Do not pre-allocate for registers which form a REG_SEQUENCE.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103041 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2010-05-04 20:38:12 +00:00
parent afff40a62d
commit 826bdfa603

View File

@ -12,12 +12,14 @@
#include "ARMInstrInfo.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
using namespace llvm;
namespace {
class NEONPreAllocPass : public MachineFunctionPass {
const TargetInstrInfo *TII;
MachineRegisterInfo *MRI;
public:
static char ID;
@ -30,6 +32,8 @@ namespace {
}
private:
bool FormsRegSequence(MachineInstr *MI,
unsigned FirstOpnd, unsigned NumRegs);
bool PreAllocNEONRegisters(MachineBasicBlock &MBB);
};
@ -334,6 +338,27 @@ static bool isNEONMultiRegOp(int Opcode, unsigned &FirstOpnd, unsigned &NumRegs,
return false;
}
bool NEONPreAllocPass::FormsRegSequence(MachineInstr *MI,
unsigned FirstOpnd, unsigned NumRegs) {
MachineInstr *RegSeq = 0;
for (unsigned R = 0; R < NumRegs; ++R) {
MachineOperand &MO = MI->getOperand(FirstOpnd + R);
assert(MO.isReg() && MO.getSubReg() == 0 && "unexpected operand");
unsigned VirtReg = MO.getReg();
assert(TargetRegisterInfo::isVirtualRegister(VirtReg) &&
"expected a virtual register");
if (!MRI->hasOneNonDBGUse(VirtReg))
return false;
MachineInstr *UseMI = &*MRI->use_nodbg_begin(VirtReg);
if (UseMI->getOpcode() != TargetOpcode::REG_SEQUENCE)
return false;
if (RegSeq && RegSeq != UseMI)
return false;
RegSeq = UseMI;
}
return true;
}
bool NEONPreAllocPass::PreAllocNEONRegisters(MachineBasicBlock &MBB) {
bool Modified = false;
@ -343,6 +368,8 @@ bool NEONPreAllocPass::PreAllocNEONRegisters(MachineBasicBlock &MBB) {
unsigned FirstOpnd, NumRegs, Offset, Stride;
if (!isNEONMultiRegOp(MI->getOpcode(), FirstOpnd, NumRegs, Offset, Stride))
continue;
if (FormsRegSequence(MI, FirstOpnd, NumRegs))
continue;
MachineBasicBlock::iterator NextI = llvm::next(MBBI);
for (unsigned R = 0; R < NumRegs; ++R) {
@ -382,6 +409,7 @@ bool NEONPreAllocPass::PreAllocNEONRegisters(MachineBasicBlock &MBB) {
bool NEONPreAllocPass::runOnMachineFunction(MachineFunction &MF) {
TII = MF.getTarget().getInstrInfo();
MRI = &MF.getRegInfo();
bool Modified = false;
for (MachineFunction::iterator MFI = MF.begin(), E = MF.end(); MFI != E;