llvm-project/mlir/lib/IR/StmtBlock.cpp

146 lines
4.6 KiB
C++

//===- StmtBlock.cpp - MLIR Statement Instruction Classes -----------------===//
//
// Copyright 2019 The MLIR Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// =============================================================================
#include "mlir/IR/StmtBlock.h"
#include "mlir/IR/MLFunction.h"
#include "mlir/IR/Statements.h"
using namespace mlir;
StmtBlock::~StmtBlock() {
clear();
llvm::DeleteContainerPointers(arguments);
}
Statement *StmtBlock::getContainingStmt() {
switch (kind) {
case StmtBlockKind::MLFunc:
return nullptr;
case StmtBlockKind::ForBody:
return cast<ForStmtBody>(this)->getFor();
case StmtBlockKind::IfClause:
return cast<IfClause>(this)->getIf();
}
}
MLFunction *StmtBlock::findFunction() const {
// FIXME: const incorrect.
StmtBlock *block = const_cast<StmtBlock *>(this);
while (block->getContainingStmt()) {
block = block->getContainingStmt()->getBlock();
if (!block)
return nullptr;
}
return dyn_cast<MLFunction>(block);
}
/// Returns 'stmt' if 'stmt' lies in this block, or otherwise finds the ancestor
/// statement of 'stmt' that lies in this block. Returns nullptr if the latter
/// fails.
const Statement *
StmtBlock::findAncestorStmtInBlock(const Statement &stmt) const {
// Traverse up the statement hierarchy starting from the owner of operand to
// find the ancestor statement that resides in the block of 'forStmt'.
const auto *currStmt = &stmt;
while (currStmt->getBlock() != this) {
currStmt = currStmt->getParentStmt();
if (!currStmt)
return nullptr;
}
return currStmt;
}
//===----------------------------------------------------------------------===//
// Argument list management.
//===----------------------------------------------------------------------===//
BlockArgument *StmtBlock::addArgument(Type type) {
auto *arg = new BlockArgument(type, this);
arguments.push_back(arg);
return arg;
}
/// Add one argument to the argument list for each type specified in the list.
auto StmtBlock::addArguments(ArrayRef<Type> types)
-> llvm::iterator_range<args_iterator> {
arguments.reserve(arguments.size() + types.size());
auto initialSize = arguments.size();
for (auto type : types) {
addArgument(type);
}
return {arguments.data() + initialSize, arguments.data() + arguments.size()};
}
void StmtBlock::eraseArgument(unsigned index) {
assert(index < arguments.size());
// Delete the argument.
delete arguments[index];
arguments.erase(arguments.begin() + index);
// Erase this argument from each of the predecessor's terminator.
for (auto predIt = pred_begin(), predE = pred_end(); predIt != predE;
++predIt) {
auto *predTerminator = (*predIt)->getTerminator();
predTerminator->eraseSuccessorOperand(predIt.getSuccessorIndex(), index);
}
}
//===----------------------------------------------------------------------===//
// Terminator management
//===----------------------------------------------------------------------===//
OperationStmt *StmtBlock::getTerminator() {
if (empty())
return nullptr;
// Check if the last instruction is a terminator.
auto &backInst = statements.back();
auto *opStmt = dyn_cast<OperationStmt>(&backInst);
if (!opStmt || !opStmt->isTerminator())
return nullptr;
return opStmt;
}
/// Return true if this block has no predecessors.
bool StmtBlock::hasNoPredecessors() const { return pred_begin() == pred_end(); }
// Indexed successor access.
unsigned StmtBlock::getNumSuccessors() const {
return getTerminator()->getNumSuccessors();
}
StmtBlock *StmtBlock::getSuccessor(unsigned i) {
return getTerminator()->getSuccessor(i);
}
/// If this block has exactly one predecessor, return it. Otherwise, return
/// null.
///
/// Note that multiple edges from a single block (e.g. if you have a cond
/// branch with the same block as the true/false destinations) is not
/// considered to be a single predecessor.
StmtBlock *StmtBlock::getSinglePredecessor() {
auto it = pred_begin();
if (it == pred_end())
return nullptr;
auto *firstPred = *it;
++it;
return it == pred_end() ? firstPred : nullptr;
}