Change MachineBasicBlock's vector of MachineInstr pointers into an
ilist of MachineInstr objects. This allows constant time removal and
insertion of MachineInstr instances from anywhere in each
MachineBasicBlock. It also allows for constant time splicing of
MachineInstrs into or out of MachineBasicBlocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11340 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86PeepholeOpt.cpp b/lib/Target/X86/X86PeepholeOpt.cpp
index 59ebb15..f09e8d7 100644
--- a/lib/Target/X86/X86PeepholeOpt.cpp
+++ b/lib/Target/X86/X86PeepholeOpt.cpp
@@ -50,8 +50,11 @@
bool PH::PeepholeOptimize(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &I) {
- MachineInstr *MI = *I;
- MachineInstr *Next = (I+1 != MBB.end()) ? *(I+1) : 0;
+ assert(I != MBB.end());
+ MachineBasicBlock::iterator NextI = I; ++NextI;
+
+ MachineInstr *MI = I;
+ MachineInstr *Next = (NextI != MBB.end()) ? &*NextI : (MachineInstr*)0;
unsigned Size = 0;
switch (MI->getOpcode()) {
case X86::MOVrr8:
@@ -59,7 +62,6 @@
case X86::MOVrr32: // Destroy X = X copies...
if (MI->getOperand(0).getReg() == MI->getOperand(1).getReg()) {
I = MBB.erase(I);
- delete MI;
return true;
}
return false;
@@ -82,8 +84,8 @@
}
unsigned R0 = MI->getOperand(0).getReg();
unsigned R1 = MI->getOperand(1).getReg();
- *I = BuildMI(Opcode, 2, R0).addReg(R1).addZImm((char)Val);
- delete MI;
+ I = MBB.insert(MBB.erase(I),
+ BuildMI(Opcode, 2, R0).addReg(R1).addZImm((char)Val));
return true;
}
}
@@ -114,8 +116,8 @@
case X86::XORri32: Opcode = X86::XORri32b; break;
}
unsigned R0 = MI->getOperand(0).getReg();
- *I = BuildMI(Opcode, 1, R0, MOTy::UseAndDef).addZImm((char)Val);
- delete MI;
+ I = MBB.insert(MBB.erase(I),
+ BuildMI(Opcode, 1, R0, MOTy::UseAndDef).addZImm((char)Val));
return true;
}
}
@@ -132,8 +134,8 @@
if (Val == 0) { // mov EAX, 0 -> xor EAX, EAX
static const unsigned Opcode[] ={X86::XORrr8,X86::XORrr16,X86::XORrr32};
unsigned Reg = MI->getOperand(0).getReg();
- *I = BuildMI(Opcode[Size], 2, Reg).addReg(Reg).addReg(Reg);
- delete MI;
+ I = MBB.insert(MBB.erase(I),
+ BuildMI(Opcode[Size], 2, Reg).addReg(Reg).addReg(Reg));
return true;
} else if (Val == -1) { // mov EAX, -1 -> or EAX, -1
// TODO: 'or Reg, -1' has a smaller encoding than 'mov Reg, -1'
@@ -145,8 +147,6 @@
if (Next->getOpcode() == X86::BSWAPr32 &&
MI->getOperand(0).getReg() == Next->getOperand(0).getReg()) {
I = MBB.erase(MBB.erase(I));
- delete MI;
- delete Next;
return true;
}
return false;
@@ -189,12 +189,11 @@
virtual bool runOnMachineFunction(MachineFunction &MF) {
for (MachineFunction::iterator BI = MF.begin(), E = MF.end(); BI!=E; ++BI)
for (MachineBasicBlock::iterator I = BI->begin(); I != BI->end(); ++I) {
- MachineInstr *MI = *I;
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
+ for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = I->getOperand(i);
if (MO.isRegister() && MO.isDef() && !MO.isUse() &&
MRegisterInfo::isVirtualRegister(MO.getReg()))
- setDefinition(MO.getReg(), MI);
+ setDefinition(MO.getReg(), I);
}
}
return false;
@@ -377,8 +376,10 @@
bool SSAPH::PeepholeOptimize(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &I) {
- MachineInstr *MI = *I;
- MachineInstr *Next = (I+1 != MBB.end()) ? *(I+1) : 0;
+ MachineBasicBlock::iterator NextI = I; ++NextI;
+
+ MachineInstr *MI = I;
+ MachineInstr *Next = (NextI != MBB.end()) ? &*NextI : (MachineInstr*)0;
bool Changed = false;