cl::desc("Disable Machine LICM"));
static cl::opt<bool> DisableMachineCSE("disable-machine-cse", cl::Hidden,
cl::desc("Disable Machine Common Subexpression Elimination"));
+static cl::opt<cl::boolOrDefault>
+OptimizeRegAlloc("optimize-regalloc", cl::Hidden,
+ cl::desc("Enable optimized register allocation compilation path."));
+static cl::opt<cl::boolOrDefault>
+EnableMachineSched("enable-misched", cl::Hidden,
+ cl::desc("Enable the machine instruction scheduling pass."));
+static cl::opt<bool> EnableStrongPHIElim("strong-phi-elim", cl::Hidden,
+ cl::desc("Use strong PHI elimination."));
static cl::opt<bool> DisablePostRAMachineLICM("disable-postra-machine-licm",
cl::Hidden,
cl::desc("Disable Machine LICM"));
cl::desc("Verify generated machine code"),
cl::init(getenv("LLVM_VERIFY_MACHINEINSTRS")!=NULL));
+// Allow Pass selection to be overriden by command line options.
+//
+// DefaultID is the default pass to run which may be NoPassID, or may be
+// overriden by the target.
+//
+// OptionalID is a pass that may be forcibly enabled by the user when the
+// default is NoPassID.
+char &enablePass(char &DefaultID, cl::boolOrDefault Override,
+ char *OptionalIDPtr = &NoPassID) {
+ switch (Override) {
+ case cl::BOU_UNSET:
+ return DefaultID;
+ case cl::BOU_TRUE:
+ if (&DefaultID != &NoPassID)
+ return DefaultID;
+ if (OptionalIDPtr == &NoPassID)
+ report_fatal_error("Target cannot enable pass");
+ return *OptionalIDPtr;
+ case cl::BOU_FALSE:
+ return NoPassID;
+ }
+ llvm_unreachable("Invalid command line option state");
+}
+
//===---------------------------------------------------------------------===//
/// TargetPassConfig
//===---------------------------------------------------------------------===//
"Target Pass Configuration", false, false)
char TargetPassConfig::ID = 0;
+static char NoPassIDAnchor = 0;
+char &llvm::NoPassID = NoPassIDAnchor;
+
// Out of line virtual method.
TargetPassConfig::~TargetPassConfig() {}
+// Out of line constructor provides default values for pass options and
+// registers all common codegen passes.
TargetPassConfig::TargetPassConfig(TargetMachine *tm, PassManagerBase &pm)
: ImmutablePass(ID), TM(tm), PM(pm), Initialized(false),
DisableVerify(false),
}
void TargetPassConfig::addPass(char &ID) {
+ if (&ID == &NoPassID)
+ return;
+
// FIXME: check user overrides
Pass *P = Pass::createPass(ID);
if (!P)
PM.add(createVerifierPass());
}
+/// Add the complete set of target-independent postISel code generator passes.
+///
+/// This can be read as the standard order of major LLVM CodeGen stages. Stages
+/// with nontrivial configuration or multiple passes are broken out below in
+/// add%Stage routines.
+///
+/// Any TargetPassConfig::addXX routine may be overriden by the Target. The
+/// addPre/Post methods with empty header implementations allow injecting
+/// target-specific fixups just before or after major stages. Additionally,
+/// targets have the flexibility to change pass order within a stage by
+/// overriding default implementation of add%Stage routines below. Each
+/// technique has maintainability tradeoffs because alternate pass orders are
+/// not well supported. addPre/Post works better if the target pass is easily
+/// tied to a common pass. But if it has subtle dependencies on multiple passes,
+/// the target should override the stage instead.
+///
+/// TODO: We could use a single addPre/Post(ID) hook to allow pass injection
+/// before/after any target-independent pass. But it's currently overkill.
void TargetPassConfig::addMachinePasses() {
// Print the instruction selected machine code...
printAndVerify("After Instruction Selection");
// Expand pseudo-instructions emitted by ISel.
- PM.add(createExpandISelPseudosPass());
-
- // Pre-ra tail duplication.
- if (getOptLevel() != CodeGenOpt::None && !DisableEarlyTailDup) {
- PM.add(createTailDuplicatePass());
- printAndVerify("After Pre-RegAlloc TailDuplicate");
- }
-
- // Optimize PHIs before DCE: removing dead PHI cycles may make more
- // instructions dead.
- if (getOptLevel() != CodeGenOpt::None)
- PM.add(createOptimizePHIsPass());
-
- // If the target requests it, assign local variables to stack slots relative
- // to one another and simplify frame index references where possible.
- PM.add(createLocalStackSlotAllocationPass());
+ addPass(ExpandISelPseudosID);
+ // Add passes that optimize machine instructions in SSA form.
if (getOptLevel() != CodeGenOpt::None) {
- // With optimization, dead code should already be eliminated. However
- // there is one known exception: lowered code for arguments that are only
- // used by tail calls, where the tail calls reuse the incoming stack
- // arguments directly (see t11 in test/CodeGen/X86/sibcall.ll).
- if (!DisableMachineDCE)
- PM.add(createDeadMachineInstructionElimPass());
- printAndVerify("After codegen DCE pass");
-
- if (!DisableMachineLICM)
- PM.add(createMachineLICMPass());
- if (!DisableMachineCSE)
- PM.add(createMachineCSEPass());
- if (!DisableMachineSink)
- PM.add(createMachineSinkingPass());
- printAndVerify("After Machine LICM, CSE and Sinking passes");
-
- PM.add(createPeepholeOptimizerPass());
- printAndVerify("After codegen peephole optimization pass");
+ addMachineSSAOptimization();
+ }
+ else {
+ // If the target requests it, assign local variables to stack slots relative
+ // to one another and simplify frame index references where possible.
+ addPass(LocalStackSlotAllocationID);
}
// Run pre-ra passes.
if (addPreRegAlloc())
printAndVerify("After PreRegAlloc passes");
- // Perform register allocation.
- PM.add(createRegisterAllocator(getOptLevel()));
- printAndVerify("After Register Allocation");
-
- // Perform stack slot coloring and post-ra machine LICM.
- if (getOptLevel() != CodeGenOpt::None) {
- // FIXME: Re-enable coloring with register when it's capable of adding
- // kill markers.
- if (!DisableSSC)
- PM.add(createStackSlotColoringPass(false));
-
- // Run post-ra machine LICM to hoist reloads / remats.
- if (!DisablePostRAMachineLICM)
- PM.add(createMachineLICMPass(false));
-
- printAndVerify("After StackSlotColoring and postra Machine LICM");
- }
+ // Run register allocation and passes that are tightly coupled with it,
+ // including phi elimination and scheduling.
+ if (getOptimizeRegAlloc())
+ addOptimizedRegAlloc(createRegAllocPass(true));
+ else
+ addFastRegAlloc(createRegAllocPass(false));
// Run post-ra passes.
if (addPostRegAlloc())
printAndVerify("After PostRegAlloc passes");
// Insert prolog/epilog code. Eliminate abstract frame index references...
- PM.add(createPrologEpilogCodeInserter());
+ addPass(PrologEpilogCodeInserterID);
printAndVerify("After PrologEpilogCodeInserter");
- // Branch folding must be run after regalloc and prolog/epilog insertion.
- if (getOptLevel() != CodeGenOpt::None && !DisableBranchFold) {
- PM.add(createBranchFoldingPass(getEnableTailMergeDefault()));
- printNoVerify("After BranchFolding");
- }
-
- // Tail duplication.
- if (getOptLevel() != CodeGenOpt::None && !DisableTailDuplicate) {
- PM.add(createTailDuplicatePass());
- printNoVerify("After TailDuplicate");
- }
-
- // Copy propagation.
- if (getOptLevel() != CodeGenOpt::None && !DisableCopyProp) {
- PM.add(createMachineCopyPropagationPass());
- printNoVerify("After copy propagation pass");
- }
+ /// Add passes that optimize machine instructions after register allocation.
+ if (getOptLevel() != CodeGenOpt::None)
+ addMachineLateOptimization();
// Expand pseudo instructions before second scheduling pass.
- PM.add(createExpandPostRAPseudosPass());
+ addPass(ExpandPostRAPseudosID);
printNoVerify("After ExpandPostRAPseudos");
// Run pre-sched2 passes.
// Second pass scheduler.
if (getOptLevel() != CodeGenOpt::None && !DisablePostRA) {
- PM.add(createPostRAScheduler(getOptLevel()));
+ addPass(PostRASchedulerID);
printNoVerify("After PostRAScheduler");
}
- PM.add(createGCMachineCodeAnalysisPass());
-
+ // GC
+ addPass(GCMachineCodeAnalysisID);
if (PrintGCInfo)
PM.add(createGCInfoPrinter(dbgs()));
- if (getOptLevel() != CodeGenOpt::None && !DisableCodePlace) {
- if (EnableBlockPlacement) {
- // MachineBlockPlacement is an experimental pass which is disabled by
- // default currently. Eventually it should subsume CodePlacementOpt, so
- // when enabled, the other is disabled.
- PM.add(createMachineBlockPlacementPass());
- printNoVerify("After MachineBlockPlacement");
- } else {
- PM.add(createCodePlacementOptPass());
- printNoVerify("After CodePlacementOpt");
- }
-
- // Run a separate pass to collect block placement statistics.
- if (EnableBlockPlacementStats) {
- PM.add(createMachineBlockPlacementStatsPass());
- printNoVerify("After MachineBlockPlacementStats");
- }
- }
+ // Basic block placement.
+ if (getOptLevel() != CodeGenOpt::None && !DisableCodePlace)
+ addBlockPlacement();
if (addPreEmitPass())
printNoVerify("After PreEmit passes");
}
+/// Add passes that optimize machine instructions in SSA form.
+void TargetPassConfig::addMachineSSAOptimization() {
+ // Pre-ra tail duplication.
+ if (!DisableEarlyTailDup) {
+ addPass(TailDuplicateID);
+ printAndVerify("After Pre-RegAlloc TailDuplicate");
+ }
+
+ // Optimize PHIs before DCE: removing dead PHI cycles may make more
+ // instructions dead.
+ addPass(OptimizePHIsID);
+
+ // If the target requests it, assign local variables to stack slots relative
+ // to one another and simplify frame index references where possible.
+ addPass(LocalStackSlotAllocationID);
+
+ // With optimization, dead code should already be eliminated. However
+ // there is one known exception: lowered code for arguments that are only
+ // used by tail calls, where the tail calls reuse the incoming stack
+ // arguments directly (see t11 in test/CodeGen/X86/sibcall.ll).
+ if (!DisableMachineDCE)
+ addPass(DeadMachineInstructionElimID);
+ printAndVerify("After codegen DCE pass");
+
+ if (!DisableMachineLICM)
+ addPass(MachineLICMID);
+ if (!DisableMachineCSE)
+ addPass(MachineCSEID);
+ if (!DisableMachineSink)
+ addPass(MachineSinkingID);
+ printAndVerify("After Machine LICM, CSE and Sinking passes");
+
+ addPass(PeepholeOptimizerID);
+ printAndVerify("After codegen peephole optimization pass");
+}
+
//===---------------------------------------------------------------------===//
-///
-/// RegisterRegAlloc class - Track the registration of register allocators.
-///
+/// Register Allocation Pass Configuration
//===---------------------------------------------------------------------===//
+
+bool TargetPassConfig::getOptimizeRegAlloc() const {
+ switch (OptimizeRegAlloc) {
+ case cl::BOU_UNSET: return getOptLevel() != CodeGenOpt::None;
+ case cl::BOU_TRUE: return true;
+ case cl::BOU_FALSE: return false;
+ }
+ llvm_unreachable("Invalid optimize-regalloc state");
+}
+
+/// RegisterRegAlloc's global Registry tracks allocator registration.
MachinePassRegistry RegisterRegAlloc::Registry;
-static FunctionPass *createDefaultRegisterAllocator() { return 0; }
+/// A dummy default pass factory indicates whether the register allocator is
+/// overridden on the command line.
+static FunctionPass *useDefaultRegisterAllocator() { return 0; }
static RegisterRegAlloc
defaultRegAlloc("default",
"pick register allocator based on -O option",
- createDefaultRegisterAllocator);
+ useDefaultRegisterAllocator);
-//===---------------------------------------------------------------------===//
-///
-/// RegAlloc command line options.
-///
-//===---------------------------------------------------------------------===//
+/// -regalloc=... command line option.
static cl::opt<RegisterRegAlloc::FunctionPassCtor, false,
RegisterPassParser<RegisterRegAlloc> >
RegAlloc("regalloc",
- cl::init(&createDefaultRegisterAllocator),
+ cl::init(&useDefaultRegisterAllocator),
cl::desc("Register allocator to use"));
-//===---------------------------------------------------------------------===//
+/// Instantiate the default register allocator pass for this target for either
+/// the optimized or unoptimized allocation path. This will be added to the pass
+/// manager by addFastRegAlloc in the unoptimized case or addOptimizedRegAlloc
+/// in the optimized case.
+///
+/// A target that uses the standard regalloc pass order for fast or optimized
+/// allocation may still override this for per-target regalloc
+/// selection. But -regalloc=... always takes precedence.
+FunctionPass *TargetPassConfig::createTargetRegisterAllocator(bool Optimized) {
+ if (Optimized)
+ return createGreedyRegisterAllocator();
+ else
+ return createFastRegisterAllocator();
+}
+
+/// Find and instantiate the register allocation pass requested by this target
+/// at the current optimization level. Different register allocators are
+/// defined as separate passes because they may require different analysis.
///
-/// createRegisterAllocator - choose the appropriate register allocator.
+/// This helper ensures that the regalloc= option is always available,
+/// even for targets that override the default allocator.
///
-//===---------------------------------------------------------------------===//
-FunctionPass *llvm::createRegisterAllocator(CodeGenOpt::Level OptLevel) {
+/// FIXME: When MachinePassRegistry register pass IDs instead of function ptrs,
+/// this can be folded into addPass.
+FunctionPass *TargetPassConfig::createRegAllocPass(bool Optimized) {
RegisterRegAlloc::FunctionPassCtor Ctor = RegisterRegAlloc::getDefault();
+ // Initialize the global default.
if (!Ctor) {
Ctor = RegAlloc;
RegisterRegAlloc::setDefault(RegAlloc);
}
-
- if (Ctor != createDefaultRegisterAllocator)
+ if (Ctor != useDefaultRegisterAllocator)
return Ctor();
- // When the 'default' allocator is requested, pick one based on OptLevel.
- switch (OptLevel) {
- case CodeGenOpt::None:
- return createFastRegisterAllocator();
- default:
- return createGreedyRegisterAllocator();
+ // With no -regalloc= override, ask the target for a regalloc pass.
+ return createTargetRegisterAllocator(Optimized);
+}
+
+/// Add the minimum set of target-independent passes that are required for
+/// register allocation. No coalescing or scheduling.
+void TargetPassConfig::addFastRegAlloc(FunctionPass *RegAllocPass) {
+ addPass(PHIEliminationID);
+ addPass(TwoAddressInstructionPassID);
+
+ PM.add(RegAllocPass);
+ printAndVerify("After Register Allocation");
+}
+
+/// Add standard target-independent passes that are tightly coupled with
+/// optimized register allocation, including coalescing, machine instruction
+/// scheduling, and register allocation itself.
+void TargetPassConfig::addOptimizedRegAlloc(FunctionPass *RegAllocPass) {
+ // LiveVariables currently requires pure SSA form.
+ //
+ // FIXME: Once TwoAddressInstruction pass no longer uses kill flags,
+ // LiveVariables can be removed completely, and LiveIntervals can be directly
+ // computed. (We still either need to regenerate kill flags after regalloc, or
+ // preferably fix the scavenger to not depend on them).
+ addPass(LiveVariablesID);
+
+ // Add passes that move from transformed SSA into conventional SSA. This is a
+ // "copy coalescing" problem.
+ //
+ if (!EnableStrongPHIElim) {
+ // Edge splitting is smarter with machine loop info.
+ addPass(MachineLoopInfoID);
+ addPass(PHIEliminationID);
+ }
+ addPass(TwoAddressInstructionPassID);
+
+ // FIXME: Either remove this pass completely, or fix it so that it works on
+ // SSA form. We could modify LiveIntervals to be independent of this pass, But
+ // it would be even better to simply eliminate *all* IMPLICIT_DEFs before
+ // leaving SSA.
+ addPass(ProcessImplicitDefsID);
+
+ if (EnableStrongPHIElim)
+ addPass(StrongPHIEliminationID);
+
+ addPass(RegisterCoalescerID);
+
+ // PreRA instruction scheduling.
+ addPass(enablePass(getSchedPass(), EnableMachineSched, &MachineSchedulerID));
+
+ // Add the selected register allocation pass.
+ PM.add(RegAllocPass);
+ printAndVerify("After Register Allocation");
+
+ // FinalizeRegAlloc is convenient until MachineInstrBundles is more mature,
+ // but eventually, all users of it should probably be moved to addPostRA and
+ // it can go away. Currently, it's the intended place for targets to run
+ // FinalizeMachineBundles, because passes other than MachineScheduling an
+ // RegAlloc itself may not be aware of bundles.
+ if (addFinalizeRegAlloc())
+ printAndVerify("After RegAlloc finalization");
+
+ // Perform stack slot coloring and post-ra machine LICM.
+ //
+ // FIXME: Re-enable coloring with register when it's capable of adding
+ // kill markers.
+ if (!DisableSSC)
+ addPass(StackSlotColoringID);
+
+ // Run post-ra machine LICM to hoist reloads / remats.
+ //
+ // FIXME: can this move into MachineLateOptimization?
+ if (!DisablePostRAMachineLICM)
+ addPass(MachineLICMID);
+
+ printAndVerify("After StackSlotColoring and postra Machine LICM");
+}
+
+//===---------------------------------------------------------------------===//
+/// Post RegAlloc Pass Configuration
+//===---------------------------------------------------------------------===//
+
+/// Add passes that optimize machine instructions after register allocation.
+void TargetPassConfig::addMachineLateOptimization() {
+ // Branch folding must be run after regalloc and prolog/epilog insertion.
+ if (!DisableBranchFold) {
+ addPass(BranchFolderPassID);
+ printNoVerify("After BranchFolding");
+ }
+
+ // Tail duplication.
+ if (!DisableTailDuplicate) {
+ addPass(TailDuplicateID);
+ printNoVerify("After TailDuplicate");
+ }
+
+ // Copy propagation.
+ if (!DisableCopyProp) {
+ addPass(MachineCopyPropagationID);
+ printNoVerify("After copy propagation pass");
+ }
+}
+
+/// Add standard basic block placement passes.
+void TargetPassConfig::addBlockPlacement() {
+ if (EnableBlockPlacement) {
+ // MachineBlockPlacement is an experimental pass which is disabled by
+ // default currently. Eventually it should subsume CodePlacementOpt, so
+ // when enabled, the other is disabled.
+ addPass(MachineBlockPlacementID);
+ printNoVerify("After MachineBlockPlacement");
+ } else {
+ addPass(CodePlacementOptID);
+ printNoVerify("After CodePlacementOpt");
+ }
+
+ // Run a separate pass to collect block placement statistics.
+ if (EnableBlockPlacementStats) {
+ addPass(MachineBlockPlacementStatsID);
+ printNoVerify("After MachineBlockPlacementStats");
}
}
projects / oota-llvm.git / blobdiff