6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-05-21 12:38:45 +00:00
Code Issues Projects Releases Wiki Activity

RegisterPressureTracker: reword stale comments.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237544 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andrew Trick 2015-05-17 23:40:27 +00:00
parent 2bb2ea8105
commit eddedaab45
2 changed files with 13 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
lib/CodeGen/MachineScheduler.cpp
View File

@ -2611,8 +2611,7 @@ void GenericScheduler::tryCandidate(SchedCandidate &Cand,
TryCand, Cand, PhysRegCopy)) TryCand, Cand, PhysRegCopy))
return; return;
// Avoid exceeding the target's limit. If signed PSetID is negative, it is // Avoid exceeding the target's limit.
// invalid; convert it to INT_MAX to give it lowest priority.
if (DAG->isTrackingPressure() && tryPressure(TryCand.RPDelta.Excess, if (DAG->isTrackingPressure() && tryPressure(TryCand.RPDelta.Excess,
Cand.RPDelta.Excess, Cand.RPDelta.Excess,
TryCand, Cand, RegExcess)) TryCand, Cand, RegExcess))

19
lib/CodeGen/RegisterPressure.cpp
View File

@ -750,9 +750,11 @@ void RegPressureTracker::bumpUpwardPressure(const MachineInstr *MI) {
/// ///
/// This assumes that the current LiveOut set is sufficient. /// This assumes that the current LiveOut set is sufficient.
/// ///
/// FIXME: This is expensive for an on-the-fly query. We need to cache the /// This is expensive for an on-the-fly query because it calls
/// result per-SUnit with enough information to adjust for the current /// bumpUpwardPressure to recompute the pressure sets based on current
/// scheduling position. But this works as a proof of concept. /// liveness. This mainly exists to verify correctness, e.g. with
/// -verify-misched. getUpwardPressureDelta is the fast version of this query
/// that uses the per-SUnit cache of the PressureDiff.
void RegPressureTracker:: void RegPressureTracker::
getMaxUpwardPressureDelta(const MachineInstr *MI, PressureDiff *PDiff, getMaxUpwardPressureDelta(const MachineInstr *MI, PressureDiff *PDiff,
RegPressureDelta &Delta, RegPressureDelta &Delta,
@ -809,10 +811,8 @@ getMaxUpwardPressureDelta(const MachineInstr *MI, PressureDiff *PDiff,
#endif #endif
} }
/// This is a prototype of the fast version of querying register pressure that /// This is the fast version of querying register pressure that does not
/// does not directly depend on current liveness. It's still slow because we /// directly depend on current liveness.
/// recompute pressure change on-the-fly. This implementation only exists to
/// prove correctness.
/// ///
/// @param Delta captures information needed for heuristics. /// @param Delta captures information needed for heuristics.
/// ///
@ -950,6 +950,11 @@ void RegPressureTracker::bumpDownwardPressure(const MachineInstr *MI) {
/// register units of that pressure set introduced by this instruction. /// register units of that pressure set introduced by this instruction.
/// ///
/// This assumes that the current LiveIn set is sufficient. /// This assumes that the current LiveIn set is sufficient.
///
/// This is expensive for an on-the-fly query because it calls
/// bumpDownwardPressure to recompute the pressure sets based on current
/// liveness. We don't yet have a fast version of downward pressure tracking
/// analagous to getUpwardPressureDelta.
void RegPressureTracker:: void RegPressureTracker::
getMaxDownwardPressureDelta(const MachineInstr *MI, RegPressureDelta &Delta, getMaxDownwardPressureDelta(const MachineInstr *MI, RegPressureDelta &Delta,
ArrayRef<PressureChange> CriticalPSets, ArrayRef<PressureChange> CriticalPSets,