From ffd4af872c4da39c7b9dfc0aa03a4a34c8fbab16 Mon Sep 17 00:00:00 2001
From: Alexey Sedunov <alexey.sedunov@jetbrains.com>
Date: Thu, 17 Jul 2014 16:29:42 +0400
Subject: [PATCH] Pseudocode: Track merged values. Compute closure of value
 usages over merge instructions. Exclude merge instructions from usage lists

---
 .../lang/cfg/pseudocode/PseudocodeImpl.java   | 55 +++++++++++++++----
 .../jet/lang/cfg/pseudocode/pseudocodeUtil.kt | 12 ----
 .../cfg/controlStructures/Finally.values      |  4 +-
 .../OnlyWhileInFunctionBody.values            |  6 +-
 4 files changed, 50 insertions(+), 27 deletions(-)

diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/PseudocodeImpl.java b/compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/PseudocodeImpl.java
index 7c7caf967ea..f755edbc7d8 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/PseudocodeImpl.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/PseudocodeImpl.java
@@ -17,13 +17,15 @@
 package org.jetbrains.jet.lang.cfg.pseudocode;
 
 import com.google.common.collect.*;
-import com.intellij.openapi.util.NotNullLazyValue;
 import com.intellij.util.containers.BidirectionalMap;
+import kotlin.Function0;
+import kotlin.KotlinPackage;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.cfg.Label;
 import org.jetbrains.jet.lang.cfg.LoopInfo;
 import org.jetbrains.jet.lang.cfg.pseudocode.instructions.*;
+import org.jetbrains.jet.lang.cfg.pseudocode.instructions.eval.MergeInstruction;
 import org.jetbrains.jet.lang.cfg.pseudocode.instructions.jumps.AbstractJumpInstruction;
 import org.jetbrains.jet.lang.cfg.pseudocode.instructions.jumps.ConditionalJumpInstruction;
 import org.jetbrains.jet.lang.cfg.pseudocode.instructions.jumps.NondeterministicJumpInstruction;
@@ -91,14 +93,8 @@ public class PseudocodeImpl implements Pseudocode {
 
     private final BidirectionalMap<JetElement, PseudoValue> elementsToValues = new BidirectionalMap<JetElement, PseudoValue>();
 
-    private final NotNullLazyValue<Map<PseudoValue, List<? extends Instruction>>> valueUsages =
-            new NotNullLazyValue<Map<PseudoValue, List<? extends Instruction>>>() {
-                @NotNull
-                @Override
-                protected Map<PseudoValue, List<? extends Instruction>> compute() {
-                    return PseudocodePackage.collectValueUsages(PseudocodeImpl.this);
-                }
-            };
+    private final Map<PseudoValue, List<Instruction>> valueUsages = Maps.newHashMap();
+    private final Map<PseudoValue, Set<PseudoValue>> mergedValues = Maps.newHashMap();
 
     private Pseudocode parent = null;
     private Set<LocalFunctionDeclarationInstruction> localDeclarations = null;
@@ -232,6 +228,17 @@ public class PseudocodeImpl implements Pseudocode {
             JetElementInstruction elementInstruction = (JetElementInstruction) instruction;
             representativeInstructions.put(elementInstruction.getElement(), instruction);
         }
+
+        if (instruction instanceof MergeInstruction) {
+            addMergedValues((MergeInstruction) instruction);
+        }
+
+        for (PseudoValue inputValue : instruction.getInputValues()) {
+            addValueUsage(inputValue, instruction);
+            for (PseudoValue mergedValue : getMergedValues(inputValue)) {
+                addValueUsage(mergedValue, instruction);
+            }
+        }
     }
 
     /*package*/ void recordLoopInfo(JetExpression expression, LoopInfo blockInfo) {
@@ -272,7 +279,7 @@ public class PseudocodeImpl implements Pseudocode {
     @NotNull
     @Override
     public List<? extends Instruction> getUsages(@Nullable PseudoValue value) {
-        List<? extends Instruction> result = valueUsages.getValue().get(value);
+        List<? extends Instruction> result = valueUsages.get(value);
         return result != null ? result : Collections.<Instruction>emptyList();
     }
 
@@ -283,6 +290,34 @@ public class PseudocodeImpl implements Pseudocode {
     /*package*/ void bindLabel(Label label) {
         ((PseudocodeLabel) label).setTargetInstructionIndex(mutableInstructionList.size());
     }
+    
+    private Set<PseudoValue> getMergedValues(@NotNull PseudoValue value) {
+        Set<PseudoValue> result = mergedValues.get(value);
+        return result != null ? result : Collections.<PseudoValue>emptySet();
+    }
+    
+    private void addMergedValues(@NotNull MergeInstruction instruction) {
+        Set<PseudoValue> result = new LinkedHashSet<PseudoValue>();
+        for (PseudoValue value : instruction.getInputValues()) {
+            result.addAll(getMergedValues(value));
+            result.add(value);
+        }
+        mergedValues.put(instruction.getOutputValue(), result);
+    }
+
+    private void addValueUsage(PseudoValue value, Instruction usage) {
+        if (usage instanceof MergeInstruction) return;
+        KotlinPackage.getOrPut(
+                valueUsages,
+                value,
+                new Function0<List<Instruction>>() {
+                    @Override
+                    public List<Instruction> invoke() {
+                        return Lists.newArrayList();
+                    }
+                }
+        ).add(usage);
+    }
 
     public void postProcess() {
         if (postPrecessed) return;
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/pseudocodeUtil.kt b/compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/pseudocodeUtil.kt
index 39e56828bdc..3c66a32a983 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/pseudocodeUtil.kt
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/cfg/pseudocode/pseudocodeUtil.kt
@@ -135,16 +135,4 @@ public fun Instruction.getPrimaryDeclarationDescriptorIfAny(bindingContext: Bind
         is CallInstruction -> return resolvedCall.getResultingDescriptor()
         else -> PseudocodeUtil.extractVariableDescriptorIfAny(this, false, bindingContext)
     }
-}
-
-private fun Pseudocode.collectValueUsages(): Map<PseudoValue, List<Instruction>> {
-    val map = HashMap<PseudoValue, MutableList<Instruction>>()
-    traverseFollowingInstructions(getEnterInstruction(), HashSet(), TraversalOrder.FORWARD) {
-        for (value in it.inputValues) {
-            map.getOrPut(value){ ArrayList() }.add(it)
-        }
-        true
-    }
-
-    return map
 }
\ No newline at end of file
diff --git a/compiler/testData/cfg/controlStructures/Finally.values b/compiler/testData/cfg/controlStructures/Finally.values
index 0287b18c72b..88328671165 100644
--- a/compiler/testData/cfg/controlStructures/Finally.values
+++ b/compiler/testData/cfg/controlStructures/Finally.values
@@ -268,8 +268,8 @@ fun t11() {
   }
 }
 ---------------------
-1   <v0>: *      NEW: r(1) -> <v0>
-2   <v1>: Unit   NEW: r(2) -> <v1>
+1   <v0>: {<: Unit}   NEW: r(1) -> <v0>
+2   <v1>: {<: Unit}   NEW: r(2) -> <v1>
 =====================
 == t12 ==
 fun t12() : Int {
diff --git a/compiler/testData/cfg/controlStructures/OnlyWhileInFunctionBody.values b/compiler/testData/cfg/controlStructures/OnlyWhileInFunctionBody.values
index e27c2bd5512..27bf2cc3078 100644
--- a/compiler/testData/cfg/controlStructures/OnlyWhileInFunctionBody.values
+++ b/compiler/testData/cfg/controlStructures/OnlyWhileInFunctionBody.values
@@ -17,7 +17,7 @@ fun dowhile() {
     while(0 > 1)
 }
 ---------------------
-0       <v0>: *   NEW: r(0) -> <v0>
-1       <v1>: *   NEW: r(1) -> <v1>
-0 > 1   <v2>: *   NEW: call(0 > 1, compareTo|<v0>, <v1>) -> <v2>
+0       <v0>: {<: Comparable<Int>}   NEW: r(0) -> <v0>
+1       <v1>: Int                    NEW: r(1) -> <v1>
+0 > 1   <v2>: Boolean                NEW: call(0 > 1, compareTo|<v0>, <v1>) -> <v2>
 =====================