llvm-6502/lib/Target/TargetInstrInfo.cpp
2002-10-29 17:37:48 +00:00

62 lines
2.2 KiB
C++

//===-- TargetMachine.cpp - General Target Information ---------------------==//
//
// This file describes the general parts of a Target machine.
// This file also implements MachineInstrInfo and MachineCacheInfo.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/MachineInstrInfo.h"
#include "llvm/Constant.h"
#include "llvm/DerivedTypes.h"
// External object describing the machine instructions
// Initialized only when the TargetMachine class is created
// and reset when that class is destroyed.
//
const MachineInstrDescriptor* TargetInstrDescriptors = 0;
//---------------------------------------------------------------------------
// class MachineInstructionInfo
// Interface to description of machine instructions
//---------------------------------------------------------------------------
MachineInstrInfo::MachineInstrInfo(const MachineInstrDescriptor* Desc,
unsigned DescSize,
unsigned NumRealOpCodes)
: desc(Desc), descSize(DescSize), numRealOpCodes(NumRealOpCodes) {
// FIXME: TargetInstrDescriptors should not be global
assert(TargetInstrDescriptors == NULL && desc != NULL);
TargetInstrDescriptors = desc; // initialize global variable
}
MachineInstrInfo::~MachineInstrInfo() {
TargetInstrDescriptors = NULL; // reset global variable
}
bool MachineInstrInfo::constantFitsInImmedField(MachineOpCode opCode,
int64_t intValue) const {
// First, check if opCode has an immed field.
bool isSignExtended;
uint64_t maxImmedValue = maxImmedConstant(opCode, isSignExtended);
if (maxImmedValue != 0)
{
// NEED TO HANDLE UNSIGNED VALUES SINCE THEY MAY BECOME MUCH
// SMALLER AFTER CASTING TO SIGN-EXTENDED int, short, or char.
// See CreateUIntSetInstruction in SparcInstrInfo.cpp.
// Now check if the constant fits
if (intValue <= (int64_t) maxImmedValue &&
intValue >= -((int64_t) maxImmedValue+1))
return true;
}
return false;
}
bool MachineInstrInfo::ConstantTypeMustBeLoaded(const Constant* CV) const {
assert(CV->getType()->isPrimitiveType() || isa<PointerType>(CV->getType()));
return !(CV->getType()->isIntegral() || isa<PointerType>(CV->getType()));
}