Loosen the rules for instance declarations (Part 2)

[ghc-hetmet.git] / ghc / includes / Regs.h

diff --git a/ghc/includes/Regs.h b/ghc/includes/Regs.h
index b65d242..def36c3 100644 (file)
--- a/ghc/includes/Regs.h
+++ b/ghc/includes/Regs.h
@@ -24,15 +24,17 @@
 
 #include "gmp.h" // Needs MP_INT definition 
 
-/* 
- * This is the table that holds shadow-locations for all the STG
- * registers.  The shadow locations are used when:
- *
- *     1) the particular register isn't mapped to a real machine
- *        register, probably because there's a shortage of real registers.
- *     2) caller-saves registers are saved across a CCall
+/*
+ * Spark pools: used to store pending sparks (SMP & PARALLEL_HASKELL only)
+ * This is a circular buffer.  Invariants:
+ *    - base <= hd < lim
+ *    - base <= tl < lim
+ *    - if hd==tl, then the pool is empty.
+ *    - if hd == tl+1, then the pool is full.
+ * Adding to the pool is done by assigning to *tl++ (wrapping round as
+ * necessary).  When adding to a full pool, we have the option of
+ * throwing away either the oldest (hd++) or the most recent (tl--) entry.
  */
-
 typedef struct StgSparkPool_ {
   StgClosure **base;
   StgClosure **lim;
@@ -40,6 +42,12 @@ typedef struct StgSparkPool_ {
   StgClosure **tl;
 } StgSparkPool;
 
+#define ASSERT_SPARK_POOL_INVARIANTS(p)                \
+  ASSERT((p)->base <= (p)->hd);                        \
+  ASSERT((p)->hd < (p)->lim);                  \
+  ASSERT((p)->base <= (p)->tl);                        \
+  ASSERT((p)->tl < (p)->lim);
+
 typedef struct {
   StgFunPtr      stgGCEnter1;
   StgFunPtr      stgGCFun;
@@ -64,6 +72,14 @@ typedef union {
     StgTSOPtr      t;
 } StgUnion;
 
+/* 
+ * This is the table that holds shadow-locations for all the STG
+ * registers.  The shadow locations are used when:
+ *
+ *     1) the particular register isn't mapped to a real machine
+ *        register, probably because there's a shortage of real registers.
+ *     2) caller-saves registers are saved across a CCall
+ */
 typedef struct StgRegTable_ {
   StgUnion       rR1;
   StgUnion       rR2;
@@ -98,11 +114,10 @@ typedef struct StgRegTable_ {
   MP_INT          rmp_tmp2;      
   MP_INT          rmp_result1;
   MP_INT          rmp_result2;
+  StgWord         rRet;  // holds the return code of the thread
 #if defined(SMP) || defined(PAR)
   StgSparkPool    rSparks;     /* per-task spark pool */
 #endif
-    // If this flag is set, we are running Haskell code.  Used to detect
-    // uses of 'foreign import unsafe' that should be 'safe'.
 } StgRegTable;
 
 #if IN_STG_CODE