llvm-6502/lib/Target/SystemZ/SystemZConstantPoolValue.cpp
Ulrich Weigand bebd59c74b [SystemZ] Support all TLS access models - CodeGen part
The current SystemZ back-end only supports the local-exec TLS access model.
This patch adds all required CodeGen support for the other TLS models, which
means in particular:

- Expand initial-exec TLS accesses by loading TLS offsets from the GOT
  using @indntpoff relocations.

- Expand general-dynamic and local-dynamic accesses by generating the
  appropriate calls to __tls_get_offset.  Note that this routine has
  a non-standard ABI and requires loading the GOT pointer into %r12,
  so the patch also adds support for the GLOBAL_OFFSET_TABLE ISD node.

- Add a new platform-specific optimization pass to remove redundant
  __tls_get_offset calls in the local-dynamic model (modeled after
  the corresponding X86 pass).

- Add test cases verifying all access models and optimizations.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229654 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 09:13:27 +00:00

68 lines
2.1 KiB
C++

//===-- SystemZConstantPoolValue.cpp - SystemZ constant-pool value --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "SystemZConstantPoolValue.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
SystemZConstantPoolValue::
SystemZConstantPoolValue(const GlobalValue *gv,
SystemZCP::SystemZCPModifier modifier)
: MachineConstantPoolValue(gv->getType()), GV(gv), Modifier(modifier) {}
SystemZConstantPoolValue *
SystemZConstantPoolValue::Create(const GlobalValue *GV,
SystemZCP::SystemZCPModifier Modifier) {
return new SystemZConstantPoolValue(GV, Modifier);
}
unsigned SystemZConstantPoolValue::getRelocationInfo() const {
switch (Modifier) {
case SystemZCP::TLSGD:
case SystemZCP::TLSLDM:
case SystemZCP::DTPOFF:
// May require a dynamic relocation.
return 2;
case SystemZCP::NTPOFF:
// May require a relocation, but the relocations are always resolved
// by the static linker.
return 1;
}
llvm_unreachable("Unknown modifier");
}
int SystemZConstantPoolValue::
getExistingMachineCPValue(MachineConstantPool *CP, unsigned Alignment) {
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() &&
(Constants[I].getAlignment() & AlignMask) == 0) {
auto *ZCPV =
static_cast<SystemZConstantPoolValue *>(Constants[I].Val.MachineCPVal);
if (ZCPV->GV == GV && ZCPV->Modifier == Modifier)
return I;
}
}
return -1;
}
void SystemZConstantPoolValue::addSelectionDAGCSEId(FoldingSetNodeID &ID) {
ID.AddPointer(GV);
ID.AddInteger(Modifier);
}
void SystemZConstantPoolValue::print(raw_ostream &O) const {
O << GV << "@" << int(Modifier);
}