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llvm-mirror/lib/Target/Hexagon/HexagonConstExtenders.cpp
Gaurav Jain 025b28cffd [NFC] Use [MC]Register for Hexagon target 
Differential Revision: https://reviews.llvm.org/D91160
2020-11-18 08:17:07 -08:00

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//===- HexagonConstExtenders.cpp ------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "HexagonInstrInfo.h"
#include "HexagonRegisterInfo.h"
#include "HexagonSubtarget.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Register.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/raw_ostream.h"
#include <map>
#include <set>
#include <utility>
#include <vector>
#define DEBUG_TYPE "hexagon-cext-opt"
using namespace llvm;
static cl::opt<unsigned> CountThreshold("hexagon-cext-threshold",
cl::init(3), cl::Hidden, cl::ZeroOrMore,
cl::desc("Minimum number of extenders to trigger replacement"));
static cl::opt<unsigned> ReplaceLimit("hexagon-cext-limit", cl::init(0),
cl::Hidden, cl::ZeroOrMore, cl::desc("Maximum number of replacements"));
namespace llvm {
void initializeHexagonConstExtendersPass(PassRegistry&);
FunctionPass *createHexagonConstExtenders();
}
static int32_t adjustUp(int32_t V, uint8_t A, uint8_t O) {
assert(isPowerOf2_32(A));
int32_t U = (V & -A) + O;
return U >= V ? U : U+A;
}
static int32_t adjustDown(int32_t V, uint8_t A, uint8_t O) {
assert(isPowerOf2_32(A));
int32_t U = (V & -A) + O;
return U <= V ? U : U-A;
}
namespace {
struct OffsetRange {
// The range of values between Min and Max that are of form Align*N+Offset,
// for some integer N. Min and Max are required to be of that form as well,
// except in the case of an empty range.
int32_t Min = INT_MIN, Max = INT_MAX;
uint8_t Align = 1;
uint8_t Offset = 0;
OffsetRange() = default;
OffsetRange(int32_t L, int32_t H, uint8_t A, uint8_t O = 0)
: Min(L), Max(H), Align(A), Offset(O) {}
OffsetRange &intersect(OffsetRange A) {
if (Align < A.Align)
std::swap(*this, A);
// Align >= A.Align.
if (Offset >= A.Offset && (Offset - A.Offset) % A.Align == 0) {
Min = adjustUp(std::max(Min, A.Min), Align, Offset);
Max = adjustDown(std::min(Max, A.Max), Align, Offset);
} else {
// Make an empty range.
Min = 0;
Max = -1;
}
// Canonicalize empty ranges.
if (Min > Max)
std::tie(Min, Max, Align) = std::make_tuple(0, -1, 1);
return *this;
}
OffsetRange &shift(int32_t S) {
Min += S;
Max += S;
Offset = (Offset+S) % Align;
return *this;
}
OffsetRange &extendBy(int32_t D) {
// If D < 0, extend Min, otherwise extend Max.
assert(D % Align == 0);
if (D < 0)
Min = (INT_MIN-D < Min) ? Min+D : INT_MIN;
else
Max = (INT_MAX-D > Max) ? Max+D : INT_MAX;
return *this;
}
bool empty() const {
return Min > Max;
}
bool contains(int32_t V) const {
return Min <= V && V <= Max && (V-Offset) % Align == 0;
}
bool operator==(const OffsetRange &R) const {
return Min == R.Min && Max == R.Max && Align == R.Align;
}
bool operator!=(const OffsetRange &R) const {
return !operator==(R);
}
bool operator<(const OffsetRange &R) const {
if (Min != R.Min)
return Min < R.Min;
if (Max != R.Max)
return Max < R.Max;
return Align < R.Align;
}
static OffsetRange zero() { return {0, 0, 1}; }
};
struct RangeTree {
struct Node {
Node(const OffsetRange &R) : MaxEnd(R.Max), Range(R) {}
unsigned Height = 1;
unsigned Count = 1;
int32_t MaxEnd;
const OffsetRange &Range;
Node *Left = nullptr, *Right = nullptr;
};
Node *Root = nullptr;
void add(const OffsetRange &R) {
Root = add(Root, R);
}
void erase(const Node *N) {
Root = remove(Root, N);
delete N;
}
void order(SmallVectorImpl<Node*> &Seq) const {
order(Root, Seq);
}
SmallVector<Node*,8> nodesWith(int32_t P, bool CheckAlign = true) {
SmallVector<Node*,8> Nodes;
nodesWith(Root, P, CheckAlign, Nodes);
return Nodes;
}
void dump() const;
~RangeTree() {
SmallVector<Node*,8> Nodes;
order(Nodes);
for (Node *N : Nodes)
delete N;
}
private:
void dump(const Node *N) const;
void order(Node *N, SmallVectorImpl<Node*> &Seq) const;
void nodesWith(Node *N, int32_t P, bool CheckA,
SmallVectorImpl<Node*> &Seq) const;
Node *add(Node *N, const OffsetRange &R);
Node *remove(Node *N, const Node *D);
Node *rotateLeft(Node *Lower, Node *Higher);
Node *rotateRight(Node *Lower, Node *Higher);
unsigned height(Node *N) {
return N != nullptr ? N->Height : 0;
}
Node *update(Node *N) {
assert(N != nullptr);
N->Height = 1 + std::max(height(N->Left), height(N->Right));
if (N->Left)
N->MaxEnd = std::max(N->MaxEnd, N->Left->MaxEnd);
if (N->Right)
N->MaxEnd = std::max(N->MaxEnd, N->Right->MaxEnd);
return N;
}
Node *rebalance(Node *N) {
assert(N != nullptr);
int32_t Balance = height(N->Right) - height(N->Left);
if (Balance < -1)
return rotateRight(N->Left, N);
if (Balance > 1)
return rotateLeft(N->Right, N);
return N;
}
};
struct Loc {
MachineBasicBlock *Block = nullptr;
MachineBasicBlock::iterator At;
Loc(MachineBasicBlock *B, MachineBasicBlock::iterator It)
: Block(B), At(It) {
if (B->end() == It) {
Pos = -1;
} else {
assert(It->getParent() == B);
Pos = std::distance(B->begin(), It);
}
}
bool operator<(Loc A) const {
if (Block != A.Block)
return Block->getNumber() < A.Block->getNumber();
if (A.Pos == -1)
return Pos != A.Pos;
return Pos != -1 && Pos < A.Pos;
}
private:
int Pos = 0;
};
struct HexagonConstExtenders : public MachineFunctionPass {
static char ID;
HexagonConstExtenders() : MachineFunctionPass(ID) {}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequired<MachineDominatorTree>();
AU.addPreserved<MachineDominatorTree>();
MachineFunctionPass::getAnalysisUsage(AU);
}
StringRef getPassName() const override {
return "Hexagon constant-extender optimization";
}
bool runOnMachineFunction(MachineFunction &MF) override;
private:
struct Register {
Register() = default;
Register(unsigned R, unsigned S) : Reg(R), Sub(S) {}
Register(const MachineOperand &Op)
: Reg(Op.getReg()), Sub(Op.getSubReg()) {}
Register &operator=(const MachineOperand &Op) {
if (Op.isReg()) {
Reg = Op.getReg();
Sub = Op.getSubReg();
} else if (Op.isFI()) {
Reg = llvm::Register::index2StackSlot(Op.getIndex());
}
return *this;
}
bool isVReg() const {
return Reg != 0 && !Reg.isStack() && Reg.isVirtual();
}
bool isSlot() const { return Reg != 0 && Reg.isStack(); }
operator MachineOperand() const {
if (isVReg())
return MachineOperand::CreateReg(Reg, /*Def*/false, /*Imp*/false,
/*Kill*/false, /*Dead*/false, /*Undef*/false,
/*EarlyClobber*/false, Sub);
if (Reg.isStack()) {
int FI = llvm::Register::stackSlot2Index(Reg);
return MachineOperand::CreateFI(FI);
}
llvm_unreachable("Cannot create MachineOperand");
}
bool operator==(Register R) const { return Reg == R.Reg && Sub == R.Sub; }
bool operator!=(Register R) const { return !operator==(R); }
bool operator<(Register R) const {
// For std::map.
return Reg < R.Reg || (Reg == R.Reg && Sub < R.Sub);
}
llvm::Register Reg;
unsigned Sub = 0;
};
struct ExtExpr {
// A subexpression in which the extender is used. In general, this
// represents an expression where adding D to the extender will be
// equivalent to adding D to the expression as a whole. In other
// words, expr(add(##V,D) = add(expr(##V),D).
// The original motivation for this are the io/ur addressing modes,
// where the offset is extended. Consider the io example:
// In memw(Rs+##V), the ##V could be replaced by a register Rt to
// form the rr mode: memw(Rt+Rs<<0). In such case, however, the
// register Rt must have exactly the value of ##V. If there was
// another instruction memw(Rs+##V+4), it would need a different Rt.
// Now, if Rt was initialized as "##V+Rs<<0", both of these
// instructions could use the same Rt, just with different offsets.
// Here it's clear that "initializer+4" should be the same as if
// the offset 4 was added to the ##V in the initializer.
// The only kinds of expressions that support the requirement of
// commuting with addition are addition and subtraction from ##V.
// Include shifting the Rs to account for the ur addressing mode:
// ##Val + Rs << S
// ##Val - Rs
Register Rs;
unsigned S = 0;
bool Neg = false;
ExtExpr() = default;
ExtExpr(Register RS, bool NG, unsigned SH) : Rs(RS), S(SH), Neg(NG) {}
// Expression is trivial if it does not modify the extender.
bool trivial() const {
return Rs.Reg == 0;
}
bool operator==(const ExtExpr &Ex) const {
return Rs == Ex.Rs && S == Ex.S && Neg == Ex.Neg;
}
bool operator!=(const ExtExpr &Ex) const {
return !operator==(Ex);
}
bool operator<(const ExtExpr &Ex) const {
if (Rs != Ex.Rs)
return Rs < Ex.Rs;
if (S != Ex.S)
return S < Ex.S;
return !Neg && Ex.Neg;
}
};
struct ExtDesc {
MachineInstr *UseMI = nullptr;
unsigned OpNum = -1u;
// The subexpression in which the extender is used (e.g. address
// computation).
ExtExpr Expr;
// Optional register that is assigned the value of Expr.
Register Rd;
// Def means that the output of the instruction may differ from the
// original by a constant c, and that the difference can be corrected
// by adding/subtracting c in all users of the defined register.
bool IsDef = false;
MachineOperand &getOp() {
return UseMI->getOperand(OpNum);
}
const MachineOperand &getOp() const {
return UseMI->getOperand(OpNum);
}
};
struct ExtRoot {
union {
const ConstantFP *CFP; // MO_FPImmediate
const char *SymbolName; // MO_ExternalSymbol
const GlobalValue *GV; // MO_GlobalAddress
const BlockAddress *BA; // MO_BlockAddress
int64_t ImmVal; // MO_Immediate, MO_TargetIndex,
// and MO_ConstantPoolIndex
} V;
unsigned Kind; // Same as in MachineOperand.
unsigned char TF; // TargetFlags.
ExtRoot(const MachineOperand &Op);
bool operator==(const ExtRoot &ER) const {
return Kind == ER.Kind && V.ImmVal == ER.V.ImmVal;
}
bool operator!=(const ExtRoot &ER) const {
return !operator==(ER);
}
bool operator<(const ExtRoot &ER) const;
};
struct ExtValue : public ExtRoot {
int32_t Offset;
ExtValue(const MachineOperand &Op);
ExtValue(const ExtDesc &ED) : ExtValue(ED.getOp()) {}
ExtValue(const ExtRoot &ER, int32_t Off) : ExtRoot(ER), Offset(Off) {}
bool operator<(const ExtValue &EV) const;
bool operator==(const ExtValue &EV) const {
return ExtRoot(*this) == ExtRoot(EV) && Offset == EV.Offset;
}
bool operator!=(const ExtValue &EV) const {
return !operator==(EV);
}
explicit operator MachineOperand() const;
};
using IndexList = SetVector<unsigned>;
using ExtenderInit = std::pair<ExtValue, ExtExpr>;
using AssignmentMap = std::map<ExtenderInit, IndexList>;
using LocDefList = std::vector<std::pair<Loc, IndexList>>;
const HexagonSubtarget *HST = nullptr;
const HexagonInstrInfo *HII = nullptr;
const HexagonRegisterInfo *HRI = nullptr;
MachineDominatorTree *MDT = nullptr;
MachineRegisterInfo *MRI = nullptr;
std::vector<ExtDesc> Extenders;
std::vector<unsigned> NewRegs;
bool isStoreImmediate(unsigned Opc) const;
bool isRegOffOpcode(unsigned ExtOpc) const ;
unsigned getRegOffOpcode(unsigned ExtOpc) const;
unsigned getDirectRegReplacement(unsigned ExtOpc) const;
OffsetRange getOffsetRange(Register R, const MachineInstr &MI) const;
OffsetRange getOffsetRange(const ExtDesc &ED) const;
OffsetRange getOffsetRange(Register Rd) const;
void recordExtender(MachineInstr &MI, unsigned OpNum);
void collectInstr(MachineInstr &MI);
void collect(MachineFunction &MF);
void assignInits(const ExtRoot &ER, unsigned Begin, unsigned End,
AssignmentMap &IMap);
void calculatePlacement(const ExtenderInit &ExtI, const IndexList &Refs,
LocDefList &Defs);
Register insertInitializer(Loc DefL, const ExtenderInit &ExtI);
bool replaceInstrExact(const ExtDesc &ED, Register ExtR);
bool replaceInstrExpr(const ExtDesc &ED, const ExtenderInit &ExtI,
Register ExtR, int32_t &Diff);
bool replaceInstr(unsigned Idx, Register ExtR, const ExtenderInit &ExtI);
bool replaceExtenders(const AssignmentMap &IMap);
unsigned getOperandIndex(const MachineInstr &MI,
const MachineOperand &Op) const;
const MachineOperand &getPredicateOp(const MachineInstr &MI) const;
const MachineOperand &getLoadResultOp(const MachineInstr &MI) const;
const MachineOperand &getStoredValueOp(const MachineInstr &MI) const;
friend struct PrintRegister;
friend struct PrintExpr;
friend struct PrintInit;
friend struct PrintIMap;
friend raw_ostream &operator<< (raw_ostream &OS,
const struct PrintRegister &P);
friend raw_ostream &operator<< (raw_ostream &OS, const struct PrintExpr &P);
friend raw_ostream &operator<< (raw_ostream &OS, const struct PrintInit &P);
friend raw_ostream &operator<< (raw_ostream &OS, const ExtDesc &ED);
friend raw_ostream &operator<< (raw_ostream &OS, const ExtRoot &ER);
friend raw_ostream &operator<< (raw_ostream &OS, const ExtValue &EV);
friend raw_ostream &operator<< (raw_ostream &OS, const OffsetRange &OR);
friend raw_ostream &operator<< (raw_ostream &OS, const struct PrintIMap &P);
};
using HCE = HexagonConstExtenders;
LLVM_ATTRIBUTE_UNUSED
raw_ostream &operator<< (raw_ostream &OS, const OffsetRange &OR) {
if (OR.Min > OR.Max)
OS << '!';
OS << '[' << OR.Min << ',' << OR.Max << "]a" << unsigned(OR.Align)
<< '+' << unsigned(OR.Offset);
return OS;
}
struct PrintRegister {
PrintRegister(HCE::Register R, const HexagonRegisterInfo &I)
: Rs(R), HRI(I) {}
HCE::Register Rs;
const HexagonRegisterInfo &HRI;
};
LLVM_ATTRIBUTE_UNUSED
raw_ostream &operator<< (raw_ostream &OS, const PrintRegister &P) {
if (P.Rs.Reg != 0)
OS << printReg(P.Rs.Reg, &P.HRI, P.Rs.Sub);
else
OS << "noreg";
return OS;
}
struct PrintExpr {
PrintExpr(const HCE::ExtExpr &E, const HexagonRegisterInfo &I)
: Ex(E), HRI(I) {}
const HCE::ExtExpr &Ex;
const HexagonRegisterInfo &HRI;
};
LLVM_ATTRIBUTE_UNUSED
raw_ostream &operator<< (raw_ostream &OS, const PrintExpr &P) {
OS << "## " << (P.Ex.Neg ? "- " : "+ ");
if (P.Ex.Rs.Reg != 0)
OS << printReg(P.Ex.Rs.Reg, &P.HRI, P.Ex.Rs.Sub);
else
OS << "__";
OS << " << " << P.Ex.S;
return OS;
}
struct PrintInit {
PrintInit(const HCE::ExtenderInit &EI, const HexagonRegisterInfo &I)
: ExtI(EI), HRI(I) {}
const HCE::ExtenderInit &ExtI;
const HexagonRegisterInfo &HRI;
};
LLVM_ATTRIBUTE_UNUSED
raw_ostream &operator<< (raw_ostream &OS, const PrintInit &P) {
OS << '[' << P.ExtI.first << ", "
<< PrintExpr(P.ExtI.second, P.HRI) << ']';
return OS;
}
LLVM_ATTRIBUTE_UNUSED
raw_ostream &operator<< (raw_ostream &OS, const HCE::ExtDesc &ED) {
assert(ED.OpNum != -1u);
const MachineBasicBlock &MBB = *ED.getOp().getParent()->getParent();
const MachineFunction &MF = *MBB.getParent();
const auto &HRI = *MF.getSubtarget<HexagonSubtarget>().getRegisterInfo();
OS << "bb#" << MBB.getNumber() << ": ";
if (ED.Rd.Reg != 0)
OS << printReg(ED.Rd.Reg, &HRI, ED.Rd.Sub);
else
OS << "__";
OS << " = " << PrintExpr(ED.Expr, HRI);
if (ED.IsDef)
OS << ", def";
return OS;
}
LLVM_ATTRIBUTE_UNUSED
raw_ostream &operator<< (raw_ostream &OS, const HCE::ExtRoot &ER) {
switch (ER.Kind) {
case MachineOperand::MO_Immediate:
OS << "imm:" << ER.V.ImmVal;
break;
case MachineOperand::MO_FPImmediate:
OS << "fpi:" << *ER.V.CFP;
break;
case MachineOperand::MO_ExternalSymbol:
OS << "sym:" << *ER.V.SymbolName;
break;
case MachineOperand::MO_GlobalAddress:
OS << "gad:" << ER.V.GV->getName();
break;
case MachineOperand::MO_BlockAddress:
OS << "blk:" << *ER.V.BA;
break;
case MachineOperand::MO_TargetIndex:
OS << "tgi:" << ER.V.ImmVal;
break;
case MachineOperand::MO_ConstantPoolIndex:
OS << "cpi:" << ER.V.ImmVal;
break;
case MachineOperand::MO_JumpTableIndex:
OS << "jti:" << ER.V.ImmVal;
break;
default:
OS << "???:" << ER.V.ImmVal;
break;
}
return OS;
}
LLVM_ATTRIBUTE_UNUSED
raw_ostream &operator<< (raw_ostream &OS, const HCE::ExtValue &EV) {
OS << HCE::ExtRoot(EV) << " off:" << EV.Offset;
return OS;
}
struct PrintIMap {
PrintIMap(const HCE::AssignmentMap &M, const HexagonRegisterInfo &I)
: IMap(M), HRI(I) {}
const HCE::AssignmentMap &IMap;
const HexagonRegisterInfo &HRI;
};
LLVM_ATTRIBUTE_UNUSED
raw_ostream &operator<< (raw_ostream &OS, const PrintIMap &P) {
OS << "{\n";
for (const std::pair<const HCE::ExtenderInit, HCE::IndexList> &Q : P.IMap) {
OS << " " << PrintInit(Q.first, P.HRI) << " -> {";
for (unsigned I : Q.second)
OS << ' ' << I;
OS << " }\n";
}
OS << "}\n";
return OS;
}
}
INITIALIZE_PASS_BEGIN(HexagonConstExtenders, "hexagon-cext-opt",
"Hexagon constant-extender optimization", false, false)
INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
INITIALIZE_PASS_END(HexagonConstExtenders, "hexagon-cext-opt",
"Hexagon constant-extender optimization", false, false)
static unsigned ReplaceCounter = 0;
char HCE::ID = 0;
#ifndef NDEBUG
LLVM_DUMP_METHOD void RangeTree::dump() const {
dbgs() << "Root: " << Root << '\n';
if (Root)
dump(Root);
}
LLVM_DUMP_METHOD void RangeTree::dump(const Node *N) const {
dbgs() << "Node: " << N << '\n';
dbgs() << " Height: " << N->Height << '\n';
dbgs() << " Count: " << N->Count << '\n';
dbgs() << " MaxEnd: " << N->MaxEnd << '\n';
dbgs() << " Range: " << N->Range << '\n';
dbgs() << " Left: " << N->Left << '\n';
dbgs() << " Right: " << N->Right << "\n\n";
if (N->Left)
dump(N->Left);
if (N->Right)
dump(N->Right);
}
#endif
void RangeTree::order(Node *N, SmallVectorImpl<Node*> &Seq) const {
if (N == nullptr)
return;
order(N->Left, Seq);
Seq.push_back(N);
order(N->Right, Seq);
}
void RangeTree::nodesWith(Node *N, int32_t P, bool CheckA,
SmallVectorImpl<Node*> &Seq) const {
if (N == nullptr || N->MaxEnd < P)
return;
nodesWith(N->Left, P, CheckA, Seq);
if (N->Range.Min <= P) {
if ((CheckA && N->Range.contains(P)) || (!CheckA && P <= N->Range.Max))
Seq.push_back(N);
nodesWith(N->Right, P, CheckA, Seq);
}
}
RangeTree::Node *RangeTree::add(Node *N, const OffsetRange &R) {
if (N == nullptr)
return new Node(R);
if (N->Range == R) {
N->Count++;
return N;
}
if (R < N->Range)
N->Left = add(N->Left, R);
else
N->Right = add(N->Right, R);
return rebalance(update(N));
}
RangeTree::Node *RangeTree::remove(Node *N, const Node *D) {
assert(N != nullptr);
if (N != D) {
assert(N->Range != D->Range && "N and D should not be equal");
if (D->Range < N->Range)
N->Left = remove(N->Left, D);
else
N->Right = remove(N->Right, D);
return rebalance(update(N));
}
// We got to the node we need to remove. If any of its children are
// missing, simply replace it with the other child.
if (N->Left == nullptr || N->Right == nullptr)
return (N->Left == nullptr) ? N->Right : N->Left;
// Find the rightmost child of N->Left, remove it and plug it in place
// of N.
Node *M = N->Left;
while (M->Right)
M = M->Right;
M->Left = remove(N->Left, M);
M->Right = N->Right;
return rebalance(update(M));
}
RangeTree::Node *RangeTree::rotateLeft(Node *Lower, Node *Higher) {
assert(Higher->Right == Lower);
// The Lower node is on the right from Higher. Make sure that Lower's
// balance is greater to the right. Otherwise the rotation will create
// an unbalanced tree again.
if (height(Lower->Left) > height(Lower->Right))
Lower = rotateRight(Lower->Left, Lower);
assert(height(Lower->Left) <= height(Lower->Right));
Higher->Right = Lower->Left;
update(Higher);
Lower->Left = Higher;
update(Lower);
return Lower;
}
RangeTree::Node *RangeTree::rotateRight(Node *Lower, Node *Higher) {
assert(Higher->Left == Lower);
// The Lower node is on the left from Higher. Make sure that Lower's
// balance is greater to the left. Otherwise the rotation will create
// an unbalanced tree again.
if (height(Lower->Left) < height(Lower->Right))
Lower = rotateLeft(Lower->Right, Lower);
assert(height(Lower->Left) >= height(Lower->Right));
Higher->Left = Lower->Right;
update(Higher);
Lower->Right = Higher;
update(Lower);
return Lower;
}
HCE::ExtRoot::ExtRoot(const MachineOperand &Op) {
// Always store ImmVal, since it's the field used for comparisons.
V.ImmVal = 0;
if (Op.isImm())
; // Keep 0. Do not use Op.getImm() for value here (treat 0 as the root).
else if (Op.isFPImm())
V.CFP = Op.getFPImm();
else if (Op.isSymbol())
V.SymbolName = Op.getSymbolName();
else if (Op.isGlobal())
V.GV = Op.getGlobal();
else if (Op.isBlockAddress())
V.BA = Op.getBlockAddress();
else if (Op.isCPI() || Op.isTargetIndex() || Op.isJTI())
V.ImmVal = Op.getIndex();
else
llvm_unreachable("Unexpected operand type");
Kind = Op.getType();
TF = Op.getTargetFlags();
}
bool HCE::ExtRoot::operator< (const HCE::ExtRoot &ER) const {
if (Kind != ER.Kind)
return Kind < ER.Kind;
switch (Kind) {
case MachineOperand::MO_Immediate:
case MachineOperand::MO_TargetIndex:
case MachineOperand::MO_ConstantPoolIndex:
case MachineOperand::MO_JumpTableIndex:
return V.ImmVal < ER.V.ImmVal;
case MachineOperand::MO_FPImmediate: {
const APFloat &ThisF = V.CFP->getValueAPF();
const APFloat &OtherF = ER.V.CFP->getValueAPF();
return ThisF.bitcastToAPInt().ult(OtherF.bitcastToAPInt());
}
case MachineOperand::MO_ExternalSymbol:
return StringRef(V.SymbolName) < StringRef(ER.V.SymbolName);
case MachineOperand::MO_GlobalAddress:
// Do not use GUIDs, since they depend on the source path. Moving the
// source file to a different directory could cause different GUID
// values for a pair of given symbols. These symbols could then compare
// "less" in one directory, but "greater" in another.
assert(!V.GV->getName().empty() && !ER.V.GV->getName().empty());
return V.GV->getName() < ER.V.GV->getName();
case MachineOperand::MO_BlockAddress: {
const BasicBlock *ThisB = V.BA->getBasicBlock();
const BasicBlock *OtherB = ER.V.BA->getBasicBlock();
assert(ThisB->getParent() == OtherB->getParent());
const Function &F = *ThisB->getParent();
return std::distance(F.begin(), ThisB->getIterator()) <
std::distance(F.begin(), OtherB->getIterator());
}
}
return V.ImmVal < ER.V.ImmVal;
}
HCE::ExtValue::ExtValue(const MachineOperand &Op) : ExtRoot(Op) {
if (Op.isImm())
Offset = Op.getImm();
else if (Op.isFPImm() || Op.isJTI())
Offset = 0;
else if (Op.isSymbol() || Op.isGlobal() || Op.isBlockAddress() ||
Op.isCPI() || Op.isTargetIndex())
Offset = Op.getOffset();
else
llvm_unreachable("Unexpected operand type");
}
bool HCE::ExtValue::operator< (const HCE::ExtValue &EV) const {
const ExtRoot &ER = *this;
if (!(ER == ExtRoot(EV)))
return ER < EV;
return Offset < EV.Offset;
}
HCE::ExtValue::operator MachineOperand() const {
switch (Kind) {
case MachineOperand::MO_Immediate:
return MachineOperand::CreateImm(V.ImmVal + Offset);
case MachineOperand::MO_FPImmediate:
assert(Offset == 0);
return MachineOperand::CreateFPImm(V.CFP);
case MachineOperand::MO_ExternalSymbol:
assert(Offset == 0);
return MachineOperand::CreateES(V.SymbolName, TF);
case MachineOperand::MO_GlobalAddress:
return MachineOperand::CreateGA(V.GV, Offset, TF);
case MachineOperand::MO_BlockAddress:
return MachineOperand::CreateBA(V.BA, Offset, TF);
case MachineOperand::MO_TargetIndex:
return MachineOperand::CreateTargetIndex(V.ImmVal, Offset, TF);
case MachineOperand::MO_ConstantPoolIndex:
return MachineOperand::CreateCPI(V.ImmVal, Offset, TF);
case MachineOperand::MO_JumpTableIndex:
assert(Offset == 0);
return MachineOperand::CreateJTI(V.ImmVal, TF);
default:
llvm_unreachable("Unhandled kind");
}
}
bool HCE::isStoreImmediate(unsigned Opc) const {
switch (Opc) {
case Hexagon::S4_storeirbt_io:
case Hexagon::S4_storeirbf_io:
case Hexagon::S4_storeirht_io:
case Hexagon::S4_storeirhf_io:
case Hexagon::S4_storeirit_io:
case Hexagon::S4_storeirif_io:
case Hexagon::S4_storeirb_io:
case Hexagon::S4_storeirh_io:
case Hexagon::S4_storeiri_io:
return true;
default:
break;
}
return false;
}
bool HCE::isRegOffOpcode(unsigned Opc) const {
switch (Opc) {
case Hexagon::L2_loadrub_io:
case Hexagon::L2_loadrb_io:
case Hexagon::L2_loadruh_io:
case Hexagon::L2_loadrh_io:
case Hexagon::L2_loadri_io:
case Hexagon::L2_loadrd_io:
case Hexagon::L2_loadbzw2_io:
case Hexagon::L2_loadbzw4_io:
case Hexagon::L2_loadbsw2_io:
case Hexagon::L2_loadbsw4_io:
case Hexagon::L2_loadalignh_io:
case Hexagon::L2_loadalignb_io:
case Hexagon::L2_ploadrubt_io:
case Hexagon::L2_ploadrubf_io:
case Hexagon::L2_ploadrbt_io:
case Hexagon::L2_ploadrbf_io:
case Hexagon::L2_ploadruht_io:
case Hexagon::L2_ploadruhf_io:
case Hexagon::L2_ploadrht_io:
case Hexagon::L2_ploadrhf_io:
case Hexagon::L2_ploadrit_io:
case Hexagon::L2_ploadrif_io:
case Hexagon::L2_ploadrdt_io:
case Hexagon::L2_ploadrdf_io:
case Hexagon::S2_storerb_io:
case Hexagon::S2_storerh_io:
case Hexagon::S2_storerf_io:
case Hexagon::S2_storeri_io:
case Hexagon::S2_storerd_io:
case Hexagon::S2_pstorerbt_io:
case Hexagon::S2_pstorerbf_io:
case Hexagon::S2_pstorerht_io:
case Hexagon::S2_pstorerhf_io:
case Hexagon::S2_pstorerft_io:
case Hexagon::S2_pstorerff_io:
case Hexagon::S2_pstorerit_io:
case Hexagon::S2_pstorerif_io:
case Hexagon::S2_pstorerdt_io:
case Hexagon::S2_pstorerdf_io:
case Hexagon::A2_addi:
return true;
default:
break;
}
return false;
}
unsigned HCE::getRegOffOpcode(unsigned ExtOpc) const {
// If there exists an instruction that takes a register and offset,
// that corresponds to the ExtOpc, return it, otherwise return 0.
using namespace Hexagon;
switch (ExtOpc) {
case A2_tfrsi: return A2_addi;
default:
break;
}
const MCInstrDesc &D = HII->get(ExtOpc);
if (D.mayLoad() || D.mayStore()) {
uint64_t F = D.TSFlags;
unsigned AM = (F >> HexagonII::AddrModePos) & HexagonII::AddrModeMask;
switch (AM) {
case HexagonII::Absolute:
case HexagonII::AbsoluteSet:
case HexagonII::BaseLongOffset:
switch (ExtOpc) {
case PS_loadrubabs:
case L4_loadrub_ap:
case L4_loadrub_ur: return L2_loadrub_io;
case PS_loadrbabs:
case L4_loadrb_ap:
case L4_loadrb_ur: return L2_loadrb_io;
case PS_loadruhabs:
case L4_loadruh_ap:
case L4_loadruh_ur: return L2_loadruh_io;
case PS_loadrhabs:
case L4_loadrh_ap:
case L4_loadrh_ur: return L2_loadrh_io;
case PS_loadriabs:
case L4_loadri_ap:
case L4_loadri_ur: return L2_loadri_io;
case PS_loadrdabs:
case L4_loadrd_ap:
case L4_loadrd_ur: return L2_loadrd_io;
case L4_loadbzw2_ap:
case L4_loadbzw2_ur: return L2_loadbzw2_io;
case L4_loadbzw4_ap:
case L4_loadbzw4_ur: return L2_loadbzw4_io;
case L4_loadbsw2_ap:
case L4_loadbsw2_ur: return L2_loadbsw2_io;
case L4_loadbsw4_ap:
case L4_loadbsw4_ur: return L2_loadbsw4_io;
case L4_loadalignh_ap:
case L4_loadalignh_ur: return L2_loadalignh_io;
case L4_loadalignb_ap:
case L4_loadalignb_ur: return L2_loadalignb_io;
case L4_ploadrubt_abs: return L2_ploadrubt_io;
case L4_ploadrubf_abs: return L2_ploadrubf_io;
case L4_ploadrbt_abs: return L2_ploadrbt_io;
case L4_ploadrbf_abs: return L2_ploadrbf_io;
case L4_ploadruht_abs: return L2_ploadruht_io;
case L4_ploadruhf_abs: return L2_ploadruhf_io;
case L4_ploadrht_abs: return L2_ploadrht_io;
case L4_ploadrhf_abs: return L2_ploadrhf_io;
case L4_ploadrit_abs: return L2_ploadrit_io;
case L4_ploadrif_abs: return L2_ploadrif_io;
case L4_ploadrdt_abs: return L2_ploadrdt_io;
case L4_ploadrdf_abs: return L2_ploadrdf_io;
case PS_storerbabs:
case S4_storerb_ap:
case S4_storerb_ur: return S2_storerb_io;
case PS_storerhabs:
case S4_storerh_ap:
case S4_storerh_ur: return S2_storerh_io;
case PS_storerfabs:
case S4_storerf_ap:
case S4_storerf_ur: return S2_storerf_io;
case PS_storeriabs:
case S4_storeri_ap:
case S4_storeri_ur: return S2_storeri_io;
case PS_storerdabs:
case S4_storerd_ap:
case S4_storerd_ur: return S2_storerd_io;
case S4_pstorerbt_abs: return S2_pstorerbt_io;
case S4_pstorerbf_abs: return S2_pstorerbf_io;
case S4_pstorerht_abs: return S2_pstorerht_io;
case S4_pstorerhf_abs: return S2_pstorerhf_io;
case S4_pstorerft_abs: return S2_pstorerft_io;
case S4_pstorerff_abs: return S2_pstorerff_io;
case S4_pstorerit_abs: return S2_pstorerit_io;
case S4_pstorerif_abs: return S2_pstorerif_io;
case S4_pstorerdt_abs: return S2_pstorerdt_io;
case S4_pstorerdf_abs: return S2_pstorerdf_io;
default:
break;
}
break;
case HexagonII::BaseImmOffset:
if (!isStoreImmediate(ExtOpc))
return ExtOpc;
break;
default:
break;
}
}
return 0;
}
unsigned HCE::getDirectRegReplacement(unsigned ExtOpc) const {
switch (ExtOpc) {
case Hexagon::A2_addi: return Hexagon::A2_add;
case Hexagon::A2_andir: return Hexagon::A2_and;
case Hexagon::A2_combineii: return Hexagon::A4_combineri;
case Hexagon::A2_orir: return Hexagon::A2_or;
case Hexagon::A2_paddif: return Hexagon::A2_paddf;
case Hexagon::A2_paddit: return Hexagon::A2_paddt;
case Hexagon::A2_subri: return Hexagon::A2_sub;
case Hexagon::A2_tfrsi: return TargetOpcode::COPY;
case Hexagon::A4_cmpbeqi: return Hexagon::A4_cmpbeq;
case Hexagon::A4_cmpbgti: return Hexagon::A4_cmpbgt;
case Hexagon::A4_cmpbgtui: return Hexagon::A4_cmpbgtu;
case Hexagon::A4_cmpheqi: return Hexagon::A4_cmpheq;
case Hexagon::A4_cmphgti: return Hexagon::A4_cmphgt;
case Hexagon::A4_cmphgtui: return Hexagon::A4_cmphgtu;
case Hexagon::A4_combineii: return Hexagon::A4_combineir;
case Hexagon::A4_combineir: return TargetOpcode::REG_SEQUENCE;
case Hexagon::A4_combineri: return TargetOpcode::REG_SEQUENCE;
case Hexagon::A4_rcmpeqi: return Hexagon::A4_rcmpeq;
case Hexagon::A4_rcmpneqi: return Hexagon::A4_rcmpneq;
case Hexagon::C2_cmoveif: return Hexagon::A2_tfrpf;
case Hexagon::C2_cmoveit: return Hexagon::A2_tfrpt;
case Hexagon::C2_cmpeqi: return Hexagon::C2_cmpeq;
case Hexagon::C2_cmpgti: return Hexagon::C2_cmpgt;
case Hexagon::C2_cmpgtui: return Hexagon::C2_cmpgtu;
case Hexagon::C2_muxii: return Hexagon::C2_muxir;
case Hexagon::C2_muxir: return Hexagon::C2_mux;
case Hexagon::C2_muxri: return Hexagon::C2_mux;
case Hexagon::C4_cmpltei: return Hexagon::C4_cmplte;
case Hexagon::C4_cmplteui: return Hexagon::C4_cmplteu;
case Hexagon::C4_cmpneqi: return Hexagon::C4_cmpneq;
case Hexagon::M2_accii: return Hexagon::M2_acci; // T -> T
/* No M2_macsin */
case Hexagon::M2_macsip: return Hexagon::M2_maci; // T -> T
case Hexagon::M2_mpysin: return Hexagon::M2_mpyi;
case Hexagon::M2_mpysip: return Hexagon::M2_mpyi;
case Hexagon::M2_mpysmi: return Hexagon::M2_mpyi;
case Hexagon::M2_naccii: return Hexagon::M2_nacci; // T -> T
case Hexagon::M4_mpyri_addi: return Hexagon::M4_mpyri_addr;
case Hexagon::M4_mpyri_addr: return Hexagon::M4_mpyrr_addr; // _ -> T
case Hexagon::M4_mpyrr_addi: return Hexagon::M4_mpyrr_addr; // _ -> T
case Hexagon::S4_addaddi: return Hexagon::M2_acci; // _ -> T
case Hexagon::S4_addi_asl_ri: return Hexagon::S2_asl_i_r_acc; // T -> T
case Hexagon::S4_addi_lsr_ri: return Hexagon::S2_lsr_i_r_acc; // T -> T
case Hexagon::S4_andi_asl_ri: return Hexagon::S2_asl_i_r_and; // T -> T
case Hexagon::S4_andi_lsr_ri: return Hexagon::S2_lsr_i_r_and; // T -> T
case Hexagon::S4_ori_asl_ri: return Hexagon::S2_asl_i_r_or; // T -> T
case Hexagon::S4_ori_lsr_ri: return Hexagon::S2_lsr_i_r_or; // T -> T
case Hexagon::S4_subaddi: return Hexagon::M2_subacc; // _ -> T
case Hexagon::S4_subi_asl_ri: return Hexagon::S2_asl_i_r_nac; // T -> T
case Hexagon::S4_subi_lsr_ri: return Hexagon::S2_lsr_i_r_nac; // T -> T
// Store-immediates:
case Hexagon::S4_storeirbf_io: return Hexagon::S2_pstorerbf_io;
case Hexagon::S4_storeirb_io: return Hexagon::S2_storerb_io;
case Hexagon::S4_storeirbt_io: return Hexagon::S2_pstorerbt_io;
case Hexagon::S4_storeirhf_io: return Hexagon::S2_pstorerhf_io;
case Hexagon::S4_storeirh_io: return Hexagon::S2_storerh_io;
case Hexagon::S4_storeirht_io: return Hexagon::S2_pstorerht_io;
case Hexagon::S4_storeirif_io: return Hexagon::S2_pstorerif_io;
case Hexagon::S4_storeiri_io: return Hexagon::S2_storeri_io;
case Hexagon::S4_storeirit_io: return Hexagon::S2_pstorerit_io;
default:
break;
}
return 0;
}
// Return the allowable deviation from the current value of Rb (i.e. the
// range of values that can be added to the current value) which the
// instruction MI can accommodate.
// The instruction MI is a user of register Rb, which is defined via an
// extender. It may be possible for MI to be tweaked to work for a register
// defined with a slightly different value. For example
// ... = L2_loadrub_io Rb, 1
// can be modifed to be
// ... = L2_loadrub_io Rb', 0
// if Rb' = Rb+1.
// The range for Rb would be [Min+1, Max+1], where [Min, Max] is a range
// for L2_loadrub with offset 0. That means that Rb could be replaced with
// Rc, where Rc-Rb belongs to [Min+1, Max+1].
OffsetRange HCE::getOffsetRange(Register Rb, const MachineInstr &MI) const {
unsigned Opc = MI.getOpcode();
// Instructions that are constant-extended may be replaced with something
// else that no longer offers the same range as the original.
if (!isRegOffOpcode(Opc) || HII->isConstExtended(MI))
return OffsetRange::zero();
if (Opc == Hexagon::A2_addi) {
const MachineOperand &Op1 = MI.getOperand(1), &Op2 = MI.getOperand(2);
if (Rb != Register(Op1) || !Op2.isImm())
return OffsetRange::zero();
OffsetRange R = { -(1<<15)+1, (1<<15)-1, 1 };
return R.shift(Op2.getImm());
}
// HII::getBaseAndOffsetPosition returns the increment position as "offset".
if (HII->isPostIncrement(MI))
return OffsetRange::zero();
const MCInstrDesc &D = HII->get(Opc);
assert(D.mayLoad() || D.mayStore());
unsigned BaseP, OffP;
if (!HII->getBaseAndOffsetPosition(MI, BaseP, OffP) ||
Rb != Register(MI.getOperand(BaseP)) ||
!MI.getOperand(OffP).isImm())
return OffsetRange::zero();
uint64_t F = (D.TSFlags >> HexagonII::MemAccessSizePos) &
HexagonII::MemAccesSizeMask;
uint8_t A = HexagonII::getMemAccessSizeInBytes(HexagonII::MemAccessSize(F));
unsigned L = Log2_32(A);
unsigned S = 10+L; // sint11_L
int32_t Min = -alignDown((1<<S)-1, A);
// The range will be shifted by Off. To prefer non-negative offsets,
// adjust Max accordingly.
int32_t Off = MI.getOperand(OffP).getImm();
int32_t Max = Off >= 0 ? 0 : -Off;
OffsetRange R = { Min, Max, A };
return R.shift(Off);
}
// Return the allowable deviation from the current value of the extender ED,
// for which the instruction corresponding to ED can be modified without
// using an extender.
// The instruction uses the extender directly. It will be replaced with
// another instruction, say MJ, where the extender will be replaced with a
// register. MJ can allow some variability with respect to the value of
// that register, as is the case with indexed memory instructions.
OffsetRange HCE::getOffsetRange(const ExtDesc &ED) const {
// The only way that there can be a non-zero range available is if
// the instruction using ED will be converted to an indexed memory
// instruction.
unsigned IdxOpc = getRegOffOpcode(ED.UseMI->getOpcode());
switch (IdxOpc) {
case 0:
return OffsetRange::zero();
case Hexagon::A2_addi: // s16
return { -32767, 32767, 1 };
case Hexagon::A2_subri: // s10
return { -511, 511, 1 };
}
if (!ED.UseMI->mayLoad() && !ED.UseMI->mayStore())
return OffsetRange::zero();
const MCInstrDesc &D = HII->get(IdxOpc);
uint64_t F = (D.TSFlags >> HexagonII::MemAccessSizePos) &
HexagonII::MemAccesSizeMask;
uint8_t A = HexagonII::getMemAccessSizeInBytes(HexagonII::MemAccessSize(F));
unsigned L = Log2_32(A);
unsigned S = 10+L; // sint11_L
int32_t Min = -alignDown((1<<S)-1, A);
int32_t Max = 0; // Force non-negative offsets.
return { Min, Max, A };
}
// Get the allowable deviation from the current value of Rd by checking
// all uses of Rd.
OffsetRange HCE::getOffsetRange(Register Rd) const {
OffsetRange Range;
for (const MachineOperand &Op : MRI->use_operands(Rd.Reg)) {
// Make sure that the register being used by this operand is identical
// to the register that was defined: using a different subregister
// precludes any non-trivial range.
if (Rd != Register(Op))
return OffsetRange::zero();
Range.intersect(getOffsetRange(Rd, *Op.getParent()));
}
return Range;
}
void HCE::recordExtender(MachineInstr &MI, unsigned OpNum) {
unsigned Opc = MI.getOpcode();
ExtDesc ED;
ED.OpNum = OpNum;
bool IsLoad = MI.mayLoad();
bool IsStore = MI.mayStore();
// Fixed stack slots have negative indexes, and they cannot be used
// with TRI::stackSlot2Index and TRI::index2StackSlot. This is somewhat
// unfortunate, but should not be a frequent thing.
for (MachineOperand &Op : MI.operands())
if (Op.isFI() && Op.getIndex() < 0)
return;
if (IsLoad || IsStore) {
unsigned AM = HII->getAddrMode(MI);
switch (AM) {
// (Re: ##Off + Rb<<S) = Rd: ##Val
case HexagonII::Absolute: // (__: ## + __<<_)
break;
case HexagonII::AbsoluteSet: // (Rd: ## + __<<_)
ED.Rd = MI.getOperand(OpNum-1);
ED.IsDef = true;
break;
case HexagonII::BaseImmOffset: // (__: ## + Rs<<0)
// Store-immediates are treated as non-memory operations, since
// it's the value being stored that is extended (as opposed to
// a part of the address).
if (!isStoreImmediate(Opc))
ED.Expr.Rs = MI.getOperand(OpNum-1);
break;
case HexagonII::BaseLongOffset: // (__: ## + Rs<<S)
ED.Expr.Rs = MI.getOperand(OpNum-2);
ED.Expr.S = MI.getOperand(OpNum-1).getImm();
break;
default:
llvm_unreachable("Unhandled memory instruction");
}
} else {
switch (Opc) {
case Hexagon::A2_tfrsi: // (Rd: ## + __<<_)
ED.Rd = MI.getOperand(0);
ED.IsDef = true;
break;
case Hexagon::A2_combineii: // (Rd: ## + __<<_)
case Hexagon::A4_combineir:
ED.Rd = { MI.getOperand(0).getReg(), Hexagon::isub_hi };
ED.IsDef = true;
break;
case Hexagon::A4_combineri: // (Rd: ## + __<<_)
ED.Rd = { MI.getOperand(0).getReg(), Hexagon::isub_lo };
ED.IsDef = true;
break;
case Hexagon::A2_addi: // (Rd: ## + Rs<<0)
ED.Rd = MI.getOperand(0);
ED.Expr.Rs = MI.getOperand(OpNum-1);
break;
case Hexagon::M2_accii: // (__: ## + Rs<<0)
case Hexagon::M2_naccii:
case Hexagon::S4_addaddi:
ED.Expr.Rs = MI.getOperand(OpNum-1);
break;
case Hexagon::A2_subri: // (Rd: ## - Rs<<0)
ED.Rd = MI.getOperand(0);
ED.Expr.Rs = MI.getOperand(OpNum+1);
ED.Expr.Neg = true;
break;
case Hexagon::S4_subaddi: // (__: ## - Rs<<0)
ED.Expr.Rs = MI.getOperand(OpNum+1);
ED.Expr.Neg = true;
break;
default: // (__: ## + __<<_)
break;
}
}
ED.UseMI = &MI;
// Ignore unnamed globals.
ExtRoot ER(ED.getOp());
if (ER.Kind == MachineOperand::MO_GlobalAddress)
if (ER.V.GV->getName().empty())
return;
Extenders.push_back(ED);
}
void HCE::collectInstr(MachineInstr &MI) {
if (!HII->isConstExtended(MI))
return;
// Skip some non-convertible instructions.
unsigned Opc = MI.getOpcode();
switch (Opc) {
case Hexagon::M2_macsin: // There is no Rx -= mpyi(Rs,Rt).
case Hexagon::C4_addipc:
case Hexagon::S4_or_andi:
case Hexagon::S4_or_andix:
case Hexagon::S4_or_ori:
return;
}
recordExtender(MI, HII->getCExtOpNum(MI));
}
void HCE::collect(MachineFunction &MF) {
Extenders.clear();
for (MachineBasicBlock &MBB : MF) {
// Skip unreachable blocks.
if (MBB.getNumber() == -1)
continue;
for (MachineInstr &MI : MBB)
collectInstr(MI);
}
}
void HCE::assignInits(const ExtRoot &ER, unsigned Begin, unsigned End,
AssignmentMap &IMap) {
// Sanity check: make sure that all extenders in the range [Begin..End)
// share the same root ER.
for (unsigned I = Begin; I != End; ++I)
assert(ER == ExtRoot(Extenders[I].getOp()));
// Construct the list of ranges, such that for each P in Ranges[I],
// a register Reg = ER+P can be used in place of Extender[I]. If the
// instruction allows, uses in the form of Reg+Off are considered
// (here, Off = required_value - P).
std::vector<OffsetRange> Ranges(End-Begin);
// For each extender that is a def, visit all uses of the defined register,
// and produce an offset range that works for all uses. The def doesn't
// have to be checked, because it can become dead if all uses can be updated
// to use a different reg/offset.
for (unsigned I = Begin; I != End; ++I) {
const ExtDesc &ED = Extenders[I];
if (!ED.IsDef)
continue;
ExtValue EV(ED);
LLVM_DEBUG(dbgs() << " =" << I << ". " << EV << " " << ED << '\n');
assert(ED.Rd.Reg != 0);
Ranges[I-Begin] = getOffsetRange(ED.Rd).shift(EV.Offset);
// A2_tfrsi is a special case: it will be replaced with A2_addi, which
// has a 16-bit signed offset. This means that A2_tfrsi not only has a
// range coming from its uses, but also from the fact that its replacement
// has a range as well.
if (ED.UseMI->getOpcode() == Hexagon::A2_tfrsi) {
int32_t D = alignDown(32767, Ranges[I-Begin].Align); // XXX hardcoded
Ranges[I-Begin].extendBy(-D).extendBy(D);
}
}
// Visit all non-def extenders. For each one, determine the offset range
// available for it.
for (unsigned I = Begin; I != End; ++I) {
const ExtDesc &ED = Extenders[I];
if (ED.IsDef)
continue;
ExtValue EV(ED);
LLVM_DEBUG(dbgs() << " " << I << ". " << EV << " " << ED << '\n');
OffsetRange Dev = getOffsetRange(ED);
Ranges[I-Begin].intersect(Dev.shift(EV.Offset));
}
// Here for each I there is a corresponding Range[I]. Construct the
// inverse map, that to each range will assign the set of indexes in
// [Begin..End) that this range corresponds to.
std::map<OffsetRange, IndexList> RangeMap;
for (unsigned I = Begin; I != End; ++I)
RangeMap[Ranges[I-Begin]].insert(I);
LLVM_DEBUG({
dbgs() << "Ranges\n";
for (unsigned I = Begin; I != End; ++I)
dbgs() << " " << I << ". " << Ranges[I-Begin] << '\n';
dbgs() << "RangeMap\n";
for (auto &P : RangeMap) {
dbgs() << " " << P.first << " ->";
for (unsigned I : P.second)
dbgs() << ' ' << I;
dbgs() << '\n';
}
});
// Select the definition points, and generate the assignment between
// these points and the uses.
// For each candidate offset, keep a pair CandData consisting of
// the total number of ranges containing that candidate, and the
// vector of corresponding RangeTree nodes.
using CandData = std::pair<unsigned, SmallVector<RangeTree::Node*,8>>;
std::map<int32_t, CandData> CandMap;
RangeTree Tree;
for (const OffsetRange &R : Ranges)
Tree.add(R);
SmallVector<RangeTree::Node*,8> Nodes;
Tree.order(Nodes);
auto MaxAlign = [](const SmallVectorImpl<RangeTree::Node*> &Nodes,
uint8_t Align, uint8_t Offset) {
for (RangeTree::Node *N : Nodes) {
if (N->Range.Align <= Align || N->Range.Offset < Offset)
continue;
if ((N->Range.Offset - Offset) % Align != 0)
continue;
Align = N->Range.Align;
Offset = N->Range.Offset;
}
return std::make_pair(Align, Offset);
};
// Construct the set of all potential definition points from the endpoints
// of the ranges. If a given endpoint also belongs to a different range,
// but with a higher alignment, also consider the more-highly-aligned
// value of this endpoint.
std::set<int32_t> CandSet;
for (RangeTree::Node *N : Nodes) {
const OffsetRange &R = N->Range;
auto P0 = MaxAlign(Tree.nodesWith(R.Min, false), R.Align, R.Offset);
CandSet.insert(R.Min);
if (R.Align < P0.first)
CandSet.insert(adjustUp(R.Min, P0.first, P0.second));
auto P1 = MaxAlign(Tree.nodesWith(R.Max, false), R.Align, R.Offset);
CandSet.insert(R.Max);
if (R.Align < P1.first)
CandSet.insert(adjustDown(R.Max, P1.first, P1.second));
}
// Build the assignment map: candidate C -> { list of extender indexes }.
// This has to be done iteratively:
// - pick the candidate that covers the maximum number of extenders,
// - add the candidate to the map,
// - remove the extenders from the pool.
while (true) {
using CMap = std::map<int32_t,unsigned>;
CMap Counts;
for (auto It = CandSet.begin(), Et = CandSet.end(); It != Et; ) {
auto &&V = Tree.nodesWith(*It);
unsigned N = std::accumulate(V.begin(), V.end(), 0u,
[](unsigned Acc, const RangeTree::Node *N) {
return Acc + N->Count;
});
if (N != 0)
Counts.insert({*It, N});
It = (N != 0) ? std::next(It) : CandSet.erase(It);
}
if (Counts.empty())
break;
// Find the best candidate with respect to the number of extenders covered.
auto BestIt = std::max_element(Counts.begin(), Counts.end(),
[](const CMap::value_type &A, const CMap::value_type &B) {
return A.second < B.second ||
(A.second == B.second && A < B);
});
int32_t Best = BestIt->first;
ExtValue BestV(ER, Best);
for (RangeTree::Node *N : Tree.nodesWith(Best)) {
for (unsigned I : RangeMap[N->Range])
IMap[{BestV,Extenders[I].Expr}].insert(I);
Tree.erase(N);
}
}
LLVM_DEBUG(dbgs() << "IMap (before fixup) = " << PrintIMap(IMap, *HRI));
// There is some ambiguity in what initializer should be used, if the
// descriptor's subexpression is non-trivial: it can be the entire
// subexpression (which is what has been done so far), or it can be
// the extender's value itself, if all corresponding extenders have the
// exact value of the initializer (i.e. require offset of 0).
// To reduce the number of initializers, merge such special cases.
for (std::pair<const ExtenderInit,IndexList> &P : IMap) {
// Skip trivial initializers.
if (P.first.second.trivial())
continue;
// If the corresponding trivial initializer does not exist, skip this
// entry.
const ExtValue &EV = P.first.first;
AssignmentMap::iterator F = IMap.find({EV, ExtExpr()});
if (F == IMap.end())
continue;
// Finally, check if all extenders have the same value as the initializer.
// Make sure that extenders that are a part of a stack address are not
// merged with those that aren't. Stack addresses need an offset field
// (to be used by frame index elimination), while non-stack expressions
// can be replaced with forms (such as rr) that do not have such a field.
// Example:
//
// Collected 3 extenders
// =2. imm:0 off:32968 bb#2: %7 = ## + __ << 0, def
// 0. imm:0 off:267 bb#0: __ = ## + SS#1 << 0
// 1. imm:0 off:267 bb#1: __ = ## + SS#1 << 0
// Ranges
// 0. [-756,267]a1+0
// 1. [-756,267]a1+0
// 2. [201,65735]a1+0
// RangeMap
// [-756,267]a1+0 -> 0 1
// [201,65735]a1+0 -> 2
// IMap (before fixup) = {
// [imm:0 off:267, ## + __ << 0] -> { 2 }
// [imm:0 off:267, ## + SS#1 << 0] -> { 0 1 }
// }
// IMap (after fixup) = {
// [imm:0 off:267, ## + __ << 0] -> { 2 0 1 }
// [imm:0 off:267, ## + SS#1 << 0] -> { }
// }
// Inserted def in bb#0 for initializer: [imm:0 off:267, ## + __ << 0]
// %12:intregs = A2_tfrsi 267
//
// The result was
// %12:intregs = A2_tfrsi 267
// S4_pstorerbt_rr %3, %12, %stack.1, 0, killed %4
// Which became
// r0 = #267
// if (p0.new) memb(r0+r29<<#4) = r2
bool IsStack = any_of(F->second, [this](unsigned I) {
return Extenders[I].Expr.Rs.isSlot();
});
auto SameValue = [&EV,this,IsStack](unsigned I) {
const ExtDesc &ED = Extenders[I];
return ED.Expr.Rs.isSlot() == IsStack &&
ExtValue(ED).Offset == EV.Offset;
};
if (all_of(P.second, SameValue)) {
F->second.insert(P.second.begin(), P.second.end());
P.second.clear();
}
}
LLVM_DEBUG(dbgs() << "IMap (after fixup) = " << PrintIMap(IMap, *HRI));
}
void HCE::calculatePlacement(const ExtenderInit &ExtI, const IndexList &Refs,
LocDefList &Defs) {
if (Refs.empty())
return;
// The placement calculation is somewhat simple right now: it finds a
// single location for the def that dominates all refs. Since this may
// place the def far from the uses, producing several locations for
// defs that collectively dominate all refs could be better.
// For now only do the single one.
DenseSet<MachineBasicBlock*> Blocks;
DenseSet<MachineInstr*> RefMIs;
const ExtDesc &ED0 = Extenders[Refs[0]];
MachineBasicBlock *DomB = ED0.UseMI->getParent();
RefMIs.insert(ED0.UseMI);
Blocks.insert(DomB);
for (unsigned i = 1, e = Refs.size(); i != e; ++i) {
const ExtDesc &ED = Extenders[Refs[i]];
MachineBasicBlock *MBB = ED.UseMI->getParent();
RefMIs.insert(ED.UseMI);
DomB = MDT->findNearestCommonDominator(DomB, MBB);
Blocks.insert(MBB);
}
#ifndef NDEBUG
// The block DomB should be dominated by the def of each register used
// in the initializer.
Register Rs = ExtI.second.Rs; // Only one reg allowed now.
const MachineInstr *DefI = Rs.isVReg() ? MRI->getVRegDef(Rs.Reg) : nullptr;
// This should be guaranteed given that the entire expression is used
// at each instruction in Refs. Add an assertion just in case.
assert(!DefI || MDT->dominates(DefI->getParent(), DomB));
#endif
MachineBasicBlock::iterator It;
if (Blocks.count(DomB)) {
// Try to find the latest possible location for the def.
MachineBasicBlock::iterator End = DomB->end();
for (It = DomB->begin(); It != End; ++It)
if (RefMIs.count(&*It))
break;
assert(It != End && "Should have found a ref in DomB");
} else {
// DomB does not contain any refs.
It = DomB->getFirstTerminator();
}
Loc DefLoc(DomB, It);
Defs.emplace_back(DefLoc, Refs);
}
HCE::Register HCE::insertInitializer(Loc DefL, const ExtenderInit &ExtI) {
llvm::Register DefR = MRI->createVirtualRegister(&Hexagon::IntRegsRegClass);
MachineBasicBlock &MBB = *DefL.Block;
MachineBasicBlock::iterator At = DefL.At;
DebugLoc dl = DefL.Block->findDebugLoc(DefL.At);
const ExtValue &EV = ExtI.first;
MachineOperand ExtOp(EV);
const ExtExpr &Ex = ExtI.second;
const MachineInstr *InitI = nullptr;
if (Ex.Rs.isSlot()) {
assert(Ex.S == 0 && "Cannot have a shift of a stack slot");
assert(!Ex.Neg && "Cannot subtract a stack slot");
// DefR = PS_fi Rb,##EV
InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::PS_fi), DefR)
.add(MachineOperand(Ex.Rs))
.add(ExtOp);
} else {
assert((Ex.Rs.Reg == 0 || Ex.Rs.isVReg()) && "Expecting virtual register");
if (Ex.trivial()) {
// DefR = ##EV
InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::A2_tfrsi), DefR)
.add(ExtOp);
} else if (Ex.S == 0) {
if (Ex.Neg) {
// DefR = sub(##EV,Rb)
InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::A2_subri), DefR)
.add(ExtOp)
.add(MachineOperand(Ex.Rs));
} else {
// DefR = add(Rb,##EV)
InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::A2_addi), DefR)
.add(MachineOperand(Ex.Rs))
.add(ExtOp);
}
} else {
if (HST->useCompound()) {
unsigned NewOpc = Ex.Neg ? Hexagon::S4_subi_asl_ri
: Hexagon::S4_addi_asl_ri;
// DefR = add(##EV,asl(Rb,S))
InitI = BuildMI(MBB, At, dl, HII->get(NewOpc), DefR)
.add(ExtOp)
.add(MachineOperand(Ex.Rs))
.addImm(Ex.S);
} else {
// No compounds are available. It is not clear whether we should
// even process such extenders where the initializer cannot be
// a single instruction, but do it for now.
unsigned TmpR = MRI->createVirtualRegister(&Hexagon::IntRegsRegClass);
BuildMI(MBB, At, dl, HII->get(Hexagon::S2_asl_i_r), TmpR)
.add(MachineOperand(Ex.Rs))
.addImm(Ex.S);
if (Ex.Neg)
InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::A2_subri), DefR)
.add(ExtOp)
.add(MachineOperand(Register(TmpR, 0)));
else
InitI = BuildMI(MBB, At, dl, HII->get(Hexagon::A2_addi), DefR)
.add(MachineOperand(Register(TmpR, 0)))
.add(ExtOp);
}
}
}
assert(InitI);
(void)InitI;
LLVM_DEBUG(dbgs() << "Inserted def in bb#" << MBB.getNumber()
<< " for initializer: " << PrintInit(ExtI, *HRI) << "\n "
<< *InitI);
return { DefR, 0 };
}
// Replace the extender at index Idx with the register ExtR.
bool HCE::replaceInstrExact(const ExtDesc &ED, Register ExtR) {
MachineInstr &MI = *ED.UseMI;
MachineBasicBlock &MBB = *MI.getParent();
MachineBasicBlock::iterator At = MI.getIterator();
DebugLoc dl = MI.getDebugLoc();
unsigned ExtOpc = MI.getOpcode();
// With a few exceptions, direct replacement amounts to creating an
// instruction with a corresponding register opcode, with all operands
// the same, except for the register used in place of the extender.
unsigned RegOpc = getDirectRegReplacement(ExtOpc);
if (RegOpc == TargetOpcode::REG_SEQUENCE) {
if (ExtOpc == Hexagon::A4_combineri)
BuildMI(MBB, At, dl, HII->get(RegOpc))
.add(MI.getOperand(0))
.add(MI.getOperand(1))
.addImm(Hexagon::isub_hi)
.add(MachineOperand(ExtR))
.addImm(Hexagon::isub_lo);
else if (ExtOpc == Hexagon::A4_combineir)
BuildMI(MBB, At, dl, HII->get(RegOpc))
.add(MI.getOperand(0))
.add(MachineOperand(ExtR))
.addImm(Hexagon::isub_hi)
.add(MI.getOperand(2))
.addImm(Hexagon::isub_lo);
else
llvm_unreachable("Unexpected opcode became REG_SEQUENCE");
MBB.erase(MI);
return true;
}
if (ExtOpc == Hexagon::C2_cmpgei || ExtOpc == Hexagon::C2_cmpgeui) {
unsigned NewOpc = ExtOpc == Hexagon::C2_cmpgei ? Hexagon::C2_cmplt
: Hexagon::C2_cmpltu;
BuildMI(MBB, At, dl, HII->get(NewOpc))
.add(MI.getOperand(0))
.add(MachineOperand(ExtR))
.add(MI.getOperand(1));
MBB.erase(MI);
return true;
}
if (RegOpc != 0) {
MachineInstrBuilder MIB = BuildMI(MBB, At, dl, HII->get(RegOpc));
unsigned RegN = ED.OpNum;
// Copy all operands except the one that has the extender.
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
if (i != RegN)
MIB.add(MI.getOperand(i));
else
MIB.add(MachineOperand(ExtR));
}
MIB.cloneMemRefs(MI);
MBB.erase(MI);
return true;
}
if (MI.mayLoadOrStore() && !isStoreImmediate(ExtOpc)) {
// For memory instructions, there is an asymmetry in the addressing
// modes. Addressing modes allowing extenders can be replaced with
// addressing modes that use registers, but the order of operands
// (or even their number) may be different.
// Replacements:
// BaseImmOffset (io) -> BaseRegOffset (rr)
// BaseLongOffset (ur) -> BaseRegOffset (rr)
unsigned RegOpc, Shift;
unsigned AM = HII->getAddrMode(MI);
if (AM == HexagonII::BaseImmOffset) {
RegOpc = HII->changeAddrMode_io_rr(ExtOpc);
Shift = 0;
} else if (AM == HexagonII::BaseLongOffset) {
// Loads: Rd = L4_loadri_ur Rs, S, ##
// Stores: S4_storeri_ur Rs, S, ##, Rt
RegOpc = HII->changeAddrMode_ur_rr(ExtOpc);
Shift = MI.getOperand(MI.mayLoad() ? 2 : 1).getImm();
} else {
llvm_unreachable("Unexpected addressing mode");
}
#ifndef NDEBUG
if (RegOpc == -1u) {
dbgs() << "\nExtOpc: " << HII->getName(ExtOpc) << " has no rr version\n";
llvm_unreachable("No corresponding rr instruction");
}
#endif
unsigned BaseP, OffP;
HII->getBaseAndOffsetPosition(MI, BaseP, OffP);
// Build an rr instruction: (RegOff + RegBase<<0)
MachineInstrBuilder MIB = BuildMI(MBB, At, dl, HII->get(RegOpc));
// First, add the def for loads.
if (MI.mayLoad())
MIB.add(getLoadResultOp(MI));
// Handle possible predication.
if (HII->isPredicated(MI))
MIB.add(getPredicateOp(MI));
// Build the address.
MIB.add(MachineOperand(ExtR)); // RegOff
MIB.add(MI.getOperand(BaseP)); // RegBase
MIB.addImm(Shift); // << Shift
// Add the stored value for stores.
if (MI.mayStore())
MIB.add(getStoredValueOp(MI));
MIB.cloneMemRefs(MI);
MBB.erase(MI);
return true;
}
#ifndef NDEBUG
dbgs() << '\n' << MI;
#endif
llvm_unreachable("Unhandled exact replacement");
return false;
}
// Replace the extender ED with a form corresponding to the initializer ExtI.
bool HCE::replaceInstrExpr(const ExtDesc &ED, const ExtenderInit &ExtI,
Register ExtR, int32_t &Diff) {
MachineInstr &MI = *ED.UseMI;
MachineBasicBlock &MBB = *MI.getParent();
MachineBasicBlock::iterator At = MI.getIterator();
DebugLoc dl = MI.getDebugLoc();
unsigned ExtOpc = MI.getOpcode();
if (ExtOpc == Hexagon::A2_tfrsi) {
// A2_tfrsi is a special case: it's replaced with A2_addi, which introduces
// another range. One range is the one that's common to all tfrsi's uses,
// this one is the range of immediates in A2_addi. When calculating ranges,
// the addi's 16-bit argument was included, so now we need to make it such
// that the produced value is in the range for the uses alone.
// Most of the time, simply adding Diff will make the addi produce exact
// result, but if Diff is outside of the 16-bit range, some adjustment
// will be needed.
unsigned IdxOpc = getRegOffOpcode(ExtOpc);
assert(IdxOpc == Hexagon::A2_addi);
// Clamp Diff to the 16 bit range.
int32_t D = isInt<16>(Diff) ? Diff : (Diff > 0 ? 32767 : -32768);
if (Diff > 32767) {
// Split Diff into two values: one that is close to min/max int16,
// and the other being the rest, and such that both have the same
// "alignment" as Diff.
uint32_t UD = Diff;
OffsetRange R = getOffsetRange(MI.getOperand(0));
uint32_t A = std::min<uint32_t>(R.Align, 1u << countTrailingZeros(UD));
D &= ~(A-1);
}
BuildMI(MBB, At, dl, HII->get(IdxOpc))
.add(MI.getOperand(0))
.add(MachineOperand(ExtR))
.addImm(D);
Diff -= D;
#ifndef NDEBUG
// Make sure the output is within allowable range for uses.
// "Diff" is a difference in the "opposite direction", i.e. Ext - DefV,
// not DefV - Ext, as the getOffsetRange would calculate.
OffsetRange Uses = getOffsetRange(MI.getOperand(0));
if (!Uses.contains(-Diff))
dbgs() << "Diff: " << -Diff << " out of range " << Uses
<< " for " << MI;
assert(Uses.contains(-Diff));
#endif
MBB.erase(MI);
return true;
}
const ExtValue &EV = ExtI.first; (void)EV;
const ExtExpr &Ex = ExtI.second; (void)Ex;
if (ExtOpc == Hexagon::A2_addi || ExtOpc == Hexagon::A2_subri) {
// If addi/subri are replaced with the exactly matching initializer,
// they amount to COPY.
// Check that the initializer is an exact match (for simplicity).
#ifndef NDEBUG
bool IsAddi = ExtOpc == Hexagon::A2_addi;
const MachineOperand &RegOp = MI.getOperand(IsAddi ? 1 : 2);
const MachineOperand &ImmOp = MI.getOperand(IsAddi ? 2 : 1);
assert(Ex.Rs == RegOp && EV == ImmOp && Ex.Neg != IsAddi &&
"Initializer mismatch");
#endif
BuildMI(MBB, At, dl, HII->get(TargetOpcode::COPY))
.add(MI.getOperand(0))
.add(MachineOperand(ExtR));
Diff = 0;
MBB.erase(MI);
return true;
}
if (ExtOpc == Hexagon::M2_accii || ExtOpc == Hexagon::M2_naccii ||
ExtOpc == Hexagon::S4_addaddi || ExtOpc == Hexagon::S4_subaddi) {
// M2_accii: add(Rt,add(Rs,V)) (tied)
// M2_naccii: sub(Rt,add(Rs,V))
// S4_addaddi: add(Rt,add(Rs,V))
// S4_subaddi: add(Rt,sub(V,Rs))
// Check that Rs and V match the initializer expression. The Rs+V is the
// combination that is considered "subexpression" for V, although Rx+V
// would also be valid.
#ifndef NDEBUG
bool IsSub = ExtOpc == Hexagon::S4_subaddi;
Register Rs = MI.getOperand(IsSub ? 3 : 2);
ExtValue V = MI.getOperand(IsSub ? 2 : 3);
assert(EV == V && Rs == Ex.Rs && IsSub == Ex.Neg && "Initializer mismatch");
#endif
unsigned NewOpc = ExtOpc == Hexagon::M2_naccii ? Hexagon::A2_sub
: Hexagon::A2_add;
BuildMI(MBB, At, dl, HII->get(NewOpc))
.add(MI.getOperand(0))
.add(MI.getOperand(1))
.add(MachineOperand(ExtR));
MBB.erase(MI);
return true;
}
if (MI.mayLoadOrStore()) {
unsigned IdxOpc = getRegOffOpcode(ExtOpc);
assert(IdxOpc && "Expecting indexed opcode");
MachineInstrBuilder MIB = BuildMI(MBB, At, dl, HII->get(IdxOpc));
// Construct the new indexed instruction.
// First, add the def for loads.
if (MI.mayLoad())
MIB.add(getLoadResultOp(MI));
// Handle possible predication.
if (HII->isPredicated(MI))
MIB.add(getPredicateOp(MI));
// Build the address.
MIB.add(MachineOperand(ExtR));
MIB.addImm(Diff);
// Add the stored value for stores.
if (MI.mayStore())
MIB.add(getStoredValueOp(MI));
MIB.cloneMemRefs(MI);
MBB.erase(MI);
return true;
}
#ifndef NDEBUG
dbgs() << '\n' << PrintInit(ExtI, *HRI) << " " << MI;
#endif
llvm_unreachable("Unhandled expr replacement");
return false;
}
bool HCE::replaceInstr(unsigned Idx, Register ExtR, const ExtenderInit &ExtI) {
if (ReplaceLimit.getNumOccurrences()) {
if (ReplaceLimit <= ReplaceCounter)
return false;
++ReplaceCounter;
}
const ExtDesc &ED = Extenders[Idx];
assert((!ED.IsDef || ED.Rd.Reg != 0) && "Missing Rd for def");
const ExtValue &DefV = ExtI.first;
assert(ExtRoot(ExtValue(ED)) == ExtRoot(DefV) && "Extender root mismatch");
const ExtExpr &DefEx = ExtI.second;
ExtValue EV(ED);
int32_t Diff = EV.Offset - DefV.Offset;
const MachineInstr &MI = *ED.UseMI;
LLVM_DEBUG(dbgs() << __func__ << " Idx:" << Idx << " ExtR:"
<< PrintRegister(ExtR, *HRI) << " Diff:" << Diff << '\n');
// These two addressing modes must be converted into indexed forms
// regardless of what the initializer looks like.
bool IsAbs = false, IsAbsSet = false;
if (MI.mayLoadOrStore()) {
unsigned AM = HII->getAddrMode(MI);
IsAbs = AM == HexagonII::Absolute;
IsAbsSet = AM == HexagonII::AbsoluteSet;
}
// If it's a def, remember all operands that need to be updated.
// If ED is a def, and Diff is not 0, then all uses of the register Rd
// defined by ED must be in the form (Rd, imm), i.e. the immediate offset
// must follow the Rd in the operand list.
std::vector<std::pair<MachineInstr*,unsigned>> RegOps;
if (ED.IsDef && Diff != 0) {
for (MachineOperand &Op : MRI->use_operands(ED.Rd.Reg)) {
MachineInstr &UI = *Op.getParent();
RegOps.push_back({&UI, getOperandIndex(UI, Op)});
}
}
// Replace the instruction.
bool Replaced = false;
if (Diff == 0 && DefEx.trivial() && !IsAbs && !IsAbsSet)
Replaced = replaceInstrExact(ED, ExtR);
else
Replaced = replaceInstrExpr(ED, ExtI, ExtR, Diff);
if (Diff != 0 && Replaced && ED.IsDef) {
// Update offsets of the def's uses.
for (std::pair<MachineInstr*,unsigned> P : RegOps) {
unsigned J = P.second;
assert(P.first->getNumOperands() > J+1 &&
P.first->getOperand(J+1).isImm());
MachineOperand &ImmOp = P.first->getOperand(J+1);
ImmOp.setImm(ImmOp.getImm() + Diff);
}
// If it was an absolute-set instruction, the "set" part has been removed.
// ExtR will now be the register with the extended value, and since all
// users of Rd have been updated, all that needs to be done is to replace
// Rd with ExtR.
if (IsAbsSet) {
assert(ED.Rd.Sub == 0 && ExtR.Sub == 0);
MRI->replaceRegWith(ED.Rd.Reg, ExtR.Reg);
}
}
return Replaced;
}
bool HCE::replaceExtenders(const AssignmentMap &IMap) {
LocDefList Defs;
bool Changed = false;
for (const std::pair<const ExtenderInit, IndexList> &P : IMap) {
const IndexList &Idxs = P.second;
if (Idxs.size() < CountThreshold)
continue;
Defs.clear();
calculatePlacement(P.first, Idxs, Defs);
for (const std::pair<Loc,IndexList> &Q : Defs) {
Register DefR = insertInitializer(Q.first, P.first);
NewRegs.push_back(DefR.Reg);
for (unsigned I : Q.second)
Changed |= replaceInstr(I, DefR, P.first);
}
}
return Changed;
}
unsigned HCE::getOperandIndex(const MachineInstr &MI,
const MachineOperand &Op) const {
for (unsigned i = 0, n = MI.getNumOperands(); i != n; ++i)
if (&MI.getOperand(i) == &Op)
return i;
llvm_unreachable("Not an operand of MI");
}
const MachineOperand &HCE::getPredicateOp(const MachineInstr &MI) const {
assert(HII->isPredicated(MI));
for (const MachineOperand &Op : MI.operands()) {
if (!Op.isReg() || !Op.isUse() ||
MRI->getRegClass(Op.getReg()) != &Hexagon::PredRegsRegClass)
continue;
assert(Op.getSubReg() == 0 && "Predicate register with a subregister");
return Op;
}
llvm_unreachable("Predicate operand not found");
}
const MachineOperand &HCE::getLoadResultOp(const MachineInstr &MI) const {
assert(MI.mayLoad());
return MI.getOperand(0);
}
const MachineOperand &HCE::getStoredValueOp(const MachineInstr &MI) const {
assert(MI.mayStore());
return MI.getOperand(MI.getNumExplicitOperands()-1);
}
bool HCE::runOnMachineFunction(MachineFunction &MF) {
if (skipFunction(MF.getFunction()))
return false;
if (MF.getFunction().hasPersonalityFn()) {
LLVM_DEBUG(dbgs() << getPassName() << ": skipping " << MF.getName()
<< " due to exception handling\n");
return false;
}
LLVM_DEBUG(MF.print(dbgs() << "Before " << getPassName() << '\n', nullptr));
HST = &MF.getSubtarget<HexagonSubtarget>();
HII = HST->getInstrInfo();
HRI = HST->getRegisterInfo();
MDT = &getAnalysis<MachineDominatorTree>();
MRI = &MF.getRegInfo();
AssignmentMap IMap;
collect(MF);
llvm::sort(Extenders, [this](const ExtDesc &A, const ExtDesc &B) {
ExtValue VA(A), VB(B);
if (VA != VB)
return VA < VB;
const MachineInstr *MA = A.UseMI;
const MachineInstr *MB = B.UseMI;
if (MA == MB) {
// If it's the same instruction, compare operand numbers.
return A.OpNum < B.OpNum;
}
const MachineBasicBlock *BA = MA->getParent();
const MachineBasicBlock *BB = MB->getParent();
assert(BA->getNumber() != -1 && BB->getNumber() != -1);
if (BA != BB)
return BA->getNumber() < BB->getNumber();
return MDT->dominates(MA, MB);
});
bool Changed = false;
LLVM_DEBUG(dbgs() << "Collected " << Extenders.size() << " extenders\n");
for (unsigned I = 0, E = Extenders.size(); I != E; ) {
unsigned B = I;
const ExtRoot &T = Extenders[B].getOp();
while (I != E && ExtRoot(Extenders[I].getOp()) == T)
++I;
IMap.clear();
assignInits(T, B, I, IMap);
Changed |= replaceExtenders(IMap);
}
LLVM_DEBUG({
if (Changed)
MF.print(dbgs() << "After " << getPassName() << '\n', nullptr);
else
dbgs() << "No changes\n";
});
return Changed;
}
FunctionPass *llvm::createHexagonConstExtenders() {
return new HexagonConstExtenders();
}
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