Refactor memory coloring pass (#1380)

Refactors memory coloring to only handle allocation instructions. It also handles allocations for tuple shapes.

src/CMakeLists.txt

@@ -58,6 +58,7 @@ add_library(migraphx
     layout_nhwc.cpp
     load_save.cpp
     make_op.cpp
+    memory_coloring.cpp
     module.cpp
     msgpack.cpp
     normalize_attributes.cpp
@@ -65,8 +66,6 @@ add_library(migraphx
     op_enums.cpp
     operation.cpp
     optimize_module.cpp
-    opt/memory_coloring.cpp
-    opt/memory_coloring_impl.cpp
     pad_calc.cpp
     pass_manager.cpp
     permutation.cpp

src/include/migraphx/memory_coloring.hpp

@@ -39,7 +39,7 @@ struct memory_coloring
 {
     std::string allocation_op{};
     bool verify = false;
-    std::string name() const { return "memory coloring"; }
+    std::string name() const { return "memory_coloring"; }
     void apply(module& m) const;
 };
 

src/memory_coloring.cpp

+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015-2022 Advanced Micro Devices, Inc. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include <migraphx/memory_coloring.hpp>
+#include <migraphx/module.hpp>
+#include <migraphx/operators.hpp>
+#include <migraphx/instruction.hpp>
+#include <migraphx/iterator_for.hpp>
+#include <migraphx/functional.hpp>
+#include <migraphx/algorithm.hpp>
+#include <migraphx/ranges.hpp>
+#include <migraphx/stringutils.hpp>
+#include <unordered_set>
+#include <unordered_map>
+#include <map>
+#include <set>
+
+namespace migraphx {
+inline namespace MIGRAPHX_INLINE_NS {
+
+MIGRAPHX_DECLARE_ENV_VAR(MIGRAPHX_DEBUG_MEMORY_COLORING);
+
+using instruction_set     = std::unordered_set<instruction_ref>;
+using instruction_set_map = std::unordered_map<instruction_ref, instruction_set>;
+
+// This will do liveness analysis on the module, and it will call the
+// function `f` with the instruction and the set of the other instructions
+// that are live
+template <class F>
+void liveness(const module& m, F f)
+{
+    auto implicit_deps = m.calc_implicit_deps();
+    instruction_set live_set;
+    auto rp = reverse(m);
+    for(auto rins : iterator_for(rp)) // NOLINT
+    {
+        // The base iterator is one ahead, so we need to use the previous iterator
+        auto ins = std::prev(rins.base());
+        // Add live variables
+        auto add_live_variables = [&](const auto& inputs) {
+            for(auto input : inputs)
+            {
+                auto i = instruction::get_output_alias(input);
+                // Skip if variable comes from parent
+                if(not m.has_instruction(i))
+                    continue;
+                live_set.insert(i);
+            }
+        };
+        add_live_variables(ins->inputs());
+        add_live_variables(implicit_deps[ins]);
+        // Remove last usage
+        auto it = live_set.find(ins);
+        if(it != live_set.end())
+        {
+            live_set.erase(it);
+            f(ins, live_set);
+        }
+    }
+}
+
+// This will build the conflict table or interference graph. This is
+// essentially a map from one instruction to a set of instruction that are
+// used together. Each instruction will be the allocation instruction.
+instruction_set_map build_conflict_table(const module& m, std::string allocation_op)
+{
+    instruction_set_map conflict_table;
+    liveness(m, [&](auto ins, auto live_set) {
+        // Skip variables that aren't allocations
+        if(ins->name() != allocation_op)
+            return;
+        // Skip zero allocations
+        if(ins->get_shape().bytes() == 0)
+            return;
+        conflict_table[ins];
+        for(auto i : live_set)
+        {
+            if(i == ins)
+                continue;
+            // Skip variables that aren't allocations
+            if(i->name() != allocation_op)
+                continue;
+            // Skip zero allocations
+            if(i->get_shape().bytes() == 0)
+                continue;
+            conflict_table[i].insert(ins);
+            conflict_table[ins].insert(i);
+        }
+    });
+    assert(std::all_of(conflict_table.begin(), conflict_table.end(), [](auto&& pp) {
+        return pp.second.count(pp.first) == 0;
+    }));
+    return conflict_table;
+}
+
+// Check if intervals overlap
+bool is_overlap(std::pair<std::size_t, std::size_t> x, std::pair<std::size_t, std::size_t> y)
+{
+    return std::max(x.first, y.first) < std::min(x.second, y.second);
+}
+
+struct allocation_segment
+{
+    using segment = std::pair<std::size_t, std::size_t>;
+    std::unordered_map<instruction_ref, segment> ins2segment;
+
+    const segment* add_segment(instruction_ref ins, segment s) { return &(ins2segment[ins] = s); }
+
+    const segment* get_segment(instruction_ref ins) const
+    {
+        auto it = ins2segment.find(ins);
+        if(it == ins2segment.end())
+            return nullptr;
+        return &it->second;
+    }
+
+    // Remove segment for an instruction
+    void remove(instruction_ref ins)
+    {
+        auto it = ins2segment.find(ins);
+        if(it != ins2segment.end())
+        {
+            ins2segment.erase(it);
+        }
+    }
+
+    std::size_t max()
+    {
+        std::size_t n = 0;
+        for(auto&& pp : ins2segment)
+        {
+            auto seg = pp.second;
+            n        = std::max(n, seg.second);
+        }
+        return n;
+    }
+
+    template <class Iterator>
+    static bool overlaps(Iterator first, Iterator last, const segment& s)
+    {
+        return std::any_of(first, last, [&](auto&& t) { return is_overlap(s, t); });
+    }
+
+    static bool overlaps(const std::set<segment>& segments, const segment& s)
+    {
+        return overlaps(segments.begin(), segments.end(), s);
+    }
+
+    static auto find_gap(const std::set<segment>& segments, std::size_t n)
+    {
+        std::size_t max_end = 0;
+        return std::adjacent_find(segments.begin(), segments.end(), [&](segment x, segment y) {
+            if(x.second < max_end)
+                return false;
+            max_end = x.second;
+            if(is_overlap(x, y))
+                return false;
+            assert(y.first >= x.second);
+            auto k = y.first - x.second;
+            return (k >= n);
+        });
+    }
+
+    static std::size_t max_type_size(const shape& s)
+    {
+        return std::accumulate(
+            s.sub_shapes().begin(),
+            s.sub_shapes().end(),
+            s.type_size(),
+            [](auto size, const auto& sub) { return std::max(size, max_type_size(sub)); });
+    }
+
+    static std::size_t compute_alignment(instruction_ref ins)
+    {
+        auto alignment = max_type_size(ins->get_shape());
+        // A rough estimate for the total number of elements
+        auto n = ins->get_shape().bytes() / alignment;
+        // Check for vectorized alignment
+        if(n > 4)
+        {
+            auto d = n % 4;
+            if(d == 0)
+                alignment *= 4;
+            if(d == 2)
+                alignment *= 2;
+        }
+        return alignment;
+    }
+
+    static segment
+    next_segment(std::set<segment>& segments, instruction_ref ins, std::size_t alignment)
+    {
+        assert(ins->get_shape().bytes() > 0);
+        // Compute alignment
+        auto n = 1 + (ins->get_shape().bytes() - 1) / alignment;
+        assert(n > 0);
+        auto start = 0;
+        // Insert at end if it cant fit at the begining
+        if(segments.empty() or segments.begin()->first <= n)
+        {
+            auto it = find_gap(segments, n);
+            if(it == segments.end())
+                it = std::max_element(segments.begin(), segments.end(), [&](segment x, segment y) {
+                    return x.second < y.second;
+                });
+            if(it != segments.end())
+                start = it->second;
+        }
+        auto s = segment{start, start + n};
+        assert(not overlaps(segments, s));
+        segments.insert(s);
+        return s;
+    }
+
+    static std::unordered_map<instruction_ref, int>
+    create_allocation_index(const module& m, const instruction_set_map& conflict_table)
+    {
+        std::unordered_map<instruction_ref, int> result;
+        int i = 0;
+        for(auto ins : iterator_for(m))
+        {
+            if(not contains(conflict_table, ins))
+                continue;
+            result[ins] = i++;
+        }
+        return result;
+    }
+
+    // Build the allocation_color class from the conflict_table
+    static allocation_segment
+    build(const module& m, const instruction_set_map& conflict_table, std::size_t alignment)
+    {
+        allocation_segment as{};
+        std::vector<instruction_ref> conflict_queue;
+        // Add all allocations to the conflict_queue
+        std::transform(conflict_table.begin(),
+                       conflict_table.end(),
+                       std::back_inserter(conflict_queue),
+                       [](auto&& pp) { return pp.first; });
+
+        auto alloc_index = create_allocation_index(m, conflict_table);
+
+        // Sort the conflict queue so we process the allocation with the most
+        // number of adjacent allocations first
+        std::sort(conflict_queue.begin(), conflict_queue.end(), by(std::greater<>{}, [&](auto x) {
+                      return std::make_tuple(
+                          conflict_table.at(x).size(), x->get_shape().bytes(), alloc_index.at(x));
+                  }));
+        // Process the conflict_queue, we refer to the current allocation as
+        // the parent and the adjacent allocations as children
+        for(auto parent : conflict_queue)
+        {
+            // Sort children by size
+            std::vector<instruction_ref> children(conflict_table.at(parent).begin(),
+                                                  conflict_table.at(parent).end());
+            std::sort(children.begin(), children.end(), by(std::less<>{}, [&](auto x) {
+                          return std::make_tuple(x->get_shape().bytes(), alloc_index.at(x));
+                      }));
+            assert(not contains(children, parent));
+            // This set is to track the segments already processed
+            std::set<segment> segments;
+            // Add all segments for the children to the segments already processed
+            transform_if(
+                children.begin(),
+                children.end(),
+                std::inserter(segments, segments.begin()),
+                [&](auto child) { return as.get_segment(child); },
+                [&](auto child) { return *as.get_segment(child); });
+
+            assert(as.get_segment(parent) == nullptr);
+            as.add_segment(parent, next_segment(segments, parent, alignment));
+        }
+        // Reduce the number of segments
+        for(std::size_t n = 0; n < 3; n++)
+        {
+            for(auto parent : conflict_queue)
+            {
+                auto children = conflict_table.at(parent);
+                // This set is to track the segments already processed
+                std::set<segment> segments;
+                // Add all segments for the children to the segments already processed
+                transform_if(
+                    children.begin(),
+                    children.end(),
+                    std::inserter(segments, segments.begin()),
+                    [&](auto child) { return as.get_segment(child); },
+                    [&](auto child) { return *as.get_segment(child); });
+                // Get the segment for the parent
+                const auto* parent_segment = as.get_segment(parent);
+                assert(parent_segment != nullptr);
+
+                auto s = next_segment(segments, parent, alignment);
+                if(s != *parent_segment and s.second <= as.max())
+                {
+                    as.add_segment(parent, s);
+                }
+            }
+        }
+        return as;
+    }
+};
+
+static std::size_t find_max_alignment(const module& m, const std::string& allocation_op)
+{
+    std::size_t alignment = 1;
+    for(auto ins : iterator_for(m))
+    {
+        if(ins->name() != allocation_op)
+            continue;
+        alignment = std::max(allocation_segment::compute_alignment(ins), alignment);
+    }
+    return alignment;
+}
+
+void memory_coloring::apply(module& m) const
+{
+    const std::size_t alignment = find_max_alignment(m, allocation_op);
+    auto conflict_table         = build_conflict_table(m, allocation_op);
+    auto as                     = allocation_segment::build(m, conflict_table, alignment);
+
+    // All allocations should have a segment
+    assert(std::all_of(conflict_table.begin(), conflict_table.end(), [&](auto&& pp) {
+        return as.get_segment(pp.first);
+    }));
+
+    // Adjacent allocations should not have overlapping segments
+    assert(std::none_of(conflict_table.begin(), conflict_table.end(), [&](auto&& pp) {
+        auto* x = as.get_segment(pp.first);
+        return std::any_of(pp.second.begin(), pp.second.end(), [&](auto ins) {
+            auto* y = as.get_segment(ins);
+            assert(x and y);
+            return is_overlap(*x, *y);
+        });
+    }));
+
+    // Print out segments
+    if(enabled(MIGRAPHX_DEBUG_MEMORY_COLORING{}))
+    {
+        for(auto&& pp : conflict_table)
+        {
+            std::cout << "------- conflict -------" << std::endl;
+            auto s1 = as.ins2segment.at(pp.first);
+            std::cout << s1.first << ", " << s1.second << ": ";
+            m.debug_print(pp.first);
+            for(auto ins : pp.second)
+            {
+                auto s2 = as.ins2segment.at(ins);
+                std::cout << s2.first << ", " << s2.second << ": ";
+                m.debug_print(ins);
+            }
+        }
+    }
+
+    // Total memory
+    std::size_t n = as.max() * alignment;
+
+    // Replace allocations
+    auto mem = m.add_parameter("scratch", shape{shape::int8_type, {n}});
+    for(auto&& [ins, seg] : as.ins2segment)
+    {
+        assert(ins->name() == allocation_op);
+        auto s             = ins->get_shape();
+        std::size_t offset = seg.first * alignment;
+        assert(offset < n);
+        m.replace_instruction(ins, op::load{s, offset}, mem);
+    }
+
+    // Replace zero allocation
+    for(auto ins : iterator_for(m))
+    {
+        if(ins->name() != allocation_op)
+            continue;
+        assert(ins->get_shape().bytes() == 0);
+        m.replace_instruction(ins, op::load{ins->get_shape(), 0}, mem);
+    }
+
+    // Remove scratch parameter if its not used
+    if(mem->outputs().empty())
+    {
+        m.remove_instruction(mem);
+    }
+}
+
+} // namespace MIGRAPHX_INLINE_NS
+} // namespace migraphx

src/pass_manager.cpp

@@ -39,6 +39,7 @@ namespace migraphx {
 inline namespace MIGRAPHX_INLINE_NS {
 
 MIGRAPHX_DECLARE_ENV_VAR(MIGRAPHX_TRACE_PASSES);
+MIGRAPHX_DECLARE_ENV_VAR(MIGRAPHX_TIME_PASSES);
 
 void validate_pass(module& mod, const pass& p, tracer trace)
 {
@@ -94,19 +95,19 @@ struct module_pm : module_pass_manager
     virtual void run_pass(const pass& p) override
     {
         assert(mod);
-
-        timer ts{};
-        using seconds = std::chrono::duration<double>;
-
-        trace("Module: ", mod->name(), ", Pass: ", p.name());
-        const double t1 = ts.record<seconds>();
         assert(mod->validate() == mod->end());
+        if(enabled(MIGRAPHX_TIME_PASSES{}))
+        {
+            using milliseconds = std::chrono::duration<double, std::milli>;
+            auto ms            = time<milliseconds>([&] { p.apply(*this); });
+            std::cout << p.name() << ": " << ms << "ms\n";
+        }
+        else
+        {
             p.apply(*this);
+        }
         trace(*mod);
         validate_pass(*mod, p, *t);
-
-        const double t2 = ts.record<seconds>();
-        trace("Pass: ", p.name(), " completed in (s): ", (t2 - t1));
     }
 };
 

test/memory_coloring_test.cpp

@@ -691,7 +691,7 @@ TEST_CASE(test38)
     auto p83    = m.add_instruction(pass_op{}, p78, p77);
     m.add_instruction(pass_op{}, output, p83, p63);
     run_pass(m);
-    CHECK(m.get_parameter_shape("scratch").bytes() == 7225344); // Optimal solution is 6422528
+    CHECK(m.get_parameter_shape("scratch").bytes() == 6422528);
     CHECK(no_allocate(m));
 }
 
@@ -729,7 +729,7 @@ TEST_CASE(test39)
         run_pass(*smod);
     }
 
-    CHECK(mm->get_parameter_shape("scratch").bytes() == 4);
+    CHECK(mm->get_parameter_shape("scratch").bytes() == 1);
     CHECK(then_mod->get_parameter_shape("scratch").bytes() == 24);
     CHECK(else_mod->get_parameter_shape("scratch").bytes() == 24);
     CHECK(no_allocate(*mm));
@@ -3374,7 +3374,7 @@ TEST_CASE(rnn_dom)
     m.add_instruction(pass_op{}, moutput, mx250, mx249, mx248);
 
     run_pass(m);
-    CHECK(m.get_parameter_shape("scratch").bytes() == 1600);
+    CHECK(m.get_parameter_shape("scratch").bytes() == 1824); // Optimal is 1600
     CHECK(no_allocate(m));
     CHECK(is_disjoint({mx0, mx8}));
     CHECK(is_disjoint({mx0, mx8}));
@@ -3790,4 +3790,23 @@ TEST_CASE(literal_test)
     CHECK(lit == result);
 }
 
+TEST_CASE(test_tuple)
+{
+    migraphx::module m;
+
+    auto s1 = migraphx::shape{migraphx::shape::float_type, {8}};
+    auto s2 = migraphx::shape{migraphx::shape::half_type, {10}};
+
+    auto s = migraphx::shape{{s1, s2}};
+
+    auto a1 = add_alloc(m, s);
+    auto m1 = m.add_instruction(pass_op{}, a1);
+    auto a2 = add_alloc(m, {migraphx::shape::float_type, {4}});
+    m.add_instruction(pass_op{}, a2, m1);
+    run_pass(m);
+    CHECK(m.get_parameter_shape("scratch").bytes() == 68);
+    CHECK(no_allocate(m));
+    CHECK(is_disjoint({a1, a2}));
+}
+
 int main(int argc, const char* argv[]) { test::run(argc, argv); }