pass arguments to unknown function calls in registers
[ghc-hetmet.git] / ghc / rts / PrimOps.cmm
index f704570..6a2b36f 100644 (file)
@@ -49,7 +49,7 @@ newByteArrayzh_fast
     n = R1;
     payload_words = ROUNDUP_BYTES_TO_WDS(n);
     words = BYTES_TO_WDS(SIZEOF_StgArrWords) + payload_words;
-    "ptr" p = foreign "C" allocateLocal(BaseReg "ptr",words);
+    "ptr" p = foreign "C" allocateLocal(MyCapability() "ptr",words) [];
     TICK_ALLOC_PRIM(SIZEOF_StgArrWords,WDS(payload_words),0);
     SET_HDR(p, stg_ARR_WORDS_info, W_[CCCS]);
     StgArrWords_words(p) = payload_words;
@@ -73,7 +73,7 @@ newPinnedByteArrayzh_fast
        words = words + 1;
     }
 
-    "ptr" p = foreign "C" allocatePinned(words);
+    "ptr" p = foreign "C" allocatePinned(words) [];
     TICK_ALLOC_PRIM(SIZEOF_StgArrWords,WDS(payload_words),0);
 
     // Again, if the ArrWords header isn't a multiple of 8 bytes, we
@@ -97,10 +97,10 @@ newArrayzh_fast
     MAYBE_GC(R2_PTR,newArrayzh_fast);
 
     words = BYTES_TO_WDS(SIZEOF_StgMutArrPtrs) + n;
-    "ptr" arr = foreign "C" allocateLocal(BaseReg "ptr",words);
+    "ptr" arr = foreign "C" allocateLocal(MyCapability() "ptr",words) [R2];
     TICK_ALLOC_PRIM(SIZEOF_StgMutArrPtrs, WDS(n), 0);
 
-    SET_HDR(arr, stg_MUT_ARR_PTRS_info, W_[CCCS]);
+    SET_HDR(arr, stg_MUT_ARR_PTRS_DIRTY_info, W_[CCCS]);
     StgMutArrPtrs_ptrs(arr) = n;
 
     // Initialise all elements of the the array with the value in R2
@@ -126,21 +126,25 @@ unsafeThawArrayzh_fast
   // the mutable list is not easy, because the mut_list is only singly-linked).
   // 
   // So that we can tell whether a MUT_ARR_PTRS_FROZEN is on the mutable list,
-  // when we freeze it we set the info ptr to be MUT_ARR_PTRS_FROZEN0 to indicate
-  // that it is still on the mutable list.
-
+  // when we freeze it we set the info ptr to be MUT_ARR_PTRS_FROZEN0
+  // to indicate that it is still on the mutable list.
+  //
   // So, when we thaw a MUT_ARR_PTRS_FROZEN, we must cope with two cases:
   // either it is on a mut_list, or it isn't.  We adopt the convention that
-  // the mut_link field is NULL if it isn't on a mut_list, and the GC
-  // maintains this invariant.
+  // the closure type is MUT_ARR_PTRS_FROZEN0 if it is on the mutable list,
+  // and MUT_ARR_PTRS_FROZEN otherwise.  In fact it wouldn't matter if
+  // we put it on the mutable list more than once, but it would get scavenged
+  // multiple times during GC, which would be unnecessarily slow.
   //
-  if (%INFO_TYPE(%GET_STD_INFO(R1)) != HALF_W_(MUT_ARR_PTRS_FROZEN0)) {
-       foreign "C" recordMutableLock(R1 "ptr");
+  if (StgHeader_info(R1) != stg_MUT_ARR_PTRS_FROZEN0_info) {
+       SET_INFO(R1,stg_MUT_ARR_PTRS_DIRTY_info);
+       foreign "C" recordMutableLock(R1 "ptr") [R1];
+       // must be done after SET_INFO, because it ASSERTs closure_MUTABLE()
+       RET_P(R1);
+  } else {
+       SET_INFO(R1,stg_MUT_ARR_PTRS_DIRTY_info);
+       RET_P(R1);
   }
-
-  SET_INFO(R1,stg_MUT_ARR_PTRS_info);
-
-  RET_P(R1);
 }
 
 /* -----------------------------------------------------------------------------
@@ -155,7 +159,7 @@ newMutVarzh_fast
     ALLOC_PRIM( SIZEOF_StgMutVar, R1_PTR, newMutVarzh_fast);
 
     mv = Hp - SIZEOF_StgMutVar + WDS(1);
-    SET_HDR(mv,stg_MUT_VAR_info,W_[CCCS]);
+    SET_HDR(mv,stg_MUT_VAR_DIRTY_info,W_[CCCS]);
     StgMutVar_var(mv) = R1;
     
     RET_P(mv);
@@ -202,8 +206,8 @@ atomicModifyMutVarzh_fast
 
    HP_CHK_GEN_TICKY(SIZE, R1_PTR & R2_PTR, atomicModifyMutVarzh_fast);
 
-#if defined(SMP)
-    foreign "C" ACQUIRE_LOCK(sm_mutex "ptr");
+#if defined(THREADED_RTS)
+    foreign "C" ACQUIRE_LOCK(atomic_modify_mutvar_mutex "ptr") [R1,R2];
 #endif
 
    x = StgMutVar_var(R1);
@@ -224,6 +228,7 @@ atomicModifyMutVarzh_fast
    StgThunk_payload(y,0) = z;
 
    StgMutVar_var(R1) = y;
+   foreign "C" dirty_MUT_VAR(BaseReg "ptr", R1 "ptr") [R1];
 
    TICK_ALLOC_THUNK_1();
    CCCS_ALLOC(THUNK_1_SIZE);
@@ -232,34 +237,14 @@ atomicModifyMutVarzh_fast
    LDV_RECORD_CREATE(r);
    StgThunk_payload(r,0) = z;
 
-#if defined(SMP)
-    foreign "C" RELEASE_LOCK(sm_mutex "ptr");
+#if defined(THREADED_RTS)
+    foreign "C" RELEASE_LOCK(atomic_modify_mutvar_mutex "ptr") [];
 #endif
 
    RET_P(r);
 }
 
 /* -----------------------------------------------------------------------------
-   Foreign Object Primitives
-   -------------------------------------------------------------------------- */
-
-mkForeignObjzh_fast
-{
-  /* R1 = ptr to foreign object,
-  */
-  W_ result;
-
-  ALLOC_PRIM( SIZEOF_StgForeignObj, NO_PTRS, mkForeignObjzh_fast);
-
-  result = Hp - SIZEOF_StgForeignObj + WDS(1);
-  SET_HDR(result,stg_FOREIGN_info,W_[CCCS]);
-  StgForeignObj_data(result) = R1;
-
-  /* returns (# s#, ForeignObj# #) */
-  RET_P(result);
-}
-
-/* -----------------------------------------------------------------------------
    Weak Pointer Primitives
    -------------------------------------------------------------------------- */
 
@@ -289,7 +274,7 @@ mkWeakzh_fast
   StgWeak_link(w)      = W_[weak_ptr_list];
   W_[weak_ptr_list]    = w;
 
-  IF_DEBUG(weak, foreign "C" debugBelch(stg_weak_msg,w));
+  IF_DEBUG(weak, foreign "C" debugBelch(stg_weak_msg,w) []);
 
   RET_P(w);
 }
@@ -527,6 +512,7 @@ word64ToIntegerzh_fast
 
 /* ToDo: this is shockingly inefficient */
 
+#ifndef THREADED_RTS
 section "bss" {
   mp_tmp1:
     bits8 [SIZEOF_MP_INT];
@@ -538,101 +524,120 @@ section "bss" {
 }
 
 section "bss" {
-  result1:
+  mp_result1:
     bits8 [SIZEOF_MP_INT];
 }
 
 section "bss" {
-  result2:
+  mp_result2:
     bits8 [SIZEOF_MP_INT];
 }
+#endif
 
-#define GMP_TAKE2_RET1(name,mp_fun)                    \
-name                                                   \
-{                                                      \
-  CInt s1, s2;                                         \
-  W_ d1, d2;                                           \
-                                                       \
-  /* call doYouWantToGC() */                           \
-  MAYBE_GC(R2_PTR & R4_PTR, name);                     \
-                                                       \
-  s1 = W_TO_INT(R1);                                   \
-  d1 = R2;                                             \
-  s2 = W_TO_INT(R3);                                   \
-  d2 = R4;                                             \
-                                                       \
-  MP_INT__mp_alloc(mp_tmp1) = W_TO_INT(StgArrWords_words(d1)); \
-  MP_INT__mp_size(mp_tmp1)  = (s1);                    \
-  MP_INT__mp_d(mp_tmp1)            = BYTE_ARR_CTS(d1);         \
-  MP_INT__mp_alloc(mp_tmp2) = W_TO_INT(StgArrWords_words(d2)); \
-  MP_INT__mp_size(mp_tmp2)  = (s2);                    \
-  MP_INT__mp_d(mp_tmp2)            = BYTE_ARR_CTS(d2);         \
-                                                       \
-  foreign "C" mpz_init(result1);                       \
-                                                       \
-  /* Perform the operation */                          \
-  foreign "C" mp_fun(result1,mp_tmp1,mp_tmp2);         \
-                                                       \
-  RET_NP(TO_W_(MP_INT__mp_size(result1)),              \
-         MP_INT__mp_d(result1) - SIZEOF_StgArrWords);  \
-}
-
-#define GMP_TAKE1_RET1(name,mp_fun)                            \
-name                                                           \
-{                                                              \
-  CInt s1;                                                     \
-  W_ d1;                                                       \
-                                                               \
-  /* call doYouWantToGC() */                                   \
-  MAYBE_GC(R2_PTR, name);                                      \
-                                                               \
-  d1 = R2;                                                     \
-  s1 = W_TO_INT(R1);                                           \
-                                                               \
-  MP_INT__mp_alloc(mp_tmp1)    = W_TO_INT(StgArrWords_words(d1));      \
-  MP_INT__mp_size(mp_tmp1)     = (s1);                         \
-  MP_INT__mp_d(mp_tmp1)                = BYTE_ARR_CTS(d1);             \
-                                                               \
-  foreign "C" mpz_init(result1);                               \
-                                                               \
-  /* Perform the operation */                                  \
-  foreign "C" mp_fun(result1,mp_tmp1);                         \
-                                                               \
-  RET_NP(TO_W_(MP_INT__mp_size(result1)),                      \
-         MP_INT__mp_d(result1) - SIZEOF_StgArrWords);          \
-}
+#ifdef THREADED_RTS
+#define FETCH_MP_TEMP(X) \
+W_ X; \
+X = BaseReg + (OFFSET_StgRegTable_r ## X);
+#else
+#define FETCH_MP_TEMP(X) /* Nothing */
+#endif
 
-#define GMP_TAKE2_RET2(name,mp_fun)                            \
-name                                                           \
-{                                                              \
-  CInt s1, s2;                                                 \
-  W_ d1, d2;                                                   \
-                                                               \
-  /* call doYouWantToGC() */                                   \
-  MAYBE_GC(R2_PTR & R4_PTR, name);                             \
-                                                               \
-  s1 = W_TO_INT(R1);                                           \
-  d1 = R2;                                                     \
-  s2 = W_TO_INT(R3);                                           \
-  d2 = R4;                                                     \
-                                                               \
-  MP_INT__mp_alloc(mp_tmp1)    = W_TO_INT(StgArrWords_words(d1));      \
-  MP_INT__mp_size(mp_tmp1)     = (s1);                         \
-  MP_INT__mp_d(mp_tmp1)                = BYTE_ARR_CTS(d1);             \
-  MP_INT__mp_alloc(mp_tmp2)    = W_TO_INT(StgArrWords_words(d2));      \
-  MP_INT__mp_size(mp_tmp2)     = (s2);                         \
-  MP_INT__mp_d(mp_tmp2)                = BYTE_ARR_CTS(d2);             \
-                                                               \
-  foreign "C" mpz_init(result1);                               \
-  foreign "C" mpz_init(result2);                               \
-                                                               \
-  /* Perform the operation */                                  \
-  foreign "C" mp_fun(result1,result2,mp_tmp1,mp_tmp2);         \
-                                                               \
-  RET_NPNP(TO_W_(MP_INT__mp_size(result1)),                    \
-           MP_INT__mp_d(result1) - SIZEOF_StgArrWords,         \
-          TO_W_(MP_INT__mp_size(result2)),                     \
-           MP_INT__mp_d(result2) - SIZEOF_StgArrWords);                \
+#define GMP_TAKE2_RET1(name,mp_fun)                                     \
+name                                                                    \
+{                                                                       \
+  CInt s1, s2;                                                          \
+  W_ d1, d2;                                                            \
+  FETCH_MP_TEMP(mp_tmp1);                                               \
+  FETCH_MP_TEMP(mp_tmp2);                                               \
+  FETCH_MP_TEMP(mp_result1)                                             \
+  FETCH_MP_TEMP(mp_result2);                                            \
+                                                                        \
+  /* call doYouWantToGC() */                                            \
+  MAYBE_GC(R2_PTR & R4_PTR, name);                                      \
+                                                                        \
+  s1 = W_TO_INT(R1);                                                    \
+  d1 = R2;                                                              \
+  s2 = W_TO_INT(R3);                                                    \
+  d2 = R4;                                                              \
+                                                                        \
+  MP_INT__mp_alloc(mp_tmp1) = W_TO_INT(StgArrWords_words(d1));          \
+  MP_INT__mp_size(mp_tmp1)  = (s1);                                     \
+  MP_INT__mp_d(mp_tmp1)            = BYTE_ARR_CTS(d1);                         \
+  MP_INT__mp_alloc(mp_tmp2) = W_TO_INT(StgArrWords_words(d2));          \
+  MP_INT__mp_size(mp_tmp2)  = (s2);                                     \
+  MP_INT__mp_d(mp_tmp2)            = BYTE_ARR_CTS(d2);                         \
+                                                                        \
+  foreign "C" mpz_init(mp_result1 "ptr") [];                            \
+                                                                        \
+  /* Perform the operation */                                           \
+  foreign "C" mp_fun(mp_result1 "ptr",mp_tmp1  "ptr",mp_tmp2  "ptr") []; \
+                                                                        \
+  RET_NP(TO_W_(MP_INT__mp_size(mp_result1)),                            \
+         MP_INT__mp_d(mp_result1) - SIZEOF_StgArrWords);                \
+}
+
+#define GMP_TAKE1_RET1(name,mp_fun)                                     \
+name                                                                    \
+{                                                                       \
+  CInt s1;                                                              \
+  W_ d1;                                                                \
+  FETCH_MP_TEMP(mp_tmp1);                                               \
+  FETCH_MP_TEMP(mp_result1)                                             \
+                                                                        \
+  /* call doYouWantToGC() */                                            \
+  MAYBE_GC(R2_PTR, name);                                               \
+                                                                        \
+  d1 = R2;                                                              \
+  s1 = W_TO_INT(R1);                                                    \
+                                                                        \
+  MP_INT__mp_alloc(mp_tmp1)    = W_TO_INT(StgArrWords_words(d1));      \
+  MP_INT__mp_size(mp_tmp1)     = (s1);                                 \
+  MP_INT__mp_d(mp_tmp1)                = BYTE_ARR_CTS(d1);                     \
+                                                                        \
+  foreign "C" mpz_init(mp_result1 "ptr") [];                            \
+                                                                        \
+  /* Perform the operation */                                           \
+  foreign "C" mp_fun(mp_result1 "ptr",mp_tmp1 "ptr") [];                \
+                                                                        \
+  RET_NP(TO_W_(MP_INT__mp_size(mp_result1)),                            \
+         MP_INT__mp_d(mp_result1) - SIZEOF_StgArrWords);                \
+}
+
+#define GMP_TAKE2_RET2(name,mp_fun)                                                     \
+name                                                                                    \
+{                                                                                       \
+  CInt s1, s2;                                                                          \
+  W_ d1, d2;                                                                            \
+  FETCH_MP_TEMP(mp_tmp1);                                                               \
+  FETCH_MP_TEMP(mp_tmp2);                                                               \
+  FETCH_MP_TEMP(mp_result1)                                                             \
+  FETCH_MP_TEMP(mp_result2)                                                             \
+                                                                                        \
+  /* call doYouWantToGC() */                                                            \
+  MAYBE_GC(R2_PTR & R4_PTR, name);                                                      \
+                                                                                        \
+  s1 = W_TO_INT(R1);                                                                    \
+  d1 = R2;                                                                              \
+  s2 = W_TO_INT(R3);                                                                    \
+  d2 = R4;                                                                              \
+                                                                                        \
+  MP_INT__mp_alloc(mp_tmp1)    = W_TO_INT(StgArrWords_words(d1));                      \
+  MP_INT__mp_size(mp_tmp1)     = (s1);                                                 \
+  MP_INT__mp_d(mp_tmp1)                = BYTE_ARR_CTS(d1);                                     \
+  MP_INT__mp_alloc(mp_tmp2)    = W_TO_INT(StgArrWords_words(d2));                      \
+  MP_INT__mp_size(mp_tmp2)     = (s2);                                                 \
+  MP_INT__mp_d(mp_tmp2)                = BYTE_ARR_CTS(d2);                                     \
+                                                                                        \
+  foreign "C" mpz_init(mp_result1 "ptr") [];                                               \
+  foreign "C" mpz_init(mp_result2 "ptr") [];                                               \
+                                                                                        \
+  /* Perform the operation */                                                           \
+  foreign "C" mp_fun(mp_result1 "ptr",mp_result2 "ptr",mp_tmp1 "ptr",mp_tmp2 "ptr") [];    \
+                                                                                        \
+  RET_NPNP(TO_W_(MP_INT__mp_size(mp_result1)),                                          \
+           MP_INT__mp_d(mp_result1) - SIZEOF_StgArrWords,                               \
+          TO_W_(MP_INT__mp_size(mp_result2)),                                          \
+           MP_INT__mp_d(mp_result2) - SIZEOF_StgArrWords);                              \
 }
 
 GMP_TAKE2_RET1(plusIntegerzh_fast,     mpz_add)
@@ -650,17 +655,20 @@ GMP_TAKE1_RET1(complementIntegerzh_fast, mpz_com)
 GMP_TAKE2_RET2(quotRemIntegerzh_fast, mpz_tdiv_qr)
 GMP_TAKE2_RET2(divModIntegerzh_fast,  mpz_fdiv_qr)
 
+#ifndef THREADED_RTS
 section "bss" {
-  aa:  W_; // NB. aa is really an mp_limb_t
+  mp_tmp_w:  W_; // NB. mp_tmp_w is really an here mp_limb_t
 }
+#endif
 
 gcdIntzh_fast
 {
     /* R1 = the first Int#; R2 = the second Int# */
     W_ r; 
+    FETCH_MP_TEMP(mp_tmp_w);
 
-    W_[aa] = R1;
-    r = foreign "C" mpn_gcd_1(aa, 1, R2);
+    W_[mp_tmp_w] = R1;
+    r = foreign "C" mpn_gcd_1(mp_tmp_w "ptr", 1, R2) [];
 
     R1 = r;
     /* Result parked in R1, return via info-pointer at TOS */
@@ -671,7 +679,7 @@ gcdIntzh_fast
 gcdIntegerIntzh_fast
 {
     /* R1 = s1; R2 = d1; R3 = the int */
-    R1 = foreign "C" mpn_gcd_1( BYTE_ARR_CTS(R2) "ptr", R1, R3);
+    R1 = foreign "C" mpn_gcd_1( BYTE_ARR_CTS(R2) "ptr", R1, R3) [];
     
     /* Result parked in R1, return via info-pointer at TOS */
     jump %ENTRY_CODE(Sp(0));
@@ -752,7 +760,7 @@ cmpIntegerzh_fast
     up = BYTE_ARR_CTS(R2);
     vp = BYTE_ARR_CTS(R4);
 
-    cmp = foreign "C" mpn_cmp(up "ptr", vp "ptr", size);
+    cmp = foreign "C" mpn_cmp(up "ptr", vp "ptr", size) [];
 
     if (cmp == 0 :: CInt) {
        R1 = 0; 
@@ -806,14 +814,12 @@ integer2Wordzh_fast
   jump %ENTRY_CODE(Sp(0));
 }
 
-section "bss" {
-  exponent:  W_;
-}
-
 decodeFloatzh_fast
 { 
     W_ p;
     F_ arg;
+    FETCH_MP_TEMP(mp_tmp1);
+    FETCH_MP_TEMP(mp_tmp_w);
     
     /* arguments: F1 = Float# */
     arg = F1;
@@ -828,10 +834,10 @@ decodeFloatzh_fast
     MP_INT__mp_d(mp_tmp1) = BYTE_ARR_CTS(p);
     
     /* Perform the operation */
-    foreign "C" __decodeFloat(mp_tmp1,exponent,arg);
+    foreign "C" __decodeFloat(mp_tmp1 "ptr",mp_tmp_w "ptr" ,arg) [];
     
     /* returns: (Int# (expn), Int#, ByteArray#) */
-    RET_NNP(W_[exponent], TO_W_(MP_INT__mp_size(mp_tmp1)), p);
+    RET_NNP(W_[mp_tmp_w], TO_W_(MP_INT__mp_size(mp_tmp1)), p);
 }
 
 #define DOUBLE_MANTISSA_SIZE SIZEOF_DOUBLE
@@ -841,6 +847,8 @@ decodeDoublezh_fast
 { 
     D_ arg;
     W_ p;
+    FETCH_MP_TEMP(mp_tmp1);
+    FETCH_MP_TEMP(mp_tmp_w);
 
     /* arguments: D1 = Double# */
     arg = D1;
@@ -855,10 +863,10 @@ decodeDoublezh_fast
     MP_INT__mp_d(mp_tmp1) = BYTE_ARR_CTS(p);
 
     /* Perform the operation */
-    foreign "C" __decodeDouble(mp_tmp1,exponent,arg);
+    foreign "C" __decodeDouble(mp_tmp1 "ptr", mp_tmp_w "ptr",arg) [];
     
     /* returns: (Int# (expn), Int#, ByteArray#) */
-    RET_NNP(W_[exponent], TO_W_(MP_INT__mp_size(mp_tmp1)), p);
+    RET_NNP(W_[mp_tmp_w], TO_W_(MP_INT__mp_size(mp_tmp1)), p);
 }
 
 /* -----------------------------------------------------------------------------
@@ -872,9 +880,10 @@ forkzh_fast
   MAYBE_GC(R1_PTR, forkzh_fast);
 
   // create it right now, return ThreadID in R1
-  "ptr" R1 = foreign "C" createIOThread( RtsFlags_GcFlags_initialStkSize(RtsFlags), 
-                                  R1 "ptr");
-  foreign "C" scheduleThread(R1 "ptr");
+  "ptr" R1 = foreign "C" createIOThread( MyCapability() "ptr", 
+                               RtsFlags_GcFlags_initialStkSize(RtsFlags), 
+                               R1 "ptr") [R1];
+  foreign "C" scheduleThread(MyCapability() "ptr", R1 "ptr") [R1];
 
   // switch at the earliest opportunity
   CInt[context_switch] = 1 :: CInt;
@@ -899,7 +908,7 @@ labelThreadzh_fast
        R1 = ThreadId#
        R2 = Addr# */
 #ifdef DEBUG
-  foreign "C" labelThread(R1 "ptr", R2 "ptr");
+  foreign "C" labelThread(R1 "ptr", R2 "ptr") [];
 #endif
   jump %ENTRY_CODE(Sp(0));
 }
@@ -908,7 +917,7 @@ isCurrentThreadBoundzh_fast
 {
   /* no args */
   W_ r;
-  r = foreign "C" isThreadBound(CurrentTSO);
+  r = foreign "C" isThreadBound(CurrentTSO) [];
   RET_N(r);
 }
 
@@ -968,8 +977,8 @@ INFO_TABLE_RET(stg_catch_retry_frame,
 
    frame = Sp;
    trec = StgTSO_trec(CurrentTSO);
-   "ptr" outer = foreign "C" stmGetEnclosingTRec(trec "ptr");
-   r = foreign "C" stmCommitTransaction(trec "ptr");
+   "ptr" outer = foreign "C" stmGetEnclosingTRec(trec "ptr") [];
+   r = foreign "C" stmCommitNestedTransaction(MyCapability() "ptr", trec "ptr") [];
    if (r) {
      /* Succeeded (either first branch or second branch) */
      StgTSO_trec(CurrentTSO) = outer;
@@ -979,7 +988,7 @@ INFO_TABLE_RET(stg_catch_retry_frame,
    } else {
      /* Did not commit: retry */
      W_ new_trec;
-     "ptr" new_trec = foreign "C" stmStartTransaction(outer "ptr");
+     "ptr" new_trec = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr") [];
      StgTSO_trec(CurrentTSO) = new_trec;
      if (StgCatchRetryFrame_running_alt_code(frame)) {
        R1 = StgCatchRetryFrame_alt_code(frame);
@@ -987,8 +996,7 @@ INFO_TABLE_RET(stg_catch_retry_frame,
        R1 = StgCatchRetryFrame_first_code(frame);
        StgCatchRetryFrame_first_code_trec(frame) = new_trec;
      }
-     Sp_adj(-1);
-     jump RET_LBL(stg_ap_v);
+     jump stg_ap_v_fast;
    }
 }
 
@@ -1013,11 +1021,11 @@ ATOMICALLY_FRAME_ERROR(stg_atomically_frame_7_ret)
 #endif
 
 #if defined(PROFILING)
-#define ATOMICALLY_FRAME_BITMAP 7
-#define ATOMICALLY_FRAME_WORDS  4
+#define ATOMICALLY_FRAME_BITMAP 3
+#define ATOMICALLY_FRAME_WORDS  3
 #else
-#define ATOMICALLY_FRAME_BITMAP 1
-#define ATOMICALLY_FRAME_WORDS  2
+#define ATOMICALLY_FRAME_BITMAP 0
+#define ATOMICALLY_FRAME_WORDS  1
 #endif
 
 
@@ -1033,50 +1041,64 @@ INFO_TABLE_RET(stg_atomically_frame,
               stg_atomically_frame_6_ret,
               stg_atomically_frame_7_ret)
 {
-   W_ frame, trec, valid;
-   IF_NOT_REG_R1(W_ rval;  rval = Sp(0);  Sp_adj(1); )
+  W_ frame, trec, valid;
+  IF_NOT_REG_R1(W_ rval;  rval = Sp(0);  Sp_adj(1); )
 
-   frame = Sp;
-   trec = StgTSO_trec(CurrentTSO);
-   if (StgAtomicallyFrame_waiting(frame)) {
-     /* The TSO is currently waiting: should we stop waiting? */
-     valid = foreign "C" stmReWait(CurrentTSO "ptr");
-     if (valid) {
-       /* Previous attempt is still valid: no point trying again yet */
+  frame = Sp;
+  trec = StgTSO_trec(CurrentTSO);
+
+  /* The TSO is not currently waiting: try to commit the transaction */
+  valid = foreign "C" stmCommitTransaction(MyCapability() "ptr", trec "ptr") [];
+  if (valid) {
+    /* Transaction was valid: commit succeeded */
+    StgTSO_trec(CurrentTSO) = NO_TREC;
+    Sp = Sp + SIZEOF_StgAtomicallyFrame;
+    IF_NOT_REG_R1(Sp_adj(-1); Sp(0) = rval;)
+    jump %ENTRY_CODE(Sp(SP_OFF));
+  } else {
+    /* Transaction was not valid: try again */
+    "ptr" trec = foreign "C" stmStartTransaction(MyCapability() "ptr", NO_TREC "ptr") [];
+    StgTSO_trec(CurrentTSO) = trec;
+    R1 = StgAtomicallyFrame_code(frame);
+    jump stg_ap_v_fast;
+  }
+}
+
+INFO_TABLE_RET(stg_atomically_waiting_frame,
+              ATOMICALLY_FRAME_WORDS, ATOMICALLY_FRAME_BITMAP,
+              ATOMICALLY_FRAME,
+              stg_atomically_frame_0_ret,
+              stg_atomically_frame_1_ret,
+              stg_atomically_frame_2_ret,
+              stg_atomically_frame_3_ret,
+              stg_atomically_frame_4_ret,
+              stg_atomically_frame_5_ret,
+              stg_atomically_frame_6_ret,
+              stg_atomically_frame_7_ret)
+{
+  W_ frame, trec, valid;
+  IF_NOT_REG_R1(W_ rval;  rval = Sp(0);  Sp_adj(1); )
+
+  frame = Sp;
+
+  /* The TSO is currently waiting: should we stop waiting? */
+  valid = foreign "C" stmReWait(MyCapability() "ptr", CurrentTSO "ptr") [];
+  if (valid) {
+    /* Previous attempt is still valid: no point trying again yet */
          IF_NOT_REG_R1(Sp_adj(-2);
                        Sp(1) = stg_NO_FINALIZER_closure;
                        Sp(0) = stg_ut_1_0_unreg_info;)
-       jump stg_block_noregs;
-     } else {
-       /* Previous attempt is no longer valid: try again */
-       "ptr" trec = foreign "C" stmStartTransaction(NO_TREC "ptr");
-       StgTSO_trec(CurrentTSO) = trec;
-       StgAtomicallyFrame_waiting(frame) = 0 :: CInt; /* false; */
-       R1 = StgAtomicallyFrame_code(frame);
-       Sp_adj(-1);
-       jump RET_LBL(stg_ap_v);
-     }
-   } else {
-     /* The TSO is not currently waiting: try to commit the transaction */
-     valid = foreign "C" stmCommitTransaction(trec "ptr");
-     if (valid) {
-       /* Transaction was valid: commit succeeded */
-       StgTSO_trec(CurrentTSO) = NO_TREC;
-       Sp = Sp + SIZEOF_StgAtomicallyFrame;
-       IF_NOT_REG_R1(Sp_adj(-1); Sp(0) = rval;)
-       jump %ENTRY_CODE(Sp(SP_OFF));
-     } else {
-       /* Transaction was not valid: try again */
-       "ptr" trec = foreign "C" stmStartTransaction(NO_TREC "ptr");
-       StgTSO_trec(CurrentTSO) = trec;
-       R1 = StgAtomicallyFrame_code(frame);
-       Sp_adj(-1);
-       jump RET_LBL(stg_ap_v);
-     }
-   }
+    jump stg_block_noregs;
+  } else {
+    /* Previous attempt is no longer valid: try again */
+    "ptr" trec = foreign "C" stmStartTransaction(MyCapability() "ptr", NO_TREC "ptr") [];
+    StgTSO_trec(CurrentTSO) = trec;
+    StgHeader_info(frame) = stg_atomically_frame_info;
+    R1 = StgAtomicallyFrame_code(frame);
+    jump stg_ap_v_fast;
+  }
 }
 
-
 // STM catch frame --------------------------------------------------------------
 
 #define CATCH_STM_FRAME_ENTRY_TEMPLATE(label,ret)          \
@@ -1142,25 +1164,33 @@ atomicallyzh_fast
   W_ old_trec;
   W_ new_trec;
   
+  // stmStartTransaction may allocate
+  MAYBE_GC (R1_PTR, atomicallyzh_fast); 
+
   /* Args: R1 = m :: STM a */
   STK_CHK_GEN(SIZEOF_StgAtomicallyFrame + WDS(1), R1_PTR, atomicallyzh_fast);
 
+  old_trec = StgTSO_trec(CurrentTSO);
+
+  /* Nested transactions are not allowed; raise an exception */
+  if (old_trec != NO_TREC) {
+     R1 = GHCziIOBase_NestedAtomically_closure;
+     jump raisezh_fast;
+  }
+
   /* Set up the atomically frame */
   Sp = Sp - SIZEOF_StgAtomicallyFrame;
   frame = Sp;
 
   SET_HDR(frame,stg_atomically_frame_info, W_[CCCS]);
-  StgAtomicallyFrame_waiting(frame) = 0 :: CInt; // False
   StgAtomicallyFrame_code(frame) = R1;
 
   /* Start the memory transcation */
-  old_trec = StgTSO_trec(CurrentTSO);
-  "ptr" new_trec = foreign "C" stmStartTransaction(old_trec "ptr");
+  "ptr" new_trec = foreign "C" stmStartTransaction(MyCapability() "ptr", old_trec "ptr") [R1];
   StgTSO_trec(CurrentTSO) = new_trec;
 
   /* Apply R1 to the realworld token */
-  Sp_adj(-1);
-  jump RET_LBL(stg_ap_v);
+  jump stg_ap_v_fast;
 }
 
 
@@ -1180,8 +1210,7 @@ catchSTMzh_fast
   StgCatchSTMFrame_handler(frame) = R2;
 
   /* Apply R1 to the realworld token */
-  Sp_adj(-1);
-  jump RET_LBL(stg_ap_v);
+  jump stg_ap_v_fast;
 }
 
 
@@ -1191,13 +1220,16 @@ catchRetryzh_fast
   W_ new_trec;
   W_ trec;
 
+  // stmStartTransaction may allocate
+  MAYBE_GC (R1_PTR & R2_PTR, catchRetryzh_fast); 
+
   /* Args: R1 :: STM a */
   /* Args: R2 :: STM a */
   STK_CHK_GEN(SIZEOF_StgCatchRetryFrame + WDS(1), R1_PTR & R2_PTR, catchRetryzh_fast);
 
   /* Start a nested transaction within which to run the first code */
   trec = StgTSO_trec(CurrentTSO);
-  "ptr" new_trec = foreign "C" stmStartTransaction(trec "ptr");
+  "ptr" new_trec = foreign "C" stmStartTransaction(MyCapability() "ptr", trec "ptr") [R1,R2];
   StgTSO_trec(CurrentTSO) = new_trec;
 
   /* Set up the catch-retry frame */
@@ -1211,8 +1243,7 @@ catchRetryzh_fast
   StgCatchRetryFrame_first_code_trec(frame) = new_trec;
 
   /* Apply R1 to the realworld token */
-  Sp_adj(-1);
-  jump RET_LBL(stg_ap_v);  
+  jump stg_ap_v_fast;
 }
 
 
@@ -1229,9 +1260,9 @@ retryzh_fast
   // Find the enclosing ATOMICALLY_FRAME or CATCH_RETRY_FRAME
 retry_pop_stack:
   trec = StgTSO_trec(CurrentTSO);
-  "ptr" outer = foreign "C" stmGetEnclosingTRec(trec "ptr");
+  "ptr" outer = foreign "C" stmGetEnclosingTRec(trec "ptr") [];
   StgTSO_sp(CurrentTSO) = Sp;
-  frame_type = foreign "C" findRetryFrameHelper(CurrentTSO "ptr");
+  frame_type = foreign "C" findRetryFrameHelper(CurrentTSO "ptr") [];
   Sp = StgTSO_sp(CurrentTSO);
   frame = Sp;
 
@@ -1240,19 +1271,20 @@ retry_pop_stack:
     ASSERT(outer != NO_TREC);
     if (!StgCatchRetryFrame_running_alt_code(frame)) {
       // Retry in the first code: try the alternative
-      "ptr" trec = foreign "C" stmStartTransaction(outer "ptr");
+      "ptr" trec = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr") [];
       StgTSO_trec(CurrentTSO) = trec;
       StgCatchRetryFrame_running_alt_code(frame) = 1 :: CInt; // true;
       R1 = StgCatchRetryFrame_alt_code(frame);
-      Sp_adj(-1);
-      jump RET_LBL(stg_ap_v);
+      jump stg_ap_v_fast;
     } else {
       // Retry in the alternative code: propagate
       W_ other_trec;
       other_trec = StgCatchRetryFrame_first_code_trec(frame);
-      r = foreign "C" stmMergeForWaiting(trec "ptr", other_trec "ptr");
+      r = foreign "C" stmCommitNestedTransaction(MyCapability() "ptr", other_trec "ptr") [];
       if (r) {
-        r = foreign "C" stmCommitTransaction(trec "ptr");
+        r = foreign "C" stmCommitNestedTransaction(MyCapability() "ptr", trec "ptr") [];
+      } else {
+        foreign "C" stmAbortTransaction(MyCapability() "ptr", trec "ptr") [];
       }
       if (r) {
         // Merge between siblings succeeded: commit it back to enclosing transaction
@@ -1262,13 +1294,12 @@ retry_pop_stack:
         goto retry_pop_stack;
       } else {
         // Merge failed: we musn't propagate the retry.  Try both paths again.
-        "ptr" trec = foreign "C" stmStartTransaction(outer "ptr");
+        "ptr" trec = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr") [];
         StgCatchRetryFrame_first_code_trec(frame) = trec;
         StgCatchRetryFrame_running_alt_code(frame) = 0 :: CInt; // false;
         StgTSO_trec(CurrentTSO) = trec;
         R1 = StgCatchRetryFrame_first_code(frame);
-        Sp_adj(-1);
-        jump RET_LBL(stg_ap_v);
+        jump stg_ap_v_fast;
       }
     }
   }
@@ -1276,24 +1307,24 @@ retry_pop_stack:
   // We've reached the ATOMICALLY_FRAME: attempt to wait 
   ASSERT(frame_type == ATOMICALLY_FRAME);
   ASSERT(outer == NO_TREC);
-  r = foreign "C" stmWait(CurrentTSO "ptr", trec "ptr");
+  r = foreign "C" stmWait(MyCapability() "ptr", CurrentTSO "ptr", trec "ptr") [];
   if (r) {
     // Transaction was valid: stmWait put us on the TVars' queues, we now block
-    StgAtomicallyFrame_waiting(frame) = 1 :: CInt; // true
+    StgHeader_info(frame) = stg_atomically_waiting_frame_info;
     Sp = frame;
     // Fix up the stack in the unregisterised case: the return convention is different.
     IF_NOT_REG_R1(Sp_adj(-2); 
                  Sp(1) = stg_NO_FINALIZER_closure;
                  Sp(0) = stg_ut_1_0_unreg_info;)
-    jump stg_block_noregs;
+    R3 = trec; // passing to stmWaitUnblock()
+    jump stg_block_stmwait;
   } else {
     // Transaction was not valid: retry immediately
-    "ptr" trec = foreign "C" stmStartTransaction(outer "ptr");
+    "ptr" trec = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr") [];
     StgTSO_trec(CurrentTSO) = trec;
     R1 = StgAtomicallyFrame_code(frame);
     Sp = frame;
-    Sp_adj(-1);
-    jump RET_LBL(stg_ap_v);
+    jump stg_ap_v_fast;
   }
 }
 
@@ -1301,15 +1332,13 @@ retry_pop_stack:
 newTVarzh_fast
 {
   W_ tv;
+  W_ new_value;
 
   /* Args: R1 = initialisation value */
 
-  ALLOC_PRIM( SIZEOF_StgTVar, R1_PTR, newTVarzh_fast);
-  tv = Hp - SIZEOF_StgTVar + WDS(1);
-  SET_HDR(tv,stg_TVAR_info,W_[CCCS]);
-  StgTVar_current_value(tv) = R1;
-  StgTVar_first_wait_queue_entry(tv) = stg_END_STM_WAIT_QUEUE_closure;
-    
+  MAYBE_GC (R1_PTR, newTVarzh_fast); 
+  new_value = R1;
+  "ptr" tv = foreign "C" stmNewTVar(MyCapability() "ptr", new_value "ptr") [];
   RET_P(tv);
 }
 
@@ -1325,7 +1354,7 @@ readTVarzh_fast
   MAYBE_GC (R1_PTR, readTVarzh_fast); // Call to stmReadTVar may allocate
   trec = StgTSO_trec(CurrentTSO);
   tvar = R1;
-  "ptr" result = foreign "C" stmReadTVar(trec "ptr", tvar "ptr");
+  "ptr" result = foreign "C" stmReadTVar(MyCapability() "ptr", trec "ptr", tvar "ptr") [];
 
   RET_P(result);
 }
@@ -1344,7 +1373,7 @@ writeTVarzh_fast
   trec = StgTSO_trec(CurrentTSO);
   tvar = R1;
   new_value = R2;
-  foreign "C" stmWriteTVar(trec "ptr", tvar "ptr", new_value "ptr");
+  foreign "C" stmWriteTVar(MyCapability() "ptr", trec "ptr", tvar "ptr", new_value "ptr") [];
 
   jump %ENTRY_CODE(Sp(0));
 }
@@ -1424,18 +1453,6 @@ newMVarzh_fast
     StgTSO_sp(tso) = StgTSO_sp(tso) + WDS(3);  \
     lval = W_[StgTSO_sp(tso) - WDS(1)];
 
-/*
- * Only in threaded mode: we have to be careful when manipulating another thread's TSO,
- * because the scheduler might also be manipulating it.
- */
-#if defined(RTS_SUPPORTS_THREADS)
-#define ACQUIRE_SCHED_LOCK   foreign "C" ACQUIRE_LOCK(sched_mutex "ptr");
-#define RELEASE_SCHED_LOCK   foreign "C" RELEASE_LOCK(sched_mutex "ptr");
-#else
-#define ACQUIRE_SCHED_LOCK
-#define RELEASE_SCHED_LOCK
-#endif
-
 takeMVarzh_fast
 {
     W_ mvar, val, info, tso;
@@ -1443,8 +1460,8 @@ takeMVarzh_fast
     /* args: R1 = MVar closure */
     mvar = R1;
 
-#if defined(SMP)
-    "ptr" info = foreign "C" lockClosure(mvar "ptr");
+#if defined(THREADED_RTS)
+    "ptr" info = foreign "C" lockClosure(mvar "ptr") [];
 #else
     info = GET_INFO(mvar);
 #endif
@@ -1471,8 +1488,6 @@ takeMVarzh_fast
 
   if (StgMVar_head(mvar) != stg_END_TSO_QUEUE_closure)
   {
-      ACQUIRE_SCHED_LOCK;
-
       /* There are putMVar(s) waiting... 
        * wake up the first thread on the queue
        */
@@ -1484,21 +1499,20 @@ takeMVarzh_fast
 
 #if defined(GRAN) || defined(PAR)
       /* ToDo: check 2nd arg (mvar) is right */
-      "ptr" tso = foreign "C" unblockOneLocked(StgMVar_head(mvar),mvar);
+      "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar),mvar) [];
       StgMVar_head(mvar) = tso;
 #else
-      "ptr" tso = foreign "C" unblockOneLocked(StgMVar_head(mvar) "ptr");
+      "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr", 
+                                        StgMVar_head(mvar) "ptr") [];
       StgMVar_head(mvar) = tso;
 #endif
 
-      RELEASE_SCHED_LOCK;
-
       if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
          StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
       }
 
-#if defined(SMP)
-      foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info);
+#if defined(THREADED_RTS)
+      foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info) [];
 #endif
       RET_P(val);
   } 
@@ -1507,8 +1521,8 @@ takeMVarzh_fast
       /* No further putMVars, MVar is now empty */
       StgMVar_value(mvar) = stg_END_TSO_QUEUE_closure;
  
-#if defined(SMP)
-      foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info);
+#if defined(THREADED_RTS)
+      foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info) [];
 #else
       SET_INFO(mvar,stg_EMPTY_MVAR_info);
 #endif
@@ -1526,15 +1540,15 @@ tryTakeMVarzh_fast
 
     mvar = R1;
 
-#if defined(SMP)
-    "ptr" info = foreign "C" lockClosure(mvar "ptr");
+#if defined(THREADED_RTS)
+    "ptr" info = foreign "C" lockClosure(mvar "ptr") [];
 #else
     info = GET_INFO(mvar);
 #endif
 
     if (info == stg_EMPTY_MVAR_info) {
-#if defined(SMP)
-        foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info);
+#if defined(THREADED_RTS)
+        foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info) [];
 #endif
        /* HACK: we need a pointer to pass back, 
         * so we abuse NO_FINALIZER_closure
@@ -1547,8 +1561,6 @@ tryTakeMVarzh_fast
 
     if (StgMVar_head(mvar) != stg_END_TSO_QUEUE_closure) {
 
-        ACQUIRE_SCHED_LOCK;
-
        /* There are putMVar(s) waiting... 
         * wake up the first thread on the queue
         */
@@ -1560,28 +1572,27 @@ tryTakeMVarzh_fast
 
 #if defined(GRAN) || defined(PAR)
        /* ToDo: check 2nd arg (mvar) is right */
-       "ptr" tso = foreign "C" unblockOneLocked(StgMVar_head(mvar) "ptr", mvar "ptr");
+       "ptr" tso = foreign "C" unblockOne(StgMVar_head(mvar) "ptr", mvar "ptr") [];
        StgMVar_head(mvar) = tso;
 #else
-       "ptr" tso = foreign "C" unblockOneLocked(StgMVar_head(mvar) "ptr");
+       "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr",
+                                          StgMVar_head(mvar) "ptr") [];
        StgMVar_head(mvar) = tso;
 #endif
 
-        RELEASE_SCHED_LOCK;
-
        if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
            StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
        }
-#if defined(SMP)
-        foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info);
+#if defined(THREADED_RTS)
+        foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info) [];
 #endif
     }
     else 
     {
        /* No further putMVars, MVar is now empty */
        StgMVar_value(mvar) = stg_END_TSO_QUEUE_closure;
-#if defined(SMP)
-       foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info);
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info) [];
 #else
        SET_INFO(mvar,stg_EMPTY_MVAR_info);
 #endif
@@ -1598,8 +1609,8 @@ putMVarzh_fast
     /* args: R1 = MVar, R2 = value */
     mvar = R1;
 
-#if defined(SMP)
-    "ptr" info = foreign "C" lockClosure(mvar "ptr");
+#if defined(THREADED_RTS)
+    "ptr" info = foreign "C" lockClosure(mvar "ptr") [R2];
 #else
     info = GET_INFO(mvar);
 #endif
@@ -1620,8 +1631,6 @@ putMVarzh_fast
   
     if (StgMVar_head(mvar) != stg_END_TSO_QUEUE_closure) {
 
-        ACQUIRE_SCHED_LOCK;
-
        /* There are takeMVar(s) waiting: wake up the first one
         */
        ASSERT(StgTSO_why_blocked(StgMVar_head(mvar)) == BlockedOnMVar::I16);
@@ -1632,21 +1641,19 @@ putMVarzh_fast
       
 #if defined(GRAN) || defined(PAR)
        /* ToDo: check 2nd arg (mvar) is right */
-       "ptr" tso = foreign "C" unblockOneLocked(StgMVar_head(mvar) "ptr",mvar "ptr");
+       "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr", StgMVar_head(mvar) "ptr",mvar "ptr") [];
        StgMVar_head(mvar) = tso;
 #else
-       "ptr" tso = foreign "C" unblockOneLocked(StgMVar_head(mvar) "ptr");
+       "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr", StgMVar_head(mvar) "ptr") [];
        StgMVar_head(mvar) = tso;
 #endif
 
-        RELEASE_SCHED_LOCK;
-
        if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
            StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
        }
 
-#if defined(SMP)
-       foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info);
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info) [];
 #endif
        jump %ENTRY_CODE(Sp(0));
     }
@@ -1655,8 +1662,8 @@ putMVarzh_fast
        /* No further takes, the MVar is now full. */
        StgMVar_value(mvar) = R2;
 
-#if defined(SMP)
-       foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info);
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info) [];
 #else
        SET_INFO(mvar,stg_FULL_MVAR_info);
 #endif
@@ -1674,23 +1681,21 @@ tryPutMVarzh_fast
     /* args: R1 = MVar, R2 = value */
     mvar = R1;
 
-#if defined(SMP)
-    "ptr" info = foreign "C" lockClosure(mvar "ptr");
+#if defined(THREADED_RTS)
+    "ptr" info = foreign "C" lockClosure(mvar "ptr") [R2];
 #else
     info = GET_INFO(mvar);
 #endif
 
     if (info == stg_FULL_MVAR_info) {
-#if defined(SMP)
-       foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info);
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info) [];
 #endif
        RET_N(0);
     }
   
     if (StgMVar_head(mvar) != stg_END_TSO_QUEUE_closure) {
 
-        ACQUIRE_SCHED_LOCK;
-
        /* There are takeMVar(s) waiting: wake up the first one
         */
        ASSERT(StgTSO_why_blocked(StgMVar_head(mvar)) == BlockedOnMVar::I16);
@@ -1701,37 +1706,34 @@ tryPutMVarzh_fast
       
 #if defined(GRAN) || defined(PAR)
        /* ToDo: check 2nd arg (mvar) is right */
-       "ptr" tso = foreign "C" unblockOneLocked(StgMVar_head(mvar) "ptr",mvar "ptr");
+       "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr", StgMVar_head(mvar) "ptr",mvar "ptr") [];
        StgMVar_head(mvar) = tso;
 #else
-       "ptr" tso = foreign "C" unblockOneLocked(StgMVar_head(mvar) "ptr");
+       "ptr" tso = foreign "C" unblockOne(MyCapability() "ptr", StgMVar_head(mvar) "ptr") [];
        StgMVar_head(mvar) = tso;
 #endif
 
-        RELEASE_SCHED_LOCK;
-
        if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
            StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
        }
 
-#if defined(SMP)
-       foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info);
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_EMPTY_MVAR_info) [];
 #endif
-       jump %ENTRY_CODE(Sp(0));
     }
     else
     {
        /* No further takes, the MVar is now full. */
        StgMVar_value(mvar) = R2;
 
-#if defined(SMP)
-       foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info);
+#if defined(THREADED_RTS)
+       foreign "C" unlockClosure(mvar "ptr", stg_FULL_MVAR_info) [];
 #else
        SET_INFO(mvar,stg_FULL_MVAR_info);
 #endif
-       jump %ENTRY_CODE(Sp(0));
     }
     
+    RET_N(1);
     /* ToDo: yield afterward for better communication performance? */
 }
 
@@ -1746,7 +1748,7 @@ makeStableNamezh_fast
 
     ALLOC_PRIM( SIZEOF_StgStableName, R1_PTR, makeStableNamezh_fast );
   
-    index = foreign "C" lookupStableName(R1 "ptr");
+    index = foreign "C" lookupStableName(R1 "ptr") [];
 
     /* Is there already a StableName for this heap object?
      *  stable_ptr_table is a pointer to an array of snEntry structs.
@@ -1769,7 +1771,7 @@ makeStablePtrzh_fast
     /* Args: R1 = a */
     W_ sp;
     MAYBE_GC(R1_PTR, makeStablePtrzh_fast);
-    "ptr" sp = foreign "C" getStablePtr(R1 "ptr");
+    "ptr" sp = foreign "C" getStablePtr(R1 "ptr") [];
     RET_N(sp);
 }
 
@@ -1873,7 +1875,7 @@ waitReadzh_fast
     /* args: R1 */
 #ifdef THREADED_RTS
     foreign "C" barf("waitRead# on threaded RTS");
-#endif
+#else
 
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
     StgTSO_why_blocked(CurrentTSO) = BlockedOnRead::I16;
@@ -1882,6 +1884,7 @@ waitReadzh_fast
     // threaded RTS anyway.
     APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
     jump stg_block_noregs;
+#endif
 }
 
 waitWritezh_fast
@@ -1889,7 +1892,7 @@ waitWritezh_fast
     /* args: R1 */
 #ifdef THREADED_RTS
     foreign "C" barf("waitWrite# on threaded RTS");
-#endif
+#else
 
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
     StgTSO_why_blocked(CurrentTSO) = BlockedOnWrite::I16;
@@ -1898,6 +1901,7 @@ waitWritezh_fast
     // threaded RTS anyway.
     APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
     jump stg_block_noregs;
+#endif
 }
 
 
@@ -1913,7 +1917,7 @@ delayzh_fast
 
 #ifdef THREADED_RTS
     foreign "C" barf("delay# on threaded RTS");
-#endif
+#else
 
     /* args: R1 (microsecond delay amount) */
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
@@ -1963,6 +1967,7 @@ while:
     }
     jump stg_block_noregs;
 #endif
+#endif /* !THREADED_RTS */
 }
 
 
@@ -1975,7 +1980,7 @@ asyncReadzh_fast
 
 #ifdef THREADED_RTS
     foreign "C" barf("asyncRead# on threaded RTS");
-#endif
+#else
 
     /* args: R1 = fd, R2 = isSock, R3 = len, R4 = buf */
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
@@ -1983,14 +1988,16 @@ asyncReadzh_fast
 
     /* could probably allocate this on the heap instead */
     "ptr" ares = foreign "C" stgMallocBytes(SIZEOF_StgAsyncIOResult,
-                                           stg_asyncReadzh_malloc_str);
-    reqID = foreign "C" addIORequest(R1, 0/*FALSE*/,R2,R3,R4 "ptr");
+                                           stg_asyncReadzh_malloc_str)
+                       [R1,R2,R3,R4];
+    reqID = foreign "C" addIORequest(R1, 0/*FALSE*/,R2,R3,R4 "ptr") [];
     StgAsyncIOResult_reqID(ares)   = reqID;
     StgAsyncIOResult_len(ares)     = 0;
     StgAsyncIOResult_errCode(ares) = 0;
     StgTSO_block_info(CurrentTSO)  = ares;
     APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
     jump stg_block_async;
+#endif
 }
 
 STRING(stg_asyncWritezh_malloc_str, "asyncWritezh_fast")
@@ -2001,15 +2008,16 @@ asyncWritezh_fast
 
 #ifdef THREADED_RTS
     foreign "C" barf("asyncWrite# on threaded RTS");
-#endif
+#else
 
     /* args: R1 = fd, R2 = isSock, R3 = len, R4 = buf */
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
     StgTSO_why_blocked(CurrentTSO) = BlockedOnWrite::I16;
 
     "ptr" ares = foreign "C" stgMallocBytes(SIZEOF_StgAsyncIOResult,
-                                           stg_asyncWritezh_malloc_str);
-    reqID = foreign "C" addIORequest(R1, 1/*TRUE*/,R2,R3,R4 "ptr");
+                                           stg_asyncWritezh_malloc_str)
+                       [R1,R2,R3,R4];
+    reqID = foreign "C" addIORequest(R1, 1/*TRUE*/,R2,R3,R4 "ptr") [];
 
     StgAsyncIOResult_reqID(ares)   = reqID;
     StgAsyncIOResult_len(ares)     = 0;
@@ -2017,6 +2025,7 @@ asyncWritezh_fast
     StgTSO_block_info(CurrentTSO)  = ares;
     APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
     jump stg_block_async;
+#endif
 }
 
 STRING(stg_asyncDoProczh_malloc_str, "asyncDoProczh_fast")
@@ -2025,20 +2034,26 @@ asyncDoProczh_fast
     W_ ares;
     CInt reqID;
 
+#ifdef THREADED_RTS
+    foreign "C" barf("asyncDoProc# on threaded RTS");
+#else
+
     /* args: R1 = proc, R2 = param */
     ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
     StgTSO_why_blocked(CurrentTSO) = BlockedOnDoProc::I16;
 
     /* could probably allocate this on the heap instead */
     "ptr" ares = foreign "C" stgMallocBytes(SIZEOF_StgAsyncIOResult,
-                                           stg_asyncDoProczh_malloc_str);
-    reqID = foreign "C" addDoProcRequest(R1 "ptr",R2 "ptr");
+                                           stg_asyncDoProczh_malloc_str) 
+                               [R1,R2];
+    reqID = foreign "C" addDoProcRequest(R1 "ptr",R2 "ptr") [];
     StgAsyncIOResult_reqID(ares)   = reqID;
     StgAsyncIOResult_len(ares)     = 0;
     StgAsyncIOResult_errCode(ares) = 0;
     StgTSO_block_info(CurrentTSO) = ares;
     APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
     jump stg_block_async;
+#endif
 }
 #endif