Move the FunctionLoweringInfo class and some related utility functions out
of SelectionDAGBuild.h/cpp into its own files, to help separate
general lowering logic from SelectionDAG-specific lowering logic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89667 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index f953a74..238a036 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -13,11 +13,11 @@
#define DEBUG_TYPE "isel"
#include "SelectionDAGBuild.h"
+#include "FunctionLoweringInfo.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Constants.h"
-#include "llvm/Constants.h"
#include "llvm/CallingConv.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
@@ -68,84 +68,6 @@
cl::location(LimitFloatPrecision),
cl::init(0));
-/// ComputeLinearIndex - Given an LLVM IR aggregate type and a sequence
-/// of insertvalue or extractvalue indices that identify a member, return
-/// the linearized index of the start of the member.
-///
-static unsigned ComputeLinearIndex(const TargetLowering &TLI, const Type *Ty,
- const unsigned *Indices,
- const unsigned *IndicesEnd,
- unsigned CurIndex = 0) {
- // Base case: We're done.
- if (Indices && Indices == IndicesEnd)
- return CurIndex;
-
- // Given a struct type, recursively traverse the elements.
- if (const StructType *STy = dyn_cast<StructType>(Ty)) {
- for (StructType::element_iterator EB = STy->element_begin(),
- EI = EB,
- EE = STy->element_end();
- EI != EE; ++EI) {
- if (Indices && *Indices == unsigned(EI - EB))
- return ComputeLinearIndex(TLI, *EI, Indices+1, IndicesEnd, CurIndex);
- CurIndex = ComputeLinearIndex(TLI, *EI, 0, 0, CurIndex);
- }
- return CurIndex;
- }
- // Given an array type, recursively traverse the elements.
- else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
- const Type *EltTy = ATy->getElementType();
- for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i) {
- if (Indices && *Indices == i)
- return ComputeLinearIndex(TLI, EltTy, Indices+1, IndicesEnd, CurIndex);
- CurIndex = ComputeLinearIndex(TLI, EltTy, 0, 0, CurIndex);
- }
- return CurIndex;
- }
- // We haven't found the type we're looking for, so keep searching.
- return CurIndex + 1;
-}
-
-/// ComputeValueVTs - Given an LLVM IR type, compute a sequence of
-/// EVTs that represent all the individual underlying
-/// non-aggregate types that comprise it.
-///
-/// If Offsets is non-null, it points to a vector to be filled in
-/// with the in-memory offsets of each of the individual values.
-///
-static void ComputeValueVTs(const TargetLowering &TLI, const Type *Ty,
- SmallVectorImpl<EVT> &ValueVTs,
- SmallVectorImpl<uint64_t> *Offsets = 0,
- uint64_t StartingOffset = 0) {
- // Given a struct type, recursively traverse the elements.
- if (const StructType *STy = dyn_cast<StructType>(Ty)) {
- const StructLayout *SL = TLI.getTargetData()->getStructLayout(STy);
- for (StructType::element_iterator EB = STy->element_begin(),
- EI = EB,
- EE = STy->element_end();
- EI != EE; ++EI)
- ComputeValueVTs(TLI, *EI, ValueVTs, Offsets,
- StartingOffset + SL->getElementOffset(EI - EB));
- return;
- }
- // Given an array type, recursively traverse the elements.
- if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
- const Type *EltTy = ATy->getElementType();
- uint64_t EltSize = TLI.getTargetData()->getTypeAllocSize(EltTy);
- for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
- ComputeValueVTs(TLI, EltTy, ValueVTs, Offsets,
- StartingOffset + i * EltSize);
- return;
- }
- // Interpret void as zero return values.
- if (Ty == Type::getVoidTy(Ty->getContext()))
- return;
- // Base case: we can get an EVT for this LLVM IR type.
- ValueVTs.push_back(TLI.getValueType(Ty));
- if (Offsets)
- Offsets->push_back(StartingOffset);
-}
-
namespace llvm {
/// RegsForValue - This struct represents the registers (physical or virtual)
/// that a particular set of values is assigned, and the type information about
@@ -241,150 +163,6 @@
};
}
-/// isUsedOutsideOfDefiningBlock - Return true if this instruction is used by
-/// PHI nodes or outside of the basic block that defines it, or used by a
-/// switch or atomic instruction, which may expand to multiple basic blocks.
-static bool isUsedOutsideOfDefiningBlock(Instruction *I) {
- if (isa<PHINode>(I)) return true;
- BasicBlock *BB = I->getParent();
- for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; ++UI)
- if (cast<Instruction>(*UI)->getParent() != BB || isa<PHINode>(*UI))
- return true;
- return false;
-}
-
-/// isOnlyUsedInEntryBlock - If the specified argument is only used in the
-/// entry block, return true. This includes arguments used by switches, since
-/// the switch may expand into multiple basic blocks.
-static bool isOnlyUsedInEntryBlock(Argument *A, bool EnableFastISel) {
- // With FastISel active, we may be splitting blocks, so force creation
- // of virtual registers for all non-dead arguments.
- // Don't force virtual registers for byval arguments though, because
- // fast-isel can't handle those in all cases.
- if (EnableFastISel && !A->hasByValAttr())
- return A->use_empty();
-
- BasicBlock *Entry = A->getParent()->begin();
- for (Value::use_iterator UI = A->use_begin(), E = A->use_end(); UI != E; ++UI)
- if (cast<Instruction>(*UI)->getParent() != Entry || isa<SwitchInst>(*UI))
- return false; // Use not in entry block.
- return true;
-}
-
-FunctionLoweringInfo::FunctionLoweringInfo(TargetLowering &tli)
- : TLI(tli) {
-}
-
-void FunctionLoweringInfo::set(Function &fn, MachineFunction &mf,
- SelectionDAG &DAG,
- bool EnableFastISel) {
- Fn = &fn;
- MF = &mf;
- RegInfo = &MF->getRegInfo();
-
- // Create a vreg for each argument register that is not dead and is used
- // outside of the entry block for the function.
- for (Function::arg_iterator AI = Fn->arg_begin(), E = Fn->arg_end();
- AI != E; ++AI)
- if (!isOnlyUsedInEntryBlock(AI, EnableFastISel))
- InitializeRegForValue(AI);
-
- // Initialize the mapping of values to registers. This is only set up for
- // instruction values that are used outside of the block that defines
- // them.
- Function::iterator BB = Fn->begin(), EB = Fn->end();
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
- if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
- if (ConstantInt *CUI = dyn_cast<ConstantInt>(AI->getArraySize())) {
- const Type *Ty = AI->getAllocatedType();
- uint64_t TySize = TLI.getTargetData()->getTypeAllocSize(Ty);
- unsigned Align =
- std::max((unsigned)TLI.getTargetData()->getPrefTypeAlignment(Ty),
- AI->getAlignment());
-
- TySize *= CUI->getZExtValue(); // Get total allocated size.
- if (TySize == 0) TySize = 1; // Don't create zero-sized stack objects.
- StaticAllocaMap[AI] =
- MF->getFrameInfo()->CreateStackObject(TySize, Align, false);
- }
-
- for (; BB != EB; ++BB)
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
- if (!I->use_empty() && isUsedOutsideOfDefiningBlock(I))
- if (!isa<AllocaInst>(I) ||
- !StaticAllocaMap.count(cast<AllocaInst>(I)))
- InitializeRegForValue(I);
-
- // Create an initial MachineBasicBlock for each LLVM BasicBlock in F. This
- // also creates the initial PHI MachineInstrs, though none of the input
- // operands are populated.
- for (BB = Fn->begin(), EB = Fn->end(); BB != EB; ++BB) {
- MachineBasicBlock *MBB = mf.CreateMachineBasicBlock(BB);
- MBBMap[BB] = MBB;
- MF->push_back(MBB);
-
- // Transfer the address-taken flag. This is necessary because there could
- // be multiple MachineBasicBlocks corresponding to one BasicBlock, and only
- // the first one should be marked.
- if (BB->hasAddressTaken())
- MBB->setHasAddressTaken();
-
- // Create Machine PHI nodes for LLVM PHI nodes, lowering them as
- // appropriate.
- PHINode *PN;
- DebugLoc DL;
- for (BasicBlock::iterator
- I = BB->begin(), E = BB->end(); I != E; ++I) {
-
- PN = dyn_cast<PHINode>(I);
- if (!PN || PN->use_empty()) continue;
-
- unsigned PHIReg = ValueMap[PN];
- assert(PHIReg && "PHI node does not have an assigned virtual register!");
-
- SmallVector<EVT, 4> ValueVTs;
- ComputeValueVTs(TLI, PN->getType(), ValueVTs);
- for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) {
- EVT VT = ValueVTs[vti];
- unsigned NumRegisters = TLI.getNumRegisters(*DAG.getContext(), VT);
- const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
- for (unsigned i = 0; i != NumRegisters; ++i)
- BuildMI(MBB, DL, TII->get(TargetInstrInfo::PHI), PHIReg + i);
- PHIReg += NumRegisters;
- }
- }
- }
-}
-
-unsigned FunctionLoweringInfo::MakeReg(EVT VT) {
- return RegInfo->createVirtualRegister(TLI.getRegClassFor(VT));
-}
-
-/// CreateRegForValue - Allocate the appropriate number of virtual registers of
-/// the correctly promoted or expanded types. Assign these registers
-/// consecutive vreg numbers and return the first assigned number.
-///
-/// In the case that the given value has struct or array type, this function
-/// will assign registers for each member or element.
-///
-unsigned FunctionLoweringInfo::CreateRegForValue(const Value *V) {
- SmallVector<EVT, 4> ValueVTs;
- ComputeValueVTs(TLI, V->getType(), ValueVTs);
-
- unsigned FirstReg = 0;
- for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) {
- EVT ValueVT = ValueVTs[Value];
- EVT RegisterVT = TLI.getRegisterType(V->getContext(), ValueVT);
-
- unsigned NumRegs = TLI.getNumRegisters(V->getContext(), ValueVT);
- for (unsigned i = 0; i != NumRegs; ++i) {
- unsigned R = MakeReg(RegisterVT);
- if (!FirstReg) FirstReg = R;
- }
- }
- return FirstReg;
-}
-
/// getCopyFromParts - Create a value that contains the specified legal parts
/// combined into the value they represent. If the parts combine to a type
/// larger then ValueVT then AssertOp can be used to specify whether the extra