X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=rts%2Fsm%2FEvac.h;h=78d024f3e99409549d73fa78cf77846828056868;hp=c89e4d9a7d552f4c863f669c7c0fc11a2b90cdda;hb=a2a67cd520b9841114d69a87a423dabcb3b4368e;hpb=ab0e778ccfde61aed4c22679b24d175fc6cc9bf3

diff --git a/rts/sm/Evac.h b/rts/sm/Evac.h
index c89e4d9..78d024f 100644
--- a/rts/sm/Evac.h
+++ b/rts/sm/Evac.h
@@ -1,18 +1,39 @@
 /* -----------------------------------------------------------------------------
  *
- * (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
+
 // 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;
+
+#endif /* SM_EVAC_H */
+