Shrink CompiledData::Binding by 8 bytes

Move the translation data out into a separately indexed table, which
allows to shrunk the value union down to 4 bytes, together with the
previous commit.

Saves ~4k with examples/quickcontrols/extras/flat/Content.qml and ~37K
RAM with the gallery.

Task-number: QTBUG-69588
Change-Id: Ia5016b072320ebb6b8fcfbb4dad128d53c901c74
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

5 files changed, 46 insertions, 19 deletions

diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index 1f6a702e4a..d5d7d6d6b0 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -1120,6 +1120,7 @@ void IRBuilder::tryGeneratingTranslationBinding(const QStringRef &base, AST::Arg
         } else {
             return; // first argument is not a string, stop
         }
+        translationData.stringIndex = jsGenerator->registerString(translation.toString());
 
         args = args->next;
 
@@ -1144,8 +1145,7 @@ void IRBuilder::tryGeneratingTranslationBinding(const QStringRef &base, AST::Arg
             return; // too many arguments, stop
 
         binding->type = QV4::CompiledData::Binding::Type_Translation;
-        binding->stringIndex = jsGenerator->registerString(translation.toString());
-        binding->value.translationData = translationData;
+        binding->value.translationDataIndex = jsGenerator->registerTranslation(translationData);
     } else if (base == QLatin1String("qsTrId")) {
         QV4::CompiledData::TranslationData translationData;
         translationData.number = -1;
@@ -1160,6 +1160,7 @@ void IRBuilder::tryGeneratingTranslationBinding(const QStringRef &base, AST::Arg
         } else {
             return; // first argument is not a string, stop
         }
+        translationData.stringIndex = jsGenerator->registerString(id.toString());
 
         args = args->next;
 
@@ -1176,8 +1177,7 @@ void IRBuilder::tryGeneratingTranslationBinding(const QStringRef &base, AST::Arg
             return; // too many arguments, stop
 
         binding->type = QV4::CompiledData::Binding::Type_TranslationById;
-        binding->stringIndex = jsGenerator->registerString(id.toString());
-        binding->value.translationData = translationData;
+        binding->value.translationDataIndex = jsGenerator->registerTranslation(translationData);
     } else if (base == QLatin1String("QT_TR_NOOP") || base == QLatin1String("QT_TRID_NOOP")) {
         if (!args || !args->expression)
             return; // no arguments, stop
diff --git a/src/qml/compiler/qv4compileddata.cpp b/src/qml/compiler/qv4compileddata.cpp
index 3e3859d9fb..357c6fc04a 100644
--- a/src/qml/compiler/qv4compileddata.cpp
+++ b/src/qml/compiler/qv4compileddata.cpp
@@ -604,23 +604,25 @@ QString Binding::valueAsString(const CompilationUnit *unit) const
 #if !QT_CONFIG(translation)
     case Type_TranslationById:
     case Type_Translation:
-        return unit->stringAt(stringIndex);
+        return unit->stringAt(unit->unitData->translations()[value.translationDataIndex].stringIndex);
 #else
     case Type_TranslationById: {
-        QByteArray id = unit->stringAt(stringIndex).toUtf8();
-        return qtTrId(id.constData(), value.translationData.number);
+        const TranslationData &translation = unit->unitData()->translations()[value.translationDataIndex];
+        QByteArray id = unit->stringAt(translation.stringIndex).toUtf8();
+        return qtTrId(id.constData(), translation.number);
     }
     case Type_Translation: {
+        const TranslationData &translation = unit->unitData()->translations()[value.translationDataIndex];
         // This code must match that in the qsTr() implementation
-        const QString &path = unit->stringAt(unit->data->sourceFileIndex);
+        const QString &path = unit->stringAt(unit->unitData()->sourceFileIndex);
         int lastSlash = path.lastIndexOf(QLatin1Char('/'));
         QStringRef context = (lastSlash > -1) ? path.midRef(lastSlash + 1, path.length() - lastSlash - 5)
                                               : QStringRef();
         QByteArray contextUtf8 = context.toUtf8();
-        QByteArray comment = unit->stringAt(value.translationData.commentIndex).toUtf8();
-        QByteArray text = unit->stringAt(stringIndex).toUtf8();
+        QByteArray comment = unit->stringAt(translation.commentIndex).toUtf8();
+        QByteArray text = unit->stringAt(translation.stringIndex).toUtf8();
         return QCoreApplication::translate(contextUtf8.constData(), text.constData(),
-                                           comment.constData(), value.translationData.number);
+                                           comment.constData(), translation.number);
     }
 #endif
     default:
diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index 7bbc4d2835..20e8db528e 100644
--- a/src/qml/compiler/qv4compileddata_p.h
+++ b/src/qml/compiler/qv4compileddata_p.h
@@ -362,11 +362,14 @@ static_assert(sizeof(Class) == 24, "Class structure needs to have the expected s
 
 // Qml data structures
 
-struct Q_QML_EXPORT TranslationData {
+struct Q_QML_EXPORT TranslationData
+{
+    quint32_le stringIndex;
     quint32_le commentIndex;
     qint32_le number;
+    quint32_le padding;
 };
-static_assert(sizeof(TranslationData) == 8, "TranslationData structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+static_assert(sizeof(TranslationData) == 16, "TranslationData structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Q_QML_PRIVATE_EXPORT Binding
 {
@@ -407,15 +410,13 @@ struct Q_QML_PRIVATE_EXPORT Binding
         quint32_le constantValueIndex;
         quint32_le compiledScriptIndex; // used when Type_Script
         quint32_le objectIndex;
-        TranslationData translationData; // used when Type_Translation
+        quint32_le translationDataIndex; // used when Type_Translation
     } value;
-    quint32_le stringIndex; // Set for Type_String, Type_Translation and Type_Script (the latter because of script strings)
+    quint32_le stringIndex; // Set for Type_String and Type_Script (the latter because of script strings)
 
     Location location;
     Location valueLocation;
 
-    quint32_le padding;
-
     bool isValueBinding() const
     {
         if (type == Type_AttachedProperty
@@ -490,7 +491,7 @@ struct Q_QML_PRIVATE_EXPORT Binding
 
 };
 
-static_assert(sizeof(Binding) == 32, "Binding structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+static_assert(sizeof(Binding) == 24, "Binding structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct EnumValue
 {
@@ -799,6 +800,8 @@ struct Unit
     quint32_le offsetToConstantTable;
     quint32_le jsClassTableSize;
     quint32_le offsetToJSClassTable;
+    quint32_le translationTableSize;
+    quint32_le offsetToTranslationTable;
     qint32_le indexOfRootFunction;
     quint32_le sourceFileIndex;
     quint32_le finalUrlIndex;
@@ -889,9 +892,13 @@ struct Unit
         *nMembers = klass->nMembers;
         return reinterpret_cast<const JSClassMember*>(ptr + sizeof(JSClass));
     }
+
+    const TranslationData *translations() const {
+        return reinterpret_cast<const TranslationData *>(reinterpret_cast<const char *>(this) + offsetToTranslationTable);
+    }
 };
 
-static_assert(sizeof(Unit) == 208, "Unit structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+static_assert(sizeof(Unit) == 216, "Unit structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct TypeReference
 {
diff --git a/src/qml/compiler/qv4compiler.cpp b/src/qml/compiler/qv4compiler.cpp
index a2afc7fefe..252056b2b6 100644
--- a/src/qml/compiler/qv4compiler.cpp
+++ b/src/qml/compiler/qv4compiler.cpp
@@ -208,6 +208,12 @@ int QV4::Compiler::JSUnitGenerator::registerJSClass(const QStringList &members)
     return jsClassOffsets.size() - 1;
 }
 
+int QV4::Compiler::JSUnitGenerator::registerTranslation(const QV4::CompiledData::TranslationData &translation)
+{
+    translations.append(translation);
+    return translations.size() - 1;
+}
+
 QV4::CompiledData::Unit *QV4::Compiler::JSUnitGenerator::generateUnit(GeneratorOption option)
 {
     registerString(module->fileName);
@@ -286,6 +292,8 @@ QV4::CompiledData::Unit *QV4::Compiler::JSUnitGenerator::generateUnit(GeneratorO
             jsClassOffsetTable[i] = jsClassDataOffset + jsClassOffsets.at(i);
     }
 
+    memcpy(dataPtr + unit->offsetToTranslationTable, translations.constData(), translations.count() * sizeof(CompiledData::TranslationData));
+
     // write strings and string table
     if (option == GenerateWithStringTable)
         stringTable.serialize(unit);
@@ -521,6 +529,12 @@ QV4::CompiledData::Unit QV4::Compiler::JSUnitGenerator::generateHeader(QV4::Comp
 
     nextOffset = (nextOffset + 7) & ~quint32(0x7);
 
+    unit.translationTableSize = translations.count();
+    unit.offsetToTranslationTable = nextOffset;
+    nextOffset += unit.translationTableSize * sizeof(CompiledData::TranslationData);
+
+    nextOffset = (nextOffset + 7) & ~quint32(0x7);
+
     quint32 functionSize = 0;
 
     for (int i = 0; i < module->functions.size(); ++i) {
@@ -575,6 +589,7 @@ QV4::CompiledData::Unit QV4::Compiler::JSUnitGenerator::generateHeader(QV4::Comp
     if (showStats) {
         qDebug() << "Generated JS unit that is" << unit.unitSize << "bytes contains:";
         qDebug() << "    " << functionSize << "bytes for non-code function data for" << unit.functionTableSize << "functions";
+        qDebug() << "    " << translations.count() * sizeof(CompiledData::TranslationData) << "bytes for" << translations.count() << "translations";
     }
 
     return unit;
diff --git a/src/qml/compiler/qv4compiler_p.h b/src/qml/compiler/qv4compiler_p.h
index 944c44b1ff..381b6fad21 100644
--- a/src/qml/compiler/qv4compiler_p.h
+++ b/src/qml/compiler/qv4compiler_p.h
@@ -120,6 +120,8 @@ struct Q_QML_PRIVATE_EXPORT JSUnitGenerator {
 
     int registerJSClass(const QStringList &members);
 
+    int registerTranslation(const CompiledData::TranslationData &translation);
+
     enum GeneratorOption {
         GenerateWithStringTable,
         GenerateWithoutStringTable
@@ -142,6 +144,7 @@ private:
     QVector<ReturnedValue> constants;
     QByteArray jsClassData;
     QVector<int> jsClassOffsets;
+    QVector<CompiledData::TranslationData> translations;
 };
 
 }