#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/MC/MCInstrItineraries.h"
+#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Target/TargetInstrInfo.h"
STATISTIC(NumReSchedUps, "Number of instructions re-scheduled up");
STATISTIC(NumReSchedDowns, "Number of instructions re-scheduled down");
+// Temporary flag to disable rescheduling.
+static cl::opt<bool>
+EnableRescheduling("twoaddr-reschedule",
+ cl::desc("Coalesce copies by rescheduling (default=true)"),
+ cl::init(true), cl::Hidden);
+
namespace {
class TwoAddressInstructionPass : public MachineFunctionPass {
MachineFunction *MF;
/// isTwoAddrUse - Return true if the specified MI uses the specified register
/// as a two-address use. If so, return the destination register by reference.
static bool isTwoAddrUse(MachineInstr &MI, unsigned Reg, unsigned &DstReg) {
- const MCInstrDesc &MCID = MI.getDesc();
- unsigned NumOps = MI.isInlineAsm()
- ? MI.getNumOperands() : MCID.getNumOperands();
- for (unsigned i = 0; i != NumOps; ++i) {
+ for (unsigned i = 0, NumOps = MI.getNumOperands(); i != NumOps; ++i) {
const MachineOperand &MO = MI.getOperand(i);
if (!MO.isReg() || !MO.isUse() || MO.getReg() != Reg)
continue;
// If there is one more use of regB later in the same MBB, consider
// re-schedule this MI below it.
- if (rescheduleMIBelowKill(mi, nmi, regB)) {
+ if (EnableRescheduling && rescheduleMIBelowKill(mi, nmi, regB)) {
++NumReSchedDowns;
return true;
}
// If there is one more use of regB later in the same MBB, consider
// re-schedule it before this MI if it's legal.
- if (rescheduleKillAboveMI(mi, nmi, regB)) {
+ if (EnableRescheduling && rescheduleKillAboveMI(mi, nmi, regB)) {
++NumReSchedUps;
return true;
}
// transformations that may either eliminate the tied operands or
// improve the opportunities for coalescing away the register copy.
if (TiedOperands.size() == 1) {
- SmallVector<std::pair<unsigned, unsigned>, 4> &TiedPairs
+ SmallVectorImpl<std::pair<unsigned, unsigned> > &TiedPairs
= TiedOperands.begin()->second;
if (TiedPairs.size() == 1) {
unsigned SrcIdx = TiedPairs[0].first;