| //===- InterleavedLoadCombine.cpp - Combine Interleaved Loads ---*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // \file |
| // |
| // This file defines the interleaved-load-combine pass. The pass searches for |
| // ShuffleVectorInstruction that execute interleaving loads. If a matching |
| // pattern is found, it adds a combined load and further instructions in a |
| // pattern that is detectable by InterleavedAccesPass. The old instructions are |
| // left dead to be removed later. The pass is specifically designed to be |
| // executed just before InterleavedAccesPass to find any left-over instances |
| // that are not detected within former passes. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/ADT/Statistic.h" |
| #include "llvm/Analysis/MemoryLocation.h" |
| #include "llvm/Analysis/MemorySSA.h" |
| #include "llvm/Analysis/MemorySSAUpdater.h" |
| #include "llvm/Analysis/OptimizationRemarkEmitter.h" |
| #include "llvm/Analysis/TargetTransformInfo.h" |
| #include "llvm/CodeGen/Passes.h" |
| #include "llvm/CodeGen/TargetLowering.h" |
| #include "llvm/CodeGen/TargetPassConfig.h" |
| #include "llvm/CodeGen/TargetSubtargetInfo.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/IR/Dominators.h" |
| #include "llvm/IR/Function.h" |
| #include "llvm/IR/Instructions.h" |
| #include "llvm/IR/IRBuilder.h" |
| #include "llvm/IR/LegacyPassManager.h" |
| #include "llvm/IR/Module.h" |
| #include "llvm/InitializePasses.h" |
| #include "llvm/Pass.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Target/TargetMachine.h" |
| |
| #include <algorithm> |
| #include <cassert> |
| #include <list> |
| |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "interleaved-load-combine" |
| |
| namespace { |
| |
| /// Statistic counter |
| STATISTIC(NumInterleavedLoadCombine, "Number of combined loads"); |
| |
| /// Option to disable the pass |
| static cl::opt<bool> DisableInterleavedLoadCombine( |
| "disable-" DEBUG_TYPE, cl::init(false), cl::Hidden, |
| cl::desc("Disable combining of interleaved loads")); |
| |
| struct VectorInfo; |
| |
| struct InterleavedLoadCombineImpl { |
| public: |
| InterleavedLoadCombineImpl(Function &F, DominatorTree &DT, MemorySSA &MSSA, |
| TargetMachine &TM) |
| : F(F), DT(DT), MSSA(MSSA), |
| TLI(*TM.getSubtargetImpl(F)->getTargetLowering()), |
| TTI(TM.getTargetTransformInfo(F)) {} |
| |
| /// Scan the function for interleaved load candidates and execute the |
| /// replacement if applicable. |
| bool run(); |
| |
| private: |
| /// Function this pass is working on |
| Function &F; |
| |
| /// Dominator Tree Analysis |
| DominatorTree &DT; |
| |
| /// Memory Alias Analyses |
| MemorySSA &MSSA; |
| |
| /// Target Lowering Information |
| const TargetLowering &TLI; |
| |
| /// Target Transform Information |
| const TargetTransformInfo TTI; |
| |
| /// Find the instruction in sets LIs that dominates all others, return nullptr |
| /// if there is none. |
| LoadInst *findFirstLoad(const std::set<LoadInst *> &LIs); |
| |
| /// Replace interleaved load candidates. It does additional |
| /// analyses if this makes sense. Returns true on success and false |
| /// of nothing has been changed. |
| bool combine(std::list<VectorInfo> &InterleavedLoad, |
| OptimizationRemarkEmitter &ORE); |
| |
| /// Given a set of VectorInfo containing candidates for a given interleave |
| /// factor, find a set that represents a 'factor' interleaved load. |
| bool findPattern(std::list<VectorInfo> &Candidates, |
| std::list<VectorInfo> &InterleavedLoad, unsigned Factor, |
| const DataLayout &DL); |
| }; // InterleavedLoadCombine |
| |
| /// First Order Polynomial on an n-Bit Integer Value |
| /// |
| /// Polynomial(Value) = Value * B + A + E*2^(n-e) |
| /// |
| /// A and B are the coefficients. E*2^(n-e) is an error within 'e' most |
| /// significant bits. It is introduced if an exact computation cannot be proven |
| /// (e.q. division by 2). |
| /// |
| /// As part of this optimization multiple loads will be combined. It necessary |
| /// to prove that loads are within some relative offset to each other. This |
| /// class is used to prove relative offsets of values loaded from memory. |
| /// |
| /// Representing an integer in this form is sound since addition in two's |
| /// complement is associative (trivial) and multiplication distributes over the |
| /// addition (see Proof(1) in Polynomial::mul). Further, both operations |
| /// commute. |
| // |
| // Example: |
| // declare @fn(i64 %IDX, <4 x float>* %PTR) { |
| // %Pa1 = add i64 %IDX, 2 |
| // %Pa2 = lshr i64 %Pa1, 1 |
| // %Pa3 = getelementptr inbounds <4 x float>, <4 x float>* %PTR, i64 %Pa2 |
| // %Va = load <4 x float>, <4 x float>* %Pa3 |
| // |
| // %Pb1 = add i64 %IDX, 4 |
| // %Pb2 = lshr i64 %Pb1, 1 |
| // %Pb3 = getelementptr inbounds <4 x float>, <4 x float>* %PTR, i64 %Pb2 |
| // %Vb = load <4 x float>, <4 x float>* %Pb3 |
| // ... } |
| // |
| // The goal is to prove that two loads load consecutive addresses. |
| // |
| // In this case the polynomials are constructed by the following |
| // steps. |
| // |
| // The number tag #e specifies the error bits. |
| // |
| // Pa_0 = %IDX #0 |
| // Pa_1 = %IDX + 2 #0 | add 2 |
| // Pa_2 = %IDX/2 + 1 #1 | lshr 1 |
| // Pa_3 = %IDX/2 + 1 #1 | GEP, step signext to i64 |
| // Pa_4 = (%IDX/2)*16 + 16 #0 | GEP, multiply index by sizeof(4) for floats |
| // Pa_5 = (%IDX/2)*16 + 16 #0 | GEP, add offset of leading components |
| // |
| // Pb_0 = %IDX #0 |
| // Pb_1 = %IDX + 4 #0 | add 2 |
| // Pb_2 = %IDX/2 + 2 #1 | lshr 1 |
| // Pb_3 = %IDX/2 + 2 #1 | GEP, step signext to i64 |
| // Pb_4 = (%IDX/2)*16 + 32 #0 | GEP, multiply index by sizeof(4) for floats |
| // Pb_5 = (%IDX/2)*16 + 16 #0 | GEP, add offset of leading components |
| // |
| // Pb_5 - Pa_5 = 16 #0 | subtract to get the offset |
| // |
| // Remark: %PTR is not maintained within this class. So in this instance the |
| // offset of 16 can only be assumed if the pointers are equal. |
| // |
| class Polynomial { |
| /// Operations on B |
| enum BOps { |
| LShr, |
| Mul, |
| SExt, |
| Trunc, |
| }; |
| |
| /// Number of Error Bits e |
| unsigned ErrorMSBs; |
| |
| /// Value |
| Value *V; |
| |
| /// Coefficient B |
| SmallVector<std::pair<BOps, APInt>, 4> B; |
| |
| /// Coefficient A |
| APInt A; |
| |
| public: |
| Polynomial(Value *V) : ErrorMSBs((unsigned)-1), V(V), B(), A() { |
| IntegerType *Ty = dyn_cast<IntegerType>(V->getType()); |
| if (Ty) { |
| ErrorMSBs = 0; |
| this->V = V; |
| A = APInt(Ty->getBitWidth(), 0); |
| } |
| } |
| |
| Polynomial(const APInt &A, unsigned ErrorMSBs = 0) |
| : ErrorMSBs(ErrorMSBs), V(NULL), B(), A(A) {} |
| |
| Polynomial(unsigned BitWidth, uint64_t A, unsigned ErrorMSBs = 0) |
| : ErrorMSBs(ErrorMSBs), V(NULL), B(), A(BitWidth, A) {} |
| |
| Polynomial() : ErrorMSBs((unsigned)-1), V(NULL), B(), A() {} |
| |
| /// Increment and clamp the number of undefined bits. |
| void incErrorMSBs(unsigned amt) { |
| if (ErrorMSBs == (unsigned)-1) |
| return; |
| |
| ErrorMSBs += amt; |
| if (ErrorMSBs > A.getBitWidth()) |
| ErrorMSBs = A.getBitWidth(); |
| } |
| |
| /// Decrement and clamp the number of undefined bits. |
| void decErrorMSBs(unsigned amt) { |
| if (ErrorMSBs == (unsigned)-1) |
| return; |
| |
| if (ErrorMSBs > amt) |
| ErrorMSBs -= amt; |
| else |
| ErrorMSBs = 0; |
| } |
| |
| /// Apply an add on the polynomial |
| Polynomial &add(const APInt &C) { |
| // Note: Addition is associative in two's complement even when in case of |
| // signed overflow. |
| // |
| // Error bits can only propagate into higher significant bits. As these are |
| // already regarded as undefined, there is no change. |
| // |
| // Theorem: Adding a constant to a polynomial does not change the error |
| // term. |
| // |
| // Proof: |
| // |
| // Since the addition is associative and commutes: |
| // |
| // (B + A + E*2^(n-e)) + C = B + (A + C) + E*2^(n-e) |
| // [qed] |
| |
| if (C.getBitWidth() != A.getBitWidth()) { |
| ErrorMSBs = (unsigned)-1; |
| return *this; |
| } |
| |
| A += C; |
| return *this; |
| } |
| |
| /// Apply a multiplication onto the polynomial. |
| Polynomial &mul(const APInt &C) { |
| // Note: Multiplication distributes over the addition |
| // |
| // Theorem: Multiplication distributes over the addition |
| // |
| // Proof(1): |
| // |
| // (B+A)*C =- |
| // = (B + A) + (B + A) + .. {C Times} |
| // addition is associative and commutes, hence |
| // = B + B + .. {C Times} .. + A + A + .. {C times} |
| // = B*C + A*C |
| // (see (function add) for signed values and overflows) |
| // [qed] |
| // |
| // Theorem: If C has c trailing zeros, errors bits in A or B are shifted out |
| // to the left. |
| // |
| // Proof(2): |
| // |
| // Let B' and A' be the n-Bit inputs with some unknown errors EA, |
| // EB at e leading bits. B' and A' can be written down as: |
| // |
| // B' = B + 2^(n-e)*EB |
| // A' = A + 2^(n-e)*EA |
| // |
| // Let C' be an input with c trailing zero bits. C' can be written as |
| // |
| // C' = C*2^c |
| // |
| // Therefore we can compute the result by using distributivity and |
| // commutativity. |
| // |
| // (B'*C' + A'*C') = [B + 2^(n-e)*EB] * C' + [A + 2^(n-e)*EA] * C' = |
| // = [B + 2^(n-e)*EB + A + 2^(n-e)*EA] * C' = |
| // = (B'+A') * C' = |
| // = [B + 2^(n-e)*EB + A + 2^(n-e)*EA] * C' = |
| // = [B + A + 2^(n-e)*EB + 2^(n-e)*EA] * C' = |
| // = (B + A) * C' + [2^(n-e)*EB + 2^(n-e)*EA)] * C' = |
| // = (B + A) * C' + [2^(n-e)*EB + 2^(n-e)*EA)] * C*2^c = |
| // = (B + A) * C' + C*(EB + EA)*2^(n-e)*2^c = |
| // |
| // Let EC be the final error with EC = C*(EB + EA) |
| // |
| // = (B + A)*C' + EC*2^(n-e)*2^c = |
| // = (B + A)*C' + EC*2^(n-(e-c)) |
| // |
| // Since EC is multiplied by 2^(n-(e-c)) the resulting error contains c |
| // less error bits than the input. c bits are shifted out to the left. |
| // [qed] |
| |
| if (C.getBitWidth() != A.getBitWidth()) { |
| ErrorMSBs = (unsigned)-1; |
| return *this; |
| } |
| |
| // Multiplying by one is a no-op. |
| if (C.isOne()) { |
| return *this; |
| } |
| |
| // Multiplying by zero removes the coefficient B and defines all bits. |
| if (C.isZero()) { |
| ErrorMSBs = 0; |
| deleteB(); |
| } |
| |
| // See Proof(2): Trailing zero bits indicate a left shift. This removes |
| // leading bits from the result even if they are undefined. |
| decErrorMSBs(C.countTrailingZeros()); |
| |
| A *= C; |
| pushBOperation(Mul, C); |
| return *this; |
| } |
| |
| /// Apply a logical shift right on the polynomial |
| Polynomial &lshr(const APInt &C) { |
| // Theorem(1): (B + A + E*2^(n-e)) >> 1 => (B >> 1) + (A >> 1) + E'*2^(n-e') |
| // where |
| // e' = e + 1, |
| // E is a e-bit number, |
| // E' is a e'-bit number, |
| // holds under the following precondition: |
| // pre(1): A % 2 = 0 |
| // pre(2): e < n, (see Theorem(2) for the trivial case with e=n) |
| // where >> expresses a logical shift to the right, with adding zeros. |
| // |
| // We need to show that for every, E there is a E' |
| // |
| // B = b_h * 2^(n-1) + b_m * 2 + b_l |
| // A = a_h * 2^(n-1) + a_m * 2 (pre(1)) |
| // |
| // where a_h, b_h, b_l are single bits, and a_m, b_m are (n-2) bit numbers |
| // |
| // Let X = (B + A + E*2^(n-e)) >> 1 |
| // Let Y = (B >> 1) + (A >> 1) + E*2^(n-e) >> 1 |
| // |
| // X = [B + A + E*2^(n-e)] >> 1 = |
| // = [ b_h * 2^(n-1) + b_m * 2 + b_l + |
| // + a_h * 2^(n-1) + a_m * 2 + |
| // + E * 2^(n-e) ] >> 1 = |
| // |
| // The sum is built by putting the overflow of [a_m + b+n] into the term |
| // 2^(n-1). As there are no more bits beyond 2^(n-1) the overflow within |
| // this bit is discarded. This is expressed by % 2. |
| // |
| // The bit in position 0 cannot overflow into the term (b_m + a_m). |
| // |
| // = [ ([b_h + a_h + (b_m + a_m) >> (n-2)] % 2) * 2^(n-1) + |
| // + ((b_m + a_m) % 2^(n-2)) * 2 + |
| // + b_l + E * 2^(n-e) ] >> 1 = |
| // |
| // The shift is computed by dividing the terms by 2 and by cutting off |
| // b_l. |
| // |
| // = ([b_h + a_h + (b_m + a_m) >> (n-2)] % 2) * 2^(n-2) + |
| // + ((b_m + a_m) % 2^(n-2)) + |
| // + E * 2^(n-(e+1)) = |
| // |
| // by the definition in the Theorem e+1 = e' |
| // |
| // = ([b_h + a_h + (b_m + a_m) >> (n-2)] % 2) * 2^(n-2) + |
| // + ((b_m + a_m) % 2^(n-2)) + |
| // + E * 2^(n-e') = |
| // |
| // Compute Y by applying distributivity first |
| // |
| // Y = (B >> 1) + (A >> 1) + E*2^(n-e') = |
| // = (b_h * 2^(n-1) + b_m * 2 + b_l) >> 1 + |
| // + (a_h * 2^(n-1) + a_m * 2) >> 1 + |
| // + E * 2^(n-e) >> 1 = |
| // |
| // Again, the shift is computed by dividing the terms by 2 and by cutting |
| // off b_l. |
| // |
| // = b_h * 2^(n-2) + b_m + |
| // + a_h * 2^(n-2) + a_m + |
| // + E * 2^(n-(e+1)) = |
| // |
| // Again, the sum is built by putting the overflow of [a_m + b+n] into |
| // the term 2^(n-1). But this time there is room for a second bit in the |
| // term 2^(n-2) we add this bit to a new term and denote it o_h in a |
| // second step. |
| // |
| // = ([b_h + a_h + (b_m + a_m) >> (n-2)] >> 1) * 2^(n-1) + |
| // + ([b_h + a_h + (b_m + a_m) >> (n-2)] % 2) * 2^(n-2) + |
| // + ((b_m + a_m) % 2^(n-2)) + |
| // + E * 2^(n-(e+1)) = |
| // |
| // Let o_h = [b_h + a_h + (b_m + a_m) >> (n-2)] >> 1 |
| // Further replace e+1 by e'. |
| // |
| // = o_h * 2^(n-1) + |
| // + ([b_h + a_h + (b_m + a_m) >> (n-2)] % 2) * 2^(n-2) + |
| // + ((b_m + a_m) % 2^(n-2)) + |
| // + E * 2^(n-e') = |
| // |
| // Move o_h into the error term and construct E'. To ensure that there is |
| // no 2^x with negative x, this step requires pre(2) (e < n). |
| // |
| // = ([b_h + a_h + (b_m + a_m) >> (n-2)] % 2) * 2^(n-2) + |
| // + ((b_m + a_m) % 2^(n-2)) + |
| // + o_h * 2^(e'-1) * 2^(n-e') + | pre(2), move 2^(e'-1) |
| // | out of the old exponent |
| // + E * 2^(n-e') = |
| // = ([b_h + a_h + (b_m + a_m) >> (n-2)] % 2) * 2^(n-2) + |
| // + ((b_m + a_m) % 2^(n-2)) + |
| // + [o_h * 2^(e'-1) + E] * 2^(n-e') + | move 2^(e'-1) out of |
| // | the old exponent |
| // |
| // Let E' = o_h * 2^(e'-1) + E |
| // |
| // = ([b_h + a_h + (b_m + a_m) >> (n-2)] % 2) * 2^(n-2) + |
| // + ((b_m + a_m) % 2^(n-2)) + |
| // + E' * 2^(n-e') |
| // |
| // Because X and Y are distinct only in there error terms and E' can be |
| // constructed as shown the theorem holds. |
| // [qed] |
| // |
| // For completeness in case of the case e=n it is also required to show that |
| // distributivity can be applied. |
| // |
| // In this case Theorem(1) transforms to (the pre-condition on A can also be |
| // dropped) |
| // |
| // Theorem(2): (B + A + E) >> 1 => (B >> 1) + (A >> 1) + E' |
| // where |
| // A, B, E, E' are two's complement numbers with the same bit |
| // width |
| // |
| // Let A + B + E = X |
| // Let (B >> 1) + (A >> 1) = Y |
| // |
| // Therefore we need to show that for every X and Y there is an E' which |
| // makes the equation |
| // |
| // X = Y + E' |
| // |
| // hold. This is trivially the case for E' = X - Y. |
| // |
| // [qed] |
| // |
| // Remark: Distributing lshr with and arbitrary number n can be expressed as |
| // ((((B + A) lshr 1) lshr 1) ... ) {n times}. |
| // This construction induces n additional error bits at the left. |
| |
| if (C.getBitWidth() != A.getBitWidth()) { |
| ErrorMSBs = (unsigned)-1; |
| return *this; |
| } |
| |
| if (C.isZero()) |
| return *this; |
| |
| // Test if the result will be zero |
| unsigned shiftAmt = C.getZExtValue(); |
| if (shiftAmt >= C.getBitWidth()) |
| return mul(APInt(C.getBitWidth(), 0)); |
| |
| // The proof that shiftAmt LSBs are zero for at least one summand is only |
| // possible for the constant number. |
| // |
| // If this can be proven add shiftAmt to the error counter |
| // `ErrorMSBs`. Otherwise set all bits as undefined. |
| if (A.countTrailingZeros() < shiftAmt) |
| ErrorMSBs = A.getBitWidth(); |
| else |
| incErrorMSBs(shiftAmt); |
| |
| // Apply the operation. |
| pushBOperation(LShr, C); |
| A = A.lshr(shiftAmt); |
| |
| return *this; |
| } |
| |
| /// Apply a sign-extend or truncate operation on the polynomial. |
| Polynomial &sextOrTrunc(unsigned n) { |
| if (n < A.getBitWidth()) { |
| // Truncate: Clearly undefined Bits on the MSB side are removed |
| // if there are any. |
| decErrorMSBs(A.getBitWidth() - n); |
| A = A.trunc(n); |
| pushBOperation(Trunc, APInt(sizeof(n) * 8, n)); |
| } |
| if (n > A.getBitWidth()) { |
| // Extend: Clearly extending first and adding later is different |
| // to adding first and extending later in all extended bits. |
| incErrorMSBs(n - A.getBitWidth()); |
| A = A.sext(n); |
| pushBOperation(SExt, APInt(sizeof(n) * 8, n)); |
| } |
| |
| return *this; |
| } |
| |
| /// Test if there is a coefficient B. |
| bool isFirstOrder() const { return V != nullptr; } |
| |
| /// Test coefficient B of two Polynomials are equal. |
| bool isCompatibleTo(const Polynomial &o) const { |
| // The polynomial use different bit width. |
| if (A.getBitWidth() != o.A.getBitWidth()) |
| return false; |
| |
| // If neither Polynomial has the Coefficient B. |
| if (!isFirstOrder() && !o.isFirstOrder()) |
| return true; |
| |
| // The index variable is different. |
| if (V != o.V) |
| return false; |
| |
| // Check the operations. |
| if (B.size() != o.B.size()) |
| return false; |
| |
| auto ob = o.B.begin(); |
| for (auto &b : B) { |
| if (b != *ob) |
| return false; |
| ob++; |
| } |
| |
| return true; |
| } |
| |
| /// Subtract two polynomials, return an undefined polynomial if |
| /// subtraction is not possible. |
| Polynomial operator-(const Polynomial &o) const { |
| // Return an undefined polynomial if incompatible. |
| if (!isCompatibleTo(o)) |
| return Polynomial(); |
| |
| // If the polynomials are compatible (meaning they have the same |
| // coefficient on B), B is eliminated. Thus a polynomial solely |
| // containing A is returned |
| return Polynomial(A - o.A, std::max(ErrorMSBs, o.ErrorMSBs)); |
| } |
| |
| /// Subtract a constant from a polynomial, |
| Polynomial operator-(uint64_t C) const { |
| Polynomial Result(*this); |
| Result.A -= C; |
| return Result; |
| } |
| |
| /// Add a constant to a polynomial, |
| Polynomial operator+(uint64_t C) const { |
| Polynomial Result(*this); |
| Result.A += C; |
| return Result; |
| } |
| |
| /// Returns true if it can be proven that two Polynomials are equal. |
| bool isProvenEqualTo(const Polynomial &o) { |
| // Subtract both polynomials and test if it is fully defined and zero. |
| Polynomial r = *this - o; |
| return (r.ErrorMSBs == 0) && (!r.isFirstOrder()) && (r.A.isZero()); |
| } |
| |
| /// Print the polynomial into a stream. |
| void print(raw_ostream &OS) const { |
| OS << "[{#ErrBits:" << ErrorMSBs << "} "; |
| |
| if (V) { |
| for (auto b : B) |
| OS << "("; |
| OS << "(" << *V << ") "; |
| |
| for (auto b : B) { |
| switch (b.first) { |
| case LShr: |
| OS << "LShr "; |
| break; |
| case Mul: |
| OS << "Mul "; |
| break; |
| case SExt: |
| OS << "SExt "; |
| break; |
| case Trunc: |
| OS << "Trunc "; |
| break; |
| } |
| |
| OS << b.second << ") "; |
| } |
| } |
| |
| OS << "+ " << A << "]"; |
| } |
| |
| private: |
| void deleteB() { |
| V = nullptr; |
| B.clear(); |
| } |
| |
| void pushBOperation(const BOps Op, const APInt &C) { |
| if (isFirstOrder()) { |
| B.push_back(std::make_pair(Op, C)); |
| return; |
| } |
| } |
| }; |
| |
| #ifndef NDEBUG |
| static raw_ostream &operator<<(raw_ostream &OS, const Polynomial &S) { |
| S.print(OS); |
| return OS; |
| } |
| #endif |
| |
| /// VectorInfo stores abstract the following information for each vector |
| /// element: |
| /// |
| /// 1) The the memory address loaded into the element as Polynomial |
| /// 2) a set of load instruction necessary to construct the vector, |
| /// 3) a set of all other instructions that are necessary to create the vector and |
| /// 4) a pointer value that can be used as relative base for all elements. |
| struct VectorInfo { |
| private: |
| VectorInfo(const VectorInfo &c) : VTy(c.VTy) { |
| llvm_unreachable( |
| "Copying VectorInfo is neither implemented nor necessary,"); |
| } |
| |
| public: |
| /// Information of a Vector Element |
| struct ElementInfo { |
| /// Offset Polynomial. |
| Polynomial Ofs; |
| |
| /// The Load Instruction used to Load the entry. LI is null if the pointer |
| /// of the load instruction does not point on to the entry |
| LoadInst *LI; |
| |
| ElementInfo(Polynomial Offset = Polynomial(), LoadInst *LI = nullptr) |
| : Ofs(Offset), LI(LI) {} |
| }; |
| |
| /// Basic-block the load instructions are within |
| BasicBlock *BB; |
| |
| /// Pointer value of all participation load instructions |
| Value *PV; |
| |
| /// Participating load instructions |
| std::set<LoadInst *> LIs; |
| |
| /// Participating instructions |
| std::set<Instruction *> Is; |
| |
| /// Final shuffle-vector instruction |
| ShuffleVectorInst *SVI; |
| |
| /// Information of the offset for each vector element |
| ElementInfo *EI; |
| |
| /// Vector Type |
| FixedVectorType *const VTy; |
| |
| VectorInfo(FixedVectorType *VTy) |
| : BB(nullptr), PV(nullptr), LIs(), Is(), SVI(nullptr), VTy(VTy) { |
| EI = new ElementInfo[VTy->getNumElements()]; |
| } |
| |
| virtual ~VectorInfo() { delete[] EI; } |
| |
| unsigned getDimension() const { return VTy->getNumElements(); } |
| |
| /// Test if the VectorInfo can be part of an interleaved load with the |
| /// specified factor. |
| /// |
| /// \param Factor of the interleave |
| /// \param DL Targets Datalayout |
| /// |
| /// \returns true if this is possible and false if not |
| bool isInterleaved(unsigned Factor, const DataLayout &DL) const { |
| unsigned Size = DL.getTypeAllocSize(VTy->getElementType()); |
| for (unsigned i = 1; i < getDimension(); i++) { |
| if (!EI[i].Ofs.isProvenEqualTo(EI[0].Ofs + i * Factor * Size)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /// Recursively computes the vector information stored in V. |
| /// |
| /// This function delegates the work to specialized implementations |
| /// |
| /// \param V Value to operate on |
| /// \param Result Result of the computation |
| /// |
| /// \returns false if no sensible information can be gathered. |
| static bool compute(Value *V, VectorInfo &Result, const DataLayout &DL) { |
| ShuffleVectorInst *SVI = dyn_cast<ShuffleVectorInst>(V); |
| if (SVI) |
| return computeFromSVI(SVI, Result, DL); |
| LoadInst *LI = dyn_cast<LoadInst>(V); |
| if (LI) |
| return computeFromLI(LI, Result, DL); |
| BitCastInst *BCI = dyn_cast<BitCastInst>(V); |
| if (BCI) |
| return computeFromBCI(BCI, Result, DL); |
| return false; |
| } |
| |
| /// BitCastInst specialization to compute the vector information. |
| /// |
| /// \param BCI BitCastInst to operate on |
| /// \param Result Result of the computation |
| /// |
| /// \returns false if no sensible information can be gathered. |
| static bool computeFromBCI(BitCastInst *BCI, VectorInfo &Result, |
| const DataLayout &DL) { |
| Instruction *Op = dyn_cast<Instruction>(BCI->getOperand(0)); |
| |
| if (!Op) |
| return false; |
| |
| FixedVectorType *VTy = dyn_cast<FixedVectorType>(Op->getType()); |
| if (!VTy) |
| return false; |
| |
| // We can only cast from large to smaller vectors |
| if (Result.VTy->getNumElements() % VTy->getNumElements()) |
| return false; |
| |
| unsigned Factor = Result.VTy->getNumElements() / VTy->getNumElements(); |
| unsigned NewSize = DL.getTypeAllocSize(Result.VTy->getElementType()); |
| unsigned OldSize = DL.getTypeAllocSize(VTy->getElementType()); |
| |
| if (NewSize * Factor != OldSize) |
| return false; |
| |
| VectorInfo Old(VTy); |
| if (!compute(Op, Old, DL)) |
| return false; |
| |
| for (unsigned i = 0; i < Result.VTy->getNumElements(); i += Factor) { |
| for (unsigned j = 0; j < Factor; j++) { |
| Result.EI[i + j] = |
| ElementInfo(Old.EI[i / Factor].Ofs + j * NewSize, |
| j == 0 ? Old.EI[i / Factor].LI : nullptr); |
| } |
| } |
| |
| Result.BB = Old.BB; |
| Result.PV = Old.PV; |
| Result.LIs.insert(Old.LIs.begin(), Old.LIs.end()); |
| Result.Is.insert(Old.Is.begin(), Old.Is.end()); |
| Result.Is.insert(BCI); |
| Result.SVI = nullptr; |
| |
| return true; |
| } |
| |
| /// ShuffleVectorInst specialization to compute vector information. |
| /// |
| /// \param SVI ShuffleVectorInst to operate on |
| /// \param Result Result of the computation |
| /// |
| /// Compute the left and the right side vector information and merge them by |
| /// applying the shuffle operation. This function also ensures that the left |
| /// and right side have compatible loads. This means that all loads are with |
| /// in the same basic block and are based on the same pointer. |
| /// |
| /// \returns false if no sensible information can be gathered. |
| static bool computeFromSVI(ShuffleVectorInst *SVI, VectorInfo &Result, |
| const DataLayout &DL) { |
| FixedVectorType *ArgTy = |
| cast<FixedVectorType>(SVI->getOperand(0)->getType()); |
| |
| // Compute the left hand vector information. |
| VectorInfo LHS(ArgTy); |
| if (!compute(SVI->getOperand(0), LHS, DL)) |
| LHS.BB = nullptr; |
| |
| // Compute the right hand vector information. |
| VectorInfo RHS(ArgTy); |
| if (!compute(SVI->getOperand(1), RHS, DL)) |
| RHS.BB = nullptr; |
| |
| // Neither operand produced sensible results? |
| if (!LHS.BB && !RHS.BB) |
| return false; |
| // Only RHS produced sensible results? |
| else if (!LHS.BB) { |
| Result.BB = RHS.BB; |
| Result.PV = RHS.PV; |
| } |
| // Only LHS produced sensible results? |
| else if (!RHS.BB) { |
| Result.BB = LHS.BB; |
| Result.PV = LHS.PV; |
| } |
| // Both operands produced sensible results? |
| else if ((LHS.BB == RHS.BB) && (LHS.PV == RHS.PV)) { |
| Result.BB = LHS.BB; |
| Result.PV = LHS.PV; |
| } |
| // Both operands produced sensible results but they are incompatible. |
| else { |
| return false; |
| } |
| |
| // Merge and apply the operation on the offset information. |
| if (LHS.BB) { |
| Result.LIs.insert(LHS.LIs.begin(), LHS.LIs.end()); |
| Result.Is.insert(LHS.Is.begin(), LHS.Is.end()); |
| } |
| if (RHS.BB) { |
| Result.LIs.insert(RHS.LIs.begin(), RHS.LIs.end()); |
| Result.Is.insert(RHS.Is.begin(), RHS.Is.end()); |
| } |
| Result.Is.insert(SVI); |
| Result.SVI = SVI; |
| |
| int j = 0; |
| for (int i : SVI->getShuffleMask()) { |
| assert((i < 2 * (signed)ArgTy->getNumElements()) && |
| "Invalid ShuffleVectorInst (index out of bounds)"); |
| |
| if (i < 0) |
| Result.EI[j] = ElementInfo(); |
| else if (i < (signed)ArgTy->getNumElements()) { |
| if (LHS.BB) |
| Result.EI[j] = LHS.EI[i]; |
| else |
| Result.EI[j] = ElementInfo(); |
| } else { |
| if (RHS.BB) |
| Result.EI[j] = RHS.EI[i - ArgTy->getNumElements()]; |
| else |
| Result.EI[j] = ElementInfo(); |
| } |
| j++; |
| } |
| |
| return true; |
| } |
| |
| /// LoadInst specialization to compute vector information. |
| /// |
| /// This function also acts as abort condition to the recursion. |
| /// |
| /// \param LI LoadInst to operate on |
| /// \param Result Result of the computation |
| /// |
| /// \returns false if no sensible information can be gathered. |
| static bool computeFromLI(LoadInst *LI, VectorInfo &Result, |
| const DataLayout &DL) { |
| Value *BasePtr; |
| Polynomial Offset; |
| |
| if (LI->isVolatile()) |
| return false; |
| |
| if (LI->isAtomic()) |
| return false; |
| |
| // Get the base polynomial |
| computePolynomialFromPointer(*LI->getPointerOperand(), Offset, BasePtr, DL); |
| |
| Result.BB = LI->getParent(); |
| Result.PV = BasePtr; |
| Result.LIs.insert(LI); |
| Result.Is.insert(LI); |
| |
| for (unsigned i = 0; i < Result.getDimension(); i++) { |
| Value *Idx[2] = { |
| ConstantInt::get(Type::getInt32Ty(LI->getContext()), 0), |
| ConstantInt::get(Type::getInt32Ty(LI->getContext()), i), |
| }; |
| int64_t Ofs = DL.getIndexedOffsetInType(Result.VTy, makeArrayRef(Idx, 2)); |
| Result.EI[i] = ElementInfo(Offset + Ofs, i == 0 ? LI : nullptr); |
| } |
| |
| return true; |
| } |
| |
| /// Recursively compute polynomial of a value. |
| /// |
| /// \param BO Input binary operation |
| /// \param Result Result polynomial |
| static void computePolynomialBinOp(BinaryOperator &BO, Polynomial &Result) { |
| Value *LHS = BO.getOperand(0); |
| Value *RHS = BO.getOperand(1); |
| |
| // Find the RHS Constant if any |
| ConstantInt *C = dyn_cast<ConstantInt>(RHS); |
| if ((!C) && BO.isCommutative()) { |
| C = dyn_cast<ConstantInt>(LHS); |
| if (C) |
| std::swap(LHS, RHS); |
| } |
| |
| switch (BO.getOpcode()) { |
| case Instruction::Add: |
| if (!C) |
| break; |
| |
| computePolynomial(*LHS, Result); |
| Result.add(C->getValue()); |
| return; |
| |
| case Instruction::LShr: |
| if (!C) |
| break; |
| |
| computePolynomial(*LHS, Result); |
| Result.lshr(C->getValue()); |
| return; |
| |
| default: |
| break; |
| } |
| |
| Result = Polynomial(&BO); |
| } |
| |
| /// Recursively compute polynomial of a value |
| /// |
| /// \param V input value |
| /// \param Result result polynomial |
| static void computePolynomial(Value &V, Polynomial &Result) { |
| if (auto *BO = dyn_cast<BinaryOperator>(&V)) |
| computePolynomialBinOp(*BO, Result); |
| else |
| Result = Polynomial(&V); |
| } |
| |
| /// Compute the Polynomial representation of a Pointer type. |
| /// |
| /// \param Ptr input pointer value |
| /// \param Result result polynomial |
| /// \param BasePtr pointer the polynomial is based on |
| /// \param DL Datalayout of the target machine |
| static void computePolynomialFromPointer(Value &Ptr, Polynomial &Result, |
| Value *&BasePtr, |
| const DataLayout &DL) { |
| // Not a pointer type? Return an undefined polynomial |
| PointerType *PtrTy = dyn_cast<PointerType>(Ptr.getType()); |
| if (!PtrTy) { |
| Result = Polynomial(); |
| BasePtr = nullptr; |
| return; |
| } |
| unsigned PointerBits = |
| DL.getIndexSizeInBits(PtrTy->getPointerAddressSpace()); |
| |
| /// Skip pointer casts. Return Zero polynomial otherwise |
| if (isa<CastInst>(&Ptr)) { |
| CastInst &CI = *cast<CastInst>(&Ptr); |
| switch (CI.getOpcode()) { |
| case Instruction::BitCast: |
| computePolynomialFromPointer(*CI.getOperand(0), Result, BasePtr, DL); |
| break; |
| default: |
| BasePtr = &Ptr; |
| Polynomial(PointerBits, 0); |
| break; |
| } |
| } |
| /// Resolve GetElementPtrInst. |
| else if (isa<GetElementPtrInst>(&Ptr)) { |
| GetElementPtrInst &GEP = *cast<GetElementPtrInst>(&Ptr); |
| |
| APInt BaseOffset(PointerBits, 0); |
| |
| // Check if we can compute the Offset with accumulateConstantOffset |
| if (GEP.accumulateConstantOffset(DL, BaseOffset)) { |
| Result = Polynomial(BaseOffset); |
| BasePtr = GEP.getPointerOperand(); |
| return; |
| } else { |
| // Otherwise we allow that the last index operand of the GEP is |
| // non-constant. |
| unsigned idxOperand, e; |
| SmallVector<Value *, 4> Indices; |
| for (idxOperand = 1, e = GEP.getNumOperands(); idxOperand < e; |
| idxOperand++) { |
| ConstantInt *IDX = dyn_cast<ConstantInt>(GEP.getOperand(idxOperand)); |
| if (!IDX) |
| break; |
| Indices.push_back(IDX); |
| } |
| |
| // It must also be the last operand. |
| if (idxOperand + 1 != e) { |
| Result = Polynomial(); |
| BasePtr = nullptr; |
| return; |
| } |
| |
| // Compute the polynomial of the index operand. |
| computePolynomial(*GEP.getOperand(idxOperand), Result); |
| |
| // Compute base offset from zero based index, excluding the last |
| // variable operand. |
| BaseOffset = |
| DL.getIndexedOffsetInType(GEP.getSourceElementType(), Indices); |
| |
| // Apply the operations of GEP to the polynomial. |
| unsigned ResultSize = DL.getTypeAllocSize(GEP.getResultElementType()); |
| Result.sextOrTrunc(PointerBits); |
| Result.mul(APInt(PointerBits, ResultSize)); |
| Result.add(BaseOffset); |
| BasePtr = GEP.getPointerOperand(); |
| } |
| } |
| // All other instructions are handled by using the value as base pointer and |
| // a zero polynomial. |
| else { |
| BasePtr = &Ptr; |
| Polynomial(DL.getIndexSizeInBits(PtrTy->getPointerAddressSpace()), 0); |
| } |
| } |
| |
| #ifndef NDEBUG |
| void print(raw_ostream &OS) const { |
| if (PV) |
| OS << *PV; |
| else |
| OS << "(none)"; |
| OS << " + "; |
| for (unsigned i = 0; i < getDimension(); i++) |
| OS << ((i == 0) ? "[" : ", ") << EI[i].Ofs; |
| OS << "]"; |
| } |
| #endif |
| }; |
| |
| } // anonymous namespace |
| |
| bool InterleavedLoadCombineImpl::findPattern( |
| std::list<VectorInfo> &Candidates, std::list<VectorInfo> &InterleavedLoad, |
| unsigned Factor, const DataLayout &DL) { |
| for (auto C0 = Candidates.begin(), E0 = Candidates.end(); C0 != E0; ++C0) { |
| unsigned i; |
| // Try to find an interleaved load using the front of Worklist as first line |
| unsigned Size = DL.getTypeAllocSize(C0->VTy->getElementType()); |
| |
| // List containing iterators pointing to the VectorInfos of the candidates |
| std::vector<std::list<VectorInfo>::iterator> Res(Factor, Candidates.end()); |
| |
| for (auto C = Candidates.begin(), E = Candidates.end(); C != E; C++) { |
| if (C->VTy != C0->VTy) |
| continue; |
| if (C->BB != C0->BB) |
| continue; |
| if (C->PV != C0->PV) |
| continue; |
| |
| // Check the current value matches any of factor - 1 remaining lines |
| for (i = 1; i < Factor; i++) { |
| if (C->EI[0].Ofs.isProvenEqualTo(C0->EI[0].Ofs + i * Size)) { |
| Res[i] = C; |
| } |
| } |
| |
| for (i = 1; i < Factor; i++) { |
| if (Res[i] == Candidates.end()) |
| break; |
| } |
| if (i == Factor) { |
| Res[0] = C0; |
| break; |
| } |
| } |
| |
| if (Res[0] != Candidates.end()) { |
| // Move the result into the output |
| for (unsigned i = 0; i < Factor; i++) { |
| InterleavedLoad.splice(InterleavedLoad.end(), Candidates, Res[i]); |
| } |
| |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| LoadInst * |
| InterleavedLoadCombineImpl::findFirstLoad(const std::set<LoadInst *> &LIs) { |
| assert(!LIs.empty() && "No load instructions given."); |
| |
| // All LIs are within the same BB. Select the first for a reference. |
| BasicBlock *BB = (*LIs.begin())->getParent(); |
| BasicBlock::iterator FLI = llvm::find_if( |
| *BB, [&LIs](Instruction &I) -> bool { return is_contained(LIs, &I); }); |
| assert(FLI != BB->end()); |
| |
| return cast<LoadInst>(FLI); |
| } |
| |
| bool InterleavedLoadCombineImpl::combine(std::list<VectorInfo> &InterleavedLoad, |
| OptimizationRemarkEmitter &ORE) { |
| LLVM_DEBUG(dbgs() << "Checking interleaved load\n"); |
| |
| // The insertion point is the LoadInst which loads the first values. The |
| // following tests are used to proof that the combined load can be inserted |
| // just before InsertionPoint. |
| LoadInst *InsertionPoint = InterleavedLoad.front().EI[0].LI; |
| |
| // Test if the offset is computed |
| if (!InsertionPoint) |
| return false; |
| |
| std::set<LoadInst *> LIs; |
| std::set<Instruction *> Is; |
| std::set<Instruction *> SVIs; |
| |
| InstructionCost InterleavedCost; |
| InstructionCost InstructionCost = 0; |
| const TTI::TargetCostKind CostKind = TTI::TCK_SizeAndLatency; |
| |
| // Get the interleave factor |
| unsigned Factor = InterleavedLoad.size(); |
| |
| // Merge all input sets used in analysis |
| for (auto &VI : InterleavedLoad) { |
| // Generate a set of all load instructions to be combined |
| LIs.insert(VI.LIs.begin(), VI.LIs.end()); |
| |
| // Generate a set of all instructions taking part in load |
| // interleaved. This list excludes the instructions necessary for the |
| // polynomial construction. |
| Is.insert(VI.Is.begin(), VI.Is.end()); |
| |
| // Generate the set of the final ShuffleVectorInst. |
| SVIs.insert(VI.SVI); |
| } |
| |
| // There is nothing to combine. |
| if (LIs.size() < 2) |
| return false; |
| |
| // Test if all participating instruction will be dead after the |
| // transformation. If intermediate results are used, no performance gain can |
| // be expected. Also sum the cost of the Instructions beeing left dead. |
| for (auto &I : Is) { |
| // Compute the old cost |
| InstructionCost += TTI.getInstructionCost(I, CostKind); |
| |
| // The final SVIs are allowed not to be dead, all uses will be replaced |
| if (SVIs.find(I) != SVIs.end()) |
| continue; |
| |
| // If there are users outside the set to be eliminated, we abort the |
| // transformation. No gain can be expected. |
| for (auto *U : I->users()) { |
| if (Is.find(dyn_cast<Instruction>(U)) == Is.end()) |
| return false; |
| } |
| } |
| |
| // We need to have a valid cost in order to proceed. |
| if (!InstructionCost.isValid()) |
| return false; |
| |
| // We know that all LoadInst are within the same BB. This guarantees that |
| // either everything or nothing is loaded. |
| LoadInst *First = findFirstLoad(LIs); |
| |
| // To be safe that the loads can be combined, iterate over all loads and test |
| // that the corresponding defining access dominates first LI. This guarantees |
| // that there are no aliasing stores in between the loads. |
| auto FMA = MSSA.getMemoryAccess(First); |
| for (auto LI : LIs) { |
| auto MADef = MSSA.getMemoryAccess(LI)->getDefiningAccess(); |
| if (!MSSA.dominates(MADef, FMA)) |
| return false; |
| } |
| assert(!LIs.empty() && "There are no LoadInst to combine"); |
| |
| // It is necessary that insertion point dominates all final ShuffleVectorInst. |
| for (auto &VI : InterleavedLoad) { |
| if (!DT.dominates(InsertionPoint, VI.SVI)) |
| return false; |
| } |
| |
| // All checks are done. Add instructions detectable by InterleavedAccessPass |
| // The old instruction will are left dead. |
| IRBuilder<> Builder(InsertionPoint); |
| Type *ETy = InterleavedLoad.front().SVI->getType()->getElementType(); |
| unsigned ElementsPerSVI = |
| cast<FixedVectorType>(InterleavedLoad.front().SVI->getType()) |
| ->getNumElements(); |
| FixedVectorType *ILTy = FixedVectorType::get(ETy, Factor * ElementsPerSVI); |
| |
| SmallVector<unsigned, 4> Indices; |
| for (unsigned i = 0; i < Factor; i++) |
| Indices.push_back(i); |
| InterleavedCost = TTI.getInterleavedMemoryOpCost( |
| Instruction::Load, ILTy, Factor, Indices, InsertionPoint->getAlign(), |
| InsertionPoint->getPointerAddressSpace(), CostKind); |
| |
| if (InterleavedCost >= InstructionCost) { |
| return false; |
| } |
| |
| // Create a pointer cast for the wide load. |
| auto CI = Builder.CreatePointerCast(InsertionPoint->getOperand(0), |
| ILTy->getPointerTo(), |
| "interleaved.wide.ptrcast"); |
| |
| // Create the wide load and update the MemorySSA. |
| auto LI = Builder.CreateAlignedLoad(ILTy, CI, InsertionPoint->getAlign(), |
| "interleaved.wide.load"); |
| auto MSSAU = MemorySSAUpdater(&MSSA); |
| MemoryUse *MSSALoad = cast<MemoryUse>(MSSAU.createMemoryAccessBefore( |
| LI, nullptr, MSSA.getMemoryAccess(InsertionPoint))); |
| MSSAU.insertUse(MSSALoad); |
| |
| // Create the final SVIs and replace all uses. |
| int i = 0; |
| for (auto &VI : InterleavedLoad) { |
| SmallVector<int, 4> Mask; |
| for (unsigned j = 0; j < ElementsPerSVI; j++) |
| Mask.push_back(i + j * Factor); |
| |
| Builder.SetInsertPoint(VI.SVI); |
| auto SVI = Builder.CreateShuffleVector(LI, Mask, "interleaved.shuffle"); |
| VI.SVI->replaceAllUsesWith(SVI); |
| i++; |
| } |
| |
| NumInterleavedLoadCombine++; |
| ORE.emit([&]() { |
| return OptimizationRemark(DEBUG_TYPE, "Combined Interleaved Load", LI) |
| << "Load interleaved combined with factor " |
| << ore::NV("Factor", Factor); |
| }); |
| |
| return true; |
| } |
| |
| bool InterleavedLoadCombineImpl::run() { |
| OptimizationRemarkEmitter ORE(&F); |
| bool changed = false; |
| unsigned MaxFactor = TLI.getMaxSupportedInterleaveFactor(); |
| |
| auto &DL = F.getParent()->getDataLayout(); |
| |
| // Start with the highest factor to avoid combining and recombining. |
| for (unsigned Factor = MaxFactor; Factor >= 2; Factor--) { |
| std::list<VectorInfo> Candidates; |
| |
| for (BasicBlock &BB : F) { |
| for (Instruction &I : BB) { |
| if (auto SVI = dyn_cast<ShuffleVectorInst>(&I)) { |
| // We don't support scalable vectors in this pass. |
| if (isa<ScalableVectorType>(SVI->getType())) |
| continue; |
| |
| Candidates.emplace_back(cast<FixedVectorType>(SVI->getType())); |
| |
| if (!VectorInfo::computeFromSVI(SVI, Candidates.back(), DL)) { |
| Candidates.pop_back(); |
| continue; |
| } |
| |
| if (!Candidates.back().isInterleaved(Factor, DL)) { |
| Candidates.pop_back(); |
| } |
| } |
| } |
| } |
| |
| std::list<VectorInfo> InterleavedLoad; |
| while (findPattern(Candidates, InterleavedLoad, Factor, DL)) { |
| if (combine(InterleavedLoad, ORE)) { |
| changed = true; |
| } else { |
| // Remove the first element of the Interleaved Load but put the others |
| // back on the list and continue searching |
| Candidates.splice(Candidates.begin(), InterleavedLoad, |
| std::next(InterleavedLoad.begin()), |
| InterleavedLoad.end()); |
| } |
| InterleavedLoad.clear(); |
| } |
| } |
| |
| return changed; |
| } |
| |
| namespace { |
| /// This pass combines interleaved loads into a pattern detectable by |
| /// InterleavedAccessPass. |
| struct InterleavedLoadCombine : public FunctionPass { |
| static char ID; |
| |
| InterleavedLoadCombine() : FunctionPass(ID) { |
| initializeInterleavedLoadCombinePass(*PassRegistry::getPassRegistry()); |
| } |
| |
| StringRef getPassName() const override { |
| return "Interleaved Load Combine Pass"; |
| } |
| |
| bool runOnFunction(Function &F) override { |
| if (DisableInterleavedLoadCombine) |
| return false; |
| |
| auto *TPC = getAnalysisIfAvailable<TargetPassConfig>(); |
| if (!TPC) |
| return false; |
| |
| LLVM_DEBUG(dbgs() << "*** " << getPassName() << ": " << F.getName() |
| << "\n"); |
| |
| return InterleavedLoadCombineImpl( |
| F, getAnalysis<DominatorTreeWrapperPass>().getDomTree(), |
| getAnalysis<MemorySSAWrapperPass>().getMSSA(), |
| TPC->getTM<TargetMachine>()) |
| .run(); |
| } |
| |
| void getAnalysisUsage(AnalysisUsage &AU) const override { |
| AU.addRequired<MemorySSAWrapperPass>(); |
| AU.addRequired<DominatorTreeWrapperPass>(); |
| FunctionPass::getAnalysisUsage(AU); |
| } |
| |
| private: |
| }; |
| } // anonymous namespace |
| |
| char InterleavedLoadCombine::ID = 0; |
| |
| INITIALIZE_PASS_BEGIN( |
| InterleavedLoadCombine, DEBUG_TYPE, |
| "Combine interleaved loads into wide loads and shufflevector instructions", |
| false, false) |
| INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) |
| INITIALIZE_PASS_DEPENDENCY(MemorySSAWrapperPass) |
| INITIALIZE_PASS_END( |
| InterleavedLoadCombine, DEBUG_TYPE, |
| "Combine interleaved loads into wide loads and shufflevector instructions", |
| false, false) |
| |
| FunctionPass * |
| llvm::createInterleavedLoadCombinePass() { |
| auto P = new InterleavedLoadCombine(); |
| return P; |
| } |