mirror of
https://github.com/c64scene-ar/llvm-6502.git
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19384 91177308-0d34-0410-b5e6-96231b3b80d8
830 lines
30 KiB
C++
830 lines
30 KiB
C++
//===-- LegalizeDAG.cpp - Implement SelectionDAG::Legalize ----------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file was developed by the LLVM research group and is distributed under
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// the University of Illinois Open Source License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the SelectionDAG::Legalize method.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/SelectionDAG.h"
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#include "llvm/CodeGen/MachineConstantPool.h"
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#include "llvm/CodeGen/MachineFunction.h"
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#include "llvm/Target/TargetLowering.h"
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#include "llvm/Constants.h"
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#include <iostream>
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using namespace llvm;
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static const Type *getTypeFor(MVT::ValueType VT) {
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switch (VT) {
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default: assert(0 && "Unknown MVT!");
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case MVT::i1: return Type::BoolTy;
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case MVT::i8: return Type::UByteTy;
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case MVT::i16: return Type::UShortTy;
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case MVT::i32: return Type::UIntTy;
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case MVT::i64: return Type::ULongTy;
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case MVT::f32: return Type::FloatTy;
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case MVT::f64: return Type::DoubleTy;
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}
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}
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//===----------------------------------------------------------------------===//
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/// SelectionDAGLegalize - This takes an arbitrary SelectionDAG as input and
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/// hacks on it until the target machine can handle it. This involves
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/// eliminating value sizes the machine cannot handle (promoting small sizes to
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/// large sizes or splitting up large values into small values) as well as
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/// eliminating operations the machine cannot handle.
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///
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/// This code also does a small amount of optimization and recognition of idioms
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/// as part of its processing. For example, if a target does not support a
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/// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
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/// will attempt merge setcc and brc instructions into brcc's.
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///
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namespace {
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class SelectionDAGLegalize {
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TargetLowering &TLI;
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SelectionDAG &DAG;
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/// LegalizeAction - This enum indicates what action we should take for each
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/// value type the can occur in the program.
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enum LegalizeAction {
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Legal, // The target natively supports this value type.
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Promote, // This should be promoted to the next larger type.
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Expand, // This integer type should be broken into smaller pieces.
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};
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/// TransformToType - For any value types we are promoting or expanding, this
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/// contains the value type that we are changing to. For Expanded types, this
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/// contains one step of the expand (e.g. i64 -> i32), even if there are
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/// multiple steps required (e.g. i64 -> i16)
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MVT::ValueType TransformToType[MVT::LAST_VALUETYPE];
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/// ValueTypeActions - This is a bitvector that contains two bits for each
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/// value type, where the two bits correspond to the LegalizeAction enum.
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/// This can be queried with "getTypeAction(VT)".
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unsigned ValueTypeActions;
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/// NeedsAnotherIteration - This is set when we expand a large integer
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/// operation into smaller integer operations, but the smaller operations are
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/// not set. This occurs only rarely in practice, for targets that don't have
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/// 32-bit or larger integer registers.
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bool NeedsAnotherIteration;
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/// LegalizedNodes - For nodes that are of legal width, and that have more
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/// than one use, this map indicates what regularized operand to use. This
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/// allows us to avoid legalizing the same thing more than once.
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std::map<SDOperand, SDOperand> LegalizedNodes;
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/// ExpandedNodes - For nodes that need to be expanded, and which have more
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/// than one use, this map indicates which which operands are the expanded
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/// version of the input. This allows us to avoid expanding the same node
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/// more than once.
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std::map<SDOperand, std::pair<SDOperand, SDOperand> > ExpandedNodes;
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void AddLegalizedOperand(SDOperand From, SDOperand To) {
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bool isNew = LegalizedNodes.insert(std::make_pair(From, To)).second;
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assert(isNew && "Got into the map somehow?");
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}
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/// setValueTypeAction - Set the action for a particular value type. This
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/// assumes an action has not already been set for this value type.
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void setValueTypeAction(MVT::ValueType VT, LegalizeAction A) {
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ValueTypeActions |= A << (VT*2);
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if (A == Promote) {
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MVT::ValueType PromoteTo;
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if (VT == MVT::f32)
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PromoteTo = MVT::f64;
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else {
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unsigned LargerReg = VT+1;
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while (!TLI.hasNativeSupportFor((MVT::ValueType)LargerReg)) {
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++LargerReg;
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assert(MVT::isInteger((MVT::ValueType)LargerReg) &&
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"Nothing to promote to??");
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}
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PromoteTo = (MVT::ValueType)LargerReg;
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}
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assert(MVT::isInteger(VT) == MVT::isInteger(PromoteTo) &&
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MVT::isFloatingPoint(VT) == MVT::isFloatingPoint(PromoteTo) &&
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"Can only promote from int->int or fp->fp!");
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assert(VT < PromoteTo && "Must promote to a larger type!");
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TransformToType[VT] = PromoteTo;
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} else if (A == Expand) {
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assert(MVT::isInteger(VT) && VT > MVT::i8 &&
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"Cannot expand this type: target must support SOME integer reg!");
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// Expand to the next smaller integer type!
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TransformToType[VT] = (MVT::ValueType)(VT-1);
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}
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}
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public:
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SelectionDAGLegalize(TargetLowering &TLI, SelectionDAG &DAG);
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/// Run - While there is still lowering to do, perform a pass over the DAG.
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/// Most regularization can be done in a single pass, but targets that require
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/// large values to be split into registers multiple times (e.g. i64 -> 4x
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/// i16) require iteration for these values (the first iteration will demote
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/// to i32, the second will demote to i16).
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void Run() {
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do {
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NeedsAnotherIteration = false;
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LegalizeDAG();
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} while (NeedsAnotherIteration);
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}
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/// getTypeAction - Return how we should legalize values of this type, either
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/// it is already legal or we need to expand it into multiple registers of
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/// smaller integer type, or we need to promote it to a larger type.
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LegalizeAction getTypeAction(MVT::ValueType VT) const {
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return (LegalizeAction)((ValueTypeActions >> (2*VT)) & 3);
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}
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/// isTypeLegal - Return true if this type is legal on this target.
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///
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bool isTypeLegal(MVT::ValueType VT) const {
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return getTypeAction(VT) == Legal;
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}
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private:
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void LegalizeDAG();
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SDOperand LegalizeOp(SDOperand O);
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void ExpandOp(SDOperand O, SDOperand &Lo, SDOperand &Hi);
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SDOperand getIntPtrConstant(uint64_t Val) {
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return DAG.getConstant(Val, TLI.getPointerTy());
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}
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};
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}
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SelectionDAGLegalize::SelectionDAGLegalize(TargetLowering &tli,
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SelectionDAG &dag)
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: TLI(tli), DAG(dag), ValueTypeActions(0) {
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assert(MVT::LAST_VALUETYPE <= 16 &&
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"Too many value types for ValueTypeActions to hold!");
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// Inspect all of the ValueType's possible, deciding how to process them.
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for (unsigned IntReg = MVT::i1; IntReg <= MVT::i128; ++IntReg)
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// If TLI says we are expanding this type, expand it!
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if (TLI.getNumElements((MVT::ValueType)IntReg) != 1)
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setValueTypeAction((MVT::ValueType)IntReg, Expand);
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else if (!TLI.hasNativeSupportFor((MVT::ValueType)IntReg))
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// Otherwise, if we don't have native support, we must promote to a
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// larger type.
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setValueTypeAction((MVT::ValueType)IntReg, Promote);
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// If the target does not have native support for F32, promote it to F64.
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if (!TLI.hasNativeSupportFor(MVT::f32))
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setValueTypeAction(MVT::f32, Promote);
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}
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void SelectionDAGLegalize::LegalizeDAG() {
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SDOperand OldRoot = DAG.getRoot();
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SDOperand NewRoot = LegalizeOp(OldRoot);
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DAG.setRoot(NewRoot);
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ExpandedNodes.clear();
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LegalizedNodes.clear();
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// Remove dead nodes now.
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DAG.RemoveDeadNodes(OldRoot.Val);
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}
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SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
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// If this operation defines any values that cannot be represented in a
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// register on this target, make sure to expand it.
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if (Op.Val->getNumValues() == 1) {// Fast path == assertion only
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assert(getTypeAction(Op.Val->getValueType(0)) == Legal &&
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"For a single use value, caller should check for legality!");
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} else {
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for (unsigned i = 0, e = Op.Val->getNumValues(); i != e; ++i)
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switch (getTypeAction(Op.Val->getValueType(i))) {
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case Legal: break; // Nothing to do.
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case Expand: {
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SDOperand T1, T2;
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ExpandOp(Op.getValue(i), T1, T2);
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assert(LegalizedNodes.count(Op) &&
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"Expansion didn't add legal operands!");
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return LegalizedNodes[Op];
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}
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case Promote:
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// FIXME: Implement promotion!
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assert(0 && "Promotion not implemented at all yet!");
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}
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}
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// If there is more than one use of this, see if we already legalized it.
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// There is no use remembering values that only have a single use, as the map
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// entries will never be reused.
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if (!Op.Val->hasOneUse()) {
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std::map<SDOperand, SDOperand>::iterator I = LegalizedNodes.find(Op);
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if (I != LegalizedNodes.end()) return I->second;
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}
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SDOperand Tmp1, Tmp2;
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SDOperand Result = Op;
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SDNode *Node = Op.Val;
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switch (Node->getOpcode()) {
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default:
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std::cerr << "NODE: "; Node->dump(); std::cerr << "\n";
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assert(0 && "Do not know how to legalize this operator!");
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abort();
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case ISD::EntryToken:
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case ISD::FrameIndex:
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case ISD::GlobalAddress:
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case ISD::ExternalSymbol:
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case ISD::ConstantPool:
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case ISD::CopyFromReg: // Nothing to do.
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assert(getTypeAction(Node->getValueType(0)) == Legal &&
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"This must be legal!");
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break;
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case ISD::Constant:
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// We know we don't need to expand constants here, constants only have one
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// value and we check that it is fine above.
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// FIXME: Maybe we should handle things like targets that don't support full
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// 32-bit immediates?
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break;
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case ISD::ConstantFP: {
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// Spill FP immediates to the constant pool if the target cannot directly
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// codegen them. Targets often have some immediate values that can be
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// efficiently generated into an FP register without a load. We explicitly
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// leave these constants as ConstantFP nodes for the target to deal with.
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ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
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// Check to see if this FP immediate is already legal.
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bool isLegal = false;
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for (TargetLowering::legal_fpimm_iterator I = TLI.legal_fpimm_begin(),
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E = TLI.legal_fpimm_end(); I != E; ++I)
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if (CFP->isExactlyValue(*I)) {
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isLegal = true;
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break;
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}
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if (!isLegal) {
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// Otherwise we need to spill the constant to memory.
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MachineConstantPool *CP = DAG.getMachineFunction().getConstantPool();
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bool Extend = false;
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// If a FP immediate is precise when represented as a float, we put it
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// into the constant pool as a float, even if it's is statically typed
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// as a double.
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MVT::ValueType VT = CFP->getValueType(0);
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bool isDouble = VT == MVT::f64;
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ConstantFP *LLVMC = ConstantFP::get(isDouble ? Type::DoubleTy :
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Type::FloatTy, CFP->getValue());
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if (isDouble && CFP->isExactlyValue((float)CFP->getValue())) {
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LLVMC = cast<ConstantFP>(ConstantExpr::getCast(LLVMC, Type::FloatTy));
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VT = MVT::f32;
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Extend = true;
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}
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SDOperand CPIdx = DAG.getConstantPool(CP->getConstantPoolIndex(LLVMC),
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TLI.getPointerTy());
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Result = DAG.getLoad(VT, DAG.getEntryNode(), CPIdx);
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if (Extend) Result = DAG.getNode(ISD::FP_EXTEND, MVT::f64, Result);
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}
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break;
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}
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case ISD::ADJCALLSTACKDOWN:
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case ISD::ADJCALLSTACKUP:
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Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
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// There is no need to legalize the size argument (Operand #1)
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if (Tmp1 != Node->getOperand(0))
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Result = DAG.getNode(Node->getOpcode(), MVT::Other, Tmp1,
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Node->getOperand(1));
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break;
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case ISD::CALL:
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Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
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Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the callee.
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if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1)) {
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std::vector<MVT::ValueType> RetTyVTs;
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RetTyVTs.reserve(Node->getNumValues());
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for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
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RetTyVTs.push_back(Node->getValueType(i));
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Result = SDOperand(DAG.getCall(RetTyVTs, Tmp1, Tmp2), Op.ResNo);
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}
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break;
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case ISD::BR:
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Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
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if (Tmp1 != Node->getOperand(0))
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Result = DAG.getNode(ISD::BR, MVT::Other, Tmp1, Node->getOperand(1));
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break;
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case ISD::BRCOND:
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Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
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// FIXME: booleans might not be legal!
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Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the condition.
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// Basic block destination (Op#2) is always legal.
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if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1))
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Result = DAG.getNode(ISD::BRCOND, MVT::Other, Tmp1, Tmp2,
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Node->getOperand(2));
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break;
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case ISD::LOAD:
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Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
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Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the pointer.
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if (Tmp1 != Node->getOperand(0) ||
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Tmp2 != Node->getOperand(1))
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Result = DAG.getLoad(Node->getValueType(0), Tmp1, Tmp2);
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else
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Result = SDOperand(Node, 0);
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// Since loads produce two values, make sure to remember that we legalized
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// both of them.
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AddLegalizedOperand(SDOperand(Node, 0), Result);
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AddLegalizedOperand(SDOperand(Node, 1), Result.getValue(1));
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return Result.getValue(Op.ResNo);
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case ISD::EXTRACT_ELEMENT:
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// Get both the low and high parts.
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ExpandOp(Node->getOperand(0), Tmp1, Tmp2);
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if (cast<ConstantSDNode>(Node->getOperand(1))->getValue())
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Result = Tmp2; // 1 -> Hi
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else
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Result = Tmp1; // 0 -> Lo
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break;
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case ISD::CopyToReg:
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Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
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switch (getTypeAction(Node->getOperand(1).getValueType())) {
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case Legal:
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// Legalize the incoming value (must be legal).
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Tmp2 = LegalizeOp(Node->getOperand(1));
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if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1))
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Result = DAG.getCopyToReg(Tmp1, Tmp2,
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cast<CopyRegSDNode>(Node)->getReg());
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break;
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case Expand: {
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SDOperand Lo, Hi;
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ExpandOp(Node->getOperand(1), Lo, Hi);
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unsigned Reg = cast<CopyRegSDNode>(Node)->getReg();
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Result = DAG.getCopyToReg(Tmp1, Lo, Reg);
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Result = DAG.getCopyToReg(Result, Hi, Reg+1);
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assert(isTypeLegal(Result.getValueType()) &&
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"Cannot expand multiple times yet (i64 -> i16)");
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break;
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}
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case Promote:
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assert(0 && "Don't know what it means to promote this!");
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abort();
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}
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break;
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case ISD::RET:
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Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
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switch (Node->getNumOperands()) {
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case 2: // ret val
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switch (getTypeAction(Node->getOperand(1).getValueType())) {
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case Legal:
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Tmp2 = LegalizeOp(Node->getOperand(1));
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if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1))
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Result = DAG.getNode(ISD::RET, MVT::Other, Tmp1, Tmp2);
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break;
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case Expand: {
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SDOperand Lo, Hi;
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ExpandOp(Node->getOperand(1), Lo, Hi);
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Result = DAG.getNode(ISD::RET, MVT::Other, Tmp1, Lo, Hi);
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break;
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}
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case Promote:
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assert(0 && "Can't promote return value!");
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}
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break;
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case 1: // ret void
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if (Tmp1 != Node->getOperand(0))
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Result = DAG.getNode(ISD::RET, MVT::Other, Tmp1);
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break;
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default: { // ret <values>
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std::vector<SDOperand> NewValues;
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NewValues.push_back(Tmp1);
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for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i)
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switch (getTypeAction(Node->getOperand(i).getValueType())) {
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case Legal:
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NewValues.push_back(LegalizeOp(Node->getOperand(i)));
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break;
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case Expand: {
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SDOperand Lo, Hi;
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ExpandOp(Node->getOperand(i), Lo, Hi);
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NewValues.push_back(Lo);
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NewValues.push_back(Hi);
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break;
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}
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case Promote:
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assert(0 && "Can't promote return value!");
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}
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Result = DAG.getNode(ISD::RET, MVT::Other, NewValues);
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break;
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}
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}
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break;
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case ISD::STORE:
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Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
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Tmp2 = LegalizeOp(Node->getOperand(2)); // Legalize the pointer.
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// Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
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if (ConstantFPSDNode *CFP =
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dyn_cast<ConstantFPSDNode>(Node->getOperand(1))) {
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if (CFP->getValueType(0) == MVT::f32) {
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union {
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unsigned I;
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float F;
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} V;
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V.F = CFP->getValue();
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Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1,
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DAG.getConstant(V.I, MVT::i32), Tmp2);
|
|
} else {
|
|
assert(CFP->getValueType(0) == MVT::f64 && "Unknown FP type!");
|
|
union {
|
|
uint64_t I;
|
|
double F;
|
|
} V;
|
|
V.F = CFP->getValue();
|
|
Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1,
|
|
DAG.getConstant(V.I, MVT::i64), Tmp2);
|
|
}
|
|
Op = Result;
|
|
Node = Op.Val;
|
|
}
|
|
|
|
switch (getTypeAction(Node->getOperand(1).getValueType())) {
|
|
case Legal: {
|
|
SDOperand Val = LegalizeOp(Node->getOperand(1));
|
|
if (Val != Node->getOperand(1) || Tmp1 != Node->getOperand(0) ||
|
|
Tmp2 != Node->getOperand(2))
|
|
Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1, Val, Tmp2);
|
|
break;
|
|
}
|
|
case Promote:
|
|
assert(0 && "FIXME: promote for stores not implemented!");
|
|
case Expand:
|
|
SDOperand Lo, Hi;
|
|
ExpandOp(Node->getOperand(1), Lo, Hi);
|
|
|
|
if (!TLI.isLittleEndian())
|
|
std::swap(Lo, Hi);
|
|
|
|
// FIXME: These two stores are independent of each other!
|
|
Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1, Lo, Tmp2);
|
|
|
|
unsigned IncrementSize;
|
|
switch (Lo.getValueType()) {
|
|
default: assert(0 && "Unknown ValueType to expand to!");
|
|
case MVT::i32: IncrementSize = 4; break;
|
|
case MVT::i16: IncrementSize = 2; break;
|
|
case MVT::i8: IncrementSize = 1; break;
|
|
}
|
|
Tmp2 = DAG.getNode(ISD::ADD, Tmp2.getValueType(), Tmp2,
|
|
getIntPtrConstant(IncrementSize));
|
|
assert(isTypeLegal(Tmp2.getValueType()) &&
|
|
"Pointers must be legal!");
|
|
Result = DAG.getNode(ISD::STORE, MVT::Other, Result, Hi, Tmp2);
|
|
}
|
|
break;
|
|
case ISD::SELECT: {
|
|
// FIXME: BOOLS MAY REQUIRE PROMOTION!
|
|
Tmp1 = LegalizeOp(Node->getOperand(0)); // Cond
|
|
Tmp2 = LegalizeOp(Node->getOperand(1)); // TrueVal
|
|
SDOperand Tmp3 = LegalizeOp(Node->getOperand(2)); // FalseVal
|
|
|
|
if (Tmp1 != Node->getOperand(0) ||
|
|
Tmp2 != Node->getOperand(1) ||
|
|
Tmp3 != Node->getOperand(2))
|
|
Result = DAG.getNode(ISD::SELECT, Node->getValueType(0), Tmp1, Tmp2,Tmp3);
|
|
break;
|
|
}
|
|
case ISD::SETCC:
|
|
switch (getTypeAction(Node->getOperand(0).getValueType())) {
|
|
case Legal:
|
|
Tmp1 = LegalizeOp(Node->getOperand(0)); // LHS
|
|
Tmp2 = LegalizeOp(Node->getOperand(1)); // RHS
|
|
if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1))
|
|
Result = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(),
|
|
Tmp1, Tmp2);
|
|
break;
|
|
case Promote:
|
|
assert(0 && "Can't promote setcc operands yet!");
|
|
break;
|
|
case Expand:
|
|
SDOperand LHSLo, LHSHi, RHSLo, RHSHi;
|
|
ExpandOp(Node->getOperand(0), LHSLo, LHSHi);
|
|
ExpandOp(Node->getOperand(1), RHSLo, RHSHi);
|
|
switch (cast<SetCCSDNode>(Node)->getCondition()) {
|
|
case ISD::SETEQ:
|
|
case ISD::SETNE:
|
|
Tmp1 = DAG.getNode(ISD::XOR, LHSLo.getValueType(), LHSLo, RHSLo);
|
|
Tmp2 = DAG.getNode(ISD::XOR, LHSLo.getValueType(), LHSHi, RHSHi);
|
|
Tmp1 = DAG.getNode(ISD::OR, Tmp1.getValueType(), Tmp1, Tmp2);
|
|
Result = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(), Tmp1,
|
|
DAG.getConstant(0, Tmp1.getValueType()));
|
|
break;
|
|
default:
|
|
// FIXME: This generated code sucks.
|
|
ISD::CondCode LowCC;
|
|
switch (cast<SetCCSDNode>(Node)->getCondition()) {
|
|
default: assert(0 && "Unknown integer setcc!");
|
|
case ISD::SETLT:
|
|
case ISD::SETULT: LowCC = ISD::SETULT; break;
|
|
case ISD::SETGT:
|
|
case ISD::SETUGT: LowCC = ISD::SETUGT; break;
|
|
case ISD::SETLE:
|
|
case ISD::SETULE: LowCC = ISD::SETULE; break;
|
|
case ISD::SETGE:
|
|
case ISD::SETUGE: LowCC = ISD::SETUGE; break;
|
|
}
|
|
|
|
// Tmp1 = lo(op1) < lo(op2) // Always unsigned comparison
|
|
// Tmp2 = hi(op1) < hi(op2) // Signedness depends on operands
|
|
// dest = hi(op1) == hi(op2) ? Tmp1 : Tmp2;
|
|
|
|
// NOTE: on targets without efficient SELECT of bools, we can always use
|
|
// this identity: (B1 ? B2 : B3) --> (B1 & B2)|(!B1&B3)
|
|
Tmp1 = DAG.getSetCC(LowCC, LHSLo, RHSLo);
|
|
Tmp2 = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(),
|
|
LHSHi, RHSHi);
|
|
Result = DAG.getSetCC(ISD::SETEQ, LHSHi, RHSHi);
|
|
Result = DAG.getNode(ISD::SELECT, MVT::i1, Result, Tmp1, Tmp2);
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case ISD::ADD:
|
|
case ISD::SUB:
|
|
case ISD::MUL:
|
|
case ISD::UDIV:
|
|
case ISD::SDIV:
|
|
case ISD::UREM:
|
|
case ISD::SREM:
|
|
case ISD::AND:
|
|
case ISD::OR:
|
|
case ISD::XOR:
|
|
case ISD::SHL:
|
|
case ISD::SRL:
|
|
case ISD::SRA:
|
|
Tmp1 = LegalizeOp(Node->getOperand(0)); // LHS
|
|
Tmp2 = LegalizeOp(Node->getOperand(1)); // RHS
|
|
if (Tmp1 != Node->getOperand(0) ||
|
|
Tmp2 != Node->getOperand(1))
|
|
Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1,Tmp2);
|
|
break;
|
|
case ISD::ZERO_EXTEND:
|
|
case ISD::SIGN_EXTEND:
|
|
case ISD::TRUNCATE:
|
|
case ISD::FP_EXTEND:
|
|
case ISD::FP_ROUND:
|
|
case ISD::FP_TO_SINT:
|
|
case ISD::FP_TO_UINT:
|
|
case ISD::SINT_TO_FP:
|
|
case ISD::UINT_TO_FP:
|
|
|
|
switch (getTypeAction(Node->getOperand(0).getValueType())) {
|
|
case Legal:
|
|
Tmp1 = LegalizeOp(Node->getOperand(0));
|
|
if (Tmp1 != Node->getOperand(0))
|
|
Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1);
|
|
break;
|
|
case Expand:
|
|
// In the expand case, we must be dealing with a truncate, because
|
|
// otherwise the result would be larger than the source.
|
|
assert(Node->getOpcode() == ISD::TRUNCATE &&
|
|
"Shouldn't need to expand other operators here!");
|
|
ExpandOp(Node->getOperand(0), Tmp1, Tmp2);
|
|
|
|
// Since the result is legal, we should just be able to truncate the low
|
|
// part of the source.
|
|
Result = DAG.getNode(ISD::TRUNCATE, Node->getValueType(0), Tmp1);
|
|
break;
|
|
|
|
default:
|
|
assert(0 && "Do not know how to promote this yet!");
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (!Op.Val->hasOneUse())
|
|
AddLegalizedOperand(Op, Result);
|
|
|
|
return Result;
|
|
}
|
|
|
|
|
|
/// ExpandOp - Expand the specified SDOperand into its two component pieces
|
|
/// Lo&Hi. Note that the Op MUST be an expanded type. As a result of this, the
|
|
/// LegalizeNodes map is filled in for any results that are not expanded, the
|
|
/// ExpandedNodes map is filled in for any results that are expanded, and the
|
|
/// Lo/Hi values are returned.
|
|
void SelectionDAGLegalize::ExpandOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi){
|
|
MVT::ValueType VT = Op.getValueType();
|
|
MVT::ValueType NVT = TransformToType[VT];
|
|
SDNode *Node = Op.Val;
|
|
assert(getTypeAction(VT) == Expand && "Not an expanded type!");
|
|
assert(MVT::isInteger(VT) && "Cannot expand FP values!");
|
|
assert(MVT::isInteger(NVT) && NVT < VT &&
|
|
"Cannot expand to FP value or to larger int value!");
|
|
|
|
// If there is more than one use of this, see if we already expanded it.
|
|
// There is no use remembering values that only have a single use, as the map
|
|
// entries will never be reused.
|
|
if (!Node->hasOneUse()) {
|
|
std::map<SDOperand, std::pair<SDOperand, SDOperand> >::iterator I
|
|
= ExpandedNodes.find(Op);
|
|
if (I != ExpandedNodes.end()) {
|
|
Lo = I->second.first;
|
|
Hi = I->second.second;
|
|
return;
|
|
}
|
|
}
|
|
|
|
// Expanding to multiple registers needs to perform an optimization step, and
|
|
// is not careful to avoid operations the target does not support. Make sure
|
|
// that all generated operations are legalized in the next iteration.
|
|
NeedsAnotherIteration = true;
|
|
const char *LibCallName = 0;
|
|
|
|
switch (Node->getOpcode()) {
|
|
default:
|
|
std::cerr << "NODE: "; Node->dump(); std::cerr << "\n";
|
|
assert(0 && "Do not know how to expand this operator!");
|
|
abort();
|
|
case ISD::Constant: {
|
|
uint64_t Cst = cast<ConstantSDNode>(Node)->getValue();
|
|
Lo = DAG.getConstant(Cst, NVT);
|
|
Hi = DAG.getConstant(Cst >> MVT::getSizeInBits(NVT), NVT);
|
|
break;
|
|
}
|
|
|
|
case ISD::CopyFromReg: {
|
|
unsigned Reg = cast<CopyRegSDNode>(Node)->getReg();
|
|
// Aggregate register values are always in consequtive pairs.
|
|
Lo = DAG.getCopyFromReg(Reg, NVT);
|
|
Hi = DAG.getCopyFromReg(Reg+1, NVT);
|
|
assert(isTypeLegal(NVT) && "Cannot expand this multiple times yet!");
|
|
break;
|
|
}
|
|
|
|
case ISD::LOAD: {
|
|
SDOperand Ch = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
|
|
SDOperand Ptr = LegalizeOp(Node->getOperand(1)); // Legalize the pointer.
|
|
Lo = DAG.getLoad(NVT, Ch, Ptr);
|
|
|
|
// Increment the pointer to the other half.
|
|
unsigned IncrementSize;
|
|
switch (Lo.getValueType()) {
|
|
default: assert(0 && "Unknown ValueType to expand to!");
|
|
case MVT::i32: IncrementSize = 4; break;
|
|
case MVT::i16: IncrementSize = 2; break;
|
|
case MVT::i8: IncrementSize = 1; break;
|
|
}
|
|
Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr,
|
|
getIntPtrConstant(IncrementSize));
|
|
// FIXME: This load is independent of the first one.
|
|
Hi = DAG.getLoad(NVT, Lo.getValue(1), Ptr);
|
|
|
|
// Remember that we legalized the chain.
|
|
AddLegalizedOperand(Op.getValue(1), Hi.getValue(1));
|
|
if (!TLI.isLittleEndian())
|
|
std::swap(Lo, Hi);
|
|
break;
|
|
}
|
|
case ISD::CALL: {
|
|
SDOperand Chain = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
|
|
SDOperand Callee = LegalizeOp(Node->getOperand(1)); // Legalize the callee.
|
|
|
|
assert(Node->getNumValues() == 2 && Op.ResNo == 0 &&
|
|
"Can only expand a call once so far, not i64 -> i16!");
|
|
|
|
std::vector<MVT::ValueType> RetTyVTs;
|
|
RetTyVTs.reserve(3);
|
|
RetTyVTs.push_back(NVT);
|
|
RetTyVTs.push_back(NVT);
|
|
RetTyVTs.push_back(MVT::Other);
|
|
SDNode *NC = DAG.getCall(RetTyVTs, Chain, Callee);
|
|
Lo = SDOperand(NC, 0);
|
|
Hi = SDOperand(NC, 1);
|
|
|
|
// Insert the new chain mapping.
|
|
bool isNew = LegalizedNodes.insert(std::make_pair(Op.getValue(1),
|
|
Hi.getValue(2))).second;
|
|
assert(isNew && "This node was already legalized!");
|
|
break;
|
|
}
|
|
case ISD::AND:
|
|
case ISD::OR:
|
|
case ISD::XOR: { // Simple logical operators -> two trivial pieces.
|
|
SDOperand LL, LH, RL, RH;
|
|
ExpandOp(Node->getOperand(0), LL, LH);
|
|
ExpandOp(Node->getOperand(1), RL, RH);
|
|
Lo = DAG.getNode(Node->getOpcode(), NVT, LL, RL);
|
|
Hi = DAG.getNode(Node->getOpcode(), NVT, LH, RH);
|
|
break;
|
|
}
|
|
case ISD::SELECT: {
|
|
SDOperand C, LL, LH, RL, RH;
|
|
// FIXME: BOOLS MAY REQUIRE PROMOTION!
|
|
C = LegalizeOp(Node->getOperand(0));
|
|
ExpandOp(Node->getOperand(1), LL, LH);
|
|
ExpandOp(Node->getOperand(2), RL, RH);
|
|
Lo = DAG.getNode(ISD::SELECT, NVT, C, LL, RL);
|
|
Hi = DAG.getNode(ISD::SELECT, NVT, C, LH, RH);
|
|
break;
|
|
}
|
|
case ISD::SIGN_EXTEND: {
|
|
// The low part is just a sign extension of the input (which degenerates to
|
|
// a copy).
|
|
Lo = DAG.getNode(ISD::SIGN_EXTEND, NVT, LegalizeOp(Node->getOperand(0)));
|
|
|
|
// The high part is obtained by SRA'ing all but one of the bits of the lo
|
|
// part.
|
|
unsigned SrcSize = MVT::getSizeInBits(Node->getOperand(0).getValueType());
|
|
Hi = DAG.getNode(ISD::SRA, NVT, Lo, DAG.getConstant(SrcSize-1, MVT::i8));
|
|
break;
|
|
}
|
|
case ISD::ZERO_EXTEND:
|
|
// The low part is just a zero extension of the input (which degenerates to
|
|
// a copy).
|
|
Lo = DAG.getNode(ISD::ZERO_EXTEND, NVT, LegalizeOp(Node->getOperand(0)));
|
|
|
|
// The high part is just a zero.
|
|
Hi = DAG.getConstant(0, NVT);
|
|
break;
|
|
|
|
// These operators cannot be expanded directly, emit them as calls to
|
|
// library functions.
|
|
case ISD::FP_TO_SINT:
|
|
if (Node->getOperand(0).getValueType() == MVT::f32)
|
|
LibCallName = "__fixsfdi";
|
|
else
|
|
LibCallName = "__fixdfdi";
|
|
break;
|
|
case ISD::FP_TO_UINT:
|
|
if (Node->getOperand(0).getValueType() == MVT::f32)
|
|
LibCallName = "__fixunssfdi";
|
|
else
|
|
LibCallName = "__fixunsdfdi";
|
|
break;
|
|
|
|
case ISD::ADD: LibCallName = "__adddi3"; break;
|
|
case ISD::SUB: LibCallName = "__subdi3"; break;
|
|
case ISD::MUL: LibCallName = "__muldi3"; break;
|
|
case ISD::SDIV: LibCallName = "__divdi3"; break;
|
|
case ISD::UDIV: LibCallName = "__udivdi3"; break;
|
|
case ISD::SREM: LibCallName = "__moddi3"; break;
|
|
case ISD::UREM: LibCallName = "__umoddi3"; break;
|
|
case ISD::SHL: LibCallName = "__lshrdi3"; break;
|
|
case ISD::SRA: LibCallName = "__ashrdi3"; break;
|
|
case ISD::SRL: LibCallName = "__ashldi3"; break;
|
|
}
|
|
|
|
// Int2FP -> __floatdisf/__floatdidf
|
|
|
|
// If this is to be expanded into a libcall... do so now.
|
|
if (LibCallName) {
|
|
TargetLowering::ArgListTy Args;
|
|
for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i)
|
|
Args.push_back(std::make_pair(Node->getOperand(i),
|
|
getTypeFor(Node->getOperand(i).getValueType())));
|
|
SDOperand Callee = DAG.getExternalSymbol(LibCallName, TLI.getPointerTy());
|
|
|
|
// We don't care about token chains for libcalls. We just use the entry
|
|
// node as our input and ignore the output chain. This allows us to place
|
|
// calls wherever we need them to satisfy data dependences.
|
|
SDOperand Result = TLI.LowerCallTo(DAG.getEntryNode(),
|
|
getTypeFor(Op.getValueType()), Callee,
|
|
Args, DAG).first;
|
|
ExpandOp(Result, Lo, Hi);
|
|
}
|
|
|
|
// Remember in a map if the values will be reused later.
|
|
if (!Node->hasOneUse()) {
|
|
bool isNew = ExpandedNodes.insert(std::make_pair(Op,
|
|
std::make_pair(Lo, Hi))).second;
|
|
assert(isNew && "Value already expanded?!?");
|
|
}
|
|
}
|
|
|
|
|
|
// SelectionDAG::Legalize - This is the entry point for the file.
|
|
//
|
|
void SelectionDAG::Legalize(TargetLowering &TLI) {
|
|
/// run - This is the main entry point to this class.
|
|
///
|
|
SelectionDAGLegalize(TLI, *this).Run();
|
|
}
|
|
|