//===- llvm/CodeGen/MachineInstrBundle.h - MI bundle utilities --*- 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
//
//===----------------------------------------------------------------------===//
//
// This file provide utility functions to manipulate machine instruction
// bundles.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_MACHINEINSTRBUNDLE_H
#define LLVM_CODEGEN_MACHINEINSTRBUNDLE_H
#include "llvm/CodeGen/MachineBasicBlock.h"
namespace llvm {
/// finalizeBundle - Finalize a machine instruction bundle which includes
/// a sequence of instructions starting from FirstMI to LastMI (exclusive).
/// This routine adds a BUNDLE instruction to represent the bundle, it adds
/// IsInternalRead markers to MachineOperands which are defined inside the
/// bundle, and it copies externally visible defs and uses to the BUNDLE
/// instruction.
void finalizeBundle(MachineBasicBlock &MBB,
MachineBasicBlock::instr_iterator FirstMI,
MachineBasicBlock::instr_iterator LastMI);
/// finalizeBundle - Same functionality as the previous finalizeBundle except
/// the last instruction in the bundle is not provided as an input. This is
/// used in cases where bundles are pre-determined by marking instructions
/// with 'InsideBundle' marker. It returns the MBB instruction iterator that
/// points to the end of the bundle.
MachineBasicBlock::instr_iterator finalizeBundle(MachineBasicBlock &MBB,
MachineBasicBlock::instr_iterator FirstMI);
/// finalizeBundles - Finalize instruction bundles in the specified
/// MachineFunction. Return true if any bundles are finalized.
bool finalizeBundles(MachineFunction &MF);
/// Returns an iterator to the first instruction in the bundle containing \p I.
inline MachineBasicBlock::instr_iterator getBundleStart(
MachineBasicBlock::instr_iterator I) {
while (I->isBundledWithPred())
--I;
return I;
}
/// Returns an iterator to the first instruction in the bundle containing \p I.
inline MachineBasicBlock::const_instr_iterator getBundleStart(
MachineBasicBlock::const_instr_iterator I) {
while (I->isBundledWithPred())
--I;
return I;
}
/// Returns an iterator pointing beyond the bundle containing \p I.
inline MachineBasicBlock::instr_iterator getBundleEnd(
MachineBasicBlock::instr_iterator I) {
while (I->isBundledWithSucc())
++I;
++I;
return I;
}
/// Returns an iterator pointing beyond the bundle containing \p I.
inline MachineBasicBlock::const_instr_iterator getBundleEnd(
MachineBasicBlock::const_instr_iterator I) {
while (I->isBundledWithSucc())
++I;
++I;
return I;
}
//===----------------------------------------------------------------------===//
// MachineBundleOperand iterator
//
/// MIBundleOperandIteratorBase - Iterator that visits all operands in a bundle
/// of MachineInstrs. This class is not intended to be used directly, use one
/// of the sub-classes instead.
///
/// Intended use:
///
/// for (MIBundleOperands MIO(MI); MIO.isValid(); ++MIO) {
/// if (!MIO->isReg())
/// continue;
/// ...
/// }
///
template <typename ValueT>
class MIBundleOperandIteratorBase
: public iterator_facade_base<MIBundleOperandIteratorBase<ValueT>,
std::forward_iterator_tag, ValueT> {
MachineBasicBlock::instr_iterator InstrI, InstrE;
MachineInstr::mop_iterator OpI, OpE;
// If the operands on InstrI are exhausted, advance InstrI to the next
// bundled instruction with operands.
void advance() {
while (OpI == OpE) {
// Don't advance off the basic block, or into a new bundle.
if (++InstrI == InstrE || !InstrI->isInsideBundle()) {
InstrI = InstrE;
break;
}
OpI = InstrI->operands_begin();
OpE = InstrI->operands_end();
}
}
protected:
/// MIBundleOperandIteratorBase - Create an iterator that visits all operands
/// on MI, or all operands on every instruction in the bundle containing MI.
///
/// @param MI The instruction to examine.
///
explicit MIBundleOperandIteratorBase(MachineInstr &MI) {
InstrI = getBundleStart(MI.getIterator());
InstrE = MI.getParent()->instr_end();
OpI = InstrI->operands_begin();
OpE = InstrI->operands_end();
advance();
}
/// Constructor for an iterator past the last iteration: both instruction
/// iterators point to the end of the BB and OpI == OpE.
explicit MIBundleOperandIteratorBase(MachineBasicBlock::instr_iterator InstrE,
MachineInstr::mop_iterator OpE)
: InstrI(InstrE), InstrE(InstrE), OpI(OpE), OpE(OpE) {}
public:
/// isValid - Returns true until all the operands have been visited.
bool isValid() const { return OpI != OpE; }
/// Preincrement. Move to the next operand.
void operator++() {
assert(isValid() && "Cannot advance MIOperands beyond the last operand");
++OpI;
advance();
}
ValueT &operator*() const { return *OpI; }
ValueT *operator->() const { return &*OpI; }
bool operator==(const MIBundleOperandIteratorBase &Arg) const {
// Iterators are equal, if InstrI matches and either OpIs match or OpI ==
// OpE match for both. The second condition allows us to construct an 'end'
// iterator, without finding the last instruction in a bundle up-front.
return InstrI == Arg.InstrI &&
(OpI == Arg.OpI || (OpI == OpE && Arg.OpI == Arg.OpE));
}
/// getOperandNo - Returns the number of the current operand relative to its
/// instruction.
///
unsigned getOperandNo() const {
return OpI - InstrI->operands_begin();
}
};
/// MIBundleOperands - Iterate over all operands in a bundle of machine
/// instructions.
///
class MIBundleOperands : public MIBundleOperandIteratorBase<MachineOperand> {
/// Constructor for an iterator past the last iteration.
MIBundleOperands(MachineBasicBlock::instr_iterator InstrE,
MachineInstr::mop_iterator OpE)
: MIBundleOperandIteratorBase(InstrE, OpE) {}
public:
MIBundleOperands(MachineInstr &MI) : MIBundleOperandIteratorBase(MI) {}
/// Returns an iterator past the last iteration.
static MIBundleOperands end(const MachineBasicBlock &MBB) {
return {const_cast<MachineBasicBlock &>(MBB).instr_end(),
const_cast<MachineBasicBlock &>(MBB).instr_begin()->operands_end()};
}
};
/// ConstMIBundleOperands - Iterate over all operands in a const bundle of
/// machine instructions.
///
class ConstMIBundleOperands
: public MIBundleOperandIteratorBase<const MachineOperand> {
/// Constructor for an iterator past the last iteration.
ConstMIBundleOperands(MachineBasicBlock::instr_iterator InstrE,
MachineInstr::mop_iterator OpE)
: MIBundleOperandIteratorBase(InstrE, OpE) {}
public:
ConstMIBundleOperands(const MachineInstr &MI)
: MIBundleOperandIteratorBase(const_cast<MachineInstr &>(MI)) {}
/// Returns an iterator past the last iteration.
static ConstMIBundleOperands end(const MachineBasicBlock &MBB) {
return {const_cast<MachineBasicBlock &>(MBB).instr_end(),
const_cast<MachineBasicBlock &>(MBB).instr_begin()->operands_end()};
}
};
inline iterator_range<ConstMIBundleOperands>
const_mi_bundle_ops(const MachineInstr &MI) {
return make_range(ConstMIBundleOperands(MI),
ConstMIBundleOperands::end(*MI.getParent()));
}
inline iterator_range<MIBundleOperands> mi_bundle_ops(MachineInstr &MI) {
return make_range(MIBundleOperands(MI),
MIBundleOperands::end(*MI.getParent()));
}
/// VirtRegInfo - Information about a virtual register used by a set of
/// operands.
///
struct VirtRegInfo {
/// Reads - One of the operands read the virtual register. This does not
/// include undef or internal use operands, see MO::readsReg().
bool Reads;
/// Writes - One of the operands writes the virtual register.
bool Writes;
/// Tied - Uses and defs must use the same register. This can be because of
/// a two-address constraint, or there may be a partial redefinition of a
/// sub-register.
bool Tied;
};
/// AnalyzeVirtRegInBundle - Analyze how the current instruction or bundle uses
/// a virtual register. This function should not be called after operator++(),
/// it expects a fresh iterator.
///
/// @param Reg The virtual register to analyze.
/// @param Ops When set, this vector will receive an (MI, OpNum) entry for
/// each operand referring to Reg.
/// @returns A filled-in RegInfo struct.
VirtRegInfo AnalyzeVirtRegInBundle(
MachineInstr &MI, Register Reg,
SmallVectorImpl<std::pair<MachineInstr *, unsigned>> *Ops = nullptr);
/// Information about how a physical register Reg is used by a set of
/// operands.
struct PhysRegInfo {
/// There is a regmask operand indicating Reg is clobbered.
/// \see MachineOperand::CreateRegMask().
bool Clobbered;
/// Reg or one of its aliases is defined. The definition may only cover
/// parts of the register.
bool Defined;
/// Reg or a super-register is defined. The definition covers the full
/// register.
bool FullyDefined;
/// Reg or one of its aliases is read. The register may only be read
/// partially.
bool Read;
/// Reg or a super-register is read. The full register is read.
bool FullyRead;
/// Either:
/// - Reg is FullyDefined and all defs of reg or an overlapping
/// register are dead, or
/// - Reg is completely dead because "defined" by a clobber.
bool DeadDef;
/// Reg is Defined and all defs of reg or an overlapping register are
/// dead.
bool PartialDeadDef;
/// There is a use operand of reg or a super-register with kill flag set.
bool Killed;
};
/// AnalyzePhysRegInBundle - Analyze how the current instruction or bundle uses
/// a physical register. This function should not be called after operator++(),
/// it expects a fresh iterator.
///
/// @param Reg The physical register to analyze.
/// @returns A filled-in PhysRegInfo struct.
PhysRegInfo AnalyzePhysRegInBundle(const MachineInstr &MI, Register Reg,
const TargetRegisterInfo *TRI);
} // End llvm namespace
#endif