merge s6 and sp in variable naming pass

decompiler/analysis/variable_naming.cpp

@@ -86,6 +86,14 @@ void VarMapSSA::merge(const VarSSA& var_a, const VarSSA& var_b) {
   }
 }
 
+void VarMapSSA::merge_reg(Register reg) {
+  for (auto& entry : m_entries) {
+    if (entry.reg == reg) {
+      entry.var_id = 0;
+    }
+  }
+}
+
 /*!
  * Make all Bs A.
  */
@@ -491,6 +499,13 @@ std::string SSA::print() const {
   return result;
 }
 
+/*!
+ * Merge all variables in the same register to the given register.
+ */
+void SSA::merge_reg_to_single_variable(Register reg) {
+  map.merge_reg(reg);
+}
+
 /*!
  * Simplify the SSA while still keeping it in SSA form.
  * This does only a single pass of simplifications and returns true if it made changes.
@@ -1070,6 +1085,10 @@ std::optional<VariableNames> run_variable_renaming(const Function& function,
     fmt::print("Simplified SSA\n{}-------------------------------\n", ssa.print());
   }
 
+  // merge special registers
+  ssa.merge_reg_to_single_variable(Register(Reg::GPR, Reg::SP));
+  ssa.merge_reg_to_single_variable(Register(Reg::GPR, Reg::S6));
+
   // remember what the SSA mapping was:
   auto ssa_mapping = ssa.get_ssa_mapping();
 

decompiler/analysis/variable_naming.h

@@ -77,6 +77,7 @@ class VarMapSSA {
   bool same(const VarSSA& var_a, const VarSSA& var_b) const;
   int var_id(const VarSSA& var) const;
   void remap_reg(Register reg, const std::unordered_map<int, int>& remap);
+  void merge_reg(Register reg);
   void debug_print_map() const;
 
  private:
@@ -143,6 +144,7 @@ struct SSA {
   RegAccessMap<int> get_ssa_mapping();
 
   bool simplify();
+  void merge_reg_to_single_variable(Register reg);
   void merge_all_phis();
   void remap(int nargs);
   void make_vars(const Function& function, const DecompilerTypeSystem& dts);

goal_src/levels/common/battlecontroller.gc

@@ -741,22 +741,15 @@ battlecontroller-default-event-handler
 
 (defmethod deactivate battlecontroller ((obj battlecontroller))
   (with-pp
-   (let ((gp-0 pp))
-    (let ((s6-1 obj))
-     )
-    (battlecontroller-off)
-    (let ((s6-2 gp-0))
-     )
+    (let ((gp-0 pp))
+      (set! pp obj)
+      (battlecontroller-off)
+      (set! pp gp-0)
+      )
+    ((the-as (function process-drawable none) (find-parent-method battlecontroller 10)) obj)
+    0
+    (none)
     )
-   ((the-as
-     (function process-drawable none)
-     (find-parent-method battlecontroller 10)
-     )
-    obj
-    )
-   0
-   (none)
-   )
   )
 
 (defmethod TODO-RENAME-27 battlecontroller ((obj battlecontroller))

test/decompiler/reference/engine/game/generic-obs_REF.gc

@@ -912,11 +912,9 @@
                          ((type-type? (-> gp-0 type) process-drawable)
                           (when (zero? (logand (-> (the-as process-drawable gp-0) skel status) 4))
                             (let ((s5-0 pp))
-                              (let ((s6-1 gp-0))
-                                )
+                              (set! pp gp-0)
                               (let ((v0-1 (the-as object (ja-done? 0))))
-                                (let ((s6-2 s5-0))
-                                  )
+                                (set! pp s5-0)
                                 v0-1
                                 )
                               )

test/decompiler/reference/engine/geometry/vol_REF.gc

@@ -223,8 +223,7 @@
       (when (and (and *display-vol-marks* (logtest? (-> a0-1 flags) 1)) (logtest? (-> obj flags) 2))
         (when (zero? (-> obj debug-point))
           (let ((s5-0 pp))
-            (let ((s6-1 (-> obj process)))
-              )
+            (set! pp (-> obj process))
             (let ((s4-0 0))
               (dotimes (v1-8 (-> obj pos-vol-count))
                 (+! s4-0 (-> obj pos-vol v1-8 num-planes))
@@ -235,8 +234,7 @@
               (set! (-> obj debug-point) (new 'debug 'vector-array (* 10 s4-0)))
               (set! (-> obj debug-normal) (new 'debug 'vector-array (* 10 s4-0)))
               )
-            (let ((s6-2 s5-0))
-              )
+            (set! pp s5-0)
             )
           (set! (-> obj debug-point length) 0)
           (set! (-> obj debug-normal length) 0)
@@ -273,7 +271,3 @@
     )
   #f
   )
-
-
-
-

test/decompiler/reference/engine/load/loader_REF.gc

@@ -103,12 +103,12 @@
 
 ;; definition for function drawable-load
 (defun drawable-load ((arg0 drawable) (arg1 kheap))
-  (local-vars (sp-0 none))
+  (local-vars (sp-0 pointer))
   (cond
     ((type-type? (-> arg0 type) string)
-     sp-0
+     (the-as none sp-0)
      (if (< (the-as uint sp-0) (the-as uint *stack-top*))
-         (&+ *kernel-sp* -1024)
+         (set! sp-0 (&+ *kernel-sp* -1024))
          )
      (let ((s5-1 (the-as drawable (loado (the-as string arg0) arg1))))
        (if (and s5-1 (type-type? (-> s5-1 type) drawable))
@@ -124,10 +124,10 @@
 
 ;; definition for function art-load
 (defun art-load ((arg0 string) (arg1 kheap))
-  (local-vars (sp-0 none))
-  sp-0
+  (local-vars (sp-0 pointer))
+  (the-as none sp-0)
   (if (< (the-as uint sp-0) (the-as uint *stack-top*))
-      (&+ *kernel-sp* -1024)
+      (set! sp-0 (&+ *kernel-sp* -1024))
       )
   (let ((s5-0 (loado arg0 arg1)))
     (if (type-type? (-> (the-as art s5-0) type) art)
@@ -139,11 +139,11 @@
 
 ;; definition for function art-group-load-check
 (defun art-group-load-check ((arg0 string) (arg1 kheap) (arg2 int))
-  (local-vars (sp-0 none))
+  (local-vars (sp-0 pointer))
   (when *debug-segment*
-    sp-0
+    (the-as none sp-0)
     (if (< (the-as uint sp-0) (the-as uint *stack-top*))
-        (&+ *kernel-sp* -1024)
+        (set! sp-0 (&+ *kernel-sp* -1024))
         )
     (let ((s3-1 (the-as art-group (loado (make-file-name (file-kind art-group) arg0 arg2 #f) arg1))))
       (cond

test/decompiler/reference/kernel/gkernel_REF.gc

@@ -1383,7 +1383,8 @@
           (entity-deactivate-handler obj (-> obj entity))
           )
       (let ((s5-0 pp))
-        (let ((s4-0 (-> obj stack-frame-top)))
+        (set! pp obj)
+        (let ((s4-0 (-> pp stack-frame-top)))
           (while (the-as protect-frame s4-0)
             (case (-> s4-0 type)
               ((protect-frame state)
@@ -1393,8 +1394,7 @@
             (set! s4-0 (-> (the-as protect-frame s4-0) next))
             )
           )
-        (let ((s6-2 s5-0))
-          )
+        (set! pp s5-0)
         )
       (process-disconnect obj)
       (let ((v1-11 (-> obj child)))

test/decompiler/reference/kernel/gstate_REF.gc

@@ -47,7 +47,7 @@
 ;; WARN: Unsupported inline assembly instruction kind - [jr t9]
 ;; WARN: Unsupported inline assembly instruction kind - [sw v0, 0(sp)]
 (defun enter-state ((arg0 object) (arg1 object) (arg2 object) (arg3 object) (arg4 object) (arg5 object))
-  (local-vars (s7-0 none) (sp-0 none) (sp-1 int) (ra-0 int) (sv-0 none))
+  (local-vars (s7-0 none) (sp-0 int) (ra-0 int) (sv-0 none))
   (with-pp
     (logclear! (-> pp mask) (process-mask sleep sleep-code))
     (logior! (-> pp mask) (process-mask going))
@@ -99,7 +99,7 @@
                )
            )
          (let ((v1-28 (-> pp main-thread)))
-           (.lwu sp-1 28 v1-28)
+           (.lwu sp-0 28 v1-28)
            )
          (let ((t9-6 (-> s0-2 code)))
            (.lw ra-0 return-from-thread-dead s7-0)
@@ -113,7 +113,7 @@
         (set-to-run (-> pp main-thread) enter-state arg0 arg1 arg2 arg3 arg4 arg5)
         (when (!= (-> pp top-thread name) 'post)
           (let ((v0-2 (the-as object return-from-thread)))
-            (.sw (the-as (function none) v0-2) 0 sp-0)
+            (.sw (the-as (function none) v0-2) 0 (the-as none sp-0))
             v0-2
             )
           )
@@ -127,11 +127,9 @@
   (with-pp
     (when (and arg0 (!= (-> arg0 type) process-tree) (-> (the-as process arg0) event-hook))
       (let ((gp-0 pp))
-        (let ((s6-1 (the-as process arg0)))
-          )
+        (set! pp (the-as process arg0))
         (let ((v0-0 ((-> (the-as process arg0) event-hook) (-> arg1 from) (-> arg1 num-params) (-> arg1 message) arg1)))
-          (let ((s6-2 gp-0))
-            )
+          (set! pp gp-0)
           v0-0
           )
         )

test/decompiler/reference/levels/common/battlecontroller_REF.gc

@@ -711,11 +711,9 @@ battlecontroller-default-event-handler
 (defmethod deactivate battlecontroller ((obj battlecontroller))
   (with-pp
     (let ((gp-0 pp))
-      (let ((s6-1 obj))
-        )
+      (set! pp obj)
       (battlecontroller-off)
-      (let ((s6-2 gp-0))
-        )
+      (set! pp gp-0)
       )
     ((the-as (function process-drawable none) (find-parent-method battlecontroller 10)) obj)
     0