TargetInstrInfo.cpp revision 93fa70598c88fe14ebe4b3752daab4ea265233e1 
1//===-- TargetMachine.cpp - General Target Information ---------------------==//
2//
3// This file describes the general parts of a Target machine.
4// This file also implements MachineInstrInfo and MachineCacheInfo.
5//
6//===----------------------------------------------------------------------===//
7
8#include "llvm/Target/MachineInstrInfo.h"
9#include "llvm/Constant.h"
10#include "llvm/DerivedTypes.h"
11
12//---------------------------------------------------------------------------
13// class MachineInstructionInfo
14//	Interface to description of machine instructions
15//---------------------------------------------------------------------------
16
17
18MachineInstrInfo::MachineInstrInfo(const TargetMachine& tgt,
19                                   const MachineInstrDescriptor* Desc,
20				   unsigned DescSize,
21				   unsigned NumRealOpCodes)
22  : target(tgt), desc(Desc), descSize(DescSize), numRealOpCodes(NumRealOpCodes) {
23  // FIXME: TargetInstrDescriptors should not be global
24  assert(TargetInstrDescriptors == NULL && desc != NULL);
25  TargetInstrDescriptors = desc;	// initialize global variable
26}
27
28MachineInstrInfo::~MachineInstrInfo() {
29  TargetInstrDescriptors = NULL;	// reset global variable
30}
31
32
33bool MachineInstrInfo::constantFitsInImmedField(MachineOpCode opCode,
34                                                int64_t intValue) const {
35  // First, check if opCode has an immed field.
36  bool isSignExtended;
37  uint64_t maxImmedValue = maxImmedConstant(opCode, isSignExtended);
38  if (maxImmedValue != 0)
39    {
40      // NEED TO HANDLE UNSIGNED VALUES SINCE THEY MAY BECOME MUCH
41      // SMALLER AFTER CASTING TO SIGN-EXTENDED int, short, or char.
42      // See CreateUIntSetInstruction in SparcInstrInfo.cpp.
43
44      // Now check if the constant fits
45      if (intValue <= (int64_t) maxImmedValue &&
46	  intValue >= -((int64_t) maxImmedValue+1))
47	return true;
48    }
49
50  return false;
51}
52
53bool MachineInstrInfo::ConstantTypeMustBeLoaded(const Constant* CV) const {
54  assert(CV->getType()->isPrimitiveType() || isa<PointerType>(CV->getType()));
55  return !(CV->getType()->isIntegral() || isa<PointerType>(CV->getType()));
56}
57