llvm-6502/lib/Target/ARM/ARMConstantPoolValue.cpp

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//===- ARMConstantPoolValue.cpp - ARM constantpool value --------*- C++ -*-===//
//
// 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 ARM specific constantpool value class.
//
//===----------------------------------------------------------------------===//
#include "ARMConstantPoolValue.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/Constant.h"
#include "llvm/Constants.h"
#include "llvm/GlobalValue.h"
#include "llvm/Type.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdlib>
using namespace llvm;
ARMConstantPoolValue::ARMConstantPoolValue(const Constant *cval, unsigned id,
ARMCP::ARMCPKind K,
unsigned char PCAdj,
const char *Modif,
bool AddCA)
: MachineConstantPoolValue((const Type*)cval->getType()),
CVal(cval), S(NULL), LabelId(id), Kind(K), PCAdjust(PCAdj),
Modifier(Modif), AddCurrentAddress(AddCA) {}
ARMConstantPoolValue::ARMConstantPoolValue(LLVMContext &C,
const char *s, unsigned id,
unsigned char PCAdj,
const char *Modif,
bool AddCA)
: MachineConstantPoolValue((const Type*)Type::getInt32Ty(C)),
CVal(NULL), S(strdup(s)), LabelId(id), Kind(ARMCP::CPExtSymbol),
PCAdjust(PCAdj), Modifier(Modif), AddCurrentAddress(AddCA) {}
ARMConstantPoolValue::ARMConstantPoolValue(const GlobalValue *gv,
const char *Modif)
: MachineConstantPoolValue((const Type*)Type::getInt32Ty(gv->getContext())),
CVal(gv), S(NULL), LabelId(0), Kind(ARMCP::CPValue), PCAdjust(0),
Modifier(Modif) {}
const GlobalValue *ARMConstantPoolValue::getGV() const {
return dyn_cast_or_null<GlobalValue>(CVal);
}
const BlockAddress *ARMConstantPoolValue::getBlockAddress() const {
return dyn_cast_or_null<BlockAddress>(CVal);
}
int ARMConstantPoolValue::getExistingMachineCPValue(MachineConstantPool *CP,
unsigned Alignment) {
Fix some significant problems with constant pools that resulted in unnecessary paddings between constant pool entries, larger than necessary alignments (e.g. 8 byte alignment for .literal4 sections), and potentially other issues. 1. ConstantPoolSDNode alignment field is log2 value of the alignment requirement. This is not consistent with other SDNode variants. 2. MachineConstantPool alignment field is also a log2 value. 3. However, some places are creating ConstantPoolSDNode with alignment value rather than log2 values. This creates entries with artificially large alignments, e.g. 256 for SSE vector values. 4. Constant pool entry offsets are computed when they are created. However, asm printer group them by sections. That means the offsets are no longer valid. However, asm printer uses them to determine size of padding between entries. 5. Asm printer uses expensive data structure multimap to track constant pool entries by sections. 6. Asm printer iterate over SmallPtrSet when it's emitting constant pool entries. This is non-deterministic. Solutions: 1. ConstantPoolSDNode alignment field is changed to keep non-log2 value. 2. MachineConstantPool alignment field is also changed to keep non-log2 value. 3. Functions that create ConstantPool nodes are passing in non-log2 alignments. 4. MachineConstantPoolEntry no longer keeps an offset field. It's replaced with an alignment field. Offsets are not computed when constant pool entries are created. They are computed on the fly in asm printer and JIT. 5. Asm printer uses cheaper data structure to group constant pool entries. 6. Asm printer compute entry offsets after grouping is done. 7. Change JIT code to compute entry offsets on the fly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66875 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-13 07:51:59 +00:00
unsigned AlignMask = Alignment - 1;
const std::vector<MachineConstantPoolEntry> Constants = CP->getConstants();
for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
if (Constants[i].isMachineConstantPoolEntry() &&
Fix some significant problems with constant pools that resulted in unnecessary paddings between constant pool entries, larger than necessary alignments (e.g. 8 byte alignment for .literal4 sections), and potentially other issues. 1. ConstantPoolSDNode alignment field is log2 value of the alignment requirement. This is not consistent with other SDNode variants. 2. MachineConstantPool alignment field is also a log2 value. 3. However, some places are creating ConstantPoolSDNode with alignment value rather than log2 values. This creates entries with artificially large alignments, e.g. 256 for SSE vector values. 4. Constant pool entry offsets are computed when they are created. However, asm printer group them by sections. That means the offsets are no longer valid. However, asm printer uses them to determine size of padding between entries. 5. Asm printer uses expensive data structure multimap to track constant pool entries by sections. 6. Asm printer iterate over SmallPtrSet when it's emitting constant pool entries. This is non-deterministic. Solutions: 1. ConstantPoolSDNode alignment field is changed to keep non-log2 value. 2. MachineConstantPool alignment field is also changed to keep non-log2 value. 3. Functions that create ConstantPool nodes are passing in non-log2 alignments. 4. MachineConstantPoolEntry no longer keeps an offset field. It's replaced with an alignment field. Offsets are not computed when constant pool entries are created. They are computed on the fly in asm printer and JIT. 5. Asm printer uses cheaper data structure to group constant pool entries. 6. Asm printer compute entry offsets after grouping is done. 7. Change JIT code to compute entry offsets on the fly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66875 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-13 07:51:59 +00:00
(Constants[i].getAlignment() & AlignMask) == 0) {
ARMConstantPoolValue *CPV =
(ARMConstantPoolValue *)Constants[i].Val.MachineCPVal;
if (CPV->CVal == CVal &&
CPV->LabelId == LabelId &&
CPV->PCAdjust == PCAdjust &&
(CPV->S == S || strcmp(CPV->S, S) == 0) &&
(CPV->Modifier == Modifier || strcmp(CPV->Modifier, Modifier) == 0))
return i;
}
}
return -1;
}
ARMConstantPoolValue::~ARMConstantPoolValue() {
free((void*)S);
}
void
ARMConstantPoolValue::AddSelectionDAGCSEId(FoldingSetNodeID &ID) {
ID.AddPointer(CVal);
ID.AddPointer(S);
ID.AddInteger(LabelId);
ID.AddInteger(PCAdjust);
}
bool
ARMConstantPoolValue::hasSameValue(ARMConstantPoolValue *ACPV) {
if (ACPV->Kind == Kind &&
ACPV->CVal == CVal &&
ACPV->PCAdjust == PCAdjust &&
(ACPV->S == S || strcmp(ACPV->S, S) == 0) &&
(ACPV->Modifier == Modifier || strcmp(ACPV->Modifier, Modifier) == 0)) {
if (ACPV->LabelId == LabelId)
return true;
// Two PC relative constpool entries containing the same GV address or
// external symbols. FIXME: What about blockaddress?
if (Kind == ARMCP::CPValue || Kind == ARMCP::CPExtSymbol)
return true;
}
return false;
}
void ARMConstantPoolValue::dump() const {
errs() << " " << *this;
}
void ARMConstantPoolValue::print(raw_ostream &O) const {
if (CVal)
O << CVal->getName();
else
O << S;
if (Modifier) O << "(" << Modifier << ")";
if (PCAdjust != 0) {
O << "-(LPC" << LabelId << "+" << (unsigned)PCAdjust;
if (AddCurrentAddress) O << "-.";
O << ")";
}
}