[llvm-commits] [llvm] r38534 - /llvm/trunk/lib/CodeGen/VirtRegMap.cpp
Evan Cheng
evan.cheng at apple.com
Wed Jul 11 01:47:44 PDT 2007
Author: evancheng
Date: Wed Jul 11 03:47:44 2007
New Revision: 38534
URL: http://llvm.org/viewvc/llvm-project?rev=38534&view=rev
Log:
No longer need to track last def / use.
Modified:
llvm/trunk/lib/CodeGen/VirtRegMap.cpp
Modified: llvm/trunk/lib/CodeGen/VirtRegMap.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/VirtRegMap.cpp?rev=38534&r1=38533&r2=38534&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/VirtRegMap.cpp (original)
+++ llvm/trunk/lib/CodeGen/VirtRegMap.cpp Wed Jul 11 03:47:44 2007
@@ -277,10 +277,8 @@
// SpillSlotsAvailable - This map keeps track of all of the spilled virtual
// register values that are still available, due to being loaded or stored to,
- // but not invalidated yet. It also tracks the instructions that defined
- // or used the register.
- typedef std::pair<unsigned, std::vector<MachineInstr*> > SSInfo;
- std::map<int, SSInfo> SpillSlotsAvailable;
+ // but not invalidated yet.
+ std::map<int, unsigned> SpillSlotsAvailable;
// PhysRegsAvailable - This is the inverse of SpillSlotsAvailable, indicating
// which stack slot values are currently held by a physreg. This is used to
@@ -298,56 +296,15 @@
const MRegisterInfo *getRegInfo() const { return MRI; }
/// getSpillSlotPhysReg - If the specified stack slot is available in a
- /// physical register, return that PhysReg, otherwise return 0. It also
- /// returns by reference the instruction that either defines or last uses
- /// the register.
- unsigned getSpillSlotPhysReg(int Slot, MachineInstr *&SSMI) const {
- std::map<int, SSInfo>::const_iterator I = SpillSlotsAvailable.find(Slot);
+ /// physical register, return that PhysReg, otherwise return 0.
+ unsigned getSpillSlotPhysReg(int Slot) const {
+ std::map<int, unsigned>::const_iterator I = SpillSlotsAvailable.find(Slot);
if (I != SpillSlotsAvailable.end()) {
- if (!I->second.second.empty())
- SSMI = I->second.second.back();
- return I->second.first >> 1; // Remove the CanClobber bit.
+ return I->second >> 1; // Remove the CanClobber bit.
}
return 0;
}
- /// addLastUse - Add the last use information of all stack slots whose
- /// values are available in the specific register.
- void addLastUse(unsigned PhysReg, MachineInstr *Use) {
- std::multimap<unsigned, int>::iterator I =
- PhysRegsAvailable.lower_bound(PhysReg);
- while (I != PhysRegsAvailable.end() && I->first == PhysReg) {
- int Slot = I->second;
- I++;
-
- std::map<int, SSInfo>::iterator II = SpillSlotsAvailable.find(Slot);
- assert(II != SpillSlotsAvailable.end() && "Slot not available!");
- unsigned Val = II->second.first;
- assert((Val >> 1) == PhysReg && "Bidirectional map mismatch!");
- // This can be true if there are multiple uses of the same register.
- if (II->second.second.back() != Use)
- II->second.second.push_back(Use);
- }
- }
-
- /// removeLastUse - Remove the last use information of all stack slots whose
- /// values are available in the specific register.
- void removeLastUse(unsigned PhysReg, MachineInstr *Use) {
- std::multimap<unsigned, int>::iterator I =
- PhysRegsAvailable.lower_bound(PhysReg);
- while (I != PhysRegsAvailable.end() && I->first == PhysReg) {
- int Slot = I->second;
- I++;
-
- std::map<int, SSInfo>::iterator II = SpillSlotsAvailable.find(Slot);
- assert(II != SpillSlotsAvailable.end() && "Slot not available!");
- unsigned Val = II->second.first;
- assert((Val >> 1) == PhysReg && "Bidirectional map mismatch!");
- if (II->second.second.back() == Use)
- II->second.second.pop_back();
- }
- }
-
/// addAvailable - Mark that the specified stack slot is available in the
/// specified physreg. If CanClobber is true, the physreg can be modified at
/// any time without changing the semantics of the program.
@@ -358,10 +315,7 @@
ModifyStackSlot(Slot);
PhysRegsAvailable.insert(std::make_pair(Reg, Slot));
- std::vector<MachineInstr*> DefUses;
- DefUses.push_back(MI);
- SpillSlotsAvailable[Slot] =
- std::make_pair((Reg << 1) | (unsigned)CanClobber, DefUses);
+ SpillSlotsAvailable[Slot] = (Reg << 1) | (unsigned)CanClobber;
if (Slot > VirtRegMap::MAX_STACK_SLOT)
DOUT << "Remembering RM#" << Slot-VirtRegMap::MAX_STACK_SLOT-1;
@@ -375,7 +329,7 @@
/// stack slot must be available in a physreg for this query to make sense.
bool canClobberPhysReg(int Slot) const {
assert(SpillSlotsAvailable.count(Slot) && "Slot not available!");
- return SpillSlotsAvailable.find(Slot)->second.first & 1;
+ return SpillSlotsAvailable.find(Slot)->second & 1;
}
/// disallowClobberPhysReg - Unset the CanClobber bit of the specified
@@ -404,9 +358,9 @@
while (I != PhysRegsAvailable.end() && I->first == PhysReg) {
int Slot = I->second;
I++;
- assert((SpillSlotsAvailable[Slot].first >> 1) == PhysReg &&
+ assert((SpillSlotsAvailable[Slot] >> 1) == PhysReg &&
"Bidirectional map mismatch!");
- SpillSlotsAvailable[Slot].first &= ~1;
+ SpillSlotsAvailable[Slot] &= ~1;
DOUT << "PhysReg " << MRI->getName(PhysReg)
<< " copied, it is available for use but can no longer be modified\n";
}
@@ -429,7 +383,7 @@
while (I != PhysRegsAvailable.end() && I->first == PhysReg) {
int Slot = I->second;
PhysRegsAvailable.erase(I++);
- assert((SpillSlotsAvailable[Slot].first >> 1) == PhysReg &&
+ assert((SpillSlotsAvailable[Slot] >> 1) == PhysReg &&
"Bidirectional map mismatch!");
SpillSlotsAvailable.erase(Slot);
DOUT << "PhysReg " << MRI->getName(PhysReg)
@@ -454,9 +408,9 @@
/// changes. This removes information about which register the previous value
/// for this slot lives in (as the previous value is dead now).
void AvailableSpills::ModifyStackSlot(int Slot) {
- std::map<int, SSInfo>::iterator It = SpillSlotsAvailable.find(Slot);
+ std::map<int, unsigned>::iterator It = SpillSlotsAvailable.find(Slot);
if (It == SpillSlotsAvailable.end()) return;
- unsigned Reg = It->second.first >> 1;
+ unsigned Reg = It->second >> 1;
SpillSlotsAvailable.erase(It);
// This register may hold the value of multiple stack slots, only remove this
@@ -794,8 +748,7 @@
unsigned PhysReg;
// Check to see if this stack slot is available.
- MachineInstr *SSMI = NULL;
- if ((PhysReg = Spills.getSpillSlotPhysReg(StackSlot, SSMI))) {
+ if ((PhysReg = Spills.getSpillSlotPhysReg(StackSlot))) {
// This spilled operand might be part of a two-address operand. If this
// is the case, then changing it will necessarily require changing the
// def part of the instruction as well. However, in some cases, we
@@ -825,9 +778,6 @@
<< MRI->getName(VRM.getPhys(VirtReg)) << "\n";
MI.getOperand(i).setReg(PhysReg);
- if (ti == -1)
- Spills.addLastUse(PhysReg, &MI);
-
// The only technical detail we have is that we don't know that
// PhysReg won't be clobbered by a reloaded stack slot that occurs
// later in the instruction. In particular, consider 'op V1, V2'.
@@ -894,11 +844,8 @@
ReusedOperands.markClobbered(DesignatedReg);
MRI->copyRegToReg(MBB, &MI, DesignatedReg, PhysReg, RC);
- // Extend the live range of the MI that last kill the register if
- // necessary.
MachineInstr *CopyMI = prior(MII);
UpdateKills(*CopyMI, RegKills, KillOps);
- Spills.addLastUse(PhysReg, CopyMI);
// This invalidates DesignatedReg.
Spills.ClobberPhysReg(DesignatedReg);
@@ -973,8 +920,7 @@
if (FrameIdx == SS) {
// If this spill slot is available, turn it into a copy (or nothing)
// instead of leaving it as a load!
- MachineInstr *SSMI = NULL;
- if (unsigned InReg = Spills.getSpillSlotPhysReg(SS, SSMI)) {
+ if (unsigned InReg = Spills.getSpillSlotPhysReg(SS)) {
DOUT << "Promoted Load To Copy: " << MI;
if (DestReg != InReg) {
MRI->copyRegToReg(MBB, &MI, DestReg, InReg,
@@ -988,14 +934,6 @@
} else
DOUT << "Removing now-noop copy: " << MI;
- if (NextMII != MBB.end()) {
- // If NextMII uses InReg and the use is not a two address
- // operand, mark it killed.
- int UIdx = NextMII->findRegisterUseOperandIdx(InReg);
- if (UIdx != -1)
- Spills.addLastUse(InReg, &(*NextMII));
- }
-
VRM.RemoveFromFoldedVirtMap(&MI);
MBB.erase(&MI);
Erased = true;
@@ -1065,7 +1003,6 @@
if (TII->isMoveInstr(MI, Src, Dst) && Src == Dst) {
++NumDCE;
DOUT << "Removing now-noop copy: " << MI;
- Spills.removeLastUse(Src, &MI);
MBB.erase(&MI);
Erased = true;
VRM.RemoveFromFoldedVirtMap(&MI);
@@ -1143,7 +1080,6 @@
if (TII->isMoveInstr(MI, Src, Dst) && Src == Dst) {
++NumDCE;
DOUT << "Removing now-noop copy: " << MI;
- Spills.removeLastUse(Src, &MI);
MBB.erase(&MI);
Erased = true;
VRM.RemoveFromFoldedVirtMap(&MI);
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