[llvm-commits] [llvm] r151205 - in /llvm/trunk/lib/CodeGen: ScheduleDAGInstrs.cpp ScheduleDAGInstrs.h
Andrew Trick
atrick at apple.com
Wed Feb 22 13:59:00 PST 2012
Author: atrick
Date: Wed Feb 22 15:59:00 2012
New Revision: 151205
URL: http://llvm.org/viewvc/llvm-project?rev=151205&view=rev
Log:
misched: Use SparseSet for VRegDegs for constant time clear().
Modified:
llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp
llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.h
Modified: llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp?rev=151205&r1=151204&r2=151205&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp (original)
+++ llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp Wed Feb 22 15:59:00 2012
@@ -373,13 +373,18 @@
// uses. We're conservative for now until we have a way to guarantee the uses
// are not eliminated sometime during scheduling. The output dependence edge
// is also useful if output latency exceeds def-use latency.
- SUnit *&DefSU = VRegDefs[Reg];
- if (DefSU && DefSU != SU && DefSU != &ExitSU) {
- unsigned OutLatency = TII->getOutputLatency(InstrItins, MI, OperIdx,
- DefSU->getInstr());
- DefSU->addPred(SDep(SU, SDep::Output, OutLatency, Reg));
+ VReg2SUnitMap::iterator DefI = findVRegDef(Reg);
+ if (DefI == VRegDefs.end())
+ VRegDefs.insert(VReg2SUnit(Reg, SU));
+ else {
+ SUnit *DefSU = DefI->SU;
+ if (DefSU != SU && DefSU != &ExitSU) {
+ unsigned OutLatency = TII->getOutputLatency(InstrItins, MI, OperIdx,
+ DefSU->getInstr());
+ DefSU->addPred(SDep(SU, SDep::Output, OutLatency, Reg));
+ }
+ DefI->SU = SU;
}
- DefSU = SU;
}
/// addVRegUseDeps - Add a register data dependency if the instruction that
@@ -418,12 +423,9 @@
}
// Add antidependence to the following def of the vreg it uses.
- DenseMap<unsigned, SUnit*>::const_iterator I = VRegDefs.find(Reg);
- if (I != VRegDefs.end()) {
- SUnit *DefSU = I->second;
- if (DefSU != SU)
- DefSU->addPred(SDep(SU, SDep::Anti, 0, Reg));
- }
+ VReg2SUnitMap::iterator DefI = findVRegDef(Reg);
+ if (DefI != VRegDefs.end() && DefI->SU != SU)
+ DefI->SU->addPred(SDep(SU, SDep::Anti, 0, Reg));
}
/// Create an SUnit for each real instruction, numbered in top-down toplological
@@ -488,7 +490,11 @@
assert(Defs[i].empty() && "Only BuildGraph should push/pop Defs");
}
- assert(VRegDefs.size() == 0 && "Only BuildSchedGraph may access VRegDefs");
+ assert(VRegDefs.empty() && "Only BuildSchedGraph may access VRegDefs");
+ // FIXME: Allow SparseSet to reserve space for the creation of virtual
+ // registers during scheduling. Don't artificially inflate the Universe
+ // because we want to assert that vregs are not created during DAG building.
+ VRegDefs.setUniverse(MRI.getNumVirtRegs());
// Walk the list of instructions, from bottom moving up.
MachineInstr *PrevMI = NULL;
Modified: llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.h?rev=151205&r1=151204&r2=151205&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.h (original)
+++ llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.h Wed Feb 22 15:59:00 2012
@@ -20,8 +20,8 @@
#include "llvm/CodeGen/ScheduleDAG.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Target/TargetRegisterInfo.h"
-#include "llvm/ADT/IndexedMap.h"
#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/SparseSet.h"
#include <map>
namespace llvm {
@@ -125,9 +125,24 @@
std::vector<std::vector<SUnit *> > Defs;
std::vector<std::vector<SUnit *> > Uses;
+ /// An individual mapping from virtual register number to SUnit.
+ struct VReg2SUnit {
+ unsigned VirtReg;
+ SUnit *SU;
+
+ VReg2SUnit(unsigned reg, SUnit *su): VirtReg(reg), SU(su) {}
+
+ unsigned getSparseSetKey() const {
+ return TargetRegisterInfo::virtReg2Index(VirtReg);
+ }
+ };
+ // Use SparseSet as a SparseMap by relying on the fact that it never
+ // compares ValueT's, only unsigned keys. This allows the set to be cleared
+ // between scheduling regions in constant time.
+ typedef SparseSet<VReg2SUnit> VReg2SUnitMap;
+
// Track the last instructon in this region defining each virtual register.
- // FIXME: turn this into a sparse set with constant time clear().
- DenseMap<unsigned, SUnit*> VRegDefs;
+ VReg2SUnitMap VRegDefs;
/// PendingLoads - Remember where unknown loads are after the most recent
/// unknown store, as we iterate. As with Defs and Uses, this is here
@@ -235,6 +250,10 @@
void addPhysRegDeps(SUnit *SU, unsigned OperIdx);
void addVRegDefDeps(SUnit *SU, unsigned OperIdx);
void addVRegUseDeps(SUnit *SU, unsigned OperIdx);
+
+ VReg2SUnitMap::iterator findVRegDef(unsigned VirtReg) {
+ return VRegDefs.find(TargetRegisterInfo::virtReg2Index(VirtReg));
+ }
};
}
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