llvm-6502/lib/CodeGen/SelectionDAG/TargetLowering.cpp

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//===-- TargetLowering.cpp - Implement the TargetLowering class -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements the TargetLowering class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/CodeGen/SelectionDAG.h"
using namespace llvm;
TargetLowering::TargetLowering(TargetMachine &tm)
: TM(tm), TD(TM.getTargetData()), ValueTypeActions(0) {
assert(ISD::BUILTIN_OP_END <= 128 &&
"Fixed size array in TargetLowering is not large enough!");
// All operations default to being supported.
memset(OpActions, 0, sizeof(OpActions));
IsLittleEndian = TD.isLittleEndian();
ShiftAmountTy = SetCCResultTy = PointerTy = getValueType(TD.getIntPtrType());
ShiftAmtHandling = Undefined;
memset(RegClassForVT, 0,MVT::LAST_VALUETYPE*sizeof(TargetRegisterClass*));
}
TargetLowering::~TargetLowering() {}
/// setValueTypeAction - Set the action for a particular value type. This
/// assumes an action has not already been set for this value type.
static void SetValueTypeAction(MVT::ValueType VT,
TargetLowering::LegalizeAction Action,
TargetLowering &TLI,
MVT::ValueType *TransformToType,
unsigned &ValueTypeActions) {
ValueTypeActions |= Action << (VT*2);
if (Action == TargetLowering::Promote) {
MVT::ValueType PromoteTo;
if (VT == MVT::f32)
PromoteTo = MVT::f64;
else {
unsigned LargerReg = VT+1;
while (!TLI.hasNativeSupportFor((MVT::ValueType)LargerReg)) {
++LargerReg;
assert(MVT::isInteger((MVT::ValueType)LargerReg) &&
"Nothing to promote to??");
}
PromoteTo = (MVT::ValueType)LargerReg;
}
assert(MVT::isInteger(VT) == MVT::isInteger(PromoteTo) &&
MVT::isFloatingPoint(VT) == MVT::isFloatingPoint(PromoteTo) &&
"Can only promote from int->int or fp->fp!");
assert(VT < PromoteTo && "Must promote to a larger type!");
TransformToType[VT] = PromoteTo;
} else if (Action == TargetLowering::Expand) {
assert(MVT::isInteger(VT) && VT > MVT::i8 &&
"Cannot expand this type: target must support SOME integer reg!");
// Expand to the next smaller integer type!
TransformToType[VT] = (MVT::ValueType)(VT-1);
}
}
/// computeRegisterProperties - Once all of the register classes are added,
/// this allows us to compute derived properties we expose.
void TargetLowering::computeRegisterProperties() {
assert(MVT::LAST_VALUETYPE <= 16 &&
"Too many value types for ValueTypeActions to hold!");
// Everything defaults to one.
for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i)
NumElementsForVT[i] = 1;
// Find the largest integer register class.
unsigned LargestIntReg = MVT::i128;
for (; RegClassForVT[LargestIntReg] == 0; --LargestIntReg)
assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
// Every integer value type larger than this largest register takes twice as
// many registers to represent as the previous ValueType.
unsigned ExpandedReg = LargestIntReg; ++LargestIntReg;
for (++ExpandedReg; MVT::isInteger((MVT::ValueType)ExpandedReg);++ExpandedReg)
NumElementsForVT[ExpandedReg] = 2*NumElementsForVT[ExpandedReg-1];
// Inspect all of the ValueType's possible, deciding how to process them.
for (unsigned IntReg = MVT::i1; IntReg <= MVT::i128; ++IntReg)
// If we are expanding this type, expand it!
if (getNumElements((MVT::ValueType)IntReg) != 1)
SetValueTypeAction((MVT::ValueType)IntReg, Expand, *this, TransformToType,
ValueTypeActions);
else if (!hasNativeSupportFor((MVT::ValueType)IntReg))
// Otherwise, if we don't have native support, we must promote to a
// larger type.
SetValueTypeAction((MVT::ValueType)IntReg, Promote, *this,
TransformToType, ValueTypeActions);
else
TransformToType[(MVT::ValueType)IntReg] = (MVT::ValueType)IntReg;
// If the target does not have native support for F32, promote it to F64.
if (!hasNativeSupportFor(MVT::f32))
SetValueTypeAction(MVT::f32, Promote, *this,
TransformToType, ValueTypeActions);
else
TransformToType[MVT::f32] = MVT::f32;
assert(hasNativeSupportFor(MVT::f64) && "Target does not support FP?");
TransformToType[MVT::f64] = MVT::f64;
}