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authorDuncan P. N. Exon Smith <dexonsmith@apple.com>2014-04-19 22:46:00 +0000
committerDuncan P. N. Exon Smith <dexonsmith@apple.com>2014-04-19 22:46:00 +0000
commitf44eda4764476b9043a13df247a558998ea2ed10 (patch)
treec5250834c0fd832fbdb7363822269f603cee844f /lib
parentc404a5334ef2e03e4c89fed6da7343e2e0709631 (diff)
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Revert "blockfreq: Rewrite BlockFrequencyInfoImpl"
This reverts commit r206704, as expected. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206707 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r--lib/Analysis/BlockFrequencyInfo.cpp8
-rw-r--r--lib/Analysis/BlockFrequencyInfoImpl.cpp932
-rw-r--r--lib/Analysis/CMakeLists.txt1
-rw-r--r--lib/CodeGen/MachineBlockFrequencyInfo.cpp12
4 files changed, 5 insertions, 948 deletions
diff --git a/lib/Analysis/BlockFrequencyInfo.cpp b/lib/Analysis/BlockFrequencyInfo.cpp
index 13ab29a94d..39aef9e140 100644
--- a/lib/Analysis/BlockFrequencyInfo.cpp
+++ b/lib/Analysis/BlockFrequencyInfo.cpp
@@ -11,7 +11,6 @@
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "block-freq"
#include "llvm/Analysis/BlockFrequencyInfo.h"
#include "llvm/Analysis/BlockFrequencyInfoImpl.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
@@ -107,7 +106,6 @@ struct DOTGraphTraits<BlockFrequencyInfo*> : public DefaultDOTGraphTraits {
INITIALIZE_PASS_BEGIN(BlockFrequencyInfo, "block-freq",
"Block Frequency Analysis", true, true)
INITIALIZE_PASS_DEPENDENCY(BranchProbabilityInfo)
-INITIALIZE_PASS_DEPENDENCY(LoopInfo)
INITIALIZE_PASS_END(BlockFrequencyInfo, "block-freq",
"Block Frequency Analysis", true, true)
@@ -122,16 +120,14 @@ BlockFrequencyInfo::~BlockFrequencyInfo() {}
void BlockFrequencyInfo::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<BranchProbabilityInfo>();
- AU.addRequired<LoopInfo>();
AU.setPreservesAll();
}
bool BlockFrequencyInfo::runOnFunction(Function &F) {
BranchProbabilityInfo &BPI = getAnalysis<BranchProbabilityInfo>();
- LoopInfo &LI = getAnalysis<LoopInfo>();
if (!BFI)
BFI.reset(new ImplType);
- BFI->doFunction(&F, &BPI, &LI);
+ BFI->doFunction(&F, &BPI);
#ifndef NDEBUG
if (ViewBlockFreqPropagationDAG != GVDT_None)
view();
@@ -162,7 +158,7 @@ void BlockFrequencyInfo::view() const {
}
const Function *BlockFrequencyInfo::getFunction() const {
- return BFI ? BFI->getFunction() : nullptr;
+ return BFI ? BFI->Fn : nullptr;
}
raw_ostream &BlockFrequencyInfo::
diff --git a/lib/Analysis/BlockFrequencyInfoImpl.cpp b/lib/Analysis/BlockFrequencyInfoImpl.cpp
deleted file mode 100644
index e7424aebd7..0000000000
--- a/lib/Analysis/BlockFrequencyInfoImpl.cpp
+++ /dev/null
@@ -1,932 +0,0 @@
-//===- BlockFrequencyImplInfo.cpp - Block Frequency Info Implementation ---===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// Loops should be simplified before this analysis.
-//
-//===----------------------------------------------------------------------===//
-
-#define DEBUG_TYPE "block-freq"
-#include "llvm/Analysis/BlockFrequencyInfoImpl.h"
-#include "llvm/ADT/APFloat.h"
-#include "llvm/Support/raw_ostream.h"
-#include <deque>
-
-using namespace llvm;
-
-//===----------------------------------------------------------------------===//
-//
-// PositiveFloat implementation.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _MSC_VER
-const int32_t PositiveFloatBase::MaxExponent;
-const int32_t PositiveFloatBase::MinExponent;
-#endif
-
-static void appendDigit(std::string &Str, unsigned D) {
- assert(D < 10);
- Str += '0' + D % 10;
-}
-
-static void appendNumber(std::string &Str, uint64_t N) {
- while (N) {
- appendDigit(Str, N % 10);
- N /= 10;
- }
-}
-
-static bool doesRoundUp(char Digit) {
- switch (Digit) {
- case '5':
- case '6':
- case '7':
- case '8':
- case '9':
- return true;
- default:
- return false;
- }
-}
-
-static std::string toStringAPFloat(uint64_t D, int E, unsigned Precision) {
- assert(E >= PositiveFloatBase::MinExponent);
- assert(E <= PositiveFloatBase::MaxExponent);
-
- // Find a new E, but don't let it increase past MaxExponent.
- int LeadingZeros = PositiveFloatBase::countLeadingZeros64(D);
- int NewE = std::min(PositiveFloatBase::MaxExponent, E + 63 - LeadingZeros);
- int Shift = 63 - (NewE - E);
- assert(Shift <= LeadingZeros);
- assert(Shift == LeadingZeros || NewE == PositiveFloatBase::MaxExponent);
- D <<= Shift;
- E = NewE;
-
- // Check for a denormal.
- unsigned AdjustedE = E + 16383;
- if (!(D >> 63)) {
- assert(E == PositiveFloatBase::MaxExponent);
- AdjustedE = 0;
- }
-
- // Build the float and print it.
- uint64_t RawBits[2] = {D, AdjustedE};
- APFloat Float(APFloat::x87DoubleExtended, APInt(80, RawBits));
- SmallVector<char, 24> Chars;
- Float.toString(Chars, Precision, 0);
- return std::string(Chars.begin(), Chars.end());
-}
-
-static std::string stripTrailingZeros(const std::string &Float) {
- size_t NonZero = Float.find_last_not_of('0');
- assert(NonZero != std::string::npos && "no . in floating point string");
-
- if (Float[NonZero] == '.')
- ++NonZero;
-
- return Float.substr(0, NonZero + 1);
-}
-
-std::string PositiveFloatBase::toString(uint64_t D, int16_t E, int Width,
- unsigned Precision) {
- if (!D)
- return "0.0";
-
- // Canonicalize exponent and digits.
- uint64_t Above0 = 0;
- uint64_t Below0 = 0;
- uint64_t Extra = 0;
- int ExtraShift = 0;
- if (E == 0) {
- Above0 = D;
- } else if (E > 0) {
- if (int Shift = std::min(int16_t(countLeadingZeros64(D)), E)) {
- D <<= Shift;
- E -= Shift;
-
- if (!E)
- Above0 = D;
- }
- } else if (E > -64) {
- Above0 = D >> -E;
- Below0 = D << (64 + E);
- } else if (E > -120) {
- Below0 = D >> (-E - 64);
- Extra = D << (128 + E);
- ExtraShift = -64 - E;
- }
-
- // Fall back on APFloat for very small and very large numbers.
- if (!Above0 && !Below0)
- return toStringAPFloat(D, E, Precision);
-
- // Append the digits before the decimal.
- std::string Str;
- size_t DigitsOut = 0;
- if (Above0) {
- appendNumber(Str, Above0);
- DigitsOut = Str.size();
- } else
- appendDigit(Str, 0);
- std::reverse(Str.begin(), Str.end());
-
- // Return early if there's nothing after the decimal.
- if (!Below0)
- return Str + ".0";
-
- // Append the decimal and beyond.
- Str += '.';
- uint64_t Error = UINT64_C(1) << (64 - Width);
-
- // We need to shift Below0 to the right to make space for calculating
- // digits. Save the precision we're losing in Extra.
- Extra = (Below0 & 0xf) << 56 | (Extra >> 8);
- Below0 >>= 4;
- size_t SinceDot = 0;
- size_t AfterDot = Str.size();
- do {
- if (ExtraShift) {
- --ExtraShift;
- Error *= 5;
- } else
- Error *= 10;
-
- Below0 *= 10;
- Extra *= 10;
- Below0 += (Extra >> 60);
- Extra = Extra & (UINT64_MAX >> 4);
- appendDigit(Str, Below0 >> 60);
- Below0 = Below0 & (UINT64_MAX >> 4);
- if (DigitsOut || Str.back() != '0')
- ++DigitsOut;
- ++SinceDot;
- } while (Error && (Below0 << 4 | Extra >> 60) >= Error / 2 &&
- (!Precision || DigitsOut <= Precision || SinceDot < 2));
-
- // Return early for maximum precision.
- if (!Precision || DigitsOut <= Precision)
- return stripTrailingZeros(Str);
-
- // Find where to truncate.
- size_t Truncate =
- std::max(Str.size() - (DigitsOut - Precision), AfterDot + 1);
-
- // Check if there's anything to truncate.
- if (Truncate >= Str.size())
- return stripTrailingZeros(Str);
-
- bool Carry = doesRoundUp(Str[Truncate]);
- if (!Carry)
- return stripTrailingZeros(Str.substr(0, Truncate));
-
- // Round with the first truncated digit.
- for (std::string::reverse_iterator I(Str.begin() + Truncate), E = Str.rend();
- I != E; ++I) {
- if (*I == '.')
- continue;
- if (*I == '9') {
- *I = '0';
- continue;
- }
-
- ++*I;
- Carry = false;
- break;
- }
-
- // Add "1" in front if we still need to carry.
- return stripTrailingZeros(std::string(Carry, '1') + Str.substr(0, Truncate));
-}
-
-raw_ostream &PositiveFloatBase::print(raw_ostream &OS, uint64_t D, int16_t E,
- int Width, unsigned Precision) {
- return OS << toString(D, E, Width, Precision);
-}
-
-void PositiveFloatBase::dump(uint64_t D, int16_t E, int Width) {
- print(dbgs(), D, E, Width, 0) << "[" << Width << ":" << D << "*2^" << E
- << "]";
-}
-
-static std::pair<uint64_t, int16_t>
-getRoundedFloat(uint64_t N, bool ShouldRound, int64_t Shift) {
- if (ShouldRound)
- if (!++N)
- // Rounding caused an overflow.
- return std::make_pair(UINT64_C(1), Shift + 64);
- return std::make_pair(N, Shift);
-}
-
-std::pair<uint64_t, int16_t> PositiveFloatBase::divide64(uint64_t Dividend,
- uint64_t Divisor) {
- // Input should be sanitized.
- assert(Divisor);
- assert(Dividend);
-
- // Minimize size of divisor.
- int16_t Shift = 0;
- if (int Zeros = countTrailingZeros(Divisor)) {
- Shift -= Zeros;
- Divisor >>= Zeros;
- }
-
- // Check for powers of two.
- if (Divisor == 1)
- return std::make_pair(Dividend, Shift);
-
- // Maximize size of dividend.
- if (int Zeros = countLeadingZeros64(Dividend)) {
- Shift -= Zeros;
- Dividend <<= Zeros;
- }
-
- // Start with the result of a divide.
- uint64_t Quotient = Dividend / Divisor;
- Dividend %= Divisor;
-
- // Continue building the quotient with long division.
- //
- // TODO: continue with largers digits.
- while (!(Quotient >> 63) && Dividend) {
- // Shift Dividend, and check for overflow.
- bool IsOverflow = Dividend >> 63;
- Dividend <<= 1;
- --Shift;
-
- // Divide.
- bool DoesDivide = IsOverflow || Divisor <= Dividend;
- Quotient = (Quotient << 1) | uint64_t(DoesDivide);
- Dividend -= DoesDivide ? Divisor : 0;
- }
-
- // Round.
- if (Dividend >= getHalf(Divisor))
- if (!++Quotient)
- // Rounding caused an overflow in Quotient.
- return std::make_pair(UINT64_C(1), Shift + 64);
-
- return getRoundedFloat(Quotient, Dividend >= getHalf(Divisor), Shift);
-}
-
-std::pair<uint64_t, int16_t> PositiveFloatBase::multiply64(uint64_t L,
- uint64_t R) {
- // Separate into two 32-bit digits (U.L).
- uint64_t UL = L >> 32, LL = L & UINT32_MAX, UR = R >> 32, LR = R & UINT32_MAX;
-
- // Compute cross products.
- uint64_t P1 = UL * UR, P2 = UL * LR, P3 = LL * UR, P4 = LL * LR;
-
- // Sum into two 64-bit digits.
- uint64_t Upper = P1, Lower = P4;
- auto addWithCarry = [&](uint64_t N) {
- uint64_t NewLower = Lower + (N << 32);
- Upper += (N >> 32) + (NewLower < Lower);
- Lower = NewLower;
- };
- addWithCarry(P2);
- addWithCarry(P3);
-
- // Check whether the upper digit is empty.
- if (!Upper)
- return std::make_pair(Lower, 0);
-
- // Shift as little as possible to maximize precision.
- unsigned LeadingZeros = countLeadingZeros64(Upper);
- int16_t Shift = 64 - LeadingZeros;
- if (LeadingZeros)
- Upper = Upper << LeadingZeros | Lower >> Shift;
- bool ShouldRound = Shift && (Lower & UINT64_C(1) << (Shift - 1));
- return getRoundedFloat(Upper, ShouldRound, Shift);
-}
-
-//===----------------------------------------------------------------------===//
-//
-// BlockMass implementation.
-//
-//===----------------------------------------------------------------------===//
-BlockMass &BlockMass::operator*=(const BranchProbability &P) {
- uint32_t N = P.getNumerator(), D = P.getDenominator();
- assert(D && "divide by 0");
- assert(N <= D && "fraction greater than 1");
-
- // Fast path for multiplying by 1.0.
- if (!Mass || N == D)
- return *this;
-
- // Get as much precision as we can.
- int Shift = countLeadingZeros(Mass);
- uint64_t ShiftedQuotient = (Mass << Shift) / D;
- uint64_t Product = ShiftedQuotient * N >> Shift;
-
- // Now check for what's lost.
- uint64_t Left = ShiftedQuotient * (D - N) >> Shift;
- uint64_t Lost = Mass - Product - Left;
-
- // TODO: prove this assertion.
- assert(Lost <= UINT32_MAX);
-
- // Take the product plus a portion of the spoils.
- Mass = Product + Lost * N / D;
- return *this;
-}
-
-PositiveFloat<uint64_t> BlockMass::toFloat() const {
- if (isFull())
- return PositiveFloat<uint64_t>(1, 0);
- return PositiveFloat<uint64_t>(getMass() + 1, -64);
-}
-
-void BlockMass::dump() const { print(dbgs()); }
-
-static char getHexDigit(int N) {
- assert(N < 16);
- if (N < 10)
- return '0' + N;
- return 'a' + N - 10;
-}
-raw_ostream &BlockMass::print(raw_ostream &OS) const {
- for (int Digits = 0; Digits < 16; ++Digits)
- OS << getHexDigit(Mass >> (60 - Digits * 4) & 0xf);
- return OS;
-}
-
-//===----------------------------------------------------------------------===//
-//
-// BlockFrequencyInfoImpl implementation.
-//
-//===----------------------------------------------------------------------===//
-namespace {
-
-typedef BlockFrequencyInfoImplBase::BlockNode BlockNode;
-typedef BlockFrequencyInfoImplBase::Distribution Distribution;
-typedef BlockFrequencyInfoImplBase::Distribution::WeightList WeightList;
-typedef BlockFrequencyInfoImplBase::Float Float;
-typedef BlockFrequencyInfoImplBase::PackagedLoopData PackagedLoopData;
-typedef BlockFrequencyInfoImplBase::Weight Weight;
-typedef BlockFrequencyInfoImplBase::FrequencyData FrequencyData;
-
-/// \brief Dithering mass distributer.
-///
-/// This class splits up a single mass into portions by weight, dithering to
-/// spread out error. No mass is lost. The dithering precision depends on the
-/// precision of the product of \a BlockMass and \a BranchProbability.
-///
-/// The distribution algorithm follows.
-///
-/// 1. Initialize by saving the sum of the weights in \a RemWeight and the
-/// mass to distribute in \a RemMass.
-///
-/// 2. For each portion:
-///
-/// 1. Construct a branch probability, P, as the portion's weight divided
-/// by the current value of \a RemWeight.
-/// 2. Calculate the portion's mass as \a RemMass times P.
-/// 3. Update \a RemWeight and \a RemMass at each portion by subtracting
-/// the current portion's weight and mass.
-///
-/// Mass is distributed in two ways: full distribution and forward
-/// distribution. The latter ignores backedges, and uses the parallel fields
-/// \a RemForwardWeight and \a RemForwardMass.
-struct DitheringDistributer {
- uint32_t RemWeight;
- uint32_t RemForwardWeight;
-
- BlockMass RemMass;
- BlockMass RemForwardMass;
-
- DitheringDistributer(Distribution &Dist, const BlockMass &Mass);
-
- BlockMass takeLocalMass(uint32_t Weight) {
- (void)takeMass(Weight);
- return takeForwardMass(Weight);
- }
- BlockMass takeExitMass(uint32_t Weight) {
- (void)takeForwardMass(Weight);
- return takeMass(Weight);
- }
- BlockMass takeBackedgeMass(uint32_t Weight) { return takeMass(Weight); }
-
-private:
- BlockMass takeForwardMass(uint32_t Weight);
- BlockMass takeMass(uint32_t Weight);
-};
-}
-
-DitheringDistributer::DitheringDistributer(Distribution &Dist,
- const BlockMass &Mass) {
- Dist.normalize();
- RemWeight = Dist.Total;
- RemForwardWeight = Dist.ForwardTotal;
- RemMass = Mass;
- RemForwardMass = Dist.ForwardTotal ? Mass : BlockMass();
-}
-
-BlockMass DitheringDistributer::takeForwardMass(uint32_t Weight) {
- // Compute the amount of mass to take.
- assert(Weight && "invalid weight");
- assert(Weight <= RemForwardWeight);
- BlockMass Mass = RemForwardMass * BranchProbability(Weight, RemForwardWeight);
-
- // Decrement totals (dither).
- RemForwardWeight -= Weight;
- RemForwardMass -= Mass;
- return Mass;
-}
-BlockMass DitheringDistributer::takeMass(uint32_t Weight) {
- assert(Weight && "invalid weight");
- assert(Weight <= RemWeight);
- BlockMass Mass = RemMass * BranchProbability(Weight, RemWeight);
-
- // Decrement totals (dither).
- RemWeight -= Weight;
- RemMass -= Mass;
- return Mass;
-}
-
-void Distribution::add(const BlockNode &Node, uint64_t Amount,
- Weight::DistType Type) {
- assert(Amount && "invalid weight of 0");
- uint64_t NewTotal = Total + Amount;
-
- // Check for overflow. It should be impossible to overflow twice.
- bool IsOverflow = NewTotal < Total;
- assert(!(DidOverflow && IsOverflow) && "unexpected repeated overflow");
- DidOverflow |= IsOverflow;
-
- // Update the total.
- Total = NewTotal;
-
- // Save the weight.
- Weight W;
- W.TargetNode = Node;
- W.Amount = Amount;
- W.Type = Type;
- Weights.push_back(W);
-
- if (Type == Weight::Backedge)
- return;
-
- // Update forward total. Don't worry about overflow here, since then Total
- // will exceed 32-bits and they'll both be recomputed in normalize().
- ForwardTotal += Amount;
-}
-
-static void combineWeight(Weight &W, const Weight &OtherW) {
- assert(OtherW.TargetNode.isValid());
- if (!W.Amount) {
- W = OtherW;
- return;
- }
- assert(W.Type == OtherW.Type);
- assert(W.TargetNode == OtherW.TargetNode);
- assert(W.Amount < W.Amount + OtherW.Amount);
- W.Amount += OtherW.Amount;
-}
-static void combineWeightsBySorting(WeightList &Weights) {
- // Sort so edges to the same node are adjacent.
- std::sort(Weights.begin(), Weights.end(),
- [](const Weight &L,
- const Weight &R) { return L.TargetNode < R.TargetNode; });
-
- // Combine adjacent edges.
- WeightList::iterator O = Weights.begin();
- for (WeightList::const_iterator I = O, L = O, E = Weights.end(); I != E;
- ++O, (I = L)) {
- *O = *I;
-
- // Find the adjacent weights to the same node.
- for (++L; L != E && I->TargetNode == L->TargetNode; ++L)
- combineWeight(*O, *L);
- }
-
- // Erase extra entries.
- Weights.erase(O, Weights.end());
- return;
-}
-static void combineWeightsByHashing(WeightList &Weights) {
- // Collect weights into a DenseMap.
- typedef DenseMap<BlockNode::IndexType, Weight> HashTable;
- HashTable Combined(NextPowerOf2(2 * Weights.size()));
- for (const Weight &W : Weights)
- combineWeight(Combined[W.TargetNode.Index], W);
-
- // Check whether anything changed.
- if (Weights.size() == Combined.size())
- return;
-
- // Fill in the new weights.
- Weights.clear();
- Weights.reserve(Combined.size());
- for (const auto &I : Combined)
- Weights.push_back(I.second);
-}
-static void combineWeights(WeightList &Weights) {
- // Use a hash table for many successors to keep this linear.
- if (Weights.size() > 128) {
- combineWeightsByHashing(Weights);
- return;
- }
-
- combineWeightsBySorting(Weights);
-}
-static uint64_t shiftRightAndRound(uint64_t N, int Shift) {
- assert(Shift >= 0);
- assert(Shift < 64);
- if (!Shift)
- return N;
- return (N >> Shift) + (UINT64_C(1) & N >> (Shift - 1));
-}
-void Distribution::normalize() {
- // Early exit for termination nodes.
- if (Weights.empty())
- return;
-
- // Only bother if there are multiple successors.
- if (Weights.size() > 1)
- combineWeights(Weights);
-
- // Early exit when combined into a single successor.
- if (Weights.size() == 1) {
- Total = 1;
- ForwardTotal = Weights.front().Type != Weight::Backedge;
- Weights.front().Amount = 1;
- return;
- }
-
- // Determine how much to shift right so that the total fits into 32-bits.
- //
- // If we shift at all, shift by 1 extra. Otherwise, the lower limit of 1
- // for each weight can cause a 32-bit overflow.
- int Shift = 0;
- if (DidOverflow)
- Shift = 33;
- else if (Total > UINT32_MAX)
- Shift = 33 - countLeadingZeros(Total);
-
- // Early exit if nothing needs to be scaled.
- if (!Shift)
- return;
-
- // Recompute the total through accumulation (rather than shifting it) so that
- // it's accurate after shifting. ForwardTotal is dirty here anyway.
- Total = 0;
- ForwardTotal = 0;
-
- // Sum the weights to each node and shift right if necessary.
- for (Weight &W : Weights) {
- // Scale down below UINT32_MAX. Since Shift is larger than necessary, we
- // can round here without concern about overflow.
- assert(W.TargetNode.isValid());
- W.Amount = std::max(UINT64_C(1), shiftRightAndRound(W.Amount, Shift));
- assert(W.Amount <= UINT32_MAX);
-
- // Update the total.
- Total += W.Amount;
- if (W.Type == Weight::Backedge)
- continue;
-
- // Update the forward total.
- ForwardTotal += W.Amount;
- }
- assert(Total <= UINT32_MAX);
-}
-
-void BlockFrequencyInfoImplBase::clear() {
- *this = BlockFrequencyInfoImplBase();
-}
-
-/// \brief Clear all memory not needed downstream.
-///
-/// Releases all memory not used downstream. In particular, saves Freqs.
-static void cleanup(BlockFrequencyInfoImplBase &BFI) {
- std::vector<FrequencyData> SavedFreqs(std::move(BFI.Freqs));
- BFI.clear();
- BFI.Freqs = std::move(SavedFreqs);
-}
-
-/// \brief Get a possibly packaged node.
-///
-/// Get the node currently representing Node, which could be a containing
-/// loop.
-///
-/// This function should only be called when distributing mass. As long as
-/// there are no irreducilbe edges to Node, then it will have complexity O(1)
-/// in this context.
-///
-/// In general, the complexity is O(L), where L is the number of loop headers
-/// Node has been packaged into. Since this method is called in the context
-/// of distributing mass, L will be the number of loop headers an early exit
-/// edge jumps out of.
-static BlockNode getPackagedNode(const BlockFrequencyInfoImplBase &BFI,
- const BlockNode &Node) {
- assert(Node.isValid());
- if (!BFI.Working[Node.Index].IsPackaged)
- return Node;
- if (!BFI.Working[Node.Index].ContainingLoop.isValid())
- return Node;
- return getPackagedNode(BFI, BFI.Working[Node.Index].ContainingLoop);
-}
-
-/// \brief Get the appropriate mass for a possible pseudo-node loop package.
-///
-/// Get appropriate mass for Node. If Node is a loop-header (whose loop has
-/// been packaged), returns the mass of its pseudo-node. If it's a node inside
-/// a packaged loop, it returns the loop's pseudo-node.
-static BlockMass &getPackageMass(BlockFrequencyInfoImplBase &BFI,
- const BlockNode &Node) {
- assert(Node.isValid());
- assert(!BFI.Working[Node.Index].IsPackaged);
- if (!BFI.Working[Node.Index].IsAPackage)
- return BFI.Working[Node.Index].Mass;
-
- return BFI.getLoopPackage(Node).Mass;
-}
-
-void BlockFrequencyInfoImplBase::addToDist(Distribution &Dist,
- const BlockNode &LoopHead,
- const BlockNode &Pred,
- const BlockNode &Succ,
- uint64_t Weight) {
- if (!Weight)
- Weight = 1;
-
-#ifndef NDEBUG
- auto debugSuccessor = [&](const char *Type, const BlockNode &Resolved) {
- dbgs() << " =>"
- << " [" << Type << "] weight = " << Weight;
- if (Succ != LoopHead)
- dbgs() << ", succ = " << getBlockName(Succ);
- if (Resolved != Succ)
- dbgs() << ", resolved = " << getBlockName(Resolved);
- dbgs() << "\n";
- };
- (void)debugSuccessor;
-#endif
-
- if (Succ == LoopHead) {
- DEBUG(debugSuccessor("backedge", Succ));
- Dist.addBackedge(LoopHead, Weight);
- return;
- }
- BlockNode Resolved = getPackagedNode(*this, Succ);
- assert(Resolved != LoopHead);
-
- if (Working[Resolved.Index].ContainingLoop != LoopHead) {
- DEBUG(debugSuccessor(" exit ", Resolved));
- Dist.addExit(Resolved, Weight);
- return;
- }
-
- if (!LoopHead.isValid() && Resolved < Pred) {
- // Irreducible backedge. Skip this edge in the distribution.
- DEBUG(debugSuccessor("skipped ", Resolved));
- return;
- }
-
- DEBUG(debugSuccessor(" local ", Resolved));
- Dist.addLocal(Resolved, Weight);
-}
-
-void BlockFrequencyInfoImplBase::addLoopSuccessorsToDist(
- const BlockNode &LoopHead, const BlockNode &LocalLoopHead,
- Distribution &Dist) {
- PackagedLoopData &LoopPackage = getLoopPackage(LocalLoopHead);
- const PackagedLoopData::ExitMap &Exits = LoopPackage.Exits;
-
- // Copy the exit map into Dist.
- for (const auto &I : Exits)
- addToDist(Dist, LoopHead, LocalLoopHead, I.first, I.second.getMass());
-
- // We don't need this map any more. Clear it to prevent quadratic memory
- // usage in deeply nested loops with irreducible control flow.
- LoopPackage.Exits.clear();
-}
-
-/// \brief Get the maximum allowed loop scale.
-///
-/// Gives the maximum number of estimated iterations allowed for a loop.
-/// Downstream users have trouble with very large numbers (even within
-/// 64-bits). Perhaps they can be changed to use PositiveFloat.
-///
-/// TODO: change downstream users so that this can be increased or removed.
-static Float getMaxLoopScale() { return Float(1, 12); }
-
-/// \brief Compute the loop scale for a loop.
-void BlockFrequencyInfoImplBase::computeLoopScale(const BlockNode &LoopHead) {
- // Compute loop scale.
- DEBUG(dbgs() << "compute-loop-scale: " << getBlockName(LoopHead) << "\n");
-
- // LoopScale == 1 / ExitMass
- // ExitMass == HeadMass - BackedgeMass
- PackagedLoopData &LoopPackage = getLoopPackage(LoopHead);
- BlockMass ExitMass = BlockMass::getFull() - LoopPackage.BackedgeMass;
-
- // Block scale stores the inverse of the scale.
- LoopPackage.Scale = ExitMass.toFloat().inverse();
-
- DEBUG(dbgs() << " - exit-mass = " << ExitMass << " (" << BlockMass::getFull()
- << " - " << LoopPackage.BackedgeMass << ")\n"
- << " - scale = " << LoopPackage.Scale << "\n");
-
- if (LoopPackage.Scale > getMaxLoopScale()) {
- LoopPackage.Scale = getMaxLoopScale();
- DEBUG(dbgs() << " - reduced-to-max-scale: " << getMaxLoopScale() << "\n");
- }
-}
-
-/// \brief Package up a loop.
-void BlockFrequencyInfoImplBase::packageLoop(const BlockNode &LoopHead) {
- DEBUG(dbgs() << "packaging-loop: " << getBlockName(LoopHead) << "\n");
- Working[LoopHead.Index].IsAPackage = true;
- for (const BlockNode &M : getLoopPackage(LoopHead).Members) {
- DEBUG(dbgs() << " - node: " << getBlockName(M.Index) << "\n");
- Working[M.Index].IsPackaged = true;
- }
-}
-
-void BlockFrequencyInfoImplBase::distributeMass(const BlockNode &Source,
- const BlockNode &LoopHead,
- Distribution &Dist) {
- BlockMass Mass = getPackageMass(*this, Source);
- DEBUG(dbgs() << " => mass: " << Mass
- << " ( general | forward )\n");
-
- // Distribute mass to successors as laid out in Dist.
- DitheringDistributer D(Dist, Mass);
-
-#ifndef NDEBUG
- auto debugAssign = [&](const BlockNode &T, const BlockMass &M,
- const char *Desc) {
- dbgs() << " => assign " << M << " (" << D.RemMass << "|"
- << D.RemForwardMass << ")";
- if (Desc)
- dbgs() << " [" << Desc << "]";
- if (T.isValid())
- dbgs() << " to " << getBlockName(T);
- dbgs() << "\n";
- };
- (void)debugAssign;
-#endif
-
- PackagedLoopData *LoopPackage = 0;
- if (LoopHead.isValid())
- LoopPackage = &getLoopPackage(LoopHead);
- for (const Weight &W : Dist.Weights) {
- // Check for a local edge (forward and non-exit).
- if (W.Type == Weight::Local) {
- BlockMass Local = D.takeLocalMass(W.Amount);
- getPackageMass(*this, W.TargetNode) += Local;
- DEBUG(debugAssign(W.TargetNode, Local, nullptr));
- continue;
- }
-
- // Backedges and exits only make sense if we're processing a loop.
- assert(LoopPackage && "backedge or exit outside of loop");
-
- // Check for a backedge.
- if (W.Type == Weight::Backedge) {
- BlockMass Back = D.takeBackedgeMass(W.Amount);
- LoopPackage->BackedgeMass += Back;
- DEBUG(debugAssign(BlockNode(), Back, "back"));
- continue;
- }
-
- // This must be an exit.
- assert(W.Type == Weight::Exit);
- BlockMass Exit = D.takeExitMass(W.Amount);
- LoopPackage->Exits.push_back(std::make_pair(W.TargetNode, Exit));
- DEBUG(debugAssign(W.TargetNode, Exit, "exit"));
- }
-}
-
-static void convertFloatingToInteger(BlockFrequencyInfoImplBase &BFI,
- const Float &Min, const Float &Max) {
- // Scale the Factor to a size that creates integers. Ideally, integers would
- // be scaled so that Max == UINT64_MAX so that they can be best
- // differentiated. However, the register allocator currently deals poorly
- // with large numbers. Instead, push Min up a little from 1 to give some
- // room to differentiate small, unequal numbers.
- //
- // TODO: fix issues downstream so that ScalingFactor can be Float(1,64)/Max.
- Float ScalingFactor = Min.inverse();
- if ((Max / Min).lg() < 60)
- ScalingFactor <<= 3;
-
- // Translate the floats to integers.
- DEBUG(dbgs() << "float-to-int: min = " << Min << ", max = " << Max
- << ", factor = " << ScalingFactor << "\n");
- for (size_t Index = 0; Index < BFI.Freqs.size(); ++Index) {
- Float Scaled = BFI.Freqs[Index].Floating * ScalingFactor;
- BFI.Freqs[Index].Integer = std::max(UINT64_C(1), Scaled.toInt<uint64_t>());
- DEBUG(dbgs() << " - " << BFI.getBlockName(Index) << ": float = "
- << BFI.Freqs[Index].Floating << ", scaled = " << Scaled
- << ", int = " << BFI.Freqs[Index].Integer << "\n");
- }
-}
-
-static void scaleBlockData(BlockFrequencyInfoImplBase &BFI,
- const BlockNode &Node,
- const PackagedLoopData &Loop) {
- Float F = Loop.Mass.toFloat() * Loop.Scale;
-
- Float &Current = BFI.Freqs[Node.Index].Floating;
- Float Updated = Current * F;
-
- DEBUG(dbgs() << " - " << BFI.getBlockName(Node) << ": " << Current << " => "
- << Updated << "\n");
-
- Current = Updated;
-}
-
-/// \brief Unwrap a loop package.
-///
-/// Visits all the members of a loop, adjusting their BlockData according to
-/// the loop's pseudo-node.
-static void unwrapLoopPackage(BlockFrequencyInfoImplBase &BFI,
- const BlockNode &Head) {
- assert(Head.isValid());
-
- PackagedLoopData &LoopPackage = BFI.getLoopPackage(Head);
- DEBUG(dbgs() << "unwrap-loop-package: " << BFI.getBlockName(Head)
- << ": mass = " << LoopPackage.Mass
- << ", scale = " << LoopPackage.Scale << "\n");
- scaleBlockData(BFI, Head, LoopPackage);
-
- // Propagate the head scale through the loop. Since members are visited in
- // RPO, the head scale will be updated by the loop scale first, and then the
- // final head scale will be used for updated the rest of the members.
- for (const BlockNode &M : LoopPackage.Members) {
- const FrequencyData &HeadData = BFI.Freqs[Head.Index];
- FrequencyData &Freqs = BFI.Freqs[M.Index];
- Float NewFreq = Freqs.Floating * HeadData.Floating;
- DEBUG(dbgs() << " - " << BFI.getBlockName(M) << ": " << Freqs.Floating
- << " => " << NewFreq << "\n");
- Freqs.Floating = NewFreq;
- }
-}
-
-void BlockFrequencyInfoImplBase::finalizeMetrics() {
- // Set initial frequencies from loop-local masses.
- for (size_t Index = 0; Index < Working.size(); ++Index)
- Freqs[Index].Floating = Working[Index].Mass.toFloat();
-
- // Unwrap loop packages in reverse post-order, tracking min and max
- // frequencies.
- auto Min = Float::getLargest();
- auto Max = Float::getZero();
- for (size_t Index = 0; Index < Working.size(); ++Index) {
- if (Working[Index].isLoopHeader())
- unwrapLoopPackage(*this, BlockNode(Index));
-
- // Update max scale.
- Min = std::min(Min, Freqs[Index].Floating);
- Max = std::max(Max, Freqs[Index].Floating);
- }
-
- // Convert to integers.
- convertFloatingToInteger(*this, Min, Max);
-
- // Clean up data structures.
- cleanup(*this);
-
- // Print out the final stats.
- DEBUG(dump());
-}
-
-BlockFrequency
-BlockFrequencyInfoImplBase::getBlockFreq(const BlockNode &Node) const {
- if (!Node.isValid())
- return 0;
- return Freqs[Node.Index].Integer;
-}
-Float
-BlockFrequencyInfoImplBase::getFloatingBlockFreq(const BlockNode &Node) const {
- if (!Node.isValid())
- return Float::getZero();
- return Freqs[Node.Index].Floating;
-}
-
-std::string
-BlockFrequencyInfoImplBase::getBlockName(const BlockNode &Node) const {
- return std::string();
-}
-
-raw_ostream &
-BlockFrequencyInfoImplBase::printBlockFreq(raw_ostream &OS,
- const BlockNode &Node) const {
- return OS << getFloatingBlockFreq(Node);
-}
-
-raw_ostream &
-BlockFrequencyInfoImplBase::printBlockFreq(raw_ostream &OS,
- const BlockFrequency &Freq) const {
- Float Block(Freq.getFrequency(), 0);
- Float Entry(getEntryFreq(), 0);
-
- return OS << Block / Entry;
-}
diff --git a/lib/Analysis/CMakeLists.txt b/lib/Analysis/CMakeLists.txt
index 0b0b2f92ea..c6d4573885 100644
--- a/lib/Analysis/CMakeLists.txt
+++ b/lib/Analysis/CMakeLists.txt
@@ -7,7 +7,6 @@ add_llvm_library(LLVMAnalysis
Analysis.cpp
BasicAliasAnalysis.cpp
BlockFrequencyInfo.cpp
- BlockFrequencyInfoImpl.cpp
BranchProbabilityInfo.cpp
CFG.cpp
CFGPrinter.cpp
diff --git a/lib/CodeGen/MachineBlockFrequencyInfo.cpp b/lib/CodeGen/MachineBlockFrequencyInfo.cpp
index d3ac0c0437..70efa307d5 100644
--- a/lib/CodeGen/MachineBlockFrequencyInfo.cpp
+++ b/lib/CodeGen/MachineBlockFrequencyInfo.cpp
@@ -11,12 +11,9 @@
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "block-freq"
#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
#include "llvm/Analysis/BlockFrequencyInfoImpl.h"
#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/InitializePasses.h"
#include "llvm/Support/CommandLine.h"
@@ -115,7 +112,6 @@ struct DOTGraphTraits<MachineBlockFrequencyInfo*> :
INITIALIZE_PASS_BEGIN(MachineBlockFrequencyInfo, "machine-block-freq",
"Machine Block Frequency Analysis", true, true)
INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
-INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
INITIALIZE_PASS_END(MachineBlockFrequencyInfo, "machine-block-freq",
"Machine Block Frequency Analysis", true, true)
@@ -131,18 +127,16 @@ MachineBlockFrequencyInfo::~MachineBlockFrequencyInfo() {}
void MachineBlockFrequencyInfo::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<MachineBranchProbabilityInfo>();
- AU.addRequired<MachineLoopInfo>();
AU.setPreservesAll();
MachineFunctionPass::getAnalysisUsage(AU);
}
bool MachineBlockFrequencyInfo::runOnMachineFunction(MachineFunction &F) {
MachineBranchProbabilityInfo &MBPI =
- getAnalysis<MachineBranchProbabilityInfo>();
- MachineLoopInfo &MLI = getAnalysis<MachineLoopInfo>();
+ getAnalysis<MachineBranchProbabilityInfo>();
if (!MBFI)
MBFI.reset(new ImplType);
- MBFI->doFunction(&F, &MBPI, &MLI);
+ MBFI->doFunction(&F, &MBPI);
#ifndef NDEBUG
if (ViewMachineBlockFreqPropagationDAG != GVDT_None) {
view();
@@ -172,7 +166,7 @@ getBlockFreq(const MachineBasicBlock *MBB) const {
}
const MachineFunction *MachineBlockFrequencyInfo::getFunction() const {
- return MBFI ? MBFI->getFunction() : nullptr;
+ return MBFI ? MBFI->Fn : nullptr;
}
raw_ostream &