/* -----------------------------------------------------------------------------
*
- * (c) The GHC Team 1998-2006
+ * (c) The GHC Team 1998-2008
*
* Generational garbage collector: evacuation functions
*
+ * Documentation on the architecture of the Garbage Collector can be
+ * found in the online commentary:
+ *
+ * http://hackage.haskell.org/trac/ghc/wiki/Commentary/Rts/Storage/GC
+ *
* ---------------------------------------------------------------------------*/
+#ifndef SM_EVAC_H
+#define SM_EVAC_H
+
+BEGIN_RTS_PRIVATE
+
// Use a register argument for evacuate, if available.
-#if __GNUC__ >= 2
+// Earlier, the regparm attribute was used whenever __GNUC__ >= 2, but this
+// generated warnings on PPC. So the use is restricted further.
+// See http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html that says
+// regparm (number)
+// On the Intel 386, the regparm attribute causes the compiler to pass
+// arguments number one to number if they are of integral type in
+// registers EAX, EDX, and ECX instead of on the stack. Functions that
+// take a variable number of arguments will continue to be passed all of
+// their arguments on the stack.
+#if __GNUC__ >= 2 && (defined(x86_64_TARGET_ARCH) || defined(i386_TARGET_ARCH))
#define REGPARM1 __attribute__((regparm(1)))
#else
#define REGPARM1
#endif
-REGPARM1 StgClosure * evacuate (StgClosure *q);
+REGPARM1 void evacuate (StgClosure **p);
+REGPARM1 void evacuate1 (StgClosure **p);
extern lnat thunk_selector_depth;
+
+END_RTS_PRIVATE
+
+#endif /* SM_EVAC_H */
+