Tag cached interference with a user-provided tag instead of the virtual register number.

The live range of a virtual register may change which invalidates the cached
interference information.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127772 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2011-03-16 22:56:11 +00:00
parent c46570dc05
commit 2926733240
3 changed files with 16 additions and 7 deletions

View File

@ -163,7 +163,7 @@ public:
bool CheckedFirstInterference;
bool SeenAllInterferences;
bool SeenUnspillableVReg;
unsigned Tag, VTag;
unsigned Tag, UserTag;
public:
Query(): LiveUnion(), VirtReg() {}
@ -181,12 +181,13 @@ public:
SeenAllInterferences = false;
SeenUnspillableVReg = false;
Tag = 0;
VTag = 0;
UserTag = 0;
}
void init(LiveInterval *VReg, LiveIntervalUnion *LIU) {
void init(unsigned UTag, LiveInterval *VReg, LiveIntervalUnion *LIU) {
assert(VReg && LIU && "Invalid arguments");
if (VReg->reg == VTag && LiveUnion == LIU && !LIU->changedSince(Tag)) {
if (UserTag == UTag && VirtReg == VReg &&
LiveUnion == LIU && !LIU->changedSince(Tag)) {
// Retain cached results, e.g. firstInterference.
return;
}
@ -194,7 +195,7 @@ public:
LiveUnion = LIU;
VirtReg = VReg;
Tag = LIU->getTag();
VTag = VReg->reg;
UserTag = UTag;
}
LiveInterval &virtReg() const {

View File

@ -61,6 +61,11 @@ class LiveVirtRegQueue;
/// assignment order.
class RegAllocBase {
LiveIntervalUnion::Allocator UnionAllocator;
// Cache tag for PhysReg2LiveUnion entries. Increment whenever virtual
// registers may have changed.
unsigned UserTag;
protected:
// Array of LiveIntervalUnions indexed by physical register.
class LiveUnionArray {
@ -92,7 +97,7 @@ protected:
// query on a new live virtual register.
OwningArrayPtr<LiveIntervalUnion::Query> Queries;
RegAllocBase(): TRI(0), MRI(0), VRM(0), LIS(0) {}
RegAllocBase(): UserTag(0), TRI(0), MRI(0), VRM(0), LIS(0) {}
virtual ~RegAllocBase() {}
@ -104,7 +109,7 @@ protected:
// before querying a new live virtual register. This ties Queries and
// PhysReg2LiveUnion together.
LiveIntervalUnion::Query &query(LiveInterval &VirtReg, unsigned PhysReg) {
Queries[PhysReg].init(&VirtReg, &PhysReg2LiveUnion[PhysReg]);
Queries[PhysReg].init(UserTag, &VirtReg, &PhysReg2LiveUnion[PhysReg]);
return Queries[PhysReg];
}

View File

@ -296,6 +296,9 @@ void RegAllocBase::allocatePhysRegs() {
continue;
}
// Invalidate all interference queries, live ranges could have changed.
++UserTag;
// selectOrSplit requests the allocator to return an available physical
// register if possible and populate a list of new live intervals that
// result from splitting.