1 files changed, 59 insertions, 38 deletions

diff --git a/src/lj_api.c b/src/lj_api.c
index 4a7809bc..6ad09b9d 100644
--- a/src/lj_api.c
+++ b/src/lj_api.c
@@ -284,8 +284,8 @@ LUA_API int lua_equal(lua_State *L, int idx1, int idx2)
     } else {
       L->top = base+2;
       lj_vm_call(L, base, 1+1);
-      L->top -= 2;
-      return tvistruecond(L->top+1);
+      L->top -= 2+LJ_FR2;
+      return tvistruecond(L->top+1+LJ_FR2);
     }
   }
 }
@@ -307,8 +307,8 @@ LUA_API int lua_lessthan(lua_State *L, int idx1, int idx2)
     } else {
       L->top = base+2;
       lj_vm_call(L, base, 1+1);
-      L->top -= 2;
-      return tvistruecond(L->top+1);
+      L->top -= 2+LJ_FR2;
+      return tvistruecond(L->top+1+LJ_FR2);
     }
   }
 }
@@ -704,8 +704,8 @@ LUA_API void lua_concat(lua_State *L, int n)
       n -= (int)(L->top - top);
       L->top = top+2;
       lj_vm_call(L, top, 1+1);
-      L->top--;
-      copyTV(L, L->top-1, L->top);
+      L->top -= 1+LJ_FR2;
+      copyTV(L, L->top-1, L->top+LJ_FR2);
     } while (--n > 0);
   } else if (n == 0) {  /* Push empty string. */
     setstrV(L, L->top, &G(L)->strempty);
@@ -724,8 +724,8 @@ LUA_API void lua_gettable(lua_State *L, int idx)
   if (v == NULL) {
     L->top += 2;
     lj_vm_call(L, L->top-2, 1+1);
-    L->top -= 2;
-    v = L->top+1;
+    L->top -= 2+LJ_FR2;
+    v = L->top+1+LJ_FR2;
   }
   copyTV(L, L->top-1, v);
 }
@@ -740,8 +740,8 @@ LUA_API void lua_getfield(lua_State *L, int idx, const char *k)
   if (v == NULL) {
     L->top += 2;
     lj_vm_call(L, L->top-2, 1+1);
-    L->top -= 2;
-    v = L->top+1;
+    L->top -= 2+LJ_FR2;
+    v = L->top+1+LJ_FR2;
   }
   copyTV(L, L->top, v);
   incr_top(L);
@@ -882,13 +882,14 @@ LUA_API void lua_settable(lua_State *L, int idx)
   o = lj_meta_tset(L, t, L->top-2);
   if (o) {
     /* NOBARRIER: lj_meta_tset ensures the table is not black. */
-    copyTV(L, o, L->top-1);
     L->top -= 2;
+    copyTV(L, o, L->top+1);
   } else {
-    L->top += 3;
-    copyTV(L, L->top-1, L->top-6);
-    lj_vm_call(L, L->top-3, 0+1);
-    L->top -= 3;
+    TValue *base = L->top;
+    copyTV(L, base+2, base-3-LJ_FR2);
+    L->top = base+3;
+    lj_vm_call(L, base, 0+1);
+    L->top -= 3+LJ_FR2;
   }
 }
 
@@ -902,14 +903,14 @@ LUA_API void lua_setfield(lua_State *L, int idx, const char *k)
   setstrV(L, &key, lj_str_newz(L, k));
   o = lj_meta_tset(L, t, &key);
   if (o) {
-    L->top--;
     /* NOBARRIER: lj_meta_tset ensures the table is not black. */
-    copyTV(L, o, L->top);
+    copyTV(L, o, --L->top);
   } else {
-    L->top += 3;
-    copyTV(L, L->top-1, L->top-6);
-    lj_vm_call(L, L->top-3, 0+1);
-    L->top -= 2;
+    TValue *base = L->top;
+    copyTV(L, base+2, base-3-LJ_FR2);
+    L->top = base+3;
+    lj_vm_call(L, base, 0+1);
+    L->top -= 2+LJ_FR2;
   }
 }
 
@@ -1016,11 +1017,24 @@ LUA_API const char *lua_setupvalue(lua_State *L, int idx, int n)
 
 /* -- Calls --------------------------------------------------------------- */
 
+#if LJ_FR2
+static TValue *api_call_base(lua_State *L, int nargs)
+{
+  TValue *o = L->top, *base = o - nargs;
+  L->top = o+1;
+  for (; o > base; o--) copyTV(L, o, o-1);
+  setnilV(o);
+  return o+1;
+}
+#else
+#define api_call_base(L, nargs) (L->top - (nargs))
+#endif
+
 LUA_API void lua_call(lua_State *L, int nargs, int nresults)
 {
   api_check(L, L->status == 0 || L->status == LUA_ERRERR);
   api_checknelems(L, nargs+1);
-  lj_vm_call(L, L->top - nargs, nresults+1);
+  lj_vm_call(L, api_call_base(L, nargs), nresults+1);
 }
 
 LUA_API int lua_pcall(lua_State *L, int nargs, int nresults, int errfunc)
@@ -1038,7 +1052,7 @@ LUA_API int lua_pcall(lua_State *L, int nargs, int nresults, int errfunc)
     api_checkvalidindex(L, o);
     ef = savestack(L, o);
   }
-  status = lj_vm_pcall(L, L->top - nargs, nresults+1, ef);
+  status = lj_vm_pcall(L, api_call_base(L, nargs), nresults+1, ef);
   if (status) hook_restore(g, oldh);
   return status;
 }
@@ -1046,12 +1060,14 @@ LUA_API int lua_pcall(lua_State *L, int nargs, int nresults, int errfunc)
 static TValue *cpcall(lua_State *L, lua_CFunction func, void *ud)
 {
   GCfunc *fn = lj_func_newC(L, 0, getcurrenv(L));
+  TValue *top = L->top;
   fn->c.f = func;
-  setfuncV(L, L->top, fn);
-  setlightudV(L->top+1, checklightudptr(L, ud));
+  setfuncV(L, top++, fn);
+  if (LJ_FR2) setnilV(top++);
+  setlightudV(top++, checklightudptr(L, ud));
   cframe_nres(L->cframe) = 1+0;  /* Zero results. */
-  L->top += 2;
-  return L->top-1;  /* Now call the newly allocated C function. */
+  L->top = top;
+  return top-1;  /* Now call the newly allocated C function. */
 }
 
 LUA_API int lua_cpcall(lua_State *L, lua_CFunction func, void *ud)
@@ -1068,10 +1084,11 @@ LUA_API int lua_cpcall(lua_State *L, lua_CFunction func, void *ud)
 LUALIB_API int luaL_callmeta(lua_State *L, int idx, const char *field)
 {
   if (luaL_getmetafield(L, idx, field)) {
-    TValue *base = L->top--;
-    copyTV(L, base, index2adr(L, idx));
-    L->top = base+1;
-    lj_vm_call(L, base, 1+1);
+    TValue *top = L->top--;
+    if (LJ_FR2) setnilV(top++);
+    copyTV(L, top++, index2adr(L, idx));
+    L->top = top;
+    lj_vm_call(L, top-1, 1+1);
     return 1;
   }
   return 0;
@@ -1098,12 +1115,14 @@ LUA_API int lua_yield(lua_State *L, int nresults)
     } else {  /* Yield from hook: add a pseudo-frame. */
       TValue *top = L->top;
       hook_leave(g);
-      top->u64 = cframe_multres(cf);
-      setcont(top+1, lj_cont_hook);
-      setframe_pc(top+1, cframe_pc(cf)-1);
-      setframe_gc(top+2, obj2gco(L), LJ_TTHREAD);
-      setframe_ftsz(top+2, ((char *)(top+3)-(char *)L->base)+FRAME_CONT);
-      L->top = L->base = top+3;
+      (top++)->u64 = cframe_multres(cf);
+      setcont(top, lj_cont_hook);
+      if (LJ_FR2) top++;
+      setframe_pc(top, cframe_pc(cf)-1);
+      if (LJ_FR2) top++;
+      setframe_gc(top, obj2gco(L), LJ_TTHREAD);
+      setframe_ftsz(top, ((char *)(top+1)-(char *)L->base)+FRAME_CONT);
+      L->top = L->base = top+1;
 #if LJ_TARGET_X64
       lj_err_throw(L, LUA_YIELD);
 #else
@@ -1120,7 +1139,9 @@ LUA_API int lua_yield(lua_State *L, int nresults)
 LUA_API int lua_resume(lua_State *L, int nargs)
 {
   if (L->cframe == NULL && L->status <= LUA_YIELD)
-    return lj_vm_resume(L, L->top - nargs, 0, 0);
+    return lj_vm_resume(L,
+      L->status == 0 ? api_call_base(L, nargs) : L->top - nargs,
+      0, 0);
   L->top = L->base;
   setstrV(L, L->top, lj_err_str(L, LJ_ERR_COSUSP));
   incr_top(L);