//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Scalar.h"
+#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/CodeMetrics.h"
+#include "llvm/Analysis/FunctionTargetTransformInfo.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/TargetTransformInfo.h"
/// loop preheaders be inserted into the CFG...
///
void getAnalysisUsage(AnalysisUsage &AU) const override {
- AU.addRequired<LoopInfo>();
- AU.addPreserved<LoopInfo>();
+ AU.addRequired<AssumptionCacheTracker>();
+ AU.addRequired<LoopInfoWrapperPass>();
+ AU.addPreserved<LoopInfoWrapperPass>();
AU.addRequiredID(LoopSimplifyID);
AU.addPreservedID(LoopSimplifyID);
AU.addRequiredID(LCSSAID);
AU.addPreservedID(LCSSAID);
AU.addRequired<ScalarEvolution>();
AU.addPreserved<ScalarEvolution>();
- AU.addRequired<TargetTransformInfo>();
+ AU.addRequired<TargetTransformInfoWrapperPass>();
+ AU.addRequired<FunctionTargetTransformInfo>();
// FIXME: Loop unroll requires LCSSA. And LCSSA requires dom info.
// If loop unroll does not preserve dom info then LCSSA pass on next
// loop will receive invalid dom info.
// Fill in the UnrollingPreferences parameter with values from the
// TargetTransformationInfo.
- void getUnrollingPreferences(Loop *L, const TargetTransformInfo &TTI,
+ void getUnrollingPreferences(Loop *L, const FunctionTargetTransformInfo &FTTI,
TargetTransformInfo::UnrollingPreferences &UP) {
UP.Threshold = CurrentThreshold;
UP.OptSizeThreshold = OptSizeUnrollThreshold;
UP.MaxCount = UINT_MAX;
UP.Partial = CurrentAllowPartial;
UP.Runtime = CurrentRuntime;
- TTI.getUnrollingPreferences(L, UP);
+ FTTI.getUnrollingPreferences(L, UP);
}
// Select and return an unroll count based on parameters from
char LoopUnroll::ID = 0;
INITIALIZE_PASS_BEGIN(LoopUnroll, "loop-unroll", "Unroll loops", false, false)
-INITIALIZE_AG_DEPENDENCY(TargetTransformInfo)
-INITIALIZE_PASS_DEPENDENCY(LoopInfo)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
+INITIALIZE_PASS_DEPENDENCY(FunctionTargetTransformInfo)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
INITIALIZE_PASS_DEPENDENCY(LCSSA)
INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
/// ApproximateLoopSize - Approximate the size of the loop.
static unsigned ApproximateLoopSize(const Loop *L, unsigned &NumCalls,
bool &NotDuplicatable,
- const TargetTransformInfo &TTI) {
+ const TargetTransformInfo &TTI,
+ AssumptionCache *AC) {
+ SmallPtrSet<const Value *, 32> EphValues;
+ CodeMetrics::collectEphemeralValues(L, AC, EphValues);
+
CodeMetrics Metrics;
for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
I != E; ++I)
- Metrics.analyzeBasicBlock(*I, TTI);
+ Metrics.analyzeBasicBlock(*I, TTI, EphValues);
NumCalls = Metrics.NumInlineCandidates;
NotDuplicatable = Metrics.notDuplicatable;
// Don't allow an estimate of size zero. This would allows unrolling of loops
// with huge iteration counts, which is a compile time problem even if it's
- // not a problem for code quality.
- if (LoopSize == 0) LoopSize = 1;
+ // not a problem for code quality. Also, the code using this size may assume
+ // that each loop has at least three instructions (likely a conditional
+ // branch, a comparison feeding that branch, and some kind of loop increment
+ // feeding that comparison instruction).
+ LoopSize = std::max(LoopSize, 3u);
return LoopSize;
}
// Returns the loop hint metadata node with the given name (for example,
// "llvm.loop.unroll.count"). If no such metadata node exists, then nullptr is
// returned.
-static const MDNode *GetUnrollMetadata(const Loop *L, StringRef Name) {
+static const MDNode *GetUnrollMetadataForLoop(const Loop *L, StringRef Name) {
MDNode *LoopID = L->getLoopID();
if (!LoopID)
return nullptr;
-
- // First operand should refer to the loop id itself.
- assert(LoopID->getNumOperands() > 0 && "requires at least one operand");
- assert(LoopID->getOperand(0) == LoopID && "invalid loop id");
-
- for (unsigned i = 1, e = LoopID->getNumOperands(); i < e; ++i) {
- const MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(i));
- if (!MD)
- continue;
-
- const MDString *S = dyn_cast<MDString>(MD->getOperand(0));
- if (!S)
- continue;
-
- if (Name.equals(S->getString()))
- return MD;
- }
- return nullptr;
+ return GetUnrollMetadata(LoopID, Name);
}
// Returns true if the loop has an unroll(full) pragma.
static bool HasUnrollFullPragma(const Loop *L) {
- return GetUnrollMetadata(L, "llvm.loop.unroll.full");
+ return GetUnrollMetadataForLoop(L, "llvm.loop.unroll.full");
}
// Returns true if the loop has an unroll(disable) pragma.
static bool HasUnrollDisablePragma(const Loop *L) {
- return GetUnrollMetadata(L, "llvm.loop.unroll.disable");
+ return GetUnrollMetadataForLoop(L, "llvm.loop.unroll.disable");
}
// If loop has an unroll_count pragma return the (necessarily
// positive) value from the pragma. Otherwise return 0.
static unsigned UnrollCountPragmaValue(const Loop *L) {
- const MDNode *MD = GetUnrollMetadata(L, "llvm.loop.unroll.count");
+ const MDNode *MD = GetUnrollMetadataForLoop(L, "llvm.loop.unroll.count");
if (MD) {
assert(MD->getNumOperands() == 2 &&
"Unroll count hint metadata should have two operands.");
- unsigned Count = cast<ConstantInt>(MD->getOperand(1))->getZExtValue();
+ unsigned Count =
+ mdconst::extract<ConstantInt>(MD->getOperand(1))->getZExtValue();
assert(Count >= 1 && "Unroll count must be positive.");
return Count;
}
if (!LoopID) return;
// First remove any existing loop unrolling metadata.
- SmallVector<Value *, 4> Vals;
+ SmallVector<Metadata *, 4> MDs;
// Reserve first location for self reference to the LoopID metadata node.
- Vals.push_back(nullptr);
+ MDs.push_back(nullptr);
for (unsigned i = 1, ie = LoopID->getNumOperands(); i < ie; ++i) {
bool IsUnrollMetadata = false;
MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(i));
const MDString *S = dyn_cast<MDString>(MD->getOperand(0));
IsUnrollMetadata = S && S->getString().startswith("llvm.loop.unroll.");
}
- if (!IsUnrollMetadata) Vals.push_back(LoopID->getOperand(i));
+ if (!IsUnrollMetadata)
+ MDs.push_back(LoopID->getOperand(i));
}
// Add unroll(disable) metadata to disable future unrolling.
LLVMContext &Context = L->getHeader()->getContext();
- SmallVector<Value *, 1> DisableOperands;
+ SmallVector<Metadata *, 1> DisableOperands;
DisableOperands.push_back(MDString::get(Context, "llvm.loop.unroll.disable"));
MDNode *DisableNode = MDNode::get(Context, DisableOperands);
- Vals.push_back(DisableNode);
+ MDs.push_back(DisableNode);
- MDNode *NewLoopID = MDNode::get(Context, Vals);
+ MDNode *NewLoopID = MDNode::get(Context, MDs);
// Set operand 0 to refer to the loop id itself.
NewLoopID->replaceOperandWith(0, NewLoopID);
L->setLoopID(NewLoopID);
if (skipOptnoneFunction(L))
return false;
- LoopInfo *LI = &getAnalysis<LoopInfo>();
+ Function &F = *L->getHeader()->getParent();
+
+ LoopInfo *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
ScalarEvolution *SE = &getAnalysis<ScalarEvolution>();
- const TargetTransformInfo &TTI = getAnalysis<TargetTransformInfo>();
+ const TargetTransformInfo &TTI =
+ getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
+ const FunctionTargetTransformInfo &FTTI =
+ getAnalysis<FunctionTargetTransformInfo>();
+ auto &AC = getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
BasicBlock *Header = L->getHeader();
DEBUG(dbgs() << "Loop Unroll: F[" << Header->getParent()->getName()
bool HasPragma = PragmaFullUnroll || PragmaCount > 0;
TargetTransformInfo::UnrollingPreferences UP;
- getUnrollingPreferences(L, TTI, UP);
+ getUnrollingPreferences(L, FTTI, UP);
// Find trip count and trip multiple if count is not available
unsigned TripCount = 0;
unsigned TripMultiple = 1;
- // Find "latch trip count". UnrollLoop assumes that control cannot exit
- // via the loop latch on any iteration prior to TripCount. The loop may exit
- // early via an earlier branch.
- BasicBlock *LatchBlock = L->getLoopLatch();
- if (LatchBlock) {
- TripCount = SE->getSmallConstantTripCount(L, LatchBlock);
- TripMultiple = SE->getSmallConstantTripMultiple(L, LatchBlock);
+ // If there are multiple exiting blocks but one of them is the latch, use the
+ // latch for the trip count estimation. Otherwise insist on a single exiting
+ // block for the trip count estimation.
+ BasicBlock *ExitingBlock = L->getLoopLatch();
+ if (!ExitingBlock || !L->isLoopExiting(ExitingBlock))
+ ExitingBlock = L->getExitingBlock();
+ if (ExitingBlock) {
+ TripCount = SE->getSmallConstantTripCount(L, ExitingBlock);
+ TripMultiple = SE->getSmallConstantTripMultiple(L, ExitingBlock);
}
// Select an initial unroll count. This may be reduced later based
unsigned NumInlineCandidates;
bool notDuplicatable;
unsigned LoopSize =
- ApproximateLoopSize(L, NumInlineCandidates, notDuplicatable, TTI);
+ ApproximateLoopSize(L, NumInlineCandidates, notDuplicatable, TTI, &AC);
DEBUG(dbgs() << " Loop Size = " << LoopSize << "\n");
- uint64_t UnrolledSize = (uint64_t)LoopSize * Count;
+
+ // When computing the unrolled size, note that the conditional branch on the
+ // backedge and the comparison feeding it are not replicated like the rest of
+ // the loop body (which is why 2 is subtracted).
+ uint64_t UnrolledSize = (uint64_t)(LoopSize-2) * Count + 2;
if (notDuplicatable) {
DEBUG(dbgs() << " Not unrolling loop which contains non-duplicatable"
<< " instructions.\n");
}
if (PartialThreshold != NoThreshold && UnrolledSize > PartialThreshold) {
// Reduce unroll count to be modulo of TripCount for partial unrolling.
- Count = PartialThreshold / LoopSize;
+ Count = (std::max(PartialThreshold, 3u)-2) / (LoopSize-2);
while (Count != 0 && TripCount % Count != 0)
Count--;
}
// the original count which satisfies the threshold limit.
while (Count != 0 && UnrolledSize > PartialThreshold) {
Count >>= 1;
- UnrolledSize = LoopSize * Count;
+ UnrolledSize = (LoopSize-2) * Count + 2;
}
if (Count > UP.MaxCount)
Count = UP.MaxCount;
}
// Unroll the loop.
- if (!UnrollLoop(L, Count, TripCount, AllowRuntime, TripMultiple, LI, this, &LPM))
+ if (!UnrollLoop(L, Count, TripCount, AllowRuntime, TripMultiple, LI, this,
+ &LPM, &AC))
return false;
return true;
projects / oota-llvm.git / blobdiff