X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FStgStartup.cmm;h=2f2a759c81b752b0f4c7f686b958ed82fb127f93;hb=876b4ef2093cb9c104db33c7db1200b941b6d079;hp=2d5d4d89415270204b8f8a00012bd18eb47d08cf;hpb=1621421619df6f19dce3b8cb29471e5d3c731acb;p=ghc-hetmet.git

diff --git a/ghc/rts/StgStartup.cmm b/ghc/rts/StgStartup.cmm
index 2d5d4d8..2f2a759 100644
--- a/ghc/rts/StgStartup.cmm
+++ b/ghc/rts/StgStartup.cmm
@@ -29,7 +29,7 @@
     ASSERT(Sp != 0);			\
     ASSERT(SpLim != 0);			\
     ASSERT(HpLim != 0);			\
-    ASSERT(SpLim - RESERVED_STACK_WORDS <= Sp); \
+    ASSERT(SpLim - WDS(RESERVED_STACK_WORDS) <= Sp); \
     ASSERT(HpLim >= Hp);
 
 /* -----------------------------------------------------------------------------
@@ -92,8 +92,9 @@ INFO_TABLE_RET( stg_stop_thread, STOP_THREAD_WORDS, STOP_THREAD_BITMAP,
 
     SAVE_THREAD_STATE();
 
-    /* R1 contains the return value of the thread */
-    R1 = ThreadFinished;
+    /* The return code goes in BaseReg->rRet, and BaseReg is returned in R1 */
+    StgRegTable_rRet(BaseReg) = ThreadFinished;
+    R1 = BaseReg;
 
     jump StgReturn;
 }
@@ -102,6 +103,9 @@ INFO_TABLE_RET( stg_stop_thread, STOP_THREAD_WORDS, STOP_THREAD_BITMAP,
    Start a thread from the scheduler by returning to the address on
    the top of the stack.  This is used for all entries to STG code
    from C land.
+
+   On the way back, we (usually) pass through stg_returnToSched which saves
+   the thread's state away nicely.
    -------------------------------------------------------------------------- */
 
 stg_returnToStackTop
@@ -111,6 +115,34 @@ stg_returnToStackTop
   jump %ENTRY_CODE(Sp(0));
 }
 
+stg_returnToSched
+{
+  SAVE_THREAD_STATE();
+  foreign "C" threadPaused(MyCapability() "ptr", CurrentTSO);
+  jump StgReturn;
+}
+
+// A variant of stg_returntToSched that doesn't call threadPaused() on the
+// current thread.  This is used for switching from compiled execution to the
+// interpreter, where calling threadPaused() on every switch would be too
+// expensive.
+stg_returnToSchedNotPaused
+{
+  SAVE_THREAD_STATE();
+  jump StgReturn;
+}
+
+// A variant of stg_returnToSched, but instead of returning directly to the
+// scheduler, we jump to the code fragment pointed to by R2.  This lets us
+// perform some final actions after making the thread safe, such as unlocking
+// the MVar on which we are about to block in SMP mode.
+stg_returnToSchedButFirst
+{
+  SAVE_THREAD_STATE();
+  foreign "C" threadPaused(MyCapability() "ptr", CurrentTSO);
+  jump R2;
+}
+
 /* -----------------------------------------------------------------------------
     Strict IO application - performing an IO action and entering its result.