Factor out the code for mapping LLVM IR condition opcodes to

ISD condition opcodes into helper functions.

llvm-svn: 57726
This commit is contained in:
Dan Gohman 2008-10-17 21:16:08 +00:00
parent fe15bedff4
commit d01ddb51ee
2 changed files with 46 additions and 33 deletions

View File

@ -1051,32 +1051,26 @@ static ISD::CondCode getICmpCondCode(ICmpInst::Predicate Pred) {
}
}
/// FindMergedConditions - If Cond is an expression like
void SelectionDAGLowering::FindMergedConditions(Value *Cond,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
MachineBasicBlock *CurBB,
unsigned Opc) {
// If this node is not part of the or/and tree, emit it as a branch.
Instruction *BOp = dyn_cast<Instruction>(Cond);
/// EmitBranchForMergedCondition - Helper method for FindMergedConditions.
/// This function emits a branch and is used at the leaves of an OR or an
/// AND operator tree.
///
void
SelectionDAGLowering::EmitBranchForMergedCondition(Value *Cond,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
MachineBasicBlock *CurBB) {
const BasicBlock *BB = CurBB->getBasicBlock();
if (!BOp || !(isa<BinaryOperator>(BOp) || isa<CmpInst>(BOp)) ||
(unsigned)BOp->getOpcode() != Opc || !BOp->hasOneUse() ||
BOp->getParent() != CurBB->getBasicBlock() ||
!InBlock(BOp->getOperand(0), CurBB->getBasicBlock()) ||
!InBlock(BOp->getOperand(1), CurBB->getBasicBlock())) {
const BasicBlock *BB = CurBB->getBasicBlock();
// If the leaf of the tree is a comparison, merge the condition into
// the caseblock.
if (isa<CmpInst>(Cond) &&
// The operands of the cmp have to be in this block. We don't know
// how to export them from some other block. If this is the first block
// of the sequence, no exporting is needed.
(CurBB == CurMBB ||
(isExportableFromCurrentBlock(BOp->getOperand(0), BB) &&
isExportableFromCurrentBlock(BOp->getOperand(1), BB)))) {
BOp = cast<Instruction>(Cond);
// If the leaf of the tree is a comparison, merge the condition into
// the caseblock.
if (CmpInst *BOp = dyn_cast<CmpInst>(Cond)) {
// The operands of the cmp have to be in this block. We don't know
// how to export them from some other block. If this is the first block
// of the sequence, no exporting is needed.
if (CurBB == CurMBB ||
(isExportableFromCurrentBlock(BOp->getOperand(0), BB) &&
isExportableFromCurrentBlock(BOp->getOperand(1), BB))) {
ISD::CondCode Condition;
if (ICmpInst *IC = dyn_cast<ICmpInst>(Cond)) {
Condition = getICmpCondCode(IC->getPredicate());
@ -1086,21 +1080,37 @@ void SelectionDAGLowering::FindMergedConditions(Value *Cond,
Condition = ISD::SETEQ; // silence warning.
assert(0 && "Unknown compare instruction");
}
CaseBlock CB(Condition, BOp->getOperand(0),
CaseBlock CB(Condition, BOp->getOperand(0),
BOp->getOperand(1), NULL, TBB, FBB, CurBB);
SwitchCases.push_back(CB);
return;
}
// Create a CaseBlock record representing this branch.
CaseBlock CB(ISD::SETEQ, Cond, ConstantInt::getTrue(),
NULL, TBB, FBB, CurBB);
SwitchCases.push_back(CB);
}
// Create a CaseBlock record representing this branch.
CaseBlock CB(ISD::SETEQ, Cond, ConstantInt::getTrue(),
NULL, TBB, FBB, CurBB);
SwitchCases.push_back(CB);
}
/// FindMergedConditions - If Cond is an expression like
void SelectionDAGLowering::FindMergedConditions(Value *Cond,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
MachineBasicBlock *CurBB,
unsigned Opc) {
// If this node is not part of the or/and tree, emit it as a branch.
Instruction *BOp = dyn_cast<Instruction>(Cond);
if (!BOp || !(isa<BinaryOperator>(BOp) || isa<CmpInst>(BOp)) ||
(unsigned)BOp->getOpcode() != Opc || !BOp->hasOneUse() ||
BOp->getParent() != CurBB->getBasicBlock() ||
!InBlock(BOp->getOperand(0), CurBB->getBasicBlock()) ||
!InBlock(BOp->getOperand(1), CurBB->getBasicBlock())) {
EmitBranchForMergedCondition(Cond, TBB, FBB, CurBB);
return;
}
// Create TmpBB after CurBB.
MachineFunction::iterator BBI = CurBB;
MachineFunction &MF = DAG.getMachineFunction();

View File

@ -405,6 +405,9 @@ public:
void FindMergedConditions(Value *Cond, MachineBasicBlock *TBB,
MachineBasicBlock *FBB, MachineBasicBlock *CurBB,
unsigned Opc);
void EmitBranchForMergedCondition(Value *Cond, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
MachineBasicBlock *CurBB);
bool ShouldEmitAsBranches(const std::vector<CaseBlock> &Cases);
bool isExportableFromCurrentBlock(Value *V, const BasicBlock *FromBB);
void ExportFromCurrentBlock(Value *V);