mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-10-24 13:33:37 +02:00
4156ee11bb
On z13, if eliminateFrameIndex() chooses LE (and not LEY), immediately transform that LE to LDE32 to avoid partial register dependencies. LEY should be generally preferred for big offsets over an expansion into LAY + LDE32. Reviewed by Ulrich Weigand. llvm-svn: 266060
147 lines
5.3 KiB
C++
147 lines
5.3 KiB
C++
//===-- SystemZRegisterInfo.cpp - SystemZ register information ------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "SystemZInstrInfo.h"
|
|
#include "SystemZRegisterInfo.h"
|
|
#include "SystemZSubtarget.h"
|
|
#include "llvm/CodeGen/MachineInstrBuilder.h"
|
|
#include "llvm/CodeGen/MachineRegisterInfo.h"
|
|
#include "llvm/Target/TargetFrameLowering.h"
|
|
|
|
using namespace llvm;
|
|
|
|
#define GET_REGINFO_TARGET_DESC
|
|
#include "SystemZGenRegisterInfo.inc"
|
|
|
|
SystemZRegisterInfo::SystemZRegisterInfo()
|
|
: SystemZGenRegisterInfo(SystemZ::R14D) {}
|
|
|
|
const MCPhysReg *
|
|
SystemZRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
|
|
return CSR_SystemZ_SaveList;
|
|
}
|
|
|
|
const uint32_t *
|
|
SystemZRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
|
|
CallingConv::ID CC) const {
|
|
return CSR_SystemZ_RegMask;
|
|
}
|
|
|
|
BitVector
|
|
SystemZRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
|
|
BitVector Reserved(getNumRegs());
|
|
const SystemZFrameLowering *TFI = getFrameLowering(MF);
|
|
|
|
if (TFI->hasFP(MF)) {
|
|
// R11D is the frame pointer. Reserve all aliases.
|
|
Reserved.set(SystemZ::R11D);
|
|
Reserved.set(SystemZ::R11L);
|
|
Reserved.set(SystemZ::R11H);
|
|
Reserved.set(SystemZ::R10Q);
|
|
}
|
|
|
|
// R15D is the stack pointer. Reserve all aliases.
|
|
Reserved.set(SystemZ::R15D);
|
|
Reserved.set(SystemZ::R15L);
|
|
Reserved.set(SystemZ::R15H);
|
|
Reserved.set(SystemZ::R14Q);
|
|
return Reserved;
|
|
}
|
|
|
|
void
|
|
SystemZRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MI,
|
|
int SPAdj, unsigned FIOperandNum,
|
|
RegScavenger *RS) const {
|
|
assert(SPAdj == 0 && "Outgoing arguments should be part of the frame");
|
|
|
|
MachineBasicBlock &MBB = *MI->getParent();
|
|
MachineFunction &MF = *MBB.getParent();
|
|
auto *TII =
|
|
static_cast<const SystemZInstrInfo *>(MF.getSubtarget().getInstrInfo());
|
|
const SystemZFrameLowering *TFI = getFrameLowering(MF);
|
|
DebugLoc DL = MI->getDebugLoc();
|
|
|
|
// Decompose the frame index into a base and offset.
|
|
int FrameIndex = MI->getOperand(FIOperandNum).getIndex();
|
|
unsigned BasePtr;
|
|
int64_t Offset = (TFI->getFrameIndexReference(MF, FrameIndex, BasePtr) +
|
|
MI->getOperand(FIOperandNum + 1).getImm());
|
|
|
|
// Special handling of dbg_value instructions.
|
|
if (MI->isDebugValue()) {
|
|
MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, /*isDef*/ false);
|
|
MI->getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
|
|
return;
|
|
}
|
|
|
|
// See if the offset is in range, or if an equivalent instruction that
|
|
// accepts the offset exists.
|
|
unsigned Opcode = MI->getOpcode();
|
|
unsigned OpcodeForOffset = TII->getOpcodeForOffset(Opcode, Offset);
|
|
if (OpcodeForOffset) {
|
|
if (OpcodeForOffset == SystemZ::LE &&
|
|
MF.getSubtarget<SystemZSubtarget>().hasVector()) {
|
|
// If LE is ok for offset, use LDE instead on z13.
|
|
OpcodeForOffset = SystemZ::LDE32;
|
|
}
|
|
MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, false);
|
|
}
|
|
else {
|
|
// Create an anchor point that is in range. Start at 0xffff so that
|
|
// can use LLILH to load the immediate.
|
|
int64_t OldOffset = Offset;
|
|
int64_t Mask = 0xffff;
|
|
do {
|
|
Offset = OldOffset & Mask;
|
|
OpcodeForOffset = TII->getOpcodeForOffset(Opcode, Offset);
|
|
Mask >>= 1;
|
|
assert(Mask && "One offset must be OK");
|
|
} while (!OpcodeForOffset);
|
|
|
|
unsigned ScratchReg =
|
|
MF.getRegInfo().createVirtualRegister(&SystemZ::ADDR64BitRegClass);
|
|
int64_t HighOffset = OldOffset - Offset;
|
|
|
|
if (MI->getDesc().TSFlags & SystemZII::HasIndex
|
|
&& MI->getOperand(FIOperandNum + 2).getReg() == 0) {
|
|
// Load the offset into the scratch register and use it as an index.
|
|
// The scratch register then dies here.
|
|
TII->loadImmediate(MBB, MI, ScratchReg, HighOffset);
|
|
MI->getOperand(FIOperandNum).ChangeToRegister(BasePtr, false);
|
|
MI->getOperand(FIOperandNum + 2).ChangeToRegister(ScratchReg,
|
|
false, false, true);
|
|
} else {
|
|
// Load the anchor address into a scratch register.
|
|
unsigned LAOpcode = TII->getOpcodeForOffset(SystemZ::LA, HighOffset);
|
|
if (LAOpcode)
|
|
BuildMI(MBB, MI, DL, TII->get(LAOpcode),ScratchReg)
|
|
.addReg(BasePtr).addImm(HighOffset).addReg(0);
|
|
else {
|
|
// Load the high offset into the scratch register and use it as
|
|
// an index.
|
|
TII->loadImmediate(MBB, MI, ScratchReg, HighOffset);
|
|
BuildMI(MBB, MI, DL, TII->get(SystemZ::AGR),ScratchReg)
|
|
.addReg(ScratchReg, RegState::Kill).addReg(BasePtr);
|
|
}
|
|
|
|
// Use the scratch register as the base. It then dies here.
|
|
MI->getOperand(FIOperandNum).ChangeToRegister(ScratchReg,
|
|
false, false, true);
|
|
}
|
|
}
|
|
MI->setDesc(TII->get(OpcodeForOffset));
|
|
MI->getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
|
|
}
|
|
|
|
unsigned
|
|
SystemZRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
|
|
const SystemZFrameLowering *TFI = getFrameLowering(MF);
|
|
return TFI->hasFP(MF) ? SystemZ::R11D : SystemZ::R15D;
|
|
}
|