Conservatively mark
-      // this store unsafe.
-      if (BackEdgesMap.count(std::make_pair(B, *I)))
-        return false;
-      WorkList.push_back(*I);
-    }
-  }
-
-  return true;
-}
-
-/// handleNonLocalStoreDeletion - Handle non local dead store elimination.
-/// This works by finding candidate stores using PDT and then running DFS
-/// from candidate store block checking all paths to make sure the store is
-/// safe to delete.
-void DSE::handleNonLocalStoreDeletion(StoreInst *SI, BasicBlock::iterator &BBI,
-                                      BasicBlock &CurBlock) {
-  BasicBlock *BB = SI->getParent();
-  Value *Pointer = SI->getPointerOperand();
-  DomTreeNode *DTNode = PDT->getNode(BB);
-  if (!DTNode)
-    return;
-
-  int DFSNumIn = DTNode->getDFSNumIn();
-  int DFSNumOut = DTNode->getDFSNumOut();
-  for (int i = DFSNumIn + 1; i < DFSNumOut; ++i) {
-    for (auto &I : Candidates[i]) {
-      StoreInst *CandidateSI = I;
-      if (DeadStores.count(CandidateSI))
-        continue;
-      Value *MemPtr = CandidateSI->getPointerOperand();
-      if (!MemPtr)
-        continue;
-      if (Pointer->getType() != MemPtr->getType())
-        continue;
-      AliasResult R =
-          AA->alias(MemoryLocation::get(SI), MemoryLocation::get(CandidateSI));
-      if (R != MustAlias)
-        continue;
-      if (isSafeCandidateForDeletion(CandidateSI->getParent(), BB,
-                                     CandidateSI)) {
-        DeleteDeadInstruction(CandidateSI, *MD, *TLI);
-        ++NumCrossBlockStores;
-        // DeleteDeadInstruction can delete the current instruction in loop
-        // cases, reset BBI.
-        BBI = SI;
-        if (BBI != CurBlock.begin())
-          --BBI;
-      }
-    }
-  }
-}

Removed: llvm/trunk/test/Transforms/DeadStoreElimination/cross_block_dse.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/DeadStoreElimination/cross_block_dse.ll?rev=245401&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/DeadStoreElimination/cross_block_dse.ll (original)
+++ llvm/trunk/test/Transforms/DeadStoreElimination/cross_block_dse.ll (removed)
@@ -1,104 +0,0 @@
-; RUN: opt < %s -basicaa -dse -S | FileCheck %s
-target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
-
- at x = common global i32 0
- at y = common global i32 0
- at a = external global i32
- at b = external global i32
-
-define void @test_01(i32 %N) {
-  %1 = alloca i32
-  store i32 %N, i32* %1
-  store i32 10, i32* @x
-  %2 = load i32, i32* %1
-  %3 = icmp ne i32 %2, 0
-  br i1 %3, label %4, label %5
-
-; <label>:4
-  store i32 5, i32* @x
-  br label %5
-
-; <label>:5
-  store i32 15, i32* @x
-  ret void
-}
-; CHECK-LABEL: @test_01(
-; CHECK-NOT: store i32 10, i32* @x
-; CHECK-NOT: store i32 5, i32* @x
-; CHECK: store i32 15, i32* @x
-
-
-define void @test_02(i32 %N) {
-  %1 = alloca i32
-  store i32 %N, i32* %1
-  store i32 10, i32* @x
-  %2 = load i32, i32* %1
-  %3 = icmp ne i32 %2, 0
-  br i1 %3, label %4, label %5
-
-; <label>:4
-  store i32 5, i32* @x
-  br label %7
-
-; <label>:5
-  %6 = load i32, i32* @x
-  store i32 %6, i32* @y
-  br label %7
-
-; <label>:7
-  store i32 15, i32* @x
-  ret void
-}
-; CHECK-LABEL: @test_02(
-; CHECK: store i32 10, i32* @x
-; CHECK-NOT: store i32 5, i32* @x
-; CHECK: store i32 %6, i32* @y
-
-
-define void @test_03(i32 %N) #0 {
-  %1 = alloca i32
-  store i32 %N, i32* %1
-  store i32 10, i32* @x
-  %2 = load i32, i32* %1
-  %3 = icmp ne i32 %2, 0
-  br i1 %3, label %4, label %6
-
-; <label>:4                                       ; preds = %0
-  %5 = load i32, i32* @x
-  store i32 %5, i32* @y
-  br label %6
-
-; <label>:6                                       ; preds = %4, %0
-  store i32 15, i32* @x
-  ret void
-}
-; CHECK-LABEL: @test_03(
-; CHECK: store i32 10, i32* @x
-; CHECK: store i32 %5, i32* @y
-; CHECK: store i32 15, i32* @x
-
-
-
-; Check we safely delete store i32 %g.02, i32* @b below.(PR24469)
-define void @test_04() {
-entry:
-  br i1 false, label %for.body, label %for.end.9
-
-for.cond.1.loopexit:                              ; preds = %for.body
-  store i32 0, i32* @b
-  %0 = load i32, i32* @a
-  br i1 false, label %for.body, label %for.end.9
-
-for.body:                                         ; preds = %for.cond.1.loopexit, %entry
-  %g.02 = phi i32 [ undef, %entry ], [ %0, %for.cond.1.loopexit ]
-  store i32 %g.02, i32* @b
-  br label %for.cond.1.loopexit
-
-for.end.9:                                        ; preds = %for.cond.1.loopexit, %entry
-  ret void
-}
-
-; CHECK-LABEL: @test_04(
-; CHECK-NOT: store i32 %g.02, i32* @b
-; CHECK-NOT: %g.02 = phi i32 [ undef, %entry ], [ %0, %for.cond.1.loopexit ]
-; CHECK-NOT: %0 = load i32, i32* @a

Removed: llvm/trunk/test/Transforms/DeadStoreElimination/cross_block_dse_loop.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/DeadStoreElimination/cross_block_dse_loop.ll?rev=245401&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/DeadStoreElimination/cross_block_dse_loop.ll (original)
+++ llvm/trunk/test/Transforms/DeadStoreElimination/cross_block_dse_loop.ll (removed)
@@ -1,104 +0,0 @@
-; RUN: opt < %s -basicaa -dse -S | FileCheck %s
-target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
-
- at A = common global [100 x i32] zeroinitializer, align 16
- at x = common global i32 0
-
-; Negative Test case-
-;void foo(int N) {
-;  A[0] = N;
-;  for(int i=0;i<N;++i)
-;    A[i]+=i;
-;  A[0] = 10;
-;}
-;; Stores should not be optimized away.
-
-define void @test_01(i32 %N) #0 {
-  %1 = alloca i32
-  %i = alloca i32
-  store i32 %N, i32* %1
-  %2 = load i32, i32* %1
-  store i32 %2, i32* getelementptr inbounds ([100 x i32], [100 x i32]* @A, i32 0, i64 0)
-  store i32 0, i32* %i
-  br label %3
-
-; <label>:3                                       ; preds = %14, %0
-  %4 = load i32, i32* %i
-  %5 = load i32, i32* %1
-  %6 = icmp slt i32 %4, %5
-  br i1 %6, label %7, label %17
-
-; <label>:7                                       ; preds = %3
-  %8 = load i32, i32* %i
-  %9 = load i32, i32* %i
-  %10 = sext i32 %9 to i64
-  %11 = getelementptr inbounds [100 x i32], [100 x i32]* @A, i32 0, i64 %10
-  %12 = load i32, i32* %11
-  %13 = add nsw i32 %12, %8
-  store i32 %13, i32* %11
-  br label %14
-
-; <label>:14                                      ; preds = %7
-  %15 = load i32, i32* %i
-  %16 = add nsw i32 %15, 1
-  store i32 %16, i32* %i
-  br label %3
-
-; <label>:17                                      ; preds = %3
-  store i32 10, i32* getelementptr inbounds ([100 x i32], [100 x i32]* @A, i32 0, i64 0)
-  ret void
-}
-; CHECK-LABEL: @test_01(
-; CHECK: store i32 %2, i32* getelementptr inbounds ([100 x i32], [100 x i32]* @A, i32 0, i64 0)
-; CHECK: store i32 %13, i32* %11
-; CHECK: store i32 10, i32* getelementptr inbounds ([100 x i32], [100 x i32]* @A, i32 0, i64 0)
-
-
-; Postive Test case-
-;void foo(int N) {
-;  A[0] = N;
-;  for(int i=0;i<N;++i)
-;    A[i]=i;
-;  A[0] = 10;
-;}
-;; Stores should not be optimized away.
-define void @test_02(i32 %N) #0 {
-  %1 = alloca i32
-  %i = alloca i32
-  store i32 %N, i32* %1
-  %2 = load i32, i32* %1
-  store i32 %2, i32* getelementptr inbounds ([100 x i32], [100 x i32]* @A, i32 0, i64 0)
-  store i32 0, i32* %i
-  br label %3
-
-; <label>:3                                       ; preds = %12, %0
-  %4 = load i32, i32* %i
-  %5 = load i32, i32* %1
-  %6 = icmp slt i32 %4, %5
-  br i1 %6, label %7, label %15
-
-; <label>:7                                       ; preds = %3
-  %8 = load i32, i32* %i
-  %9 = load i32, i32* %i
-  %10 = sext i32 %9 to i64
-  %11 = getelementptr inbounds [100 x i32], [100 x i32]* @A, i32 0, i64 %10
-  store i32 %8, i32* %11
-  br label %12
-
-; <label>:12                                      ; preds = %7
-  %13 = load i32, i32* %i
-  %14 = add nsw i32 %13, 1
-  store i32 %14, i32* %i
-  br label %3
-
-; <label>:15                                      ; preds = %3
-  store i32 10, i32* getelementptr inbounds ([100 x i32], [100 x i32]* @A, i32 0, i64 0)
-  ret void
-}
-
-; CHECK-LABEL: @test_02(
-; CHECK-NOT: store i32 %2, i32* getelementptr inbounds ([100 x i32], [100 x i32]* @A, i32 0, i64 0)
-; CHECK: store i32 %7, i32* %10
-; CHECK: store i32 10, i32* getelementptr inbounds ([100 x i32], [100 x i32]* @A, i32 0, i64 0)
-
-




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