#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
-#include "llvm/CallingConv.h"
+#include "llvm/GlobalVariable.h"
#include "llvm/DerivedTypes.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/STLExtras.h"
TargetLowering::TargetLowering(TargetMachine &tm)
: TM(tm), TD(TM.getTargetData()) {
- assert(ISD::BUILTIN_OP_END <= 156 &&
+ assert(ISD::BUILTIN_OP_END <= OpActionsCapacity &&
"Fixed size array in TargetLowering is not large enough!");
// All operations default to being supported.
memset(OpActions, 0, sizeof(OpActions));
TargetLowering::~TargetLowering() {}
-
-SDOperand TargetLowering::LowerMEMCPY(SDOperand Op, SelectionDAG &DAG) {
- assert(getSubtarget() && "Subtarget not defined");
- SDOperand ChainOp = Op.getOperand(0);
- SDOperand DestOp = Op.getOperand(1);
- SDOperand SourceOp = Op.getOperand(2);
- SDOperand CountOp = Op.getOperand(3);
- SDOperand AlignOp = Op.getOperand(4);
- SDOperand AlwaysInlineOp = Op.getOperand(5);
-
- bool AlwaysInline = (bool)cast<ConstantSDNode>(AlwaysInlineOp)->getValue();
- unsigned Align = (unsigned)cast<ConstantSDNode>(AlignOp)->getValue();
- if (Align == 0) Align = 1;
-
- // If size is unknown, call memcpy.
- ConstantSDNode *I = dyn_cast<ConstantSDNode>(CountOp);
- if (!I) {
- assert(!AlwaysInline && "Cannot inline copy of unknown size");
- return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
- }
-
- // If not DWORD aligned or if size is more than threshold, then call memcpy.
- // The libc version is likely to be faster for the following cases. It can
- // use the address value and run time information about the CPU.
- // With glibc 2.6.1 on a core 2, coping an array of 100M longs was 30% faster
- unsigned Size = I->getValue();
- if (AlwaysInline ||
- (Size <= getSubtarget()->getMaxInlineSizeThreshold() &&
- (Align & 3) == 0))
- return LowerMEMCPYInline(ChainOp, DestOp, SourceOp, Size, Align, DAG);
- return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
-}
-
-
-SDOperand TargetLowering::LowerMEMCPYCall(SDOperand Chain,
- SDOperand Dest,
- SDOperand Source,
- SDOperand Count,
- SelectionDAG &DAG) {
- MVT::ValueType IntPtr = getPointerTy();
- TargetLowering::ArgListTy Args;
- TargetLowering::ArgListEntry Entry;
- Entry.Ty = getTargetData()->getIntPtrType();
- Entry.Node = Dest; Args.push_back(Entry);
- Entry.Node = Source; Args.push_back(Entry);
- Entry.Node = Count; Args.push_back(Entry);
- std::pair<SDOperand,SDOperand> CallResult =
- LowerCallTo(Chain, Type::VoidTy, false, false, false, CallingConv::C,
- false, DAG.getExternalSymbol("memcpy", IntPtr), Args, DAG);
- return CallResult.second;
-}
-
-
/// computeRegisterProperties - Once all of the register classes are added,
/// this allows us to compute derived properties we expose.
void TargetLowering::computeRegisterProperties() {
}
#endif
break;
- case ISD::ADD:
- case ISD::SUB:
- case ISD::INTRINSIC_WO_CHAIN:
- case ISD::INTRINSIC_W_CHAIN:
- case ISD::INTRINSIC_VOID:
- case ISD::CTTZ:
- case ISD::CTLZ:
- case ISD::CTPOP:
- case ISD::LOAD:
- case ISD::SETCC:
- case ISD::FGETSIGN:
+ default:
// Just use ComputeMaskedBits to compute output bits.
TLO.DAG.ComputeMaskedBits(Op, NewMask, KnownZero, KnownOne, Depth);
break;
return SDOperand();
}
+/// isGAPlusOffset - Returns true (and the GlobalValue and the offset) if the
+/// node is a GlobalAddress + offset.
+bool TargetLowering::isGAPlusOffset(SDNode *N, GlobalValue* &GA,
+ int64_t &Offset) const {
+ if (isa<GlobalAddressSDNode>(N)) {
+ GA = cast<GlobalAddressSDNode>(N)->getGlobal();
+ return true;
+ }
+
+ if (N->getOpcode() == ISD::ADD) {
+ SDOperand N1 = N->getOperand(0);
+ SDOperand N2 = N->getOperand(1);
+ if (isGAPlusOffset(N1.Val, GA, Offset)) {
+ ConstantSDNode *V = dyn_cast<ConstantSDNode>(N2);
+ if (V) {
+ Offset += V->getSignExtended();
+ return true;
+ }
+ } else if (isGAPlusOffset(N2.Val, GA, Offset)) {
+ ConstantSDNode *V = dyn_cast<ConstantSDNode>(N1);
+ if (V) {
+ Offset += V->getSignExtended();
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+
+/// isConsecutiveLoad - Return true if LD (which must be a LoadSDNode) is
+/// loading 'Bytes' bytes from a location that is 'Dist' units away from the
+/// location that the 'Base' load is loading from.
+bool TargetLowering::isConsecutiveLoad(SDNode *LD, SDNode *Base,
+ unsigned Bytes, int Dist,
+ const MachineFrameInfo *MFI) const {
+ if (LD->getOperand(0).Val != Base->getOperand(0).Val)
+ return false;
+ MVT::ValueType VT = LD->getValueType(0);
+ if (MVT::getSizeInBits(VT) / 8 != Bytes)
+ return false;
+
+ SDOperand Loc = LD->getOperand(1);
+ SDOperand BaseLoc = Base->getOperand(1);
+ if (Loc.getOpcode() == ISD::FrameIndex) {
+ if (BaseLoc.getOpcode() != ISD::FrameIndex)
+ return false;
+ int FI = cast<FrameIndexSDNode>(Loc)->getIndex();
+ int BFI = cast<FrameIndexSDNode>(BaseLoc)->getIndex();
+ int FS = MFI->getObjectSize(FI);
+ int BFS = MFI->getObjectSize(BFI);
+ if (FS != BFS || FS != (int)Bytes) return false;
+ return MFI->getObjectOffset(FI) == (MFI->getObjectOffset(BFI) + Dist*Bytes);
+ }
+
+ GlobalValue *GV1 = NULL;
+ GlobalValue *GV2 = NULL;
+ int64_t Offset1 = 0;
+ int64_t Offset2 = 0;
+ bool isGA1 = isGAPlusOffset(Loc.Val, GV1, Offset1);
+ bool isGA2 = isGAPlusOffset(BaseLoc.Val, GV2, Offset2);
+ if (isGA1 && isGA2 && GV1 == GV2)
+ return Offset1 == (Offset2 + Dist*Bytes);
+ return false;
+}
+
+
SDOperand TargetLowering::
PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const {
// Default implementation: no optimization.
// Inline Assembler Implementation Methods
//===----------------------------------------------------------------------===//
+
TargetLowering::ConstraintType
TargetLowering::getConstraintType(const std::string &Constraint) const {
// FIXME: lots more standard ones to handle.
/// LowerXConstraint - try to replace an X constraint, which matches anything,
/// with another that has more specific requirements based on the type of the
/// corresponding operand.
-void TargetLowering::lowerXConstraint(MVT::ValueType ConstraintVT,
- std::string& s) const {
+const char *TargetLowering::LowerXConstraint(MVT::ValueType ConstraintVT) const{
if (MVT::isInteger(ConstraintVT))
- s = "r";
- else if (MVT::isFloatingPoint(ConstraintVT))
- s = "f"; // works for many targets
- else
- s = "";
+ return "r";
+ if (MVT::isFloatingPoint(ConstraintVT))
+ return "f"; // works for many targets
+ return 0;
}
/// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
void TargetLowering::LowerAsmOperandForConstraint(SDOperand Op,
char ConstraintLetter,
std::vector<SDOperand> &Ops,
- SelectionDAG &DAG) {
+ SelectionDAG &DAG) const {
switch (ConstraintLetter) {
default: break;
case 'X': // Allows any operand; labels (basic block) use this.
return std::pair<unsigned, const TargetRegisterClass*>(0, 0);
}
+//===----------------------------------------------------------------------===//
+// Constraint Selection.
+
+/// getConstraintGenerality - Return an integer indicating how general CT
+/// is.
+static unsigned getConstraintGenerality(TargetLowering::ConstraintType CT) {
+ switch (CT) {
+ default: assert(0 && "Unknown constraint type!");
+ case TargetLowering::C_Other:
+ case TargetLowering::C_Unknown:
+ return 0;
+ case TargetLowering::C_Register:
+ return 1;
+ case TargetLowering::C_RegisterClass:
+ return 2;
+ case TargetLowering::C_Memory:
+ return 3;
+ }
+}
+
+/// ChooseConstraint - If there are multiple different constraints that we
+/// could pick for this operand (e.g. "imr") try to pick the 'best' one.
+/// This is somewhat tricky: constraints fall into four classes:
+/// Other -> immediates and magic values
+/// Register -> one specific register
+/// RegisterClass -> a group of regs
+/// Memory -> memory
+/// Ideally, we would pick the most specific constraint possible: if we have
+/// something that fits into a register, we would pick it. The problem here
+/// is that if we have something that could either be in a register or in
+/// memory that use of the register could cause selection of *other*
+/// operands to fail: they might only succeed if we pick memory. Because of
+/// this the heuristic we use is:
+///
+/// 1) If there is an 'other' constraint, and if the operand is valid for
+/// that constraint, use it. This makes us take advantage of 'i'
+/// constraints when available.
+/// 2) Otherwise, pick the most general constraint present. This prefers
+/// 'm' over 'r', for example.
+///
+static void ChooseConstraint(TargetLowering::AsmOperandInfo &OpInfo,
+ const TargetLowering &TLI,
+ SDOperand Op, SelectionDAG *DAG) {
+ assert(OpInfo.Codes.size() > 1 && "Doesn't have multiple constraint options");
+ unsigned BestIdx = 0;
+ TargetLowering::ConstraintType BestType = TargetLowering::C_Unknown;
+ int BestGenerality = -1;
+
+ // Loop over the options, keeping track of the most general one.
+ for (unsigned i = 0, e = OpInfo.Codes.size(); i != e; ++i) {
+ TargetLowering::ConstraintType CType =
+ TLI.getConstraintType(OpInfo.Codes[i]);
+
+ // If this is an 'other' constraint, see if the operand is valid for it.
+ // For example, on X86 we might have an 'rI' constraint. If the operand
+ // is an integer in the range [0..31] we want to use I (saving a load
+ // of a register), otherwise we must use 'r'.
+ if (CType == TargetLowering::C_Other && Op.Val) {
+ assert(OpInfo.Codes[i].size() == 1 &&
+ "Unhandled multi-letter 'other' constraint");
+ std::vector<SDOperand> ResultOps;
+ TLI.LowerAsmOperandForConstraint(Op, OpInfo.Codes[i][0],
+ ResultOps, *DAG);
+ if (!ResultOps.empty()) {
+ BestType = CType;
+ BestIdx = i;
+ break;
+ }
+ }
+
+ // This constraint letter is more general than the previous one, use it.
+ int Generality = getConstraintGenerality(CType);
+ if (Generality > BestGenerality) {
+ BestType = CType;
+ BestIdx = i;
+ BestGenerality = Generality;
+ }
+ }
+
+ OpInfo.ConstraintCode = OpInfo.Codes[BestIdx];
+ OpInfo.ConstraintType = BestType;
+}
+
+/// ComputeConstraintToUse - Determines the constraint code and constraint
+/// type to use for the specific AsmOperandInfo, setting
+/// OpInfo.ConstraintCode and OpInfo.ConstraintType.
+void TargetLowering::ComputeConstraintToUse(AsmOperandInfo &OpInfo,
+ SDOperand Op,
+ SelectionDAG *DAG) const {
+ assert(!OpInfo.Codes.empty() && "Must have at least one constraint");
+
+ // Single-letter constraints ('r') are very common.
+ if (OpInfo.Codes.size() == 1) {
+ OpInfo.ConstraintCode = OpInfo.Codes[0];
+ OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode);
+ } else {
+ ChooseConstraint(OpInfo, *this, Op, DAG);
+ }
+
+ // 'X' matches anything.
+ if (OpInfo.ConstraintCode == "X" && OpInfo.CallOperandVal) {
+ // Labels and constants are handled elsewhere ('X' is the only thing
+ // that matches labels).
+ if (isa<BasicBlock>(OpInfo.CallOperandVal) ||
+ isa<ConstantInt>(OpInfo.CallOperandVal))
+ return;
+
+ // Otherwise, try to resolve it to something we know about by looking at
+ // the actual operand type.
+ if (const char *Repl = LowerXConstraint(OpInfo.ConstraintVT)) {
+ OpInfo.ConstraintCode = Repl;
+ OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode);
+ }
+ }
+}
+
//===----------------------------------------------------------------------===//
// Loop Strength Reduction hooks
//===----------------------------------------------------------------------===//
projects / oota-llvm.git / blobdiff