1 //===-- TargetLowering.cpp - Implement the TargetLowering class -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This implements the TargetLowering class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Target/TargetLowering.h"
15 #include "llvm/Target/TargetMachine.h"
16 #include "llvm/CodeGen/SelectionDAG.h"
19 TargetLowering::TargetLowering(TargetMachine &tm)
20 : TM(tm), TD(TM.getTargetData()), ValueTypeActions(0) {
21 assert(ISD::BUILTIN_OP_END <= 128 &&
22 "Fixed size array in TargetLowering is not large enough!");
23 // All operations default to being supported.
24 memset(OpActions, 0, sizeof(OpActions));
26 IsLittleEndian = TD.isLittleEndian();
27 ShiftAmountTy = SetCCResultTy = PointerTy = getValueType(TD.getIntPtrType());
28 ShiftAmtHandling = Undefined;
29 memset(RegClassForVT, 0,MVT::LAST_VALUETYPE*sizeof(TargetRegisterClass*));
30 maxStoresPerMemSet = maxStoresPerMemCpy = maxStoresPerMemMove = 8;
31 allowUnalignedMemoryAccesses = false;
32 UseUnderscoreSetJmpLongJmp = false;
33 IntDivIsCheap = false;
34 Pow2DivIsCheap = false;
35 SchedPreferenceInfo = SchedulingForLatency;
38 TargetLowering::~TargetLowering() {}
40 /// setValueTypeAction - Set the action for a particular value type. This
41 /// assumes an action has not already been set for this value type.
42 static void SetValueTypeAction(MVT::ValueType VT,
43 TargetLowering::LegalizeAction Action,
45 MVT::ValueType *TransformToType,
46 unsigned long long &ValueTypeActions) {
47 ValueTypeActions |= (unsigned long long)Action << (VT*2);
48 if (Action == TargetLowering::Promote) {
49 MVT::ValueType PromoteTo;
53 unsigned LargerReg = VT+1;
54 while (!TLI.isTypeLegal((MVT::ValueType)LargerReg)) {
56 assert(MVT::isInteger((MVT::ValueType)LargerReg) &&
57 "Nothing to promote to??");
59 PromoteTo = (MVT::ValueType)LargerReg;
62 assert(MVT::isInteger(VT) == MVT::isInteger(PromoteTo) &&
63 MVT::isFloatingPoint(VT) == MVT::isFloatingPoint(PromoteTo) &&
64 "Can only promote from int->int or fp->fp!");
65 assert(VT < PromoteTo && "Must promote to a larger type!");
66 TransformToType[VT] = PromoteTo;
67 } else if (Action == TargetLowering::Expand) {
68 assert((VT == MVT::Vector || MVT::isInteger(VT)) && VT > MVT::i8 &&
69 "Cannot expand this type: target must support SOME integer reg!");
70 // Expand to the next smaller integer type!
71 TransformToType[VT] = (MVT::ValueType)(VT-1);
76 /// computeRegisterProperties - Once all of the register classes are added,
77 /// this allows us to compute derived properties we expose.
78 void TargetLowering::computeRegisterProperties() {
79 assert(MVT::LAST_VALUETYPE <= 32 &&
80 "Too many value types for ValueTypeActions to hold!");
82 // Everything defaults to one.
83 for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i)
84 NumElementsForVT[i] = 1;
86 // Find the largest integer register class.
87 unsigned LargestIntReg = MVT::i128;
88 for (; RegClassForVT[LargestIntReg] == 0; --LargestIntReg)
89 assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
91 // Every integer value type larger than this largest register takes twice as
92 // many registers to represent as the previous ValueType.
93 unsigned ExpandedReg = LargestIntReg; ++LargestIntReg;
94 for (++ExpandedReg; MVT::isInteger((MVT::ValueType)ExpandedReg);++ExpandedReg)
95 NumElementsForVT[ExpandedReg] = 2*NumElementsForVT[ExpandedReg-1];
97 // Inspect all of the ValueType's possible, deciding how to process them.
98 for (unsigned IntReg = MVT::i1; IntReg <= MVT::i128; ++IntReg)
99 // If we are expanding this type, expand it!
100 if (getNumElements((MVT::ValueType)IntReg) != 1)
101 SetValueTypeAction((MVT::ValueType)IntReg, Expand, *this, TransformToType,
103 else if (!isTypeLegal((MVT::ValueType)IntReg))
104 // Otherwise, if we don't have native support, we must promote to a
106 SetValueTypeAction((MVT::ValueType)IntReg, Promote, *this,
107 TransformToType, ValueTypeActions);
109 TransformToType[(MVT::ValueType)IntReg] = (MVT::ValueType)IntReg;
111 // If the target does not have native support for F32, promote it to F64.
112 if (!isTypeLegal(MVT::f32))
113 SetValueTypeAction(MVT::f32, Promote, *this,
114 TransformToType, ValueTypeActions);
116 TransformToType[MVT::f32] = MVT::f32;
118 // Set MVT::Vector to always be Expanded
119 SetValueTypeAction(MVT::Vector, Expand, *this, TransformToType,
122 assert(isTypeLegal(MVT::f64) && "Target does not support FP?");
123 TransformToType[MVT::f64] = MVT::f64;
126 const char *TargetLowering::getTargetNodeName(unsigned Opcode) const {
130 bool TargetLowering::isMaskedValueZeroForTargetNode(const SDOperand &Op,
131 uint64_t Mask) const {