Revert "Revert the dual-CPU P_CheckSights implementation"

This reverts commit 79bb7f5.

mars.h

@@ -49,6 +49,8 @@ enum
 
 	MARS_SECCMD_AM_DRAW,
 
+	MARS_SECCMD_P_SIGHT_CHECKS,
+
 	MARS_SECCMD_MELT_DO_WIPE,
 
 	MARS_SECCMD_NUMCMDS
@@ -63,6 +65,7 @@ void Mars_Sec_R_DrawPlanes(void) ATTR_DATA_CACHE_ALIGN;
 void Mars_Sec_R_PreDrawPlanes(void) ATTR_DATA_CACHE_ALIGN;
 void Mars_Sec_R_DrawSprites(int sprscreenhalf, int *sortedsprites) ATTR_DATA_CACHE_ALIGN;
 void Mars_Sec_R_DrawPSprites(int sprscreenhalf) ATTR_DATA_CACHE_ALIGN;
+void Mars_Sec_P_CheckSights(void) ATTR_DATA_CACHE_ALIGN;
 void Mars_Sec_wipe_doMelt(void);
 
 void Mars_Sec_M_AnimateFire(void) ATTR_OPTIMIZE_EXTREME;
@@ -162,6 +165,18 @@ static inline void Mars_AM_EndDrawer(void)
 	Mars_R_SecWait();
 }
 
+static inline void Mars_P_BeginCheckSights(void)
+{
+	while (MARS_SYS_COMM4 != 0) {};
+	MARS_SYS_COMM6 = 0;
+	MARS_SYS_COMM4 = MARS_SECCMD_P_SIGHT_CHECKS;
+}
+
+static inline void Mars_P_EndCheckSights(void)
+{
+	while (MARS_SYS_COMM4 != 0);
+}
+
 static inline void Mars_melt_BeginWipe(short *yy)
 {
 	while (MARS_SYS_COMM4 != 0) {};

marsnew.c

@@ -341,6 +341,9 @@ void Mars_Secondary(void)
 		case MARS_SECCMD_AM_DRAW:
 			Mars_Sec_AM_Drawer();
 			break;
+		case MARS_SECCMD_P_SIGHT_CHECKS:
+			Mars_Sec_P_CheckSights();
+			break;
 		case MARS_SECCMD_MELT_DO_WIPE:
 			Mars_Sec_wipe_doMelt();
 			break;

p_base.c

@@ -538,6 +538,12 @@ void P_RunMobjBase2(void)
 
     for (mo = mobjhead.next; mo != (void*)&mobjhead; mo = next)
     {
+#ifdef MARS
+        // clear cache for mobj flags following the sight check as 
+        // the other CPU might have modified the MF_SEETARGET state
+        if (mo->tics == 1)
+            Mars_ClearCacheLine(&mo->flags);
+#endif
         next = mo->next;	/* in case mo is removed this time */
         if (!mo->player)
             P_MobjThinker(mo);

p_sight.c

@@ -45,8 +45,13 @@ static boolean PS_CrossSubsector(sightWork_t* sw, int num) ATTR_DATA_CACHE_ALIGN
 static boolean PS_CrossBSPNode(sightWork_t* sw, int bspnum) ATTR_DATA_CACHE_ALIGN;
 static boolean PS_RejectCheckSight(mobj_t* t1, mobj_t* t2) ATTR_DATA_CACHE_ALIGN;
 static boolean P_MobjCanSightCheck(mobj_t *mobj) ATTR_DATA_CACHE_ALIGN;
+static mobj_t *P_GetSightMobj(mobj_t *pmobj, int c, int *pcnt) ATTR_DATA_CACHE_ALIGN;
 static boolean PS_CheckSight2(mobj_t* t1, mobj_t* t2) ATTR_DATA_CACHE_ALIGN;
-void P_CheckSights2(void) ATTR_DATA_CACHE_ALIGN __attribute__((noinline));
+#ifdef MARS
+void P_CheckSights2(int c) ATTR_DATA_CACHE_ALIGN;
+#else
+void P_CheckSights2(void) ATTR_DATA_CACHE_ALIGN;
+#endif
 
 //
 // Returns side 0 (front), 1 (back), or 2 (on).
@@ -389,18 +394,120 @@ static boolean P_MobjCanSightCheck(mobj_t *mobj)
    return true;
 }
 
+#ifdef MARS
+static char ps_lock = 0;
+
+static void P_LockSight(void)
+{
+    int res;
+    do {
+        __asm volatile (\
+        "tas.b %1\n\t" \
+            "movt %0\n\t" \
+            : "=&r" (res) \
+            : "m" (ps_lock) \
+            );
+    } while (res == 0);
+}
+
+static void P_UnlockSight(void)
+{
+   ps_lock = 0;
+}
+
+static mobj_t *P_GetSightMobj(mobj_t *mobj, int c, int *pcnt)
+{
+   int next;
+   int cnt = *pcnt;
+
+   P_LockSight();
+
+   for (next = MARS_SYS_COMM6; ; next++)
+   {
+      if (c == 1)
+      {
+         for (; cnt < next; cnt++)
+         {
+            if (mobj == (void*)&mobjhead)
+               goto done;
+            Mars_ClearCacheLine(&mobj->next);
+            mobj = mobj->next;
+         }
+         Mars_ClearCacheLines(mobj, (sizeof(mobj_t)+31)/16);
+      }
+      else
+      {
+         for (; cnt < next; cnt++)
+         {
+            if (mobj == (void*)&mobjhead)
+               goto done;
+            mobj = mobj->next;
+         }
+      }
+
+      if (P_MobjCanSightCheck(mobj))
+        break;
+   }
+
+done:
+   MARS_SYS_COMM6 = cnt + 1;
+
+   P_UnlockSight();
+
+   *pcnt = cnt;
+   return mobj;
+}
+
+#define P_NextSightMobj(mobj) (mobj)
+
+#else
+
+static mobj_t *P_GetSightMobj(mobj_t *mobj, int c, int *pcnt)
+{
+   for ( ; mobj != (void*)&mobjhead; mobj = mobj->next)
+   {
+      if (P_MobjCanSightCheck(mobj))
+         break;
+   }
+   return mobj;
+}
+
+#define P_NextSightMobj(mobj) (mobj)->next
+
+#endif
+
 //
 // Optimal mobj sight checking that checks sights in the main tick loop rather
 // than from multiple mobj action routines.
 //
+#ifdef MARS
+void P_CheckSights2(int c)
+#else
 void P_CheckSights2(void)
+#endif
 {
     mobj_t *mobj;
+    int cnt = 0;
+#ifndef MARS
+    int c = 0;
+#else
+    mobj_t *ctrgt = NULL;
+    Mars_ClearCacheLines(&mobjhead.next, 1);
+#endif
 
-    for (mobj = mobjhead.next; mobj != (void*)&mobjhead; mobj = mobj->next)
+    for (mobj = mobjhead.next; ; mobj = P_NextSightMobj(mobj))
     {
-        if (!P_MobjCanSightCheck(mobj))
-            continue;
+        if ((mobj = P_GetSightMobj(mobj, c, &cnt)) == (void*)&mobjhead)
+            return;
+
+#ifdef MARS
+        if (c == 1 && ctrgt != mobj->target)
+        {
+           Mars_ClearCacheLines(mobj->target, (sizeof(mobj_t)+31)/16);
+           ctrgt = mobj->target;
+        }
+#endif
+
         if (PS_CheckSight2(mobj, mobj->target))
            mobj->flags |= MF_SEETARGET;
     }

p_tick.c

@@ -133,13 +133,28 @@ void P_RunThinkers (void)
 ===============
 */
 
-void P_CheckSights2(void);
+#ifdef MARS
+void P_CheckSights2(int c) ATTR_DATA_CACHE_ALIGN ATTR_OPTIMIZE_SIZE;
+#else
+void P_CheckSights2(void) ATTR_DATA_CACHE_ALIGN ATTR_OPTIMIZE_SIZE;
+#endif
+
+#ifdef MARS
+void Mars_Sec_P_CheckSights(void)
+{
+	P_CheckSights2(1);
+}
+#endif
 
 void P_CheckSights (void)
 {
 #ifdef JAGUAR
 	extern	int p_sight_start;
 	DSPFunction (&p_sight_start);
+#elif defined(MARS)
+	Mars_P_BeginCheckSights();
+	P_CheckSights2(0);
+	Mars_P_EndCheckSights();
 #else
 	P_CheckSights2();
 #endif