From db7b11719b89002e3ceaf8fa3b5d66bf87559fed Mon Sep 17 00:00:00 2001 From: Yan Chunwei Date: Fri, 20 Oct 2017 14:08:48 -0400 Subject: [PATCH] change lod tensor to absolute offsets (#4952) --- paddle/framework/lod_tensor.cc | 69 ++++++++++++++++------------- paddle/framework/lod_tensor.h | 25 ++++++++--- paddle/framework/lod_tensor_test.cc | 31 +++++++------ 3 files changed, 73 insertions(+), 52 deletions(-) diff --git a/paddle/framework/lod_tensor.cc b/paddle/framework/lod_tensor.cc index 5b7badf89c..7c0ea0df78 100644 --- a/paddle/framework/lod_tensor.cc +++ b/paddle/framework/lod_tensor.cc @@ -25,31 +25,50 @@ LoD SliceLevels(const LoD& in, size_t level_begin, size_t level_end) { for (size_t i = level_begin; i < level_end; i++) { new_lod.emplace_back(in.at(i)); } + // transform the lowest level to absolute offset. + LoD abs_offset_lod = ToAbsOffset(in); + new_lod.back() = abs_offset_lod[level_end - 1]; return new_lod; } LoD SliceInLevel(const LoD& in, size_t level, size_t elem_begin, size_t elem_end) { - // slice the lod. - LoD new_lod; - new_lod.reserve(in.size() - level); - auto start = in.at(level)[elem_begin]; - auto end = in.at(level)[elem_end]; - - for (auto it = in.begin() + level; it != in.end(); it++) { - auto it_begin = std::find(it->begin(), it->end(), start); - auto it_end = std::find(it_begin, it->end(), end); - PADDLE_ENFORCE(it_begin != it->end(), "error in parsing lod info"); - PADDLE_ENFORCE(it_end != it->end(), "error in parsing lod info"); - new_lod.emplace_back(it_begin, it_end + 1); - // reset offset if tensor is copyed and sliced. - std::transform(new_lod.back().begin(), new_lod.back().end(), - new_lod.back().begin(), - [start](int v) { return v - start; }); - PADDLE_ENFORCE_EQ(new_lod.back().front(), 0, "error in slice LoD"); + PADDLE_ENFORCE_LT(level, in.size()); + PADDLE_ENFORCE_LT(elem_end, in[level].size()); + + LoD res; + res.resize(in.size() - level); + // copy the first level + res[0].assign(in[level].begin() + elem_begin, + in[level].begin() + elem_end + 1); + for (size_t lvl = 1; lvl < res.size(); lvl++) { + const auto& in_level = in[level + lvl]; + const auto& above_level = res[lvl - 1]; + auto& out_level = res[lvl]; + out_level.assign(in_level.begin() + above_level.front(), + in_level.begin() + above_level.back() + 1); } - PADDLE_ENFORCE_LE(new_lod.size(), in.size()); - return new_lod; + for (size_t lvl = 0; lvl < res.size(); lvl++) { + // to make the first offset equals 0, all the elements minus the first + // element + size_t front = res[lvl].front(); + for (auto& ele : res[lvl]) { + ele -= front; + } + } + return res; +} + +LoD ToAbsOffset(const LoD& in) { + // the lowest level stores relative offsets + if (in.empty() || in.size() == 1) return in; + LoD result = in; + for (int level = result.size() - 2; level >= 0; level--) { + for (auto& ele : result[level]) { + ele = result[level + 1][ele]; + } + } + return result; } bool operator==(const LoD& a, const LoD& b) { @@ -75,17 +94,7 @@ bool operator==(const LoD& a, const LoD& b) { size_t LoDTensor::NumElements(size_t level, size_t idx) const { PADDLE_ENFORCE_LT(level, NumLevels()); PADDLE_ENFORCE_LT(idx, NumElements(level)); - // the last level of LoD, just return number of records in Tensor - if (level == NumLevels() - 1) { - return lod_[level][idx + 1] - lod_[level][idx]; - } - // high level of LoD, and there is another lower level, return number of - // lower-level elements - auto tmp = SliceInLevel(lod_, level, idx, idx + 1); - PADDLE_ENFORCE_GE(tmp.size(), 2); - // there is a 0 as a placeholder stored in LoD, so the number of elements - // equals lod.size() - 1 - return tmp[1].size() - 1; + return lod_[level][idx + 1] - lod_[level][idx]; } void LoDTensor::ShrinkLevels(size_t level_begin, size_t level_end) { diff --git a/paddle/framework/lod_tensor.h b/paddle/framework/lod_tensor.h index 3d893baa35..dec59a5750 100644 --- a/paddle/framework/lod_tensor.h +++ b/paddle/framework/lod_tensor.h @@ -39,23 +39,36 @@ using Vector = thrust::host_vector< #endif /* - * 3-level LoD stores + * LoD is short for Level of Details. * - * 0 10 20 - * 0 5 10 15 20 - * 0 2 5 7 10 12 15 20 - * - * - in a level, each element indicates offset in the underlying Tensor + * - in a level, each element indicates relative offset of the lower level * - the first element should be 0 and that indicates that this sequence start * from 0 * - each sequence's begin and end(no-inclusive) is level[id, id+1] + * + * For example: + * 3-level LoD stores + * + * 0 2 3 + * 0 2 4 7 + * 0 2 5 7 10 12 15 20 */ using LoD = std::vector>; +/* + * Slice levels from a LoD. + * NOTE the lowest level should always be the absolute offsets of the underlying + * tensor instances. So if higher layers are sliced without the lowest level, + * the lower level of the sliced LoD will be transformed to the absolute offset. + */ LoD SliceLevels(const LoD& in, size_t level_begin, size_t level_end); LoD SliceInLevel(const LoD& in, size_t level, size_t elem_begin, size_t elem_end); +/* + * Transform an LoD from relative offsets to absolute offsets. + */ +LoD ToAbsOffset(const LoD& in); bool operator==(const LoD& a, const LoD& b); diff --git a/paddle/framework/lod_tensor_test.cc b/paddle/framework/lod_tensor_test.cc index 44f09f584f..e1e15abecf 100644 --- a/paddle/framework/lod_tensor_test.cc +++ b/paddle/framework/lod_tensor_test.cc @@ -30,8 +30,8 @@ class LoDTensorTester : public ::testing::Test { // 0 5 10 15 20 // 0 2 5 7 10 12 15 20 LoD lod; - lod.push_back(std::vector{0, 10, 20}); - lod.push_back(std::vector{0, 5, 10, 15, 20}); + lod.push_back(std::vector{0, 2, 3}); + lod.push_back(std::vector{0, 2, 5, 8}); lod.push_back(std::vector{0, 2, 5, 7, 10, 12, 15, 17, 20}); ASSERT_EQ(lod.size(), 3UL); @@ -52,14 +52,14 @@ TEST_F(LoDTensorTester, NumLevels) { ASSERT_EQ(lod_tensor_.NumLevels(), 3UL); } TEST_F(LoDTensorTester, NumElements) { ASSERT_EQ(lod_tensor_.NumElements(0), 2UL); - ASSERT_EQ(lod_tensor_.NumElements(1), 4UL); + ASSERT_EQ(lod_tensor_.NumElements(1), 3UL); ASSERT_EQ(lod_tensor_.NumElements(2), 8UL); } TEST_F(LoDTensorTester, NumElements2) { ASSERT_EQ(lod_tensor_.NumElements(0, 0), 2UL); - ASSERT_EQ(lod_tensor_.NumElements(0, 1), 2UL); - ASSERT_EQ(lod_tensor_.NumElements(1, 1), 2UL); + ASSERT_EQ(lod_tensor_.NumElements(0, 1), 1UL); + ASSERT_EQ(lod_tensor_.NumElements(1, 1), 3UL); } TEST_F(LoDTensorTester, ShrinkLevels) { @@ -68,17 +68,16 @@ TEST_F(LoDTensorTester, ShrinkLevels) { LoDTensor new_lod_tensor = lod_tensor_; new_lod_tensor.ShrinkLevels(level, level + 1); ASSERT_EQ(new_lod_tensor.NumLevels(), 1UL); - ASSERT_EQ(new_lod_tensor.NumElements(0), lod_tensor_.NumElements(level)); ASSERT_EQ(new_lod_tensor.data(), lod_tensor_.data()); } // shrink 2 level for (size_t level = 0; level < 2UL; ++level) { LoDTensor new_lod_tensor = lod_tensor_; new_lod_tensor.ShrinkLevels(level, level + 2); + // the lowest level's last element should be the tensor's batch_size. + ASSERT_EQ(new_lod_tensor.lod().back().back(), + lod_tensor_.lod().back().back()); ASSERT_EQ(new_lod_tensor.NumLevels(), 2UL); - ASSERT_EQ(new_lod_tensor.NumElements(0), lod_tensor_.NumElements(level)); - ASSERT_EQ(new_lod_tensor.NumElements(1), - lod_tensor_.NumElements(level + 1)); ASSERT_EQ(new_lod_tensor.data(), lod_tensor_.data()); } } @@ -86,19 +85,19 @@ TEST_F(LoDTensorTester, ShrinkLevels) { TEST_F(LoDTensorTester, ShrinkInLevel) { size_t level = 0; LoDTensor new_lod_tensor = lod_tensor_; - new_lod_tensor.ShrinkInLevel(level, 0, 2); + new_lod_tensor.ShrinkInLevel(level, 0, 1); EXPECT_EQ(new_lod_tensor.NumLevels(), 3UL); - EXPECT_EQ(new_lod_tensor.NumElements(0), 2UL); - EXPECT_EQ(new_lod_tensor.NumElements(1), 4UL); - EXPECT_EQ(new_lod_tensor.NumElements(2), 8UL); + EXPECT_EQ(new_lod_tensor.NumElements(0), 1UL); + EXPECT_EQ(new_lod_tensor.NumElements(1), 2UL); + EXPECT_EQ(new_lod_tensor.NumElements(2), 5UL); ASSERT_EQ(new_lod_tensor.data(), lod_tensor_.data()); level = 1; new_lod_tensor = lod_tensor_; - new_lod_tensor.ShrinkInLevel(level, 0, 2); + new_lod_tensor.ShrinkInLevel(level, 1, 2); ASSERT_EQ(new_lod_tensor.NumLevels(), 2UL); - ASSERT_EQ(new_lod_tensor.NumElements(0), 2UL); - ASSERT_EQ(new_lod_tensor.NumElements(1), 4UL); + ASSERT_EQ(new_lod_tensor.NumElements(0), 1UL); + ASSERT_EQ(new_lod_tensor.NumElements(1), 3UL); ASSERT_EQ(new_lod_tensor.data(), lod_tensor_.data()); } -- GitLab