[llvm] e121269 - [NFC][regalloc] Pass RAGreedy to eviction adviser
Mircea Trofin via llvm-commits
llvm-commits at lists.llvm.org
Mon Jan 10 11:56:01 PST 2022
Author: Mircea Trofin
Date: 2022-01-10T11:55:16-08:00
New Revision: e12126913139bb42be1faaefea62eaaa80509626
URL: https://github.com/llvm/llvm-project/commit/e12126913139bb42be1faaefea62eaaa80509626
DIFF: https://github.com/llvm/llvm-project/commit/e12126913139bb42be1faaefea62eaaa80509626.diff
LOG: [NFC][regalloc] Pass RAGreedy to eviction adviser
This patch simplifies the interface between RAGreedy and the eviction
adviser by passing the allocator to the adviser, which allows the latter
to extract needed information as needed, rather than requiring it be passed
piecemeal at construction time (which would also complicate later
evolution).
Part of this, the patch also moves ExtraRegInfo back to RAGreedy. We
keep the encapsulation of ExtraRegInfo because it has benefits (e.g.
improved readability by abstracting access to the cascade info) and also
simpler re-initialization at regalloc pass re-entry time (we just flush
the Optional).
Differential Revision: https://reviews.llvm.org/D116669
Added:
Modified:
llvm/lib/CodeGen/RegAllocEvictionAdvisor.cpp
llvm/lib/CodeGen/RegAllocEvictionAdvisor.h
llvm/lib/CodeGen/RegAllocGreedy.cpp
llvm/lib/CodeGen/RegAllocGreedy.h
Removed:
################################################################################
diff --git a/llvm/lib/CodeGen/RegAllocEvictionAdvisor.cpp b/llvm/lib/CodeGen/RegAllocEvictionAdvisor.cpp
index 9f1012c959649..a41da98977c7d 100644
--- a/llvm/lib/CodeGen/RegAllocEvictionAdvisor.cpp
+++ b/llvm/lib/CodeGen/RegAllocEvictionAdvisor.cpp
@@ -11,6 +11,7 @@
//===----------------------------------------------------------------------===//
#include "RegAllocEvictionAdvisor.h"
+#include "RegAllocGreedy.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/RegisterClassInfo.h"
#include "llvm/CodeGen/VirtRegMap.h"
@@ -62,12 +63,8 @@ class DefaultEvictionAdvisorAnalysis final
private:
std::unique_ptr<RegAllocEvictionAdvisor>
- getAdvisor(const MachineFunction &MF, LiveRegMatrix *Matrix,
- LiveIntervals *LIS, VirtRegMap *VRM,
- const RegisterClassInfo &RegClassInfo,
- ExtraRegInfo *ExtraInfo) override {
- return std::make_unique<DefaultEvictionAdvisor>(MF, Matrix, LIS, VRM,
- RegClassInfo, ExtraInfo);
+ getAdvisor(const MachineFunction &MF, const RAGreedy &RA) override {
+ return std::make_unique<DefaultEvictionAdvisor>(MF, RA);
}
bool doInitialization(Module &M) override {
if (NotAsRequested)
@@ -109,13 +106,12 @@ StringRef RegAllocEvictionAdvisorAnalysis::getPassName() const {
llvm_unreachable("Unknown advisor kind");
}
-RegAllocEvictionAdvisor::RegAllocEvictionAdvisor(
- const MachineFunction &MF, LiveRegMatrix *Matrix, LiveIntervals *LIS,
- VirtRegMap *VRM, const RegisterClassInfo &RegClassInfo,
- ExtraRegInfo *ExtraInfo)
- : MF(MF), Matrix(Matrix), LIS(LIS), VRM(VRM), MRI(&VRM->getRegInfo()),
- TRI(MF.getSubtarget().getRegisterInfo()), RegClassInfo(RegClassInfo),
- RegCosts(TRI->getRegisterCosts(MF)), ExtraInfo(ExtraInfo),
+RegAllocEvictionAdvisor::RegAllocEvictionAdvisor(const MachineFunction &MF,
+ const RAGreedy &RA)
+ : MF(MF), RA(RA), Matrix(RA.getInterferenceMatrix()),
+ LIS(RA.getLiveIntervals()), VRM(RA.getVirtRegMap()),
+ MRI(&VRM->getRegInfo()), TRI(MF.getSubtarget().getRegisterInfo()),
+ RegClassInfo(RA.getRegClassInfo()), RegCosts(TRI->getRegisterCosts(MF)),
EnableLocalReassign(EnableLocalReassignment ||
MF.getSubtarget().enableRALocalReassignment(
MF.getTarget().getOptLevel())) {}
diff --git a/llvm/lib/CodeGen/RegAllocEvictionAdvisor.h b/llvm/lib/CodeGen/RegAllocEvictionAdvisor.h
index debb75ed50204..d99ebfc7c534b 100644
--- a/llvm/lib/CodeGen/RegAllocEvictionAdvisor.h
+++ b/llvm/lib/CodeGen/RegAllocEvictionAdvisor.h
@@ -87,87 +87,9 @@ struct EvictionCost {
}
};
-/// Track allocation stage and eviction loop prevention during allocation.
-// TODO(mtrofin): Consider exposing RAGreedy in a header instead, and folding
-// this back into it.
-class ExtraRegInfo final {
- // RegInfo - Keep additional information about each live range.
- struct RegInfo {
- LiveRangeStage Stage = RS_New;
-
- // Cascade - Eviction loop prevention. See
- // canEvictInterferenceBasedOnCost().
- unsigned Cascade = 0;
-
- RegInfo() = default;
- };
-
- IndexedMap<RegInfo, VirtReg2IndexFunctor> Info;
- unsigned NextCascade = 1;
-
-public:
- ExtraRegInfo() = default;
- ExtraRegInfo(const ExtraRegInfo &) = delete;
-
- LiveRangeStage getStage(Register Reg) const { return Info[Reg].Stage; }
-
- LiveRangeStage getStage(const LiveInterval &VirtReg) const {
- return getStage(VirtReg.reg());
- }
-
- void setStage(Register Reg, LiveRangeStage Stage) {
- Info.grow(Reg.id());
- Info[Reg].Stage = Stage;
- }
-
- void setStage(const LiveInterval &VirtReg, LiveRangeStage Stage) {
- setStage(VirtReg.reg(), Stage);
- }
-
- /// Return the current stage of the register, if present, otherwise initialize
- /// it and return that.
- LiveRangeStage getOrInitStage(Register Reg) {
- Info.grow(Reg.id());
- return getStage(Reg);
- }
-
- unsigned getCascade(Register Reg) const { return Info[Reg].Cascade; }
-
- void setCascade(Register Reg, unsigned Cascade) {
- Info.grow(Reg.id());
- Info[Reg].Cascade = Cascade;
- }
-
- unsigned getOrAssignNewCascade(Register Reg) {
- unsigned Cascade = getCascade(Reg);
- if (!Cascade) {
- Cascade = NextCascade++;
- setCascade(Reg, Cascade);
- }
- return Cascade;
- }
-
- unsigned getCascadeOrCurrentNext(Register Reg) const {
- unsigned Cascade = getCascade(Reg);
- if (!Cascade)
- Cascade = NextCascade;
- return Cascade;
- }
-
- template <typename Iterator>
- void setStage(Iterator Begin, Iterator End, LiveRangeStage NewStage) {
- for (; Begin != End; ++Begin) {
- Register Reg = *Begin;
- Info.grow(Reg.id());
- if (Info[Reg].Stage == RS_New)
- Info[Reg].Stage = NewStage;
- }
- }
- void LRE_DidCloneVirtReg(Register New, Register Old);
-};
-
/// Interface to the eviction advisor, which is responsible for making a
/// decision as to which live ranges should be evicted (if any).
+class RAGreedy;
class RegAllocEvictionAdvisor {
public:
RegAllocEvictionAdvisor(const RegAllocEvictionAdvisor &) = delete;
@@ -193,14 +115,12 @@ class RegAllocEvictionAdvisor {
bool isUnusedCalleeSavedReg(MCRegister PhysReg) const;
protected:
- RegAllocEvictionAdvisor(const MachineFunction &MF, LiveRegMatrix *Matrix,
- LiveIntervals *LIS, VirtRegMap *VRM,
- const RegisterClassInfo &RegClassInfo,
- ExtraRegInfo *ExtraInfo);
+ RegAllocEvictionAdvisor(const MachineFunction &MF, const RAGreedy &RA);
Register canReassign(LiveInterval &VirtReg, Register PrevReg) const;
const MachineFunction &MF;
+ const RAGreedy &RA;
LiveRegMatrix *const Matrix;
LiveIntervals *const LIS;
VirtRegMap *const VRM;
@@ -208,7 +128,6 @@ class RegAllocEvictionAdvisor {
const TargetRegisterInfo *const TRI;
const RegisterClassInfo &RegClassInfo;
const ArrayRef<uint8_t> RegCosts;
- ExtraRegInfo *const ExtraInfo;
/// Run or not the local reassignment heuristic. This information is
/// obtained from the TargetSubtargetInfo.
@@ -243,10 +162,7 @@ class RegAllocEvictionAdvisorAnalysis : public ImmutablePass {
/// Get an advisor for the given context (i.e. machine function, etc)
virtual std::unique_ptr<RegAllocEvictionAdvisor>
- getAdvisor(const MachineFunction &MF, LiveRegMatrix *Matrix,
- LiveIntervals *LIS, VirtRegMap *VRM,
- const RegisterClassInfo &RegClassInfo,
- ExtraRegInfo *ExtraInfo) = 0;
+ getAdvisor(const MachineFunction &MF, const RAGreedy &RA) = 0;
AdvisorMode getAdvisorMode() const { return Mode; }
private:
@@ -277,12 +193,8 @@ RegAllocEvictionAdvisorAnalysis *createDevelopmentModeAdvisor();
// out of RegAllocGreedy.cpp
class DefaultEvictionAdvisor : public RegAllocEvictionAdvisor {
public:
- DefaultEvictionAdvisor(const MachineFunction &MF, LiveRegMatrix *Matrix,
- LiveIntervals *LIS, VirtRegMap *VRM,
- const RegisterClassInfo &RegClassInfo,
- ExtraRegInfo *ExtraInfo)
- : RegAllocEvictionAdvisor(MF, Matrix, LIS, VRM, RegClassInfo, ExtraInfo) {
- }
+ DefaultEvictionAdvisor(const MachineFunction &MF, const RAGreedy &RA)
+ : RegAllocEvictionAdvisor(MF, RA) {}
private:
MCRegister tryFindEvictionCandidate(LiveInterval &, const AllocationOrder &,
diff --git a/llvm/lib/CodeGen/RegAllocGreedy.cpp b/llvm/lib/CodeGen/RegAllocGreedy.cpp
index 7088c944f5b1b..7b1f6d156625d 100644
--- a/llvm/lib/CodeGen/RegAllocGreedy.cpp
+++ b/llvm/lib/CodeGen/RegAllocGreedy.cpp
@@ -258,7 +258,7 @@ void RAGreedy::LRE_DidCloneVirtReg(Register New, Register Old) {
ExtraInfo->LRE_DidCloneVirtReg(New, Old);
}
-void ExtraRegInfo::LRE_DidCloneVirtReg(Register New, Register Old) {
+void RAGreedy::ExtraRegInfo::LRE_DidCloneVirtReg(Register New, Register Old) {
// Cloning a register we haven't even heard about yet? Just ignore it.
if (!Info.inBounds(Old))
return;
@@ -456,7 +456,7 @@ Register RegAllocEvictionAdvisor::canReassign(LiveInterval &VirtReg,
bool DefaultEvictionAdvisor::shouldEvict(LiveInterval &A, bool IsHint,
LiveInterval &B,
bool BreaksHint) const {
- bool CanSplit = ExtraInfo->getStage(B) < RS_Spill;
+ bool CanSplit = RA.getExtraInfo().getStage(B) < RS_Spill;
// Be fairly aggressive about following hints as long as the evictee can be
// split.
@@ -506,7 +506,7 @@ bool DefaultEvictionAdvisor::canEvictInterferenceBasedOnCost(
//
// This works out so a register without a cascade number is allowed to evict
// anything, and it can be evicted by anything.
- unsigned Cascade = ExtraInfo->getCascadeOrCurrentNext(VirtReg.reg());
+ unsigned Cascade = RA.getExtraInfo().getCascadeOrCurrentNext(VirtReg.reg());
EvictionCost Cost;
for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units) {
@@ -528,7 +528,7 @@ bool DefaultEvictionAdvisor::canEvictInterferenceBasedOnCost(
return false;
// Never evict spill products. They cannot split or spill.
- if (ExtraInfo->getStage(*Intf) == RS_Done)
+ if (RA.getExtraInfo().getStage(*Intf) == RS_Done)
return false;
// Once a live range becomes small enough, it is urgent that we find a
// register for it. This is indicated by an infinite spill weight. These
@@ -543,7 +543,7 @@ bool DefaultEvictionAdvisor::canEvictInterferenceBasedOnCost(
RegClassInfo.getNumAllocatableRegs(
MRI->getRegClass(Intf->reg())));
// Only evict older cascades or live ranges without a cascade.
- unsigned IntfCascade = ExtraInfo->getCascade(Intf->reg());
+ unsigned IntfCascade = RA.getExtraInfo().getCascade(Intf->reg());
if (Cascade <= IntfCascade) {
if (!Urgent)
return false;
@@ -2914,8 +2914,8 @@ bool RAGreedy::runOnMachineFunction(MachineFunction &mf) {
SA.reset(new SplitAnalysis(*VRM, *LIS, *Loops));
SE.reset(new SplitEditor(*SA, *AA, *LIS, *VRM, *DomTree, *MBFI, *VRAI));
ExtraInfo.emplace();
- EvictAdvisor = getAnalysis<RegAllocEvictionAdvisorAnalysis>().getAdvisor(
- *MF, Matrix, LIS, VRM, RegClassInfo, &*ExtraInfo);
+ EvictAdvisor =
+ getAnalysis<RegAllocEvictionAdvisorAnalysis>().getAdvisor(*MF, *this);
IntfCache.init(MF, Matrix->getLiveUnions(), Indexes, LIS, TRI);
GlobalCand.resize(32); // This will grow as needed.
SetOfBrokenHints.clear();
diff --git a/llvm/lib/CodeGen/RegAllocGreedy.h b/llvm/lib/CodeGen/RegAllocGreedy.h
index 3d8f541bc5e7a..bb8c3e7a5b461 100644
--- a/llvm/lib/CodeGen/RegAllocGreedy.h
+++ b/llvm/lib/CodeGen/RegAllocGreedy.h
@@ -72,6 +72,93 @@ namespace llvm {
class LLVM_LIBRARY_VISIBILITY RAGreedy : public MachineFunctionPass,
public RegAllocBase,
private LiveRangeEdit::Delegate {
+ // Interface to eviction advisers
+public:
+ /// Track allocation stage and eviction loop prevention during allocation.
+ class ExtraRegInfo final {
+ // RegInfo - Keep additional information about each live range.
+ struct RegInfo {
+ LiveRangeStage Stage = RS_New;
+
+ // Cascade - Eviction loop prevention. See
+ // canEvictInterferenceBasedOnCost().
+ unsigned Cascade = 0;
+
+ RegInfo() = default;
+ };
+
+ IndexedMap<RegInfo, VirtReg2IndexFunctor> Info;
+ unsigned NextCascade = 1;
+
+ public:
+ ExtraRegInfo() = default;
+ ExtraRegInfo(const ExtraRegInfo &) = delete;
+
+ LiveRangeStage getStage(Register Reg) const { return Info[Reg].Stage; }
+
+ LiveRangeStage getStage(const LiveInterval &VirtReg) const {
+ return getStage(VirtReg.reg());
+ }
+
+ void setStage(Register Reg, LiveRangeStage Stage) {
+ Info.grow(Reg.id());
+ Info[Reg].Stage = Stage;
+ }
+
+ void setStage(const LiveInterval &VirtReg, LiveRangeStage Stage) {
+ setStage(VirtReg.reg(), Stage);
+ }
+
+ /// Return the current stage of the register, if present, otherwise
+ /// initialize it and return that.
+ LiveRangeStage getOrInitStage(Register Reg) {
+ Info.grow(Reg.id());
+ return getStage(Reg);
+ }
+
+ unsigned getCascade(Register Reg) const { return Info[Reg].Cascade; }
+
+ void setCascade(Register Reg, unsigned Cascade) {
+ Info.grow(Reg.id());
+ Info[Reg].Cascade = Cascade;
+ }
+
+ unsigned getOrAssignNewCascade(Register Reg) {
+ unsigned Cascade = getCascade(Reg);
+ if (!Cascade) {
+ Cascade = NextCascade++;
+ setCascade(Reg, Cascade);
+ }
+ return Cascade;
+ }
+
+ unsigned getCascadeOrCurrentNext(Register Reg) const {
+ unsigned Cascade = getCascade(Reg);
+ if (!Cascade)
+ Cascade = NextCascade;
+ return Cascade;
+ }
+
+ template <typename Iterator>
+ void setStage(Iterator Begin, Iterator End, LiveRangeStage NewStage) {
+ for (; Begin != End; ++Begin) {
+ Register Reg = *Begin;
+ Info.grow(Reg.id());
+ if (Info[Reg].Stage == RS_New)
+ Info[Reg].Stage = NewStage;
+ }
+ }
+ void LRE_DidCloneVirtReg(Register New, Register Old);
+ };
+
+ LiveRegMatrix *getInterferenceMatrix() const { return Matrix; }
+ LiveIntervals *getLiveIntervals() const { return LIS; }
+ VirtRegMap *getVirtRegMap() const { return VRM; }
+ const RegisterClassInfo &getRegClassInfo() const { return RegClassInfo; }
+ const ExtraRegInfo &getExtraInfo() const { return *ExtraInfo; }
+ // end (interface to eviction advisers)
+
+private:
// Convenient shortcuts.
using PQueue = std::priority_queue<std::pair<unsigned, unsigned>>;
using SmallLISet = SmallPtrSet<LiveInterval *, 4>;
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