Added dominated check elimination

CMakeLists.txt

@@ -23,6 +23,7 @@ set(COMPILER_SOURCES
     ${CMAKE_SOURCE_DIR}/src/optimizations/peepholes.cpp
     ${CMAKE_SOURCE_DIR}/src/optimizations/constant_folding.cpp
     ${CMAKE_SOURCE_DIR}/src/optimizations/inlining.cpp
+    ${CMAKE_SOURCE_DIR}/src/optimizations/checks_elimination.cpp
 )
 
 add_library(CompilerLibBase ${COMPILER_SOURCES})

src/inst.cpp

@@ -382,7 +382,18 @@ void ParameterInst::DumpInputs(std::ostream &out) {
 
 void Inst::ReplaceAllUsers(Inst *from) {
     ReplaceDataUsers(from);
-    ReplaceCtrUser(from);
+    UpdateCtrConnection(from);
+}
+
+void Inst::UpdateCtrConnection(Inst *from) {
+    // ASSERT(HasSingleDataUser());
+    auto c_user = from->GetControlUser();
+    if (c_user == nullptr) {
+        return;
+    }
+    auto c_input = from->GetControlInput();
+    c_user->SetControlInput(c_input);
+    from->SetControlUser(nullptr);
 }
 
 void Inst::ReplaceCtrUser(Inst *from) {
@@ -401,4 +412,29 @@ void DynamicInputs::DeleteInput(Inst *inst) {
     inputs_.erase(it);
 }
 
+RegionInst *FindRegion(Inst *inst) {
+    ASSERT(inst->HasControlProp());
+    while (!inst->IsRegion()) {
+        inst = inst->GetControlInput();
+    }
+    return inst->CastToRegion();
+}
+
+bool Inst::IsDominated(Inst *other) {
+    ASSERT(HasControlProp() && other->HasControlProp());
+    auto *our_region = FindRegion(this);
+    auto *other_region = FindRegion(other);
+
+    if (our_region == other_region) {
+        auto *inst = other;
+        while (inst != other_region && inst != this) {
+            inst = inst->GetControlInput();
+        }
+        return inst == this;
+    }
+    // Insts in different regions
+    return our_region->IsDominated(other_region);
+}
+
+
 }

src/inst.h

@@ -227,6 +227,9 @@ class Inst
     void ReplaceDataUsers(Inst *from);
     void ReplaceAllUsers(Inst *from);
     void ReplaceCtrUser(Inst *from);
+    void UpdateCtrConnection(Inst *from);
+
+    bool IsDominated(Inst *other);
 
 private:
     auto StartIteratorDataUsers() {
@@ -711,4 +714,22 @@ class CallInst : public ControlProp<DynamicInputs>
     std::string name_func_;
 };
 
+class NullCheckInst : public ControlProp<FixedInputs<2>>
+{
+public:
+    using Base = ControlProp<FixedInputs<2>>;
+    NullCheckInst():
+        Base(Opcode::NullCheck) {};
+    // Need to add check type of input
+};
+
+class BoundsCheckInst : public ControlProp<FixedInputs<3>>
+{
+public:
+    using Base = ControlProp<FixedInputs<3>>;
+    BoundsCheckInst():
+        Base(Opcode::BoundsCheck) {};
+    // Need to add check type of input
+};
+
 }

src/opcodes.h

@@ -23,6 +23,8 @@ namespace compiler {
     ACTION( Phi         , PhiInst                       ) \
     ACTION( Return      , ReturnInst                    ) \
     ACTION( Parameter   , ParameterInst                 ) \
+    ACTION( NullCheck   , NullCheckInst                 ) \
+    ACTION( BoundsCheck , BoundsCheckInst               ) \
     ACTION( Call        , CallInst                      )
 
 #define REGIONS_OPCODE_LIST(ACTION)                       \
@@ -96,12 +98,13 @@ constexpr std::array<const char *const, static_cast<size_t>(ConditionCode::NUM_C
 
 //===================================================================
 
-#define TYPE_LIST(ACTION)           \
-    ACTION( BOOL    , b     )       \
-    ACTION( INT32   , i32   )       \
-    ACTION( UINT32  , u32   )       \
-    ACTION( INT64   , i64   )       \
-    ACTION( UINT64  , u64   )
+#define TYPE_LIST(ACTION)       \
+    ACTION( BOOL     , b     )  \
+    ACTION( INT32    , i32   )  \
+    ACTION( UINT32   , u32   )  \
+    ACTION( INT64    , i64   )  \
+    ACTION( UINT64   , u64   )  \
+    ACTION( REFERENCE, ref   )
 
 enum class Type {
     NONE = 0,

src/optimizations/analysis/rpo.cpp

@@ -45,10 +45,11 @@ void RpoRegions::AddInstInVector(Inst *inst) {
 RpoInsts::RpoInsts(Graph *graph):
     graph_ (graph) {}
 
-void RpoInsts::Run() {
+RpoInsts* RpoInsts::Run() {
     auto end = graph_->GetInstByIndex(1);
     auto marker = Marker(graph_);
     DFSInsts(end, marker);
+    return this;
 }
 
 void RpoInsts::DFSInsts(Inst *inst, Marker &marker) {

src/optimizations/analysis/rpo.h

@@ -25,7 +25,7 @@ class RpoInsts
 public:
     RpoInsts(Graph *graph);
 
-    void Run();
+    RpoInsts* Run();
     void DFSInsts(Inst *inst, Marker &marker);
     std::vector<Inst *> &GetVector();
 

src/optimizations/checks_elimination.cpp

@@ -0,0 +1,53 @@
+#include "checks_elimination.h"
+#include "analysis/domtree.h"
+#include "analysis/rpo.h"
+
+namespace compiler {
+
+void ChecksElimination::Run() {
+    DomTreeSlow(graph_).Run();
+    auto rpo_vector = RpoInsts(graph_).Run()->GetVector();
+
+    VisitChecks(rpo_vector);
+}
+
+void ChecksElimination::VisitChecks(std::vector<Inst *> &rpo_vector) {
+    for (auto inst : rpo_vector) {
+        switch (inst->GetOpcode()) {
+            case Opcode::NullCheck:
+                VisitNullCheck(inst);
+                break;
+            case Opcode::BoundsCheck:
+                VisitBoundCheck(inst);
+                break;
+            default:
+                break;
+        }
+    }
+}
+
+void ChecksElimination::VisitNullCheck(Inst *inst) {
+    auto* input = inst->GetDataInput(0);
+    for (auto* user : input->GetDataUsers()) {
+        if (user->GetOpcode() == Opcode::NullCheck &&
+            user != inst &&
+            user->IsDominated(inst)) {
+            user->ReplaceAllUsers(inst);
+        }
+    }
+}
+
+void ChecksElimination::VisitBoundCheck(Inst *inst) {
+    auto* checked_value = inst->GetDataInput(0);
+    auto* up_bound = inst->GetDataInput(1);
+    for (auto* user : checked_value->GetDataUsers()) {
+        if (user->GetOpcode() == Opcode::BoundsCheck &&
+            user != inst &&
+            user->GetDataInput(1) == up_bound &&
+            user->IsDominated(inst)) {
+            user->ReplaceAllUsers(inst);
+        }
+    }
+}
+
+}

src/optimizations/checks_elimination.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include "vector"
+
+namespace compiler {
+
+class Graph;
+class Inst;
+
+class ChecksElimination
+{
+public:
+    ChecksElimination(Graph *graph):
+        graph_(graph) {};
+
+    void Run();
+
+private:
+    void VisitChecks(std::vector<Inst *> &rpo);
+    void VisitNullCheck(Inst *inst);
+    void VisitBoundCheck(Inst *inst);
+
+private:
+    Graph *graph_;
+};
+
+}

tests/CMakeLists.txt

@@ -84,7 +84,27 @@ add_custom_target(
     COMMAND inlining_test
 )
 
+add_executable(
+    checks_elimination
+    checks_elimination_tests.cpp
+    graph_comparator.cpp
+)
+
+target_link_libraries(
+    checks_elimination
+    ${ALL_LIBS_FOR_TESTS}
+)
+
+target_include_directories(checks_elimination PUBLIC "${CMAKE_SOURCE_DIR}/src")
+
+gtest_discover_tests(checks_elimination)
+
+add_custom_target(
+    checks_elimination_gtest
+    COMMAND checks_elimination
+)
+
 add_custom_target(
     tests
-    DEPENDS graph_tests_gtest analysis_tests_gtest peepholes_tests_gtest
+    DEPENDS graph_tests_gtest analysis_tests_gtest peepholes_tests_gtest checks_elimination_gtest
 )