llvm-project/llvm/lib/Target/TargetInstrInfo.cpp

100 lines
3.4 KiB
C++

//===-- TargetInstrInfo.cpp - Target Instruction Information --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// TargetOperandInfo
//===----------------------------------------------------------------------===//
/// getRegClass - Get the register class for the operand, handling resolution
/// of "symbolic" pointer register classes etc. If this is not a register
/// operand, this returns null.
const TargetRegisterClass *
TargetOperandInfo::getRegClass(const TargetRegisterInfo *TRI) const {
if (isLookupPtrRegClass())
return TRI->getPointerRegClass(RegClass);
// Instructions like INSERT_SUBREG do not have fixed register classes.
if (RegClass < 0)
return 0;
// Otherwise just look it up normally.
return TRI->getRegClass(RegClass);
}
//===----------------------------------------------------------------------===//
// TargetInstrInfo
//===----------------------------------------------------------------------===//
TargetInstrInfo::TargetInstrInfo(const TargetInstrDesc* Desc,
unsigned numOpcodes)
: Descriptors(Desc), NumOpcodes(numOpcodes) {
}
TargetInstrInfo::~TargetInstrInfo() {
}
/// insertNoop - Insert a noop into the instruction stream at the specified
/// point.
void TargetInstrInfo::insertNoop(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const {
llvm_unreachable("Target didn't implement insertNoop!");
}
bool TargetInstrInfo::isUnpredicatedTerminator(const MachineInstr *MI) const {
const TargetInstrDesc &TID = MI->getDesc();
if (!TID.isTerminator()) return false;
// Conditional branch is a special case.
if (TID.isBranch() && !TID.isBarrier())
return true;
if (!TID.isPredicable())
return true;
return !isPredicated(MI);
}
/// Measure the specified inline asm to determine an approximation of its
/// length.
/// Comments (which run till the next SeparatorChar or newline) do not
/// count as an instruction.
/// Any other non-whitespace text is considered an instruction, with
/// multiple instructions separated by SeparatorChar or newlines.
/// Variable-length instructions are not handled here; this function
/// may be overloaded in the target code to do that.
unsigned TargetInstrInfo::getInlineAsmLength(const char *Str,
const MCAsmInfo &MAI) const {
// Count the number of instructions in the asm.
bool atInsnStart = true;
unsigned Length = 0;
for (; *Str; ++Str) {
if (*Str == '\n' || *Str == MAI.getSeparatorChar())
atInsnStart = true;
if (atInsnStart && !isspace(*Str)) {
Length += MAI.getMaxInstLength();
atInsnStart = false;
}
if (atInsnStart && strncmp(Str, MAI.getCommentString(),
strlen(MAI.getCommentString())) == 0)
atInsnStart = false;
}
return Length;
}