MLIR  21.0.0git
StaticValueUtils.cpp
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1 //===- StaticValueUtils.cpp - Utilities for dealing with static values ----===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
10 #include "mlir/IR/Matchers.h"
11 #include "mlir/Support/LLVM.h"
12 #include "llvm/ADT/APSInt.h"
13 #include "llvm/ADT/STLExtras.h"
14 #include "llvm/Support/MathExtras.h"
15 
16 namespace mlir {
17 
19 
20 bool isOneInteger(OpFoldResult v) { return isConstantIntValue(v, 1); }
21 
22 std::tuple<SmallVector<OpFoldResult>, SmallVector<OpFoldResult>,
23  SmallVector<OpFoldResult>>
25  SmallVector<OpFoldResult> offsets, sizes, strides;
26  offsets.reserve(ranges.size());
27  sizes.reserve(ranges.size());
28  strides.reserve(ranges.size());
29  for (const auto &[offset, size, stride] : ranges) {
30  offsets.push_back(offset);
31  sizes.push_back(size);
32  strides.push_back(stride);
33  }
34  return std::make_tuple(offsets, sizes, strides);
35 }
36 
37 /// Helper function to dispatch an OpFoldResult into `staticVec` if:
38 /// a) it is an IntegerAttr
39 /// In other cases, the OpFoldResult is dispached to the `dynamicVec`.
40 /// In such dynamic cases, a copy of the `sentinel` value is also pushed to
41 /// `staticVec`. This is useful to extract mixed static and dynamic entries that
42 /// come from an AttrSizedOperandSegments trait.
44  SmallVectorImpl<Value> &dynamicVec,
45  SmallVectorImpl<int64_t> &staticVec) {
46  auto v = llvm::dyn_cast_if_present<Value>(ofr);
47  if (!v) {
48  APInt apInt = cast<IntegerAttr>(cast<Attribute>(ofr)).getValue();
49  staticVec.push_back(apInt.getSExtValue());
50  return;
51  }
52  dynamicVec.push_back(v);
53  staticVec.push_back(ShapedType::kDynamic);
54 }
55 
56 std::pair<int64_t, OpFoldResult>
58  int64_t tileSizeForShape =
59  getConstantIntValue(tileSizeOfr).value_or(ShapedType::kDynamic);
60 
61  OpFoldResult tileSizeOfrSimplified =
62  (tileSizeForShape != ShapedType::kDynamic)
63  ? b.getIndexAttr(tileSizeForShape)
64  : tileSizeOfr;
65 
66  return std::pair<int64_t, OpFoldResult>(tileSizeForShape,
67  tileSizeOfrSimplified);
68 }
69 
71  SmallVectorImpl<Value> &dynamicVec,
72  SmallVectorImpl<int64_t> &staticVec) {
73  for (OpFoldResult ofr : ofrs)
74  dispatchIndexOpFoldResult(ofr, dynamicVec, staticVec);
75 }
76 
77 /// Given a value, try to extract a constant Attribute. If this fails, return
78 /// the original value.
80  if (!val)
81  return OpFoldResult();
82  Attribute attr;
83  if (matchPattern(val, m_Constant(&attr)))
84  return attr;
85  return val;
86 }
87 
88 /// Given an array of values, try to extract a constant Attribute from each
89 /// value. If this fails, return the original value.
91  return llvm::to_vector(
92  llvm::map_range(values, [](Value v) { return getAsOpFoldResult(v); }));
93 }
94 
95 /// Convert `arrayAttr` to a vector of OpFoldResult.
98  res.reserve(arrayAttr.size());
99  for (Attribute a : arrayAttr)
100  res.push_back(a);
101  return res;
102 }
103 
105  return IntegerAttr::get(IndexType::get(ctx), val);
106 }
107 
109  ArrayRef<int64_t> values) {
110  return llvm::to_vector(llvm::map_range(
111  values, [ctx](int64_t v) { return getAsIndexOpFoldResult(ctx, v); }));
112 }
113 
114 /// If ofr is a constant integer or an IntegerAttr, return the integer.
115 std::optional<int64_t> getConstantIntValue(OpFoldResult ofr) {
116  // Case 1: Check for Constant integer.
117  if (auto val = llvm::dyn_cast_if_present<Value>(ofr)) {
118  APSInt intVal;
119  if (matchPattern(val, m_ConstantInt(&intVal)))
120  return intVal.getSExtValue();
121  return std::nullopt;
122  }
123  // Case 2: Check for IntegerAttr.
124  Attribute attr = llvm::dyn_cast_if_present<Attribute>(ofr);
125  if (auto intAttr = dyn_cast_or_null<IntegerAttr>(attr))
126  return intAttr.getValue().getSExtValue();
127  return std::nullopt;
128 }
129 
130 std::optional<SmallVector<int64_t>>
132  bool failed = false;
133  SmallVector<int64_t> res = llvm::map_to_vector(ofrs, [&](OpFoldResult ofr) {
134  auto cv = getConstantIntValue(ofr);
135  if (!cv.has_value())
136  failed = true;
137  return cv.value_or(0);
138  });
139  if (failed)
140  return std::nullopt;
141  return res;
142 }
143 
144 bool isConstantIntValue(OpFoldResult ofr, int64_t value) {
145  auto val = getConstantIntValue(ofr);
146  return val && *val == value;
147 }
148 
150  return llvm::all_of(
151  ofrs, [&](OpFoldResult ofr) { return isConstantIntValue(ofr, value); });
152 }
153 
155  ArrayRef<int64_t> values) {
156  if (ofrs.size() != values.size())
157  return false;
158  std::optional<SmallVector<int64_t>> constOfrs = getConstantIntValues(ofrs);
159  return constOfrs && llvm::equal(constOfrs.value(), values);
160 }
161 
162 /// Return true if ofr1 and ofr2 are the same integer constant attribute values
163 /// or the same SSA value.
164 /// Ignore integer bitwidth and type mismatch that come from the fact there is
165 /// no IndexAttr and that IndexType has no bitwidth.
167  auto cst1 = getConstantIntValue(ofr1), cst2 = getConstantIntValue(ofr2);
168  if (cst1 && cst2 && *cst1 == *cst2)
169  return true;
170  auto v1 = llvm::dyn_cast_if_present<Value>(ofr1),
171  v2 = llvm::dyn_cast_if_present<Value>(ofr2);
172  return v1 && v1 == v2;
173 }
174 
176  ArrayRef<OpFoldResult> ofrs2) {
177  if (ofrs1.size() != ofrs2.size())
178  return false;
179  for (auto [ofr1, ofr2] : llvm::zip_equal(ofrs1, ofrs2))
180  if (!isEqualConstantIntOrValue(ofr1, ofr2))
181  return false;
182  return true;
183 }
184 
185 /// Return a vector of OpFoldResults with the same size a staticValues, but all
186 /// elements for which ShapedType::isDynamic is true, will be replaced by
187 /// dynamicValues.
189  ValueRange dynamicValues,
190  MLIRContext *context) {
192  res.reserve(staticValues.size());
193  unsigned numDynamic = 0;
194  unsigned count = static_cast<unsigned>(staticValues.size());
195  for (unsigned idx = 0; idx < count; ++idx) {
196  int64_t value = staticValues[idx];
197  res.push_back(ShapedType::isDynamic(value)
198  ? OpFoldResult{dynamicValues[numDynamic++]}
200  IntegerType::get(context, 64), staticValues[idx])});
201  }
202  return res;
203 }
205  ValueRange dynamicValues, Builder &b) {
206  return getMixedValues(staticValues, dynamicValues, b.getContext());
207 }
208 
209 /// Decompose a vector of mixed static or dynamic values into the corresponding
210 /// pair of arrays. This is the inverse function of `getMixedValues`.
211 std::pair<SmallVector<int64_t>, SmallVector<Value>>
213  SmallVector<int64_t> staticValues;
214  SmallVector<Value> dynamicValues;
215  for (const auto &it : mixedValues) {
216  if (auto attr = dyn_cast<Attribute>(it)) {
217  staticValues.push_back(cast<IntegerAttr>(attr).getInt());
218  } else {
219  staticValues.push_back(ShapedType::kDynamic);
220  dynamicValues.push_back(cast<Value>(it));
221  }
222  }
223  return {staticValues, dynamicValues};
224 }
225 
226 /// Helper to sort `values` according to matching `keys`.
227 template <typename K, typename V>
228 static SmallVector<V>
230  llvm::function_ref<bool(K, K)> compare) {
231  if (keys.empty())
232  return SmallVector<V>{values};
233  assert(keys.size() == values.size() && "unexpected mismatching sizes");
234  auto indices = llvm::to_vector(llvm::seq<int64_t>(0, values.size()));
235  llvm::sort(indices,
236  [&](int64_t i, int64_t j) { return compare(keys[i], keys[j]); });
237  SmallVector<V> res;
238  res.reserve(values.size());
239  for (int64_t i = 0, e = indices.size(); i < e; ++i)
240  res.push_back(values[indices[i]]);
241  return res;
242 }
243 
244 SmallVector<Value>
247  return getValuesSortedByKeyImpl(keys, values, compare);
248 }
249 
250 SmallVector<OpFoldResult>
253  return getValuesSortedByKeyImpl(keys, values, compare);
254 }
255 
256 SmallVector<int64_t>
259  return getValuesSortedByKeyImpl(keys, values, compare);
260 }
261 
262 /// Return the number of iterations for a loop with a lower bound `lb`, upper
263 /// bound `ub` and step `step`.
264 std::optional<int64_t> constantTripCount(OpFoldResult lb, OpFoldResult ub,
265  OpFoldResult step) {
266  if (lb == ub)
267  return 0;
268 
269  std::optional<int64_t> lbConstant = getConstantIntValue(lb);
270  if (!lbConstant)
271  return std::nullopt;
272  std::optional<int64_t> ubConstant = getConstantIntValue(ub);
273  if (!ubConstant)
274  return std::nullopt;
275  std::optional<int64_t> stepConstant = getConstantIntValue(step);
276  if (!stepConstant)
277  return std::nullopt;
278 
279  return llvm::divideCeilSigned(*ubConstant - *lbConstant, *stepConstant);
280 }
281 
283  return llvm::none_of(sizesOrOffsets, [](int64_t value) {
284  return !ShapedType::isDynamic(value) && value < 0;
285  });
286 }
287 
289  return llvm::none_of(strides, [](int64_t value) {
290  return !ShapedType::isDynamic(value) && value == 0;
291  });
292 }
293 
295  bool onlyNonNegative, bool onlyNonZero) {
296  bool valuesChanged = false;
297  for (OpFoldResult &ofr : ofrs) {
298  if (isa<Attribute>(ofr))
299  continue;
300  Attribute attr;
301  if (matchPattern(cast<Value>(ofr), m_Constant(&attr))) {
302  // Note: All ofrs have index type.
303  if (onlyNonNegative && *getConstantIntValue(attr) < 0)
304  continue;
305  if (onlyNonZero && *getConstantIntValue(attr) == 0)
306  continue;
307  ofr = attr;
308  valuesChanged = true;
309  }
310  }
311  return success(valuesChanged);
312 }
313 
314 LogicalResult
316  return foldDynamicIndexList(offsetsOrSizes, /*onlyNonNegative=*/true,
317  /*onlyNonZero=*/false);
318 }
319 
321  return foldDynamicIndexList(strides, /*onlyNonNegative=*/false,
322  /*onlyNonZero=*/true);
323 }
324 
325 } // namespace mlir
Attributes are known-constant values of operations.
Definition: Attributes.h:25
This class is a general helper class for creating context-global objects like types,...
Definition: Builders.h:50
IntegerAttr getIndexAttr(int64_t value)
Definition: Builders.cpp:106
MLIRContext * getContext() const
Definition: Builders.h:55
MLIRContext is the top-level object for a collection of MLIR operations.
Definition: MLIRContext.h:60
This class represents a single result from folding an operation.
Definition: OpDefinition.h:271
This class provides an abstraction over the different types of ranges over Values.
Definition: ValueRange.h:387
This class represents an instance of an SSA value in the MLIR system, representing a computable value...
Definition: Value.h:96
int compare(const Fraction &x, const Fraction &y)
Three-way comparison between two fractions.
Definition: Fraction.h:68
Include the generated interface declarations.
bool matchPattern(Value value, const Pattern &pattern)
Entry point for matching a pattern over a Value.
Definition: Matchers.h:490
bool isConstantIntValue(OpFoldResult ofr, int64_t value)
Return true if ofr is constant integer equal to value.
detail::constant_int_value_binder m_ConstantInt(IntegerAttr::ValueType *bind_value)
Matches a constant holding a scalar/vector/tensor integer (splat) and writes the integer value to bin...
Definition: Matchers.h:527
bool areConstantIntValues(ArrayRef< OpFoldResult > ofrs, ArrayRef< int64_t > values)
Return true if all of ofrs are constant integers equal to the corresponding value in values.
OpFoldResult getAsIndexOpFoldResult(MLIRContext *ctx, int64_t val)
Convert int64_t to integer attributes of index type and return them as OpFoldResult.
std::tuple< SmallVector< OpFoldResult >, SmallVector< OpFoldResult >, SmallVector< OpFoldResult > > getOffsetsSizesAndStrides(ArrayRef< Range > ranges)
Given an array of Range values, return a tuple of (offset vector, sizes vector, and strides vector) f...
std::optional< int64_t > getConstantIntValue(OpFoldResult ofr)
If ofr is a constant integer or an IntegerAttr, return the integer.
LogicalResult foldDynamicStrideList(SmallVectorImpl< OpFoldResult > &strides)
Returns "success" when any of the elements in strides is a constant value.
bool areAllConstantIntValue(ArrayRef< OpFoldResult > ofrs, int64_t value)
Return true if all of ofrs are constant integers equal to value.
bool isEqualConstantIntOrValue(OpFoldResult ofr1, OpFoldResult ofr2)
Return true if ofr1 and ofr2 are the same integer constant attribute values or the same SSA value.
bool hasValidSizesOffsets(SmallVector< int64_t > sizesOrOffsets)
Helper function to check whether the passed in sizes or offsets are valid.
std::optional< int64_t > constantTripCount(OpFoldResult lb, OpFoldResult ub, OpFoldResult step)
Return the number of iterations for a loop with a lower bound lb, upper bound ub and step step.
bool isZeroInteger(OpFoldResult v)
Return true if v is an IntegerAttr with value 0.
bool hasValidStrides(SmallVector< int64_t > strides)
Helper function to check whether the passed in strides are valid.
void dispatchIndexOpFoldResults(ArrayRef< OpFoldResult > ofrs, SmallVectorImpl< Value > &dynamicVec, SmallVectorImpl< int64_t > &staticVec)
Helper function to dispatch multiple OpFoldResults according to the behavior of dispatchIndexOpFoldRe...
std::pair< SmallVector< int64_t >, SmallVector< Value > > decomposeMixedValues(const SmallVectorImpl< OpFoldResult > &mixedValues)
Decompose a vector of mixed static or dynamic values into the corresponding pair of arrays.
static SmallVector< V > getValuesSortedByKeyImpl(ArrayRef< K > keys, ArrayRef< V > values, llvm::function_ref< bool(K, K)> compare)
Helper to sort values according to matching keys.
bool isEqualConstantIntOrValueArray(ArrayRef< OpFoldResult > ofrs1, ArrayRef< OpFoldResult > ofrs2)
auto get(MLIRContext *context, Ts &&...params)
Helper method that injects context only if needed, this helps unify some of the attribute constructio...
void dispatchIndexOpFoldResult(OpFoldResult ofr, SmallVectorImpl< Value > &dynamicVec, SmallVectorImpl< int64_t > &staticVec)
Helper function to dispatch an OpFoldResult into staticVec if: a) it is an IntegerAttr In other cases...
OpFoldResult getAsOpFoldResult(Value val)
Given a value, try to extract a constant Attribute.
SmallVector< OpFoldResult > getMixedValues(ArrayRef< int64_t > staticValues, ValueRange dynamicValues, MLIRContext *context)
Return a vector of OpFoldResults with the same size a staticValues, but all elements for which Shaped...
detail::constant_op_matcher m_Constant()
Matches a constant foldable operation.
Definition: Matchers.h:369
std::pair< int64_t, OpFoldResult > getSimplifiedOfrAndStaticSizePair(OpFoldResult ofr, Builder &b)
Given OpFoldResult representing dim size value (*), generates a pair of sizes:
std::optional< SmallVector< int64_t > > getConstantIntValues(ArrayRef< OpFoldResult > ofrs)
If all ofrs are constant integers or IntegerAttrs, return the integers.
SmallVector< Value > getValuesSortedByKey(ArrayRef< Attribute > keys, ArrayRef< Value > values, llvm::function_ref< bool(Attribute, Attribute)> compare)
Helper to sort values according to matching keys.
LogicalResult foldDynamicOffsetSizeList(SmallVectorImpl< OpFoldResult > &offsetsOrSizes)
Returns "success" when any of the elements in offsetsOrSizes is a constant value.
bool isOneInteger(OpFoldResult v)
Return true if v is an IntegerAttr with value 1.
LogicalResult foldDynamicIndexList(SmallVectorImpl< OpFoldResult > &ofrs, bool onlyNonNegative=false, bool onlyNonZero=false)
Returns "success" when any of the elements in ofrs is a constant value.
Eliminates variable at the specified position using Fourier-Motzkin variable elimination.