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-rw-r--r--lib/CodeGen/AggressiveAntiDepBreaker.cpp68
1 files changed, 40 insertions, 28 deletions
diff --git a/lib/CodeGen/AggressiveAntiDepBreaker.cpp b/lib/CodeGen/AggressiveAntiDepBreaker.cpp
index 2ee776711587..44345addbcb6 100644
--- a/lib/CodeGen/AggressiveAntiDepBreaker.cpp
+++ b/lib/CodeGen/AggressiveAntiDepBreaker.cpp
@@ -14,7 +14,6 @@
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "post-RA-sched"
#include "AggressiveAntiDepBreaker.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
@@ -29,6 +28,8 @@
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;
+#define DEBUG_TYPE "post-RA-sched"
+
// If DebugDiv > 0 then only break antidep with (ID % DebugDiv) == DebugMod
static cl::opt<int>
DebugDiv("agg-antidep-debugdiv",
@@ -121,7 +122,7 @@ AggressiveAntiDepBreaker(MachineFunction& MFi,
TII(MF.getTarget().getInstrInfo()),
TRI(MF.getTarget().getRegisterInfo()),
RegClassInfo(RCI),
- State(NULL) {
+ State(nullptr) {
/* Collect a bitset of all registers that are only broken if they
are on the critical path. */
for (unsigned i = 0, e = CriticalPathRCs.size(); i < e; ++i) {
@@ -144,7 +145,7 @@ AggressiveAntiDepBreaker::~AggressiveAntiDepBreaker() {
}
void AggressiveAntiDepBreaker::StartBlock(MachineBasicBlock *BB) {
- assert(State == NULL);
+ assert(!State);
State = new AggressiveAntiDepState(TRI->getNumRegs(), BB);
bool IsReturnBlock = (!BB->empty() && BB->back().isReturn());
@@ -169,7 +170,7 @@ void AggressiveAntiDepBreaker::StartBlock(MachineBasicBlock *BB) {
// callee-saved register that is not saved in the prolog.
const MachineFrameInfo *MFI = MF.getFrameInfo();
BitVector Pristine = MFI->getPristineRegs(BB);
- for (const uint16_t *I = TRI->getCalleeSavedRegs(&MF); *I; ++I) {
+ for (const MCPhysReg *I = TRI->getCalleeSavedRegs(&MF); *I; ++I) {
unsigned Reg = *I;
if (!IsReturnBlock && !Pristine.test(Reg)) continue;
for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) {
@@ -183,7 +184,7 @@ void AggressiveAntiDepBreaker::StartBlock(MachineBasicBlock *BB) {
void AggressiveAntiDepBreaker::FinishBlock() {
delete State;
- State = NULL;
+ State = nullptr;
}
void AggressiveAntiDepBreaker::Observe(MachineInstr *MI, unsigned Count,
@@ -230,13 +231,13 @@ bool AggressiveAntiDepBreaker::IsImplicitDefUse(MachineInstr *MI,
if (Reg == 0)
return false;
- MachineOperand *Op = NULL;
+ MachineOperand *Op = nullptr;
if (MO.isDef())
Op = MI->findRegisterUseOperand(Reg, true);
else
Op = MI->findRegisterDefOperand(Reg);
- return((Op != NULL) && Op->isImplicit());
+ return(Op && Op->isImplicit());
}
void AggressiveAntiDepBreaker::GetPassthruRegs(MachineInstr *MI,
@@ -273,10 +274,10 @@ static void AntiDepEdges(const SUnit *SU, std::vector<const SDep*>& Edges) {
/// CriticalPathStep - Return the next SUnit after SU on the bottom-up
/// critical path.
static const SUnit *CriticalPathStep(const SUnit *SU) {
- const SDep *Next = 0;
+ const SDep *Next = nullptr;
unsigned NextDepth = 0;
// Find the predecessor edge with the greatest depth.
- if (SU != 0) {
+ if (SU) {
for (SUnit::const_pred_iterator P = SU->Preds.begin(), PE = SU->Preds.end();
P != PE; ++P) {
const SUnit *PredSU = P->getSUnit();
@@ -292,7 +293,7 @@ static const SUnit *CriticalPathStep(const SUnit *SU) {
}
}
- return (Next) ? Next->getSUnit() : 0;
+ return (Next) ? Next->getSUnit() : nullptr;
}
void AggressiveAntiDepBreaker::HandleLastUse(unsigned Reg, unsigned KillIdx,
@@ -309,8 +310,8 @@ void AggressiveAntiDepBreaker::HandleLastUse(unsigned Reg, unsigned KillIdx,
DefIndices[Reg] = ~0u;
RegRefs.erase(Reg);
State->LeaveGroup(Reg);
- DEBUG(if (header != NULL) {
- dbgs() << header << TRI->getName(Reg); header = NULL; });
+ DEBUG(if (header) {
+ dbgs() << header << TRI->getName(Reg); header = nullptr; });
DEBUG(dbgs() << "->g" << State->GetGroup(Reg) << tag);
}
// Repeat for subregisters.
@@ -321,14 +322,14 @@ void AggressiveAntiDepBreaker::HandleLastUse(unsigned Reg, unsigned KillIdx,
DefIndices[SubregReg] = ~0u;
RegRefs.erase(SubregReg);
State->LeaveGroup(SubregReg);
- DEBUG(if (header != NULL) {
- dbgs() << header << TRI->getName(Reg); header = NULL; });
+ DEBUG(if (header) {
+ dbgs() << header << TRI->getName(Reg); header = nullptr; });
DEBUG(dbgs() << " " << TRI->getName(SubregReg) << "->g" <<
State->GetGroup(SubregReg) << tag);
}
}
- DEBUG(if ((header == NULL) && (footer != NULL)) dbgs() << footer);
+ DEBUG(if (!header && footer) dbgs() << footer);
}
void AggressiveAntiDepBreaker::PrescanInstruction(MachineInstr *MI,
@@ -382,7 +383,7 @@ void AggressiveAntiDepBreaker::PrescanInstruction(MachineInstr *MI,
}
// Note register reference...
- const TargetRegisterClass *RC = NULL;
+ const TargetRegisterClass *RC = nullptr;
if (i < MI->getDesc().getNumOperands())
RC = TII->getRegClass(MI->getDesc(), i, TRI, MF);
AggressiveAntiDepState::RegisterReference RR = { &MO, RC };
@@ -403,8 +404,18 @@ void AggressiveAntiDepBreaker::PrescanInstruction(MachineInstr *MI,
continue;
// Update def for Reg and aliases.
- for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
+ for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) {
+ // We need to be careful here not to define already-live super registers.
+ // If the super register is already live, then this definition is not
+ // a definition of the whole super register (just a partial insertion
+ // into it). Earlier subregister definitions (which we've not yet visited
+ // because we're iterating bottom-up) need to be linked to the same group
+ // as this definition.
+ if (TRI->isSuperRegister(Reg, *AI) && State->IsLive(*AI))
+ continue;
+
DefIndices[*AI] = Count;
+ }
}
}
@@ -456,7 +467,7 @@ void AggressiveAntiDepBreaker::ScanInstruction(MachineInstr *MI,
}
// Note register reference...
- const TargetRegisterClass *RC = NULL;
+ const TargetRegisterClass *RC = nullptr;
if (i < MI->getDesc().getNumOperands())
RC = TII->getRegClass(MI->getDesc(), i, TRI, MF);
AggressiveAntiDepState::RegisterReference RR = { &MO, RC };
@@ -506,7 +517,7 @@ BitVector AggressiveAntiDepBreaker::GetRenameRegisters(unsigned Reg) {
AggressiveAntiDepState::RegisterReference>::iterator Q = Range.first,
QE = Range.second; Q != QE; ++Q) {
const TargetRegisterClass *RC = Q->second.RC;
- if (RC == NULL) continue;
+ if (!RC) continue;
BitVector RCBV = TRI->getAllocatableSet(MF, RC);
if (first) {
@@ -571,7 +582,9 @@ bool AggressiveAntiDepBreaker::FindSuitableFreeRegisters(
unsigned Reg = Regs[i];
if (Reg == SuperReg) continue;
bool IsSub = TRI->isSubRegister(SuperReg, Reg);
- assert(IsSub && "Expecting group subregister");
+ // FIXME: remove this once PR18663 has been properly fixed. For now,
+ // return a conservative answer:
+ // assert(IsSub && "Expecting group subregister");
if (!IsSub)
return false;
}
@@ -724,8 +737,8 @@ unsigned AggressiveAntiDepBreaker::BreakAntiDependencies(
// Track progress along the critical path through the SUnit graph as
// we walk the instructions. This is needed for regclasses that only
// break critical-path anti-dependencies.
- const SUnit *CriticalPathSU = 0;
- MachineInstr *CriticalPathMI = 0;
+ const SUnit *CriticalPathSU = nullptr;
+ MachineInstr *CriticalPathMI = nullptr;
if (CriticalPathSet.any()) {
for (unsigned i = 0, e = SUnits.size(); i != e; ++i) {
const SUnit *SU = &SUnits[i];
@@ -778,10 +791,10 @@ unsigned AggressiveAntiDepBreaker::BreakAntiDependencies(
// If MI is not on the critical path, then we don't rename
// registers in the CriticalPathSet.
- BitVector *ExcludeRegs = NULL;
+ BitVector *ExcludeRegs = nullptr;
if (MI == CriticalPathMI) {
CriticalPathSU = CriticalPathStep(CriticalPathSU);
- CriticalPathMI = (CriticalPathSU) ? CriticalPathSU->getInstr() : 0;
+ CriticalPathMI = (CriticalPathSU) ? CriticalPathSU->getInstr() : nullptr;
} else if (CriticalPathSet.any()) {
ExcludeRegs = &CriticalPathSet;
}
@@ -805,7 +818,7 @@ unsigned AggressiveAntiDepBreaker::BreakAntiDependencies(
// Don't break anti-dependencies on non-allocatable registers.
DEBUG(dbgs() << " (non-allocatable)\n");
continue;
- } else if ((ExcludeRegs != NULL) && ExcludeRegs->test(AntiDepReg)) {
+ } else if (ExcludeRegs && ExcludeRegs->test(AntiDepReg)) {
// Don't break anti-dependencies for critical path registers
// if not on the critical path
DEBUG(dbgs() << " (not critical-path)\n");
@@ -819,9 +832,8 @@ unsigned AggressiveAntiDepBreaker::BreakAntiDependencies(
} else {
// No anti-dep breaking for implicit deps
MachineOperand *AntiDepOp = MI->findRegisterDefOperand(AntiDepReg);
- assert(AntiDepOp != NULL &&
- "Can't find index for defined register operand");
- if ((AntiDepOp == NULL) || AntiDepOp->isImplicit()) {
+ assert(AntiDepOp && "Can't find index for defined register operand");
+ if (!AntiDepOp || AntiDepOp->isImplicit()) {
DEBUG(dbgs() << " (implicit)\n");
continue;
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-31 22:28:07 +0000