diff --git a/java/src/com/android/inputmethod/keyboard/Key.java b/java/src/com/android/inputmethod/keyboard/Key.java
index b09a275..0a2b010 100644
--- a/java/src/com/android/inputmethod/keyboard/Key.java
+++ b/java/src/com/android/inputmethod/keyboard/Key.java
@@ -180,7 +180,7 @@
         mY = y;
         mHitBox.set(x, y, x + width + 1, y + height);
 
-        mHashCode = hashCode(this);
+        mHashCode = computeHashCode(this);
     }
 
     /**
@@ -334,7 +334,7 @@
         mAltCode = adjustCaseOfCodeForKeyboardId(style.getInt(keyAttr,
                 R.styleable.Keyboard_Key_altCode, Keyboard.CODE_UNSPECIFIED), preserveCase,
                 params.mId);
-        mHashCode = hashCode(this);
+        mHashCode = computeHashCode(this);
 
         keyAttr.recycle();
 
@@ -366,7 +366,7 @@
         }
     }
 
-    private static int hashCode(Key key) {
+    private static int computeHashCode(Key key) {
         return Arrays.hashCode(new Object[] {
                 key.mX,
                 key.mY,
diff --git a/java/src/com/android/inputmethod/keyboard/KeyboardId.java b/java/src/com/android/inputmethod/keyboard/KeyboardId.java
index 6703b93..3b2b11e 100644
--- a/java/src/com/android/inputmethod/keyboard/KeyboardId.java
+++ b/java/src/com/android/inputmethod/keyboard/KeyboardId.java
@@ -70,23 +70,23 @@
     public KeyboardId(int elementId, Locale locale, int orientation, int width, int mode,
             EditorInfo editorInfo, boolean clobberSettingsKey, boolean shortcutKeyEnabled,
             boolean hasShortcutKey, boolean languageSwitchKeyEnabled) {
-        this.mLocale = locale;
-        this.mOrientation = orientation;
-        this.mWidth = width;
-        this.mMode = mode;
-        this.mElementId = elementId;
-        this.mEditorInfo = editorInfo;
-        this.mClobberSettingsKey = clobberSettingsKey;
-        this.mShortcutKeyEnabled = shortcutKeyEnabled;
-        this.mHasShortcutKey = hasShortcutKey;
-        this.mLanguageSwitchKeyEnabled = languageSwitchKeyEnabled;
-        this.mCustomActionLabel = (editorInfo.actionLabel != null)
+        mLocale = locale;
+        mOrientation = orientation;
+        mWidth = width;
+        mMode = mode;
+        mElementId = elementId;
+        mEditorInfo = editorInfo;
+        mClobberSettingsKey = clobberSettingsKey;
+        mShortcutKeyEnabled = shortcutKeyEnabled;
+        mHasShortcutKey = hasShortcutKey;
+        mLanguageSwitchKeyEnabled = languageSwitchKeyEnabled;
+        mCustomActionLabel = (editorInfo.actionLabel != null)
                 ? editorInfo.actionLabel.toString() : null;
 
-        this.mHashCode = hashCode(this);
+        mHashCode = computeHashCode(this);
     }
 
-    private static int hashCode(KeyboardId id) {
+    private static int computeHashCode(KeyboardId id) {
         return Arrays.hashCode(new Object[] {
                 id.mOrientation,
                 id.mElementId,
@@ -109,21 +109,21 @@
     private boolean equals(KeyboardId other) {
         if (other == this)
             return true;
-        return other.mOrientation == this.mOrientation
-                && other.mElementId == this.mElementId
-                && other.mMode == this.mMode
-                && other.mWidth == this.mWidth
-                && other.passwordInput() == this.passwordInput()
-                && other.mClobberSettingsKey == this.mClobberSettingsKey
-                && other.mShortcutKeyEnabled == this.mShortcutKeyEnabled
-                && other.mHasShortcutKey == this.mHasShortcutKey
-                && other.mLanguageSwitchKeyEnabled == this.mLanguageSwitchKeyEnabled
-                && other.isMultiLine() == this.isMultiLine()
-                && other.imeAction() == this.imeAction()
-                && TextUtils.equals(other.mCustomActionLabel, this.mCustomActionLabel)
-                && other.navigateNext() == this.navigateNext()
-                && other.navigatePrevious() == this.navigatePrevious()
-                && other.mLocale.equals(this.mLocale);
+        return other.mOrientation == mOrientation
+                && other.mElementId == mElementId
+                && other.mMode == mMode
+                && other.mWidth == mWidth
+                && other.passwordInput() == passwordInput()
+                && other.mClobberSettingsKey == mClobberSettingsKey
+                && other.mShortcutKeyEnabled == mShortcutKeyEnabled
+                && other.mHasShortcutKey == mHasShortcutKey
+                && other.mLanguageSwitchKeyEnabled == mLanguageSwitchKeyEnabled
+                && other.isMultiLine() == isMultiLine()
+                && other.imeAction() == imeAction()
+                && TextUtils.equals(other.mCustomActionLabel, mCustomActionLabel)
+                && other.navigateNext() == navigateNext()
+                && other.navigatePrevious() == navigatePrevious()
+                && other.mLocale.equals(mLocale);
     }
 
     public boolean isAlphabetKeyboard() {
diff --git a/java/src/com/android/inputmethod/keyboard/ProximityInfo.java b/java/src/com/android/inputmethod/keyboard/ProximityInfo.java
index aa499ed..5c18086 100644
--- a/java/src/com/android/inputmethod/keyboard/ProximityInfo.java
+++ b/java/src/com/android/inputmethod/keyboard/ProximityInfo.java
@@ -79,10 +79,12 @@
         final ProximityInfo spellCheckerProximityInfo = createDummyProximityInfo();
         spellCheckerProximityInfo.mNativeProximityInfo =
                 spellCheckerProximityInfo.setProximityInfoNative("",
-                        SpellCheckerProximityInfo.ROW_SIZE, 480, 300,
+                        SpellCheckerProximityInfo.ROW_SIZE,
                         SpellCheckerProximityInfo.PROXIMITY_GRID_WIDTH,
                         SpellCheckerProximityInfo.PROXIMITY_GRID_HEIGHT,
-                        (480 / 10), proximity, 0, null, null, null, null, null, null, null, null);
+                        SpellCheckerProximityInfo.PROXIMITY_GRID_WIDTH,
+                        SpellCheckerProximityInfo.PROXIMITY_GRID_HEIGHT,
+                        1, proximity, 0, null, null, null, null, null, null, null, null);
         return spellCheckerProximityInfo;
     }
 
diff --git a/java/src/com/android/inputmethod/latin/WordComposer.java b/java/src/com/android/inputmethod/latin/WordComposer.java
index 9f23f17..231211d 100644
--- a/java/src/com/android/inputmethod/latin/WordComposer.java
+++ b/java/src/com/android/inputmethod/latin/WordComposer.java
@@ -127,12 +127,8 @@
         final int[] codes;
         final int keyX;
         final int keyY;
-        if (x == KeyboardActionListener.SPELL_CHECKER_COORDINATE
-                || y == KeyboardActionListener.SPELL_CHECKER_COORDINATE) {
-            // only used for tests in InputLogicTests
-            addKeyForSpellChecker(primaryCode, AndroidSpellCheckerService.SCRIPT_LATIN);
-            return;
-        } else if (x == KeyboardActionListener.SUGGESTION_STRIP_COORDINATE
+        if (null == keyDetector
+                || x == KeyboardActionListener.SUGGESTION_STRIP_COORDINATE
                 || y == KeyboardActionListener.SUGGESTION_STRIP_COORDINATE
                 || x == KeyboardActionListener.NOT_A_TOUCH_COORDINATE
                 || y == KeyboardActionListener.NOT_A_TOUCH_COORDINATE) {
@@ -149,27 +145,6 @@
         add(primaryCode, codes, keyX, keyY);
     }
 
-    // TODO: remove this function
-    public void addKeyForSpellChecker(int primaryCode, int script) {
-        final int[] proximities;
-        final int proximityIndex =
-                SpellCheckerProximityInfo.getIndexOfCodeForScript(primaryCode, script);
-        if (-1 == proximityIndex) {
-            proximities = new int[] { primaryCode };
-        } else {
-            // TODO: an initial examination seems to reveal this is actually used
-            // read-only. It should be possible to compute the arrays statically once
-            // and skip doing a copy each time here.
-            proximities = Arrays.copyOfRange(
-                    SpellCheckerProximityInfo.getProximityForScript(script),
-                    proximityIndex,
-                    proximityIndex + SpellCheckerProximityInfo.ROW_SIZE);
-        }
-        add(primaryCode, proximities,
-                KeyboardActionListener.NOT_A_TOUCH_COORDINATE,
-                KeyboardActionListener.NOT_A_TOUCH_COORDINATE);
-    }
-
     /**
      * Add a new keystroke, with codes[0] containing the pressed key's unicode and the rest of
      * the array containing unicode for adjacent keys, sorted by reducing probability/proximity.
diff --git a/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java b/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java
index e88ab68..70530c3 100644
--- a/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java
+++ b/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java
@@ -64,6 +64,19 @@
             mWord = word;
             mFrequency = frequency;
         }
+
+        @Override
+        public int hashCode() {
+            return Arrays.hashCode(new Object[] { mWord, mFrequency });
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (o == this) return true;
+            if (!(o instanceof WeightedString)) return false;
+            WeightedString w = (WeightedString)o;
+            return mWord.equals(w.mWord) && mFrequency == w.mFrequency;
+        }
     }
 
     /**
diff --git a/java/src/com/android/inputmethod/latin/makedict/Word.java b/java/src/com/android/inputmethod/latin/makedict/Word.java
index c2c01e1..4e0ab10 100644
--- a/java/src/com/android/inputmethod/latin/makedict/Word.java
+++ b/java/src/com/android/inputmethod/latin/makedict/Word.java
@@ -19,6 +19,7 @@
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 
 /**
  * Utility class for a word with a frequency.
@@ -32,6 +33,8 @@
     final ArrayList<WeightedString> mShortcutTargets;
     final ArrayList<WeightedString> mBigrams;
 
+    private int mHashCode = 0;
+
     public Word(final String word, final int frequency,
             final ArrayList<WeightedString> shortcutTargets,
             final ArrayList<WeightedString> bigrams, final boolean isShortcutOnly) {
@@ -42,6 +45,16 @@
         mIsShortcutOnly = isShortcutOnly;
     }
 
+    private static int computeHashCode(Word word) {
+        return Arrays.hashCode(new Object[] {
+                word.mWord,
+                word.mFrequency,
+                word.mIsShortcutOnly,
+                word.mShortcutTargets.hashCode(),
+                word.mBigrams.hashCode()
+        });
+    }
+
     /**
      * Three-way comparison.
      *
@@ -63,10 +76,20 @@
      */
     @Override
     public boolean equals(Object o) {
+        if (o == this) return true;
         if (!(o instanceof Word)) return false;
         Word w = (Word)o;
         return mFrequency == w.mFrequency && mWord.equals(w.mWord)
+                && mIsShortcutOnly == w.mIsShortcutOnly
                 && mShortcutTargets.equals(w.mShortcutTargets)
                 && mBigrams.equals(w.mBigrams);
     }
+
+    @Override
+    public int hashCode() {
+        if (mHashCode == 0) {
+            mHashCode = computeHashCode(this);
+        }
+        return mHashCode;
+    }
 }
diff --git a/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java b/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
index 35a5c0f..973a448 100644
--- a/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
+++ b/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
@@ -570,7 +570,11 @@
                 final WordComposer composer = new WordComposer();
                 final int length = text.length();
                 for (int i = 0; i < length; i = text.offsetByCodePoints(i, 1)) {
-                    composer.addKeyForSpellChecker(text.codePointAt(i), mScript);
+                    final int codePoint = text.codePointAt(i);
+                    // The getXYForCodePointAndScript method returns (Y << 16) + X
+                    final int xy = SpellCheckerProximityInfo.getXYForCodePointAndScript(
+                            codePoint, mScript);
+                    composer.add(codePoint, xy & 0xFFFF, xy >> 16, null);
                 }
 
                 final int capitalizeType = getCapitalizationType(text);
diff --git a/java/src/com/android/inputmethod/latin/spellcheck/SpellCheckerProximityInfo.java b/java/src/com/android/inputmethod/latin/spellcheck/SpellCheckerProximityInfo.java
index f4c66d0..90c0aac 100644
--- a/java/src/com/android/inputmethod/latin/spellcheck/SpellCheckerProximityInfo.java
+++ b/java/src/com/android/inputmethod/latin/spellcheck/SpellCheckerProximityInfo.java
@@ -87,7 +87,7 @@
             // Proximity for row 2. See comment above about size.
             'a', 'z', 'x', 's', 'w', 'q', 'e', 'i', 'o', 'u', NUL, NUL, NUL, NUL, NUL, NUL,
             's', 'q', 'a', 'z', 'x', 'c', 'd', 'e', 'w', NUL, NUL, NUL, NUL, NUL, NUL, NUL,
-            'd', 'w', 's', 'x', 'c', 'v', 'f', 'r', 'e', 'w', NUL, NUL, NUL, NUL, NUL, NUL,
+            'd', 'w', 's', 'x', 'c', 'v', 'f', 'r', 'e', NUL, NUL, NUL, NUL, NUL, NUL, NUL,
             'f', 'e', 'd', 'c', 'v', 'b', 'g', 't', 'r', NUL, NUL, NUL, NUL, NUL, NUL, NUL,
             'g', 'r', 'f', 'v', 'b', 'n', 'h', 'y', 't', NUL, NUL, NUL, NUL, NUL, NUL, NUL,
             'h', 't', 'g', 'b', 'n', 'm', 'j', 'u', 'y', NUL, NUL, NUL, NUL, NUL, NUL, NUL,
@@ -181,14 +181,30 @@
                 throw new RuntimeException("Wrong script supplied: " + script);
         }
     }
-    public static int getIndexOfCodeForScript(final int characterCode, final int script) {
+
+    private static int getIndexOfCodeForScript(final int codePoint, final int script) {
         switch (script) {
             case AndroidSpellCheckerService.SCRIPT_LATIN:
-                return Latin.getIndexOf(characterCode);
+                return Latin.getIndexOf(codePoint);
             case AndroidSpellCheckerService.SCRIPT_CYRILLIC:
-                return Cyrillic.getIndexOf(characterCode);
+                return Cyrillic.getIndexOf(codePoint);
             default:
                 throw new RuntimeException("Wrong script supplied: " + script);
         }
     }
+
+    // Returns (Y << 16) + X to avoid creating a temporary object. This is okay because
+    // X and Y are limited to PROXIMITY_GRID_WIDTH resp. PROXIMITY_GRID_HEIGHT which is very
+    // inferior to 1 << 16
+    public static int getXYForCodePointAndScript(final int codePoint, final int script) {
+        final int index = getIndexOfCodeForScript(codePoint, script);
+        // TODO: precompute index / ROW_SIZE
+        final int y = index / (PROXIMITY_GRID_WIDTH * ROW_SIZE);
+        final int x = (index / ROW_SIZE) % PROXIMITY_GRID_WIDTH;
+        if (y > PROXIMITY_GRID_HEIGHT) {
+            // Safety check, should be entirely useless
+            throw new RuntimeException("Wrong y coordinate in spell checker proximity");
+        }
+        return (y << 16) + x;
+    }
 }
diff --git a/native/src/proximity_info.cpp b/native/src/proximity_info.cpp
index 4d03f32..47f1376 100644
--- a/native/src/proximity_info.cpp
+++ b/native/src/proximity_info.cpp
@@ -130,6 +130,7 @@
 }
 
 bool ProximityInfo::isOnKey(const int keyId, const int x, const int y) {
+    if (keyId < 0) return true; // NOT_A_ID is -1, but return whenever < 0 just in case
     const int left = mKeyXCoordinates[keyId];
     const int top = mKeyYCoordinates[keyId];
     const int right = left + mKeyWidths[keyId] + 1;
@@ -138,6 +139,7 @@
 }
 
 int ProximityInfo::squaredDistanceToEdge(const int keyId, const int x, const int y) {
+    if (keyId < 0) return true; // NOT_A_ID is -1, but return whenever < 0 just in case
     const int left = mKeyXCoordinates[keyId];
     const int top = mKeyYCoordinates[keyId];
     const int right = left + mKeyWidths[keyId];
@@ -162,7 +164,7 @@
         const int keyIndex = getKeyIndex(c);
         const bool onKey = isOnKey(keyIndex, x, y);
         const int distance = squaredDistanceToEdge(keyIndex, x, y);
-        if (c >= KEYCODE_SPACE && (onKey || distance < MOST_COMMON_KEY_WIDTH_SQUARE)) {
+        if (onKey || distance < MOST_COMMON_KEY_WIDTH_SQUARE) {
             inputCodes[insertPos++] = c;
             if (insertPos >= MAX_PROXIMITY_CHARS_SIZE) {
                 if (DEBUG_DICT) {
@@ -211,7 +213,6 @@
     }
 }
 
-// TODO: Calculate nearby codes here.
 void ProximityInfo::setInputParams(const int32_t* inputCodes, const int inputLength,
         const int* xCoordinates, const int* yCoordinates) {
     memset(mInputCodes, 0,