Add toolbar button and Action menu item to toggle forcing the recompiler to interpret blocks, should help with some slowdowns (tested to help with Daggerfall on both recompilers and Legend of Hero III on new recompiler).

src/cpu/386_dynarec.c

@@ -51,6 +51,7 @@
 
 #define CPU_BLOCK_END() cpu_block_end = 1
 
+int cpu_force_interpreter   = 0;
 int cpu_override_dynarec    = 0;
 int inrecomp                = 0;
 int cpu_block_end           = 0;
@@ -778,7 +779,7 @@ exec386_dynarec(int32_t cycs)
             cycles_old       = cycles;
             oldtsc           = tsc;
             tsc_old          = tsc;
-            if ((!CACHE_ON()) || cpu_override_dynarec) /*Interpret block*/
+            if (cpu_force_interpreter || cpu_override_dynarec ||  (!CACHE_ON())) /*Interpret block*/
             {
                 exec386_dynarec_int();
             } else {

src/cpu/cpu.h

@@ -823,6 +823,8 @@ extern MMX_REG  *MMP[8];
 extern uint16_t *MMEP[8];
 
 extern int  cpu_block_end;
+
+extern int  cpu_force_interpreter;
 extern int  cpu_override_dynarec;
 
 extern void mmx_init(void);

src/cpu/x86.c

@@ -373,6 +373,8 @@ reset_common(int hard)
     in_lock    = 0;
 
     cpu_cpurst_on_sr = 0;
+
+    cpu_force_interpreter = 0;
 }
 
 /* Hard reset. */

src/include/86box/ui.h

@@ -71,6 +71,8 @@ extern void     ui_sb_set_text(char *str);
 extern void     ui_sb_bugui(char *str);
 extern void     ui_sb_mt32lcd(char *str);
 
+extern void     ui_update_force_interpreter(void);
+
 #ifdef __cplusplus
 }
 #endif

src/qt/languages/86box.pot

@@ -3038,3 +3038,15 @@ msgstr ""
 
 msgid "Search:"
 msgstr ""
+
+msgid "Force interpretation"
+msgstr ""
+
+msgid "Allow recompilation"
+msgstr ""
+
+msgid "&Force interpretation"
+msgstr ""
+
+msgid "&Allow recompilation"
+msgstr ""

src/qt/languages/cs-CZ.po

@@ -3044,3 +3044,15 @@ msgstr "Tmavé"
 
 msgid "Search:"
 msgstr "Hledat:"
+
+msgid "Force interpretation"
+msgstr "Vynutit interpretaci"
+
+msgid "Allow recompilation"
+msgstr "Povolit rekompilaci"
+
+msgid "&Force interpretation"
+msgstr "&Vynutit interpretaci"
+
+msgid "&Allow recompilation"
+msgstr "&Povolit rekompilaci"

src/qt/languages/de-DE.po

@@ -3044,3 +3044,15 @@ msgstr "Dunkel"
 
 msgid "Search:"
 msgstr "Suche:"
+
+msgid "Force interpretation"
+msgstr "Erzwingen der Interpretation"
+
+msgid "Allow recompilation"
+msgstr "Recompilierung zulassen"
+
+msgid "&Force interpretation"
+msgstr "&Erzwingen der Interpretation"
+
+msgid "&Allow recompilation"
+msgstr "Recompilierung &zulassen"

src/qt/languages/es-ES.po

@@ -3044,3 +3044,15 @@ msgstr "Oscuro"
 
 msgid "Search:"
 msgstr "Buscar:"
+
+msgid "Force interpretation"
+msgstr "Forzar interpretación"
+
+msgid "Allow recompilation"
+msgstr "Permitir recompilación"
+
+msgid "&Force interpretation"
+msgstr "&Forzar interpretación"
+
+msgid "&Allow recompilation"
+msgstr "&Permitir recompilación"

src/qt/languages/fi-FI.po

@@ -3038,3 +3038,15 @@ msgstr "Tumma"
 
 msgid "Search:"
 msgstr "Hae:"
+
+msgid "Force interpretation"
+msgstr "Pakota tulkinta"
+
+msgid "Allow recompilation"
+msgstr "Salli uudelleenkompilointi"
+
+msgid "&Force interpretation"
+msgstr "&Pakota tulkinta"
+
+msgid "&Allow recompilation"
+msgstr "&Salli uudelleenkompilointi"

src/qt/languages/fr-FR.po

@@ -3044,3 +3044,15 @@ msgstr "Sombre"
 
 msgid "Search:"
 msgstr "Rechercher :"
+
+msgid "Force interpretation"
+msgstr "Forcer l'interprétation"
+
+msgid "Allow recompilation"
+msgstr "Permettre la recompilation"
+
+msgid "&Force interpretation"
+msgstr "&Forcer l'interprétation"
+
+msgid "&Allow recompilation"
+msgstr "&Permettre la recompilation"

src/qt/languages/hr-HR.po

@@ -3046,3 +3046,15 @@ msgstr "Tamno"
 
 msgid "Search:"
 msgstr "Pretrag:"
+
+msgid "Force interpretation"
+msgstr "Prisilna interpretacija"
+
+msgid "Allow recompilation"
+msgstr "Omogući rekompilaciju"
+
+msgid "&Force interpretation"
+msgstr "&Prisilna interpretacija"
+
+msgid "&Allow recompilation"
+msgstr "&Omogući rekompilaciju"

src/qt/languages/it-IT.po

@@ -3044,3 +3044,15 @@ msgstr "Scura"
 
 msgid "Search:"
 msgstr "Cerca:"
+
+msgid "Force interpretation"
+msgstr "Forza interpretazione"
+
+msgid "Allow recompilation"
+msgstr "Permetti ricompilazione"
+
+msgid "&Force interpretation"
+msgstr "&Forza interpretazione"
+
+msgid "&Allow recompilation"
+msgstr "&Permetti ricompilazione"

src/qt/languages/ja-JP.po

@@ -3045,3 +3045,15 @@ msgstr "暗闇"
 
 msgid "Search:"
 msgstr "検索:"
+
+msgid "Force interpretation"
+msgstr "解釈を強制する"
+
+msgid "Allow recompilation"
+msgstr "再コンパイルを許可する"
+
+msgid "&Force interpretation"
+msgstr "解釈を強制する(&F)"
+
+msgid "&Allow recompilation"
+msgstr "再コンパイルを許可する(&A)"

src/qt/languages/ko-KR.po

@@ -3038,3 +3038,15 @@ msgstr "어둠"
 
 msgid "Search:"
 msgstr "검색:"
+
+msgid "Force interpretation"
+msgstr "강제 해석"
+
+msgid "Allow recompilation"
+msgstr "재컴파일 허용"
+
+msgid "&Force interpretation"
+msgstr "강제 해석(&F)"
+
+msgid "&Allow recompilation"
+msgstr "재컴파일 허용(&A)"

src/qt/languages/nb-NO.po

@@ -3038,3 +3038,15 @@ msgstr "Mørk"
 
 msgid "Search:"
 msgstr "Søk:"
+
+msgid "Force interpretation"
+msgstr "Tving tolkning"
+
+msgid "Allow recompilation"
+msgstr "Tillat rekompilering"
+
+msgid "&Force interpretation"
+msgstr "&Tving tolkning"
+
+msgid "&Allow recompilation"
+msgstr "&Tillat rekompilering"

src/qt/languages/nl-NL.po

@@ -3038,3 +3038,15 @@ msgstr "Donker"
 
 msgid "Search:"
 msgstr "Zoeken:"
+
+msgid "Force interpretation"
+msgstr "Interpretatie afdwingen"
+
+msgid "Allow recompilation"
+msgstr "Recompilatie toestaan"
+
+msgid "&Force interpretation"
+msgstr "Interpretatie &afdwingen"
+
+msgid "&Allow recompilation"
+msgstr "Recompilatie &toestaan"

src/qt/languages/pl-PL.po

@@ -3045,3 +3045,15 @@ msgstr "Ciemny"
 
 msgid "Search:"
 msgstr "Szukanie:"
+
+msgid "Force interpretation"
+msgstr "Wymuś interpretację"
+
+msgid "Allow recompilation"
+msgstr "Zezwól na rekompilację"
+
+msgid "&Force interpretation"
+msgstr "&Wymuś interpretację"
+
+msgid "&Allow recompilation"
+msgstr "&Zezwól na rekompilację"

src/qt/languages/pt-BR.po

@@ -3038,3 +3038,15 @@ msgstr "Escuro"
 
 msgid "Search:"
 msgstr "Pesquisar:"
+
+msgid "Force interpretation"
+msgstr "Forçar interpretação"
+
+msgid "Allow recompilation"
+msgstr "Permitir recompilação"
+
+msgid "&Force interpretation"
+msgstr "&Forçar interpretação"
+
+msgid "&Allow recompilation"
+msgstr "&Permitir recompilação"

src/qt/languages/pt-PT.po

@@ -3045,3 +3045,15 @@ msgstr "Escuro"
 
 msgid "Search:"
 msgstr "Procurar:"
+
+msgid "Force interpretation"
+msgstr "Forçar interpretação"
+
+msgid "Allow recompilation"
+msgstr "Permitir recompilação"
+
+msgid "&Force interpretation"
+msgstr "&Forçar interpretação"
+
+msgid "&Allow recompilation"
+msgstr "&Permitir recompilação"

src/qt/languages/ru-RU.po

@@ -3038,3 +3038,15 @@ msgstr "Тёмная"
 
 msgid "Search:"
 msgstr "Поиск:"
+
+msgid "Force interpretation"
+msgstr "Принудительная интерпретация"
+
+msgid "Allow recompilation"
+msgstr "Разрешить рекомпиляцию"
+
+msgid "&Force interpretation"
+msgstr "&Принудительная интерпретация"
+
+msgid "&Allow recompilation"
+msgstr "&Разрешить рекомпиляцию"

src/qt/languages/sk-SK.po

@@ -3044,3 +3044,15 @@ msgstr "Tmavá"
 
 msgid "Search:"
 msgstr "Hľadať:"
+
+msgid "Force interpretation"
+msgstr "Vynútiť interpretáciu"
+
+msgid "Allow recompilation"
+msgstr "Povoliť rekompiláciu"
+
+msgid "&Force interpretation"
+msgstr "&Vynútiť interpretáciu"
+
+msgid "&Allow recompilation"
+msgstr "&Povoliť rekompiláciu"

src/qt/languages/sl-SI.po

@@ -3046,3 +3046,15 @@ msgstr "Temno"
 
 msgid "Search:"
 msgstr "Išči:"
+
+msgid "Force interpretation"
+msgstr "Vsili interpretacijo"
+
+msgid "Allow recompilation"
+msgstr "Dovoli prevajanje"
+
+msgid "&Force interpretation"
+msgstr "&Vsili interpretacijo"
+
+msgid "&Allow recompilation"
+msgstr "&Dovoli prevajanje"

src/qt/languages/sv-SE.po

@@ -3038,3 +3038,15 @@ msgstr "Mörk"
 
 msgid "Search:"
 msgstr "Sök:"
+
+msgid "Force interpretation"
+msgstr "Tvinga tolkning"
+
+msgid "Allow recompilation"
+msgstr "Tillåt omkompilering"
+
+msgid "&Force interpretation"
+msgstr "&Tvinga tolkning"
+
+msgid "&Allow recompilation"
+msgstr "&Tillåt omkompilering"

src/qt/languages/tr-TR.po

@@ -3038,3 +3038,15 @@ msgstr "Karanlık"
 
 msgid "Search:"
 msgstr "Ara:"
+
+msgid "Force interpretation"
+msgstr "Yorumlanmasını zorla"
+
+msgid "Allow recompilation"
+msgstr "Derlenmesine izin ver"
+
+msgid "&Force interpretation"
+msgstr "&Yorumlanmasını zorla"
+
+msgid "&Allow recompilation"
+msgstr "&Derlenmesine izin ver"

src/qt/languages/uk-UA.po

@@ -3046,3 +3046,15 @@ msgstr "Темний"
 
 msgid "Search:"
 msgstr "Пошук:"
+
+msgid "Force interpretation"
+msgstr "Примусове тлумачення"
+
+msgid "Allow recompilation"
+msgstr "Дозволити рекомпіляцію"
+
+msgid "&Force interpretation"
+msgstr "&Примусове тлумачення"
+
+msgid "&Allow recompilation"
+msgstr "&Дозволити рекомпіляцію"

src/qt/languages/vi-VN.po

@@ -3038,3 +3038,15 @@ msgstr "Tối"
 
 msgid "Search:"
 msgstr "Tìm:"
+
+msgid "Force interpretation"
+msgstr "Buộc giải thích"
+
+msgid "Allow recompilation"
+msgstr "Cho phép biên dịch lại"
+
+msgid "&Force interpretation"
+msgstr "&Buộc giải thích"
+
+msgid "&Allow recompilation"
+msgstr "&Cho phép biên dịch lại"

src/qt/qt_mainwindow.cpp

@@ -164,6 +164,8 @@ keyb_filter(BMessage *message, BHandler **target, BMessageFilter *filter)
 static BMessageFilter *filter;
 #endif
 
+extern int      cpu_force_interpreter;
+
 extern void     qt_mouse_capture(int);
 extern "C" void qt_blit(int x, int y, int w, int h, int monitor_index);
 
@@ -278,8 +280,24 @@ MainWindow::MainWindow(QWidget *parent)
         vmname.truncate(vmname.size() - 1);
     this->setWindowTitle(QString("%1 - %2 %3").arg(vmname, EMU_NAME, EMU_VERSION_FULL));
 
+    connect(this, &MainWindow::forceInterpretationCompleted, this, [this]() {
+        const auto fi_icon      = cpu_force_interpreter ? QIcon(":/menuicons/qt/icons/recompiler.ico") :
+                                                          QIcon(":/menuicons/qt/icons/interpreter.ico");
+        const auto tooltip_text = cpu_force_interpreter ? QString(tr("Allow recompilation")) :
+                                                          QString(tr("Force interpretation"));
+        const auto menu_text    = cpu_force_interpreter ? QString(tr("&Allow recompilation")) :
+                                                          QString(tr("&Force interpretation"));
+
+        ui->actionForce_interpretation->setIcon(fi_icon);
+        ui->actionForce_interpretation->setToolTip(tooltip_text);
+        ui->actionForce_interpretation->setText(menu_text);
+        ui->actionForce_interpretation->setChecked(cpu_force_interpreter);
+        ui->actionForce_interpretation->setEnabled(cpu_use_dynarec);
+    });
+
     connect(this, &MainWindow::hardResetCompleted, this, [this]() {
         ui->actionMCA_devices->setVisible(machine_has_bus(machine, MACHINE_BUS_MCA));
+        ui_update_force_interpreter();
         num_label->setVisible(machine_has_bus(machine, MACHINE_BUS_PS2_PORTS | MACHINE_BUS_AT_KBD));
         scroll_label->setVisible(machine_has_bus(machine, MACHINE_BUS_PS2_PORTS | MACHINE_BUS_AT_KBD));
         caps_label->setVisible(machine_has_bus(machine, MACHINE_BUS_PS2_PORTS | MACHINE_BUS_AT_KBD));
@@ -968,6 +986,12 @@ MainWindow::closeEvent(QCloseEvent *event)
     event->accept();
 }
 
+void
+ui_update_force_interpreter()
+{
+    emit main_window->forceInterpretationCompleted();
+}
+
 void
 MainWindow::updateShortcuts()
 {
@@ -986,6 +1010,7 @@ MainWindow::updateShortcuts()
     ui->actionHard_Reset->setShortcut(QKeySequence());
     ui->actionPause->setShortcut(QKeySequence());
     ui->actionMute_Unmute->setShortcut(QKeySequence());
+    ui->actionForce_interpretation->setShortcut(QKeySequence());
 
     int          accID;
     QKeySequence seq;
@@ -1017,6 +1042,10 @@ MainWindow::updateShortcuts()
     accID = FindAccelerator("mute");
     seq   = QKeySequence::fromString(acc_keys[accID].seq);
     ui->actionMute_Unmute->setShortcut(seq);
+
+    accID = FindAccelerator("force_interpretation");
+    seq   = QKeySequence::fromString(acc_keys[accID].seq);
+    ui->actionForce_interpretation->setShortcut(seq);
 }
 
 void
@@ -1600,6 +1629,7 @@ MainWindow::refreshMediaMenu()
     status->refresh(ui->statusbar);
     ui->actionMCA_devices->setVisible(machine_has_bus(machine, MACHINE_BUS_MCA));
     ui->actionACPI_Shutdown->setEnabled(!!acpi_enabled);
+    ui_update_force_interpreter();
 
     num_label->setToolTip(QShortcut::tr("Num Lock"));
     num_label->setVisible(machine_has_bus(machine, MACHINE_BUS_PS2_PORTS | MACHINE_BUS_AT_KBD));
@@ -1788,6 +1818,13 @@ MainWindow::on_actionInverted_VGA_monitor_triggered()
     video_toggle_option(ui->actionInverted_VGA_monitor, &invert_display);
 }
 
+void
+MainWindow::on_actionForce_interpretation_triggered()
+{
+    cpu_force_interpreter ^= 1;
+    ui_update_force_interpreter();
+}
+
 static void
 update_scaled_checkboxes(Ui::MainWindow *ui, QAction *selected)
 {

src/qt/qt_mainwindow.hpp

@@ -58,6 +58,7 @@ signals:
     void destroyRendererMonitor(int monitor_index);
     void initRendererMonitorForNonQtThread(int monitor_index);
     void destroyRendererMonitorForNonQtThread(int monitor_index);
+    void forceInterpretationCompleted();
     void hardResetCompleted();
 
     void setTitle(const QString &title);
@@ -79,6 +80,7 @@ public slots:
     void updateStatusEmptyIcons();
     void updateUiPauseState();
 private slots:
+    void on_actionForce_interpretation_triggered();
     void on_actionFullscreen_triggered();
     void on_actionSettings_triggered();
     void on_actionExit_triggered();

src/qt/qt_mainwindow.ui

@@ -70,6 +70,8 @@
     </widget>
     <addaction name="menuTablet_tool"/>
     <addaction name="separator"/>
+    <addaction name="actionForce_interpretation"/>
+    <addaction name="separator"/>
     <addaction name="actionKeyboard_requires_capture"/>
     <addaction name="actionRight_CTRL_is_left_ALT"/>
     <addaction name="separator"/>
@@ -292,6 +294,8 @@
    <attribute name="toolBarBreak">
     <bool>false</bool>
    </attribute>
+   <addaction name="actionForce_interpretation"/>
+   <addaction name="separator"/>
    <addaction name="actionPause"/>
    <addaction name="actionHard_Reset"/>
    <addaction name="separator"/>
@@ -302,6 +306,14 @@
    <addaction name="separator"/>
    <addaction name="actionSettings"/>
   </widget>
+  <action name="actionForce_interpretation">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>&amp;Force interpretation</string>
+   </property>
+  </action>
   <action name="actionUpdate_mouse_every_CPU_frame">
    <property name="checkable">
     <bool>true</bool>

src/qt_resources.qrc

@@ -68,6 +68,8 @@
         <file>qt/icons/send_cad.ico</file>
         <file>qt/icons/send_cae.ico</file>
         <file>qt/icons/settings.ico</file>
+        <file>qt/icons/interpreter.ico</file>
+        <file>qt/icons/recompiler.ico</file>
     </qresource>
     <qresource prefix="/misc">
         <file>qt/icons/warning.ico</file>

src/unix/unix.c

@@ -1731,3 +1731,9 @@ ui_hard_reset_completed(void)
 {
     /* No-op. */
 }
+
+void
+ui_update_force_interpreter(void)
+{
+    /* No-op. */
+}