Introduce the wide/xwide instruction prefixes

And add proper decoding for the prefixed instructions to the
VME and bytecode dumper.

We still only generate XWide instructions, that will get fixed
in the next change.

Change-Id: I6d2dc6a0a4f706044038274ca79e019a6c9bb7d9
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

4 files changed, 77 insertions, 28 deletions

diff --git a/src/qml/compiler/qv4bytecodegenerator.cpp b/src/qml/compiler/qv4bytecodegenerator.cpp
index 72c3d4e96f..3ce3acdb86 100644
--- a/src/qml/compiler/qv4bytecodegenerator.cpp
+++ b/src/qml/compiler/qv4bytecodegenerator.cpp
@@ -71,11 +71,12 @@ void BytecodeGenerator::compressInstructions()
 {
     for (auto &i : instructions) {
         Instr instr = i.instr;
-        i.packed[0] = static_cast<char>(i.type);
-        memcpy(i.packed + 1, reinterpret_cast<char *>(&instr), i.size);
-        ++i.size;
+        i.packed[0] = static_cast<char>(Instr::Type::XWide);
+        i.packed[1] = static_cast<char>(i.type);
+        memcpy(i.packed + 2, reinterpret_cast<char *>(&instr), i.size);
+        i.size += 2;
         if (i.offsetForJump != -1)
-            ++i.offsetForJump;
+            i.offsetForJump += 2;
     }
 }
 
diff --git a/src/qml/compiler/qv4instr_moth.cpp b/src/qml/compiler/qv4instr_moth.cpp
index ba66dff577..2716bed5ad 100644
--- a/src/qml/compiler/qv4instr_moth.cpp
+++ b/src/qml/compiler/qv4instr_moth.cpp
@@ -92,7 +92,12 @@ static QString toString(QV4::ReturnedValue v)
         QDebug d = qDebug(); \
         d.noquote(); \
         d.nospace(); \
-        d << alignedLineNumber(line) << alignedNumber(int(code - start)).constData() << ":    " << #instr << " ";
+        d << alignedLineNumber(line) << alignedNumber(codeOffset).constData() << ":    " << #instr; \
+        switch(mode) { \
+            case Normal: d << " "; break; \
+            case Wide: d << ".Wide "; break; \
+            case XWide: d << ".XWide "; break; \
+        }
 
 #define MOTH_END_INSTR(instr) \
         continue; \
@@ -114,13 +119,7 @@ void dumpConstantTable(const Value *constants, uint count)
 void dumpBytecode(const char *code, int len, int nLocals, int nFormals, int startLine, const QVector<int> &lineNumberMapping)
 {
 
-#ifdef MOTH_THREADED_INTERPRETER
-#define MOTH_INSTR_ADDR(I) &&op_int_##I,
-    static void *jumpTable[] = {
-        FOR_EACH_MOTH_INSTR(MOTH_INSTR_ADDR)
-    };
-#undef MOTH_INSTR_ADDR
-#endif
+    MOTH_JUMP_TABLE;
 
     int lastLine = -1;
     const char *start = code;
@@ -131,16 +130,30 @@ void dumpBytecode(const char *code, int len, int nLocals, int nFormals, int star
             lastLine = line;
         else
             line = -1;
+        enum Mode {
+            Normal,
+            Wide,
+            XWide
+        } mode = Normal;
+
+        int codeOffset = (code - start);
+
         MOTH_DISPATCH()
 
         MOTH_BEGIN_INSTR(Nop)
         MOTH_END_INSTR(Nop)
 
-        MOTH_BEGIN_INSTR(Wide)
-        MOTH_END_INSTR(Wide)
-
-        MOTH_BEGIN_INSTR(XWide)
-        MOTH_END_INSTR(XWide)
+        {
+            INSTR_Wide(MOTH_DECODE) \
+            mode = Wide;
+            MOTH_DISPATCH_WIDE();
+        }
+
+        {
+            INSTR_XWide(MOTH_DECODE) \
+            mode = XWide;
+            MOTH_DISPATCH_XWIDE();
+        }
 
         MOTH_BEGIN_INSTR(LoadReg)
             d << StackSlot::createRegister(reg).dump(nFormals);
diff --git a/src/qml/compiler/qv4instr_moth_p.h b/src/qml/compiler/qv4instr_moth_p.h
index bffc7b2bf4..c10d48ff8e 100644
--- a/src/qml/compiler/qv4instr_moth_p.h
+++ b/src/qml/compiler/qv4instr_moth_p.h
@@ -341,6 +341,27 @@ QT_BEGIN_NAMESPACE
 #define MOTH_EMIT_INSTR_MEMBER_INSTRUCTION(name, nargs, ...) \
     instr_##name name;
 
+/* collect jump labels */
+#define COLLECT_LABELS(instr) \
+    INSTR_##instr(GET_LABEL)
+#define GET_LABEL_INSTRUCTION(name, ...) \
+    &&op_char_##name,
+
+#define COLLECT_LABELS_WIDE(instr) \
+    INSTR_##instr(GET_LABEL_WIDE)
+#define GET_LABEL_WIDE_INSTRUCTION(name, ...) \
+    &&op_short_##name,
+
+#define COLLECT_LABELS_XWIDE(instr) \
+    INSTR_##instr(GET_LABEL_XWIDE)
+#define GET_LABEL_XWIDE_INSTRUCTION(name, ...) \
+    &&op_int_##name,
+
+#define MOTH_JUMP_TABLE \
+    static const void *jumpTable[] = { FOR_EACH_MOTH_INSTR(COLLECT_LABELS) }; \
+    static const void *jumpTableWide[] = { FOR_EACH_MOTH_INSTR(COLLECT_LABELS_WIDE) }; \
+    static const void *jumpTableXWide[] = { FOR_EACH_MOTH_INSTR(COLLECT_LABELS_XWIDE) }
+
 
 #define MOTH_DECODE_ARG(arg, type, offset) \
     arg = reinterpret_cast<const type *>(code)[offset]
@@ -352,6 +373,16 @@ QT_BEGIN_NAMESPACE
     op_int_##name: \
         MOTH_DECODE_ARGS(name, int, nargs, __VA_ARGS__) \
         MOTH_ADJUST_CODE(int, nargs); \
+        goto op_main_##name; \
+    op_short_##name: \
+        MOTH_DECODE_ARGS(name, short, nargs, __VA_ARGS__) \
+        MOTH_ADJUST_CODE(short, nargs); \
+        goto op_main_##name; \
+    op_char_##name: \
+        MOTH_DECODE_ARGS(name, char, nargs, __VA_ARGS__) \
+        MOTH_ADJUST_CODE(char, nargs); \
+    op_main_##name: \
+        ; \
 
 #define MOTH_DECODE_ARGS(name, type, nargs, ...) \
     MOTH_DECODE_ARGS##nargs(name, type, __VA_ARGS__)
@@ -374,6 +405,16 @@ QT_BEGIN_NAMESPACE
     ++code; \
     goto *jumpTable[instr];
 
+#define MOTH_DISPATCH_WIDE() \
+    int winstr = *code; \
+    ++code; \
+    goto *jumpTableWide[winstr];
+
+#define MOTH_DISPATCH_XWIDE() \
+    int xwinstr = *code; \
+    ++code; \
+    goto *jumpTableXWide[xwinstr];
+
 namespace QV4 {
 namespace Moth {
 
diff --git a/src/qml/jsruntime/qv4vme_moth.cpp b/src/qml/jsruntime/qv4vme_moth.cpp
index 78970ef10d..6a58fcd42d 100644
--- a/src/qml/jsruntime/qv4vme_moth.cpp
+++ b/src/qml/jsruntime/qv4vme_moth.cpp
@@ -519,13 +519,7 @@ QV4::ReturnedValue VME::exec(const FunctionObject *jsFunction, CallData *callDat
 {
     qt_v4ResolvePendingBreakpointsHook();
 
-#ifdef MOTH_THREADED_INTERPRETER
-#define MOTH_INSTR_ADDR(I) &&op_int_##I,
-    static void *jumpTable[] = {
-        FOR_EACH_MOTH_INSTR(MOTH_INSTR_ADDR)
-    };
-#undef MOTH_INSTR_ADDR
-#endif
+    MOTH_JUMP_TABLE;
 
     ExecutionEngine *engine = function->internalClass->engine;
     Profiling::FunctionCallProfiler(engine, function);
@@ -565,12 +559,12 @@ QV4::ReturnedValue VME::exec(const FunctionObject *jsFunction, CallData *callDat
     MOTH_END_INSTR(Nop)
 
     MOTH_BEGIN_INSTR(Wide)
-            ; // nop
-    MOTH_END_INSTR(Wide)
+        MOTH_DISPATCH_WIDE()
+    }
 
     MOTH_BEGIN_INSTR(XWide)
-            ; // nop
-    MOTH_END_INSTR(XWide)
+        MOTH_DISPATCH_XWIDE()
+    }
 
     MOTH_BEGIN_INSTR(LoadConst)
         accumulator = constant(function, index);