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* Remove some unneccesary instance variables 

* Make allocateStackSpaceFor only allocate the right amount of space

llvm-svn: 5048
This commit is contained in:
Chris Lattner 2002-12-15 19:07:34 +00:00
parent 0d1447d64a
commit f2acd842b4
1 changed files with 16 additions and 19 deletions
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35
llvm/lib/CodeGen/RegAllocSimple.cpp
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@ -38,11 +38,9 @@ public:
namespace {
struct RegAllocSimple : public FunctionPass {
TargetMachine &TM;
MachineBasicBlock *CurrMBB;
MachineFunction *MF;
unsigned maxOffset;
const MRegisterInfo *RegInfo;
unsigned NumBytesAllocated, ByteAlignment;
unsigned NumBytesAllocated;
// Maps SSA Regs => offsets on the stack where these values are stored
std::map<unsigned, unsigned> VirtReg2OffsetMap;
@ -62,9 +60,8 @@ namespace {
std::map<unsigned, unsigned> RegsUsed;
std::map<const TargetRegisterClass*, unsigned> RegClassIdx;
RegAllocSimple(TargetMachine &tm) : TM(tm), CurrMBB(0), maxOffset(0),
RegAllocSimple(TargetMachine &tm) : TM(tm),
RegInfo(tm.getRegisterInfo()),
ByteAlignment(4),
PhysRegClasses(RegInfo)
{
RegsUsed[RegInfo->getFramePointer()] = 1;
@ -109,7 +106,7 @@ namespace {
void cleanupAfterFunction() {
VirtReg2OffsetMap.clear();
SSA2PhysRegMap.clear();
NumBytesAllocated = ByteAlignment;
NumBytesAllocated = 4; /* FIXME: This is X86 specific */
}
/// Moves value from memory into that register
@ -144,19 +141,19 @@ unsigned RegAllocSimple::allocateStackSpaceFor(unsigned VirtReg,
const TargetRegisterClass *regClass)
{
if (VirtReg2OffsetMap.find(VirtReg) == VirtReg2OffsetMap.end()) {
#if 0
unsigned size = regClass->getDataSize();
unsigned over = NumBytesAllocated - (NumBytesAllocated % ByteAlignment);
if (size >= ByteAlignment - over) {
// need to pad by (ByteAlignment - over)
NumBytesAllocated += ByteAlignment - over;
}
unsigned RegSize = regClass->getDataSize();
// Align NumBytesAllocated. We should be using TargetData alignment stuff
// to determine this, but we don't know the LLVM type associated with the
// virtual register. Instead, just align to a multiple of the size for now.
NumBytesAllocated += RegSize-1;
NumBytesAllocated = NumBytesAllocated/RegSize*RegSize;
// Assign the slot...
VirtReg2OffsetMap[VirtReg] = NumBytesAllocated;
NumBytesAllocated += size;
#endif
// FIXME: forcing each arg to take 4 bytes on the stack
VirtReg2OffsetMap[VirtReg] = NumBytesAllocated;
NumBytesAllocated += ByteAlignment;
// Reserve the space!
NumBytesAllocated += RegSize;
}
return VirtReg2OffsetMap[VirtReg];
}
@ -241,7 +238,7 @@ bool RegAllocSimple::runOnMachineFunction(MachineFunction &Fn) {
for (MachineFunction::iterator MBB = Fn.begin(), MBBe = Fn.end();
MBB != MBBe; ++MBB)
{
CurrMBB = &(*MBB);
MachineBasicBlock *CurrMBB = &(*MBB);
// Handle PHI instructions specially: add moves to each pred block
while (MBB->front()->getOpcode() == 0) {