Added linear scan regalloc

+ Added liveness analyzer + Improved linear order + Fixed GCM
techie-mike · Mar 5, 2024 · de92397 · de92397
1 parent a7be06b
commit de92397
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Showing 14 changed files with 951 additions and 43 deletions.
diff --git a/.github/workflows/c-cpp.yml b/.github/workflows/c-cpp.yml
@@ -10,6 +10,9 @@ jobs:
   build:
 
     runs-on: ubuntu-latest
+    env:
+      CC: gcc-9
+      CXX: g++-9
 
     steps:
     - uses: actions/checkout@v3
@@ -37,3 +40,4 @@ jobs:
         cd build
         valgrind tests/analysis_tests -s
         valgrind tests/graph_tests -s
+
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -5,7 +5,7 @@ project(Compiler)
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
-set(CMAKE_CXX_FLAGS "-pedantic -Wall -Wextra -Werror -Wshadow")
+set(CMAKE_CXX_FLAGS "-pedantic -Wall -Wextra -Werror -Wshadow -g")
 
 set(ROOT_COMPILER ${CMAKE_SOURCE_DIR})
 set(COMPILER_SOURCES
@@ -19,6 +19,7 @@ set(COMPILER_SOURCES
     ${CMAKE_SOURCE_DIR}/src/optimizations/gcm.cpp
     ${CMAKE_SOURCE_DIR}/src/optimizations/analysis/linear_order.cpp
     ${CMAKE_SOURCE_DIR}/src/optimizations/analysis/liveness_analyzer.cpp
+    ${CMAKE_SOURCE_DIR}/src/optimizations/linear_scan.cpp
 )
 
 add_subdirectory(tests)

diff --git a/src/graph.h b/src/graph.h
@@ -4,6 +4,8 @@
 
 namespace compiler {
 
+class LiveInterval;
+
 class Graph
 {
 public:
@@ -130,13 +132,15 @@ class Graph
     }
 
 private:
-    bool unit_test_mode_;
+    bool unit_test_mode_ = false;
     bool insts_placed_ = false;
     uint32_t num_loops_ = 0;
     Loop *root_loop_ = nullptr;
     std::string name_method_;
     std::vector<Inst *> all_inst_;
     std::vector<RegionInst *> all_regions_;
+    LiveInterval *live_intervals_ = nullptr;
+    LinearNumber num_linear_inst_ = 0;
 };
 
 }
diff --git a/src/inst.cpp b/src/inst.cpp
@@ -255,4 +255,9 @@ RegionInst *Inst::CastToRegion() {
     return static_cast<RegionInst *>(this);
 }
 
+IfInst *Inst::CastToIf() {
+    ASSERT(GetOpcode() == Opcode::If);
+    return static_cast<IfInst *>(this);
+}
+
 }
diff --git a/src/inst.h b/src/inst.h
@@ -43,6 +43,7 @@ std::string CcToString(ConditionCode cc);
 std::string TypeToString(Type type);
 
 class RegionInst;
+class IfInst;
 
 class Inst
 {
@@ -121,7 +122,7 @@ class Inst
     virtual void DumpUsers(std::ostream &out);
 
     uint32_t NumDataUsers();
-    std::list<Inst *> &GetRawUsers() {
+    std::list<Inst *> & GetRawUsers() {
         return users_;
     }
 
@@ -137,10 +138,14 @@ class Inst
         return;
     }
 
-    bool IsRegion() {
+    bool IsRegion() const {
         return GetOpcode() == Opcode::Start || GetOpcode() == Opcode::Region || GetOpcode() == Opcode::End;
     }
 
+    bool IsPhi() const {
+        return GetOpcode() == Opcode::Phi;
+    }
+
     void SetPrev(Inst *inst) {
         prev_ = inst;
     }
@@ -158,8 +163,9 @@ class Inst
     }
 
     RegionInst *CastToRegion();
+    IfInst *CastToIf();
 
-    bool IsPlaced() {
+    bool IsPlaced() const {
         return inst_placed_;
     }
 
@@ -449,6 +455,21 @@ class RegionInst : public ControlProp<DynamicInputs>
         return last_;
     }
 
+    id_t GetIndexPredecessor(Inst* inst) {
+        id_t index = 0;
+        id_t num_inputs_succ_region = NumDataInputs();
+        for (index = 0; index < num_inputs_succ_region; index++) {
+            if (GetDataInput(index) == inst) {
+                return index;
+            }
+        }
+        UNREACHABLE();
+    }
+
+    LifeNumber GetLifeNumberEndOfRegion() {
+        return GetLast()->GetLifeNumber() + 2;
+    }
+
 private:
     void AddFirstInst(Inst *inst);
 
@@ -501,12 +522,12 @@ class IfInst : public ControlProp<FixedInputs<2>>
         GetRawUsers().push_back(nullptr);
     }
 
-    Inst *GetTrueBranch() {
-        return *(GetRawUsers().begin());
+    RegionInst *GetTrueBranch() {
+        return (*(GetRawUsers().begin()))->CastToRegion();
     }
 
-    Inst *GetFalseBranch() {
-        return *(++GetRawUsers().begin());
+    RegionInst *GetFalseBranch() {
+        return (*(++GetRawUsers().begin()))->CastToRegion();
     }
 
     void SetTrueBranch(Inst *inst) {

diff --git a/src/optimizations/analysis/linear_order.cpp b/src/optimizations/analysis/linear_order.cpp
@@ -1,18 +1,86 @@
 #include "linear_order.h"
 #include "rpo.h"
+#include "analysis.h"
+#include "loop_analysis.h"
 
 namespace compiler {
 
 void LinearOrder::Run() {
-    // TODO: Fix temporary solution
-    auto rpo = RpoRegions(graph_);
-    rpo.Run();
-    linear_order_ = rpo.GetVector();
+    if (!graph_->IsInstsPlaced()) {
+        UNREACHABLE();
+    }
+
+    LoopAnalysis(graph_).Run();
+    RecursiveOrder(graph_->GetStartRegion());
 }
 
 std::vector<RegionInst *> &LinearOrder::GetVector() {
     return linear_order_;
 }
 
+void LinearOrder::RecursiveOrder(RegionInst *region) {
+    if (marker_.IsMarked(region)) {
+        return;
+    }
+    // If Region is loop header
+    if (region->IsLoopHeader() && !region->GetLoop()->IsIrreducible()) {
+        // Two case in this if:
+        // 1. If loop is reduceble, check preheaders is visited
+        // 2. If loop is irreduceble, don't check something
+        if (!region->GetLoop()->IsIrreducible() && !AllPreheadersIsVisited(region)) {
+            return;
+        }
+    } else {
+        if (!AllPrevIsVisited(region)) {
+            return;
+        }
+    }
+
+    linear_order_.push_back(region);
+    marker_.SetMarker(region);
+
+    if (region->GetOpcode() == Opcode::End) {
+        return;
+    }
+
+    auto last_inst = region->GetLast();
+    if (last_inst->GetOpcode() == Opcode::Jump) {
+        RecursiveOrder(last_inst->GetControlUser()->CastToRegion());
+        return;
+    }
+    ASSERT(last_inst->GetOpcode() == Opcode::If);
+    // TODO Change condition in IfInst, if false is jump back (region is already visited)
+    auto if_inst = last_inst->CastToIf();
+    RecursiveOrder(if_inst->GetFalseBranch());
+    RecursiveOrder(if_inst->GetTrueBranch());
+}
+
+void LinearOrder::AddRegionToOrder(RegionInst *region) {
+    linear_order_.push_back(region);
+}
+
+bool LinearOrder::AllPrevIsVisited(RegionInst *region) {
+    for (id_t i = 0; i < region->NumAllInputs(); i++) {
+        auto prev_region = GetRegionByInputRegion(region->GetRegionInput(i));
+        if (!marker_.IsMarked(prev_region)) {
+            return false;
+        }
+    }
+    return true;
+}
+
+bool LinearOrder::AllPreheadersIsVisited(RegionInst *region) {
+    auto backedges = region->GetLoop()->GetBackedges();
+    for (id_t i = 0; i < region->NumAllInputs(); i++) {
+        auto prev_region = GetRegionByInputRegion(region->GetRegionInput(i));
+        if (std::find(backedges.begin(), backedges.end(), prev_region) != backedges.end()) {
+            continue;
+        }
+        if (!marker_.IsMarked(prev_region)) {
+            return false;
+        }
+    }
+    return true;
+}
 
 }
diff --git a/src/optimizations/analysis/linear_order.h b/src/optimizations/analysis/linear_order.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include "inst.h"
+#include "marker.h"
 
 namespace compiler {
 
@@ -9,14 +10,22 @@ class Graph;
 class LinearOrder {
 public:
     LinearOrder(Graph *graph):
-        graph_(graph) {};
+        graph_(graph),
+        marker_(graph) {};
 
     void Run();
 
     std::vector<RegionInst *> &GetVector();
 
+private:
+    void RecursiveOrder(RegionInst *region);
+    void AddRegionToOrder(RegionInst *region);
+    bool AllPrevIsVisited(RegionInst *region);
+    bool AllPreheadersIsVisited(RegionInst *region);
+
 private:
     Graph *graph_;
+    Marker marker_;
     std::vector<RegionInst *> linear_order_;
 };