1/**
2 * Copyright (c) Glow Contributors. See CONTRIBUTORS file.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "glow/IR/IRUtils.h"
18#include "glow/IR/Instrs.h"
19
20#include "llvm/Support/Casting.h"
21
22using namespace glow;
23using llvm::dyn_cast;
24using llvm::isa;
25
26bool glow::isTensorView(glow::Value *v) { return isa<TensorViewInst>(v); }
27
28size_t glow::calculateTensorViewOffset(const TensorViewInst *TVI) {
29 // Pop tensor views off repeatedly until we reach the origin, in case there
30 // are multiple stacked together, to calculate the total offset.
31 const TensorViewInst *currTVI = TVI;
32 size_t totalOffsetLength = 0;
33 do {
34 // Get the offset into the current base Tensor in bytes. Aggregate all
35 // offsets from stacked TVIs into totalOffsetLength.
36 totalOffsetLength +=
37 getFlattenedOffset(currTVI->getSrc()->getType()->strides(),
38 currTVI->getOffsets()) *
39 currTVI->getType()->getElementSize();
40 } while ((currTVI = dyn_cast<TensorViewInst>(currTVI->getSrc())));
41
42 return totalOffsetLength;
43}
44
45Value *glow::getAllocationOrigin(Value *V) {
46 while (true) {
47 if (auto *AI = dyn_cast<AllocActivationInst>(V))
48 return AI;
49 if (auto *TVI = dyn_cast<TensorViewInst>(V)) {
50 V = TVI->getSrc();
51 continue;
52 }
53 return nullptr;
54 }
55 return nullptr;
56}
57
58Value *glow::getOrigin(Value *V) {
59 return const_cast<Value *>(getOrigin(const_cast<const Value *>(V)));
60}
61
62const Value *glow::getOrigin(const Value *V) {
63 while (true) {
64 auto *TVI = dyn_cast<TensorViewInst>(V);
65 if (!TVI)
66 return V;
67 V = TVI->getSrc();
68 }
69 return V;
70}
71
72size_t glow::getOriginOffset(Value *V) {
73 size_t off = 0;
74
75 // Since each TensorView can either maintain or decrease the size of a buffer,
76 // the linearized offset of a TensorView into its underlying buffer can be
77 // computed by adding together the linearized offsets of intermediate
78 // TensorViews relative to their sources.
79 while (true) {
80 auto *TVI = dyn_cast<TensorViewInst>(V);
81 if (!TVI) {
82 return off;
83 }
84
85 llvm::ArrayRef<dim_t> offsets = TVI->getOffsets();
86 llvm::ArrayRef<dim_t> srcDims = TVI->getSrc()->getType()->dims();
87
88 size_t numSrcDims = srcDims.size();
89
90 // Iterate backwards in order to figure out how big the slices corresponding
91 // to each offset element are.
92 for (size_t i = 0, j = numSrcDims - 1; i < numSrcDims; ++i, --j) {
93 // For each offset, add into the linearized offset the offset value
94 // multiplied by the slice size corresponding to that offset.
95 off += offsets[j] * TVI->getSrc()->getType()->getSliceSize(j);
96 }
97
98 // Move on to the src of the TensorView that was just processed.
99 V = TVI->getSrc();
100 }
101
102 return off;
103}
104