Shrink CompiledData::Function by 8 bytes

We can express the offset to the line number table relative
to the locals.

Saves ~1.4k with examples/quickcontrols/extras/flat/Content.qml and ~11K
RAM with the gallery.

Task-number: QTBUG-69588
Change-Id: I802928102b4291e05ff1462226d22303f8a6d35b
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 6 insertions, 7 deletions

diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index 20e8db528e..715882c985 100644
--- a/src/qml/compiler/qv4compileddata_p.h
+++ b/src/qml/compiler/qv4compileddata_p.h
@@ -263,18 +263,17 @@ struct Function
     quint32_le nameIndex;
     quint16_le length;
     quint16_le nFormals;
-    quint32_le formalsOffset;
+    quint32_le formalsOffset; // Can't turn this into a calculated offset because of the mutation in CompilationUnit::createUnitData.
     quint32_le localsOffset;
     quint16_le nLocals;
     quint16_le nLineNumbers;
-    quint32_le lineNumberOffset;
+    size_t lineNumberOffset() const { return localsOffset + nLocals * sizeof(quint32); }
     quint32_le nestedFunctionIndex; // for functions that only return a single closure, used in signal handlers
-    quint32_le nRegisters;
     Location location;
 
     // Qml Extensions Begin
     // Array of resolved ID objects
-    size_t dependingIdObjectsOffset() const { return lineNumberOffset + nLineNumbers * sizeof(CodeOffsetToLine); }
+    size_t dependingIdObjectsOffset() const { return lineNumberOffset() + nLineNumbers * sizeof(CodeOffsetToLine); }
     quint16_le nDependingIdObjects;
     quint16_le nDependingContextProperties;
     // Array of int pairs (property index and notify index)
@@ -287,14 +286,14 @@ struct Function
     // Keep all unaligned data at the end
     quint8 flags;
     quint8 padding1;
-    quint16_le padding2;
+    quint16_le nRegisters;
 
     //    quint32 formalsIndex[nFormals]
     //    quint32 localsIndex[nLocals]
 
     const quint32_le *formalsTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + formalsOffset); }
     const quint32_le *localsTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + localsOffset); }
-    const CodeOffsetToLine *lineNumberTable() const { return reinterpret_cast<const CodeOffsetToLine *>(reinterpret_cast<const char *>(this) + lineNumberOffset); }
+    const CodeOffsetToLine *lineNumberTable() const { return reinterpret_cast<const CodeOffsetToLine *>(reinterpret_cast<const char *>(this) + lineNumberOffset()); }
     const quint32_le *qmlIdObjectDependencyTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + dependingIdObjectsOffset()); }
     const quint32_le *qmlContextPropertiesDependencyTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + dependingContextPropertiesOffset()); }
     const quint32_le *qmlScopePropertiesDependencyTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + dependingScopePropertiesOffset()); }
@@ -320,7 +319,7 @@ struct Function
         return (a + 7) & ~size_t(7);
     }
 };
-static_assert(sizeof(Function) == 56, "Function 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(Function) == 48, "Function structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Method {
     enum Type {