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previous patch was a little too tricky for its own good. Don't try to

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overload UserInInstr. Explicitly check Allocatable. The early exit in the
condition will mean the performance impact of the extra test should be
minimal.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113016 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach 2010-09-03 21:45:15 +00:00
parent caa9ba228d
commit ee72651df4
1 changed files with 7 additions and 8 deletions
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15
lib/CodeGen/RegAllocFast.cpp
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@ -113,9 +113,6 @@ namespace {
// Allocatable - vector of allocatable physical registers.
BitVector Allocatable;
// Reserved - vector of reserved physical registers.
BitVector Reserved;
// SkippedInstrs - Descriptors of instructions whose clobber list was
// ignored because all registers were spilled. It is still necessary to
// mark all the clobbered registers as used by the function.
@ -501,7 +498,8 @@ void RAFast::allocVirtReg(MachineInstr *MI, LiveRegEntry &LRE, unsigned Hint) {
// First try to find a completely free register.
for (TargetRegisterClass::iterator I = AOB; I != AOE; ++I) {
unsigned PhysReg = *I;
if (PhysRegState[PhysReg] == regFree && !UsedInInstr.test(PhysReg))
if (PhysRegState[PhysReg] == regFree && !UsedInInstr.test(PhysReg) &&
Allocatable.test(PhysReg))
return assignVirtToPhysReg(LRE, PhysReg);
}
@ -510,6 +508,8 @@ void RAFast::allocVirtReg(MachineInstr *MI, LiveRegEntry &LRE, unsigned Hint) {
unsigned BestReg = 0, BestCost = spillImpossible;
for (TargetRegisterClass::iterator I = AOB; I != AOE; ++I) {
if (!Allocatable.test(*I))
continue;
unsigned Cost = calcSpillCost(*I);
// Cost is 0 when all aliases are already disabled.
if (Cost == 0)
@ -712,7 +712,7 @@ void RAFast::handleThroughOperands(MachineInstr *MI,
}
// Restore UsedInInstr to a state usable for allocating normal virtual uses.
UsedInInstr = Reserved;
UsedInInstr.reset();
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (!MO.isReg() || (MO.isDef() && !MO.isEarlyClobber())) continue;
@ -838,7 +838,7 @@ void RAFast::AllocateBasicBlock() {
}
// Track registers used by instruction.
UsedInInstr = Reserved;
UsedInInstr.reset();
// First scan.
// Mark physreg uses and early clobbers as used.
@ -916,7 +916,7 @@ void RAFast::AllocateBasicBlock() {
// Track registers defined by instruction - early clobbers and tied uses at
// this point.
UsedInInstr = Reserved;
UsedInInstr.reset();
if (hasEarlyClobbers) {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
@ -1014,7 +1014,6 @@ bool RAFast::runOnMachineFunction(MachineFunction &Fn) {
UsedInInstr.resize(TRI->getNumRegs());
Allocatable = TRI->getAllocatableSet(*MF);
Reserved = TRI->getReservedRegs(*MF);
// initialize the virtual->physical register map to have a 'null'
// mapping for all virtual registers