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-rw-r--r--lib/Transforms/Utils/LoopSimplify.cpp57
1 files changed, 25 insertions, 32 deletions
diff --git a/lib/Transforms/Utils/LoopSimplify.cpp b/lib/Transforms/Utils/LoopSimplify.cpp
index f43af9772771..970494eb4704 100644
--- a/lib/Transforms/Utils/LoopSimplify.cpp
+++ b/lib/Transforms/Utils/LoopSimplify.cpp
@@ -52,6 +52,7 @@
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
+#include "llvm/Transforms/Utils/Local.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
@@ -64,9 +65,8 @@
#include "llvm/IR/Type.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/LoopUtils.h"
using namespace llvm;
@@ -141,8 +141,8 @@ BasicBlock *llvm::InsertPreheaderForLoop(Loop *L, DominatorTree *DT,
if (!PreheaderBB)
return nullptr;
- DEBUG(dbgs() << "LoopSimplify: Creating pre-header "
- << PreheaderBB->getName() << "\n");
+ LLVM_DEBUG(dbgs() << "LoopSimplify: Creating pre-header "
+ << PreheaderBB->getName() << "\n");
// Make sure that NewBB is put someplace intelligent, which doesn't mess up
// code layout too horribly.
@@ -170,7 +170,7 @@ static void addBlockAndPredsToSet(BasicBlock *InputBB, BasicBlock *StopBlock,
} while (!Worklist.empty());
}
-/// \brief The first part of loop-nestification is to find a PHI node that tells
+/// The first part of loop-nestification is to find a PHI node that tells
/// us how to partition the loops.
static PHINode *findPHIToPartitionLoops(Loop *L, DominatorTree *DT,
AssumptionCache *AC) {
@@ -195,7 +195,7 @@ static PHINode *findPHIToPartitionLoops(Loop *L, DominatorTree *DT,
return nullptr;
}
-/// \brief If this loop has multiple backedges, try to pull one of them out into
+/// If this loop has multiple backedges, try to pull one of them out into
/// a nested loop.
///
/// This is important for code that looks like
@@ -242,7 +242,7 @@ static Loop *separateNestedLoop(Loop *L, BasicBlock *Preheader,
OuterLoopPreds.push_back(PN->getIncomingBlock(i));
}
}
- DEBUG(dbgs() << "LoopSimplify: Splitting out a new outer loop\n");
+ LLVM_DEBUG(dbgs() << "LoopSimplify: Splitting out a new outer loop\n");
// If ScalarEvolution is around and knows anything about values in
// this loop, tell it to forget them, because we're about to
@@ -332,7 +332,7 @@ static Loop *separateNestedLoop(Loop *L, BasicBlock *Preheader,
return NewOuter;
}
-/// \brief This method is called when the specified loop has more than one
+/// This method is called when the specified loop has more than one
/// backedge in it.
///
/// If this occurs, revector all of these backedges to target a new basic block
@@ -371,8 +371,8 @@ static BasicBlock *insertUniqueBackedgeBlock(Loop *L, BasicBlock *Preheader,
BranchInst *BETerminator = BranchInst::Create(Header, BEBlock);
BETerminator->setDebugLoc(Header->getFirstNonPHI()->getDebugLoc());
- DEBUG(dbgs() << "LoopSimplify: Inserting unique backedge block "
- << BEBlock->getName() << "\n");
+ LLVM_DEBUG(dbgs() << "LoopSimplify: Inserting unique backedge block "
+ << BEBlock->getName() << "\n");
// Move the new backedge block to right after the last backedge block.
Function::iterator InsertPos = ++BackedgeBlocks.back()->getIterator();
@@ -457,7 +457,7 @@ static BasicBlock *insertUniqueBackedgeBlock(Loop *L, BasicBlock *Preheader,
return BEBlock;
}
-/// \brief Simplify one loop and queue further loops for simplification.
+/// Simplify one loop and queue further loops for simplification.
static bool simplifyOneLoop(Loop *L, SmallVectorImpl<Loop *> &Worklist,
DominatorTree *DT, LoopInfo *LI,
ScalarEvolution *SE, AssumptionCache *AC,
@@ -484,8 +484,8 @@ ReprocessLoop:
// Delete each unique out-of-loop (and thus dead) predecessor.
for (BasicBlock *P : BadPreds) {
- DEBUG(dbgs() << "LoopSimplify: Deleting edge from dead predecessor "
- << P->getName() << "\n");
+ LLVM_DEBUG(dbgs() << "LoopSimplify: Deleting edge from dead predecessor "
+ << P->getName() << "\n");
// Zap the dead pred's terminator and replace it with unreachable.
TerminatorInst *TI = P->getTerminator();
@@ -504,16 +504,13 @@ ReprocessLoop:
if (BI->isConditional()) {
if (UndefValue *Cond = dyn_cast<UndefValue>(BI->getCondition())) {
- DEBUG(dbgs() << "LoopSimplify: Resolving \"br i1 undef\" to exit in "
- << ExitingBlock->getName() << "\n");
+ LLVM_DEBUG(dbgs()
+ << "LoopSimplify: Resolving \"br i1 undef\" to exit in "
+ << ExitingBlock->getName() << "\n");
BI->setCondition(ConstantInt::get(Cond->getType(),
!L->contains(BI->getSuccessor(0))));
- // This may make the loop analyzable, force SCEV recomputation.
- if (SE)
- SE->forgetLoop(L);
-
Changed = true;
}
}
@@ -617,11 +614,8 @@ ReprocessLoop:
// comparison and the branch.
bool AllInvariant = true;
bool AnyInvariant = false;
- for (BasicBlock::iterator I = ExitingBlock->begin(); &*I != BI; ) {
+ for (auto I = ExitingBlock->instructionsWithoutDebug().begin(); &*I != BI; ) {
Instruction *Inst = &*I++;
- // Skip debug info intrinsics.
- if (isa<DbgInfoIntrinsic>(Inst))
- continue;
if (Inst == CI)
continue;
if (!L->makeLoopInvariant(Inst, AnyInvariant,
@@ -648,15 +642,8 @@ ReprocessLoop:
// Success. The block is now dead, so remove it from the loop,
// update the dominator tree and delete it.
- DEBUG(dbgs() << "LoopSimplify: Eliminating exiting block "
- << ExitingBlock->getName() << "\n");
-
- // Notify ScalarEvolution before deleting this block. Currently assume the
- // parent loop doesn't change (spliting edges doesn't count). If blocks,
- // CFG edges, or other values in the parent loop change, then we need call
- // to forgetLoop() for the parent instead.
- if (SE)
- SE->forgetLoop(L);
+ LLVM_DEBUG(dbgs() << "LoopSimplify: Eliminating exiting block "
+ << ExitingBlock->getName() << "\n");
assert(pred_begin(ExitingBlock) == pred_end(ExitingBlock));
Changed = true;
@@ -679,6 +666,12 @@ ReprocessLoop:
}
}
+ // Changing exit conditions for blocks may affect exit counts of this loop and
+ // any of its paretns, so we must invalidate the entire subtree if we've made
+ // any changes.
+ if (Changed && SE)
+ SE->forgetTopmostLoop(L);
+
return Changed;
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-06 11:15:43 +0000