/* -----------------------------------------------------------------------------
- * $Id: StgMacros.h,v 1.51 2003/04/22 16:25:08 simonmar Exp $
+ * $Id: StgMacros.h,v 1.56 2003/08/05 14:01:34 simonpj Exp $
*
* (c) The GHC Team, 1998-1999
*
we assume that the size of a double is always 2 pointers (wasting a
word when it is only one pointer, but avoiding lots of #ifdefs).
+ NOTE: if you change the layout of RET_DYN stack frames, then you
+ might also need to adjust the value of RESERVED_STACK_WORDS in
+ Constants.h.
-------------------------------------------------------------------------- */
// VERY MAGIC CONSTANTS!
-// must agree with code in HeapStackCheck.c, stg_gen_chk
+// must agree with code in HeapStackCheck.c, stg_gen_chk, and
+// RESERVED_STACK_WORDS in Constants.h.
//
#define RET_DYN_BITMAP_SIZE 8
#define RET_DYN_NONPTR_REGS_SIZE 10
#define ALL_NON_PTRS 0xff
+// Sanity check that RESERVED_STACK_WORDS is reasonable. We can't
+// just derive RESERVED_STACK_WORDS because it's used in Haskell code
+// too.
+#if RESERVED_STACK_WORDS != (3 + RET_DYN_BITMAP_SIZE + RET_DYN_NONPTR_REGS_SIZE)
+#error RESERVED_STACK_WORDS may be wrong!
+#endif
+
#define LIVENESS_MASK(ptr_regs) (ALL_NON_PTRS ^ (ptr_regs))
// We can have up to 255 pointers and 255 nonpointers in the stack
# else
// An object is replaced by a blackhole, so we fill the slop with zeros.
//
+// This looks like it can't work - we're overwriting the contents of
+// the THUNK with slop! Perhaps this never worked??? --SDM
+// The problem is that with eager-black-holing we currently perform
+// the black-holing operation at the *beginning* of the basic block,
+// when we still need the contents of the thunk.
+// Perhaps the thing to do is to overwrite it at the *end* of the
+// basic block, when we've already sucked out the thunk's contents? -- SLPJ
+//
// Todo: maybe use SET_HDR() and remove LDV_recordCreate()?
//
# define UPD_BH_UPDATABLE(info) \
# define UPD_BH_SINGLE_ENTRY(thunk) /* nothing */
#endif /* EAGER_BLACKHOLING */
-#define UPD_FRAME_UPDATEE(p) ((P_)(((StgUpdateFrame *)(p))->updatee))
-
/* -----------------------------------------------------------------------------
Moving Floats and Doubles