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

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11 KiB
C++

//===- AffineExpr.cpp - MLIR Affine Expr 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/AffineExpr.h"
#include "AffineExprDetail.h"
#include "mlir/IR/AffineExprVisitor.h"
#include "mlir/IR/AffineMap.h"
#include "mlir/Support/STLExtras.h"
#include "llvm/ADT/STLExtras.h"
using namespace mlir;
using namespace mlir::detail;
MLIRContext *AffineExpr::getContext() const {
return expr->contextAndKind.getPointer();
}
AffineExprKind AffineExpr::getKind() const {
return expr->contextAndKind.getInt();
}
/// Walk all of the AffineExprs in this subgraph in postorder.
void AffineExpr::walk(std::function<void(AffineExpr)> callback) const {
struct AffineExprWalker : public AffineExprVisitor<AffineExprWalker> {
std::function<void(AffineExpr)> callback;
AffineExprWalker(std::function<void(AffineExpr)> callback)
: callback(callback) {}
void visitAffineBinaryOpExpr(AffineBinaryOpExpr expr) { callback(expr); }
void visitConstantExpr(AffineConstantExpr expr) { callback(expr); }
void visitDimExpr(AffineDimExpr expr) { callback(expr); }
void visitSymbolExpr(AffineSymbolExpr expr) { callback(expr); }
};
AffineExprWalker(callback).walkPostOrder(*this);
}
/// This method substitutes any uses of dimensions and symbols (e.g.
/// dim#0 with dimReplacements[0]) and returns the modified expression tree.
AffineExpr
AffineExpr::replaceDimsAndSymbols(ArrayRef<AffineExpr> dimReplacements,
ArrayRef<AffineExpr> symReplacements) const {
switch (getKind()) {
case AffineExprKind::Constant:
return *this;
case AffineExprKind::DimId: {
unsigned dimId = cast<AffineDimExpr>().getPosition();
if (dimId >= dimReplacements.size())
return *this;
return dimReplacements[dimId];
}
case AffineExprKind::SymbolId: {
unsigned symId = cast<AffineSymbolExpr>().getPosition();
if (symId >= symReplacements.size())
return *this;
return symReplacements[symId];
}
case AffineExprKind::Add:
case AffineExprKind::Mul:
case AffineExprKind::FloorDiv:
case AffineExprKind::CeilDiv:
case AffineExprKind::Mod:
auto binOp = cast<AffineBinaryOpExpr>();
auto lhs = binOp.getLHS(), rhs = binOp.getRHS();
auto newLHS = lhs.replaceDimsAndSymbols(dimReplacements, symReplacements);
auto newRHS = rhs.replaceDimsAndSymbols(dimReplacements, symReplacements);
if (newLHS == lhs && newRHS == rhs)
return *this;
return getAffineBinaryOpExpr(getKind(), newLHS, newRHS);
}
}
/// Returns true if this expression is made out of only symbols and
/// constants (no dimensional identifiers).
bool AffineExpr::isSymbolicOrConstant() const {
switch (getKind()) {
case AffineExprKind::Constant:
return true;
case AffineExprKind::DimId:
return false;
case AffineExprKind::SymbolId:
return true;
case AffineExprKind::Add:
case AffineExprKind::Mul:
case AffineExprKind::FloorDiv:
case AffineExprKind::CeilDiv:
case AffineExprKind::Mod: {
auto expr = this->cast<AffineBinaryOpExpr>();
return expr.getLHS().isSymbolicOrConstant() &&
expr.getRHS().isSymbolicOrConstant();
}
}
}
/// Returns true if this is a pure affine expression, i.e., multiplication,
/// floordiv, ceildiv, and mod is only allowed w.r.t constants.
bool AffineExpr::isPureAffine() const {
switch (getKind()) {
case AffineExprKind::SymbolId:
case AffineExprKind::DimId:
case AffineExprKind::Constant:
return true;
case AffineExprKind::Add: {
auto op = cast<AffineBinaryOpExpr>();
return op.getLHS().isPureAffine() && op.getRHS().isPureAffine();
}
case AffineExprKind::Mul: {
// TODO: Canonicalize the constants in binary operators to the RHS when
// possible, allowing this to merge into the next case.
auto op = cast<AffineBinaryOpExpr>();
return op.getLHS().isPureAffine() && op.getRHS().isPureAffine() &&
(op.getLHS().template isa<AffineConstantExpr>() ||
op.getRHS().template isa<AffineConstantExpr>());
}
case AffineExprKind::FloorDiv:
case AffineExprKind::CeilDiv:
case AffineExprKind::Mod: {
auto op = cast<AffineBinaryOpExpr>();
return op.getLHS().isPureAffine() &&
op.getRHS().template isa<AffineConstantExpr>();
}
}
}
/// Returns the greatest known integral divisor of this affine expression.
uint64_t AffineExpr::getLargestKnownDivisor() const {
AffineBinaryOpExpr binExpr(nullptr);
switch (getKind()) {
case AffineExprKind::SymbolId:
LLVM_FALLTHROUGH;
case AffineExprKind::DimId:
return 1;
case AffineExprKind::Constant:
return std::abs(this->cast<AffineConstantExpr>().getValue());
case AffineExprKind::Mul: {
binExpr = this->cast<AffineBinaryOpExpr>();
return binExpr.getLHS().getLargestKnownDivisor() *
binExpr.getRHS().getLargestKnownDivisor();
}
case AffineExprKind::Add:
LLVM_FALLTHROUGH;
case AffineExprKind::FloorDiv:
case AffineExprKind::CeilDiv:
case AffineExprKind::Mod: {
binExpr = cast<AffineBinaryOpExpr>();
return llvm::GreatestCommonDivisor64(
binExpr.getLHS().getLargestKnownDivisor(),
binExpr.getRHS().getLargestKnownDivisor());
}
}
}
bool AffineExpr::isMultipleOf(int64_t factor) const {
AffineBinaryOpExpr binExpr(nullptr);
uint64_t l, u;
switch (getKind()) {
case AffineExprKind::SymbolId:
LLVM_FALLTHROUGH;
case AffineExprKind::DimId:
return factor * factor == 1;
case AffineExprKind::Constant:
return cast<AffineConstantExpr>().getValue() % factor == 0;
case AffineExprKind::Mul: {
binExpr = cast<AffineBinaryOpExpr>();
// It's probably not worth optimizing this further (to not traverse the
// whole sub-tree under - it that would require a version of isMultipleOf
// that on a 'false' return also returns the largest known divisor).
return (l = binExpr.getLHS().getLargestKnownDivisor()) % factor == 0 ||
(u = binExpr.getRHS().getLargestKnownDivisor()) % factor == 0 ||
(l * u) % factor == 0;
}
case AffineExprKind::Add:
case AffineExprKind::FloorDiv:
case AffineExprKind::CeilDiv:
case AffineExprKind::Mod: {
binExpr = cast<AffineBinaryOpExpr>();
return llvm::GreatestCommonDivisor64(
binExpr.getLHS().getLargestKnownDivisor(),
binExpr.getRHS().getLargestKnownDivisor()) %
factor ==
0;
}
}
}
bool AffineExpr::isFunctionOfDim(unsigned position) const {
if (getKind() == AffineExprKind::DimId) {
return *this == mlir::getAffineDimExpr(position, getContext());
}
if (auto expr = this->dyn_cast<AffineBinaryOpExpr>()) {
return expr.getLHS().isFunctionOfDim(position) ||
expr.getRHS().isFunctionOfDim(position);
}
return false;
}
AffineBinaryOpExpr::AffineBinaryOpExpr(AffineExpr::ImplType *ptr)
: AffineExpr(ptr) {}
AffineExpr AffineBinaryOpExpr::getLHS() const {
return static_cast<ImplType *>(expr)->lhs;
}
AffineExpr AffineBinaryOpExpr::getRHS() const {
return static_cast<ImplType *>(expr)->rhs;
}
AffineDimExpr::AffineDimExpr(AffineExpr::ImplType *ptr) : AffineExpr(ptr) {}
unsigned AffineDimExpr::getPosition() const {
return static_cast<ImplType *>(expr)->position;
}
AffineSymbolExpr::AffineSymbolExpr(AffineExpr::ImplType *ptr)
: AffineExpr(ptr) {}
unsigned AffineSymbolExpr::getPosition() const {
return static_cast<ImplType *>(expr)->position;
}
AffineConstantExpr::AffineConstantExpr(AffineExpr::ImplType *ptr)
: AffineExpr(ptr) {}
int64_t AffineConstantExpr::getValue() const {
return static_cast<ImplType *>(expr)->constant;
}
AffineExpr AffineExpr::operator+(int64_t v) const {
return AffineBinaryOpExprStorage::get(AffineExprKind::Add, expr,
getAffineConstantExpr(v, getContext()));
}
AffineExpr AffineExpr::operator+(AffineExpr other) const {
return AffineBinaryOpExprStorage::get(AffineExprKind::Add, expr, other.expr);
}
AffineExpr AffineExpr::operator*(int64_t v) const {
return AffineBinaryOpExprStorage::get(AffineExprKind::Mul, expr,
getAffineConstantExpr(v, getContext()));
}
AffineExpr AffineExpr::operator*(AffineExpr other) const {
return AffineBinaryOpExprStorage::get(AffineExprKind::Mul, expr, other.expr);
}
// Unary minus, delegate to operator*.
AffineExpr AffineExpr::operator-() const {
return AffineBinaryOpExprStorage::get(
AffineExprKind::Mul, expr, getAffineConstantExpr(-1, getContext()));
}
// Delegate to operator+.
AffineExpr AffineExpr::operator-(int64_t v) const { return *this + (-v); }
AffineExpr AffineExpr::operator-(AffineExpr other) const {
return *this + (-other);
}
AffineExpr AffineExpr::floorDiv(uint64_t v) const {
return AffineBinaryOpExprStorage::get(AffineExprKind::FloorDiv, expr,
getAffineConstantExpr(v, getContext()));
}
AffineExpr AffineExpr::floorDiv(AffineExpr other) const {
return AffineBinaryOpExprStorage::get(AffineExprKind::FloorDiv, expr,
other.expr);
}
AffineExpr AffineExpr::ceilDiv(uint64_t v) const {
return AffineBinaryOpExprStorage::get(AffineExprKind::CeilDiv, expr,
getAffineConstantExpr(v, getContext()));
}
AffineExpr AffineExpr::ceilDiv(AffineExpr other) const {
return AffineBinaryOpExprStorage::get(AffineExprKind::CeilDiv, expr,
other.expr);
}
AffineExpr AffineExpr::operator%(uint64_t v) const {
return AffineBinaryOpExprStorage::get(AffineExprKind::Mod, expr,
getAffineConstantExpr(v, getContext()));
}
AffineExpr AffineExpr::operator%(AffineExpr other) const {
return AffineBinaryOpExprStorage::get(AffineExprKind::Mod, expr, other.expr);
}
AffineExpr AffineExpr::compose(AffineMap map) const {
SmallVector<AffineExpr, 8> dimReplacements(map.getResults().begin(),
map.getResults().end());
return replaceDimsAndSymbols(dimReplacements, {});
}
raw_ostream &operator<<(raw_ostream &os, AffineExpr &expr) {
expr.print(os);
return os;
}