Wed Jul  7 11:54:25 BRT 2010  Marco Túlio Gontijo e Silva <marcot@marcot.eti.br>
  * Don't check blocks that were swept with -DS.
diff -rN -u old-ghc-temp/includes/rts/storage/Block.h new-ghc-temp-1/includes/rts/storage/Block.h
--- old-ghc-temp/includes/rts/storage/Block.h	2010-07-07 19:24:01.000000000 -0300
+++ new-ghc-temp-1/includes/rts/storage/Block.h	2010-07-07 19:24:02.000000000 -0300
@@ -100,6 +100,8 @@
 #define BF_KNOWN     128
 /* Block contains objects larger than a line */
 #define BF_MEDIUM    256
+/* Blocks that were swept in the last GC */
+#define BF_SWEPT     512
 
 /* Finding the block descriptor for a given block -------------------------- */
 
diff -rN -u old-ghc-temp/rts/sm/GC.c new-ghc-temp-1/rts/sm/GC.c
--- old-ghc-temp/rts/sm/GC.c	2010-07-07 19:24:01.000000000 -0300
+++ new-ghc-temp-1/rts/sm/GC.c	2010-07-07 19:24:02.000000000 -0300
@@ -1302,6 +1302,10 @@
                 if (!(bd->flags & BF_FRAGMENTED)) {
                     bd->flags |= BF_MARKED;
                 }
+
+                // BF_SWEPT should be marked only for blocks that are being
+                // collected in sweep()
+                bd->flags &= ~BF_SWEPT;
             }
         }
     }
diff -rN -u old-ghc-temp/rts/sm/Sanity.c new-ghc-temp-1/rts/sm/Sanity.c
--- old-ghc-temp/rts/sm/Sanity.c	2010-07-07 19:24:01.000000000 -0300
+++ new-ghc-temp-1/rts/sm/Sanity.c	2010-07-07 19:24:02.000000000 -0300
@@ -473,17 +473,18 @@
 #endif
 
     for (; bd != NULL; bd = bd->link) {
-	p = bd->start;
-	while (p < bd->free) {
-	    nat size = checkClosure((StgClosure *)p);
-	    /* This is the smallest size of closure that can live in the heap */
-	    ASSERT( size >= MIN_PAYLOAD_SIZE + sizeofW(StgHeader) );
-	    p += size;
-	    
+        if(!(bd->flags & BF_SWEPT)) {
+            p = bd->start;
+            while (p < bd->free) {
+                nat size = checkClosure((StgClosure *)p);
+            /* This is the smallest size of closure that can live in the heap */
+            ASSERT( size >= MIN_PAYLOAD_SIZE + sizeofW(StgHeader) );
+            p += size;
 	    /* skip over slop */
 	    while (p < bd->free &&
 		   (*p < 0x1000 || !LOOKS_LIKE_INFO_PTR(*p))) { p++; } 
-	}
+            }
+        }
     }
 }
 
diff -rN -u old-ghc-temp/rts/sm/Sweep.c new-ghc-temp-1/rts/sm/Sweep.c
--- old-ghc-temp/rts/sm/Sweep.c	2010-07-07 19:24:01.000000000 -0300
+++ new-ghc-temp-1/rts/sm/Sweep.c	2010-07-07 19:24:02.000000000 -0300
@@ -64,6 +64,8 @@
         blocks++;
         resid = 0;
 
+        bd->flags |= BF_SWEPT;
+
         // The block is analyzed in groups of BITS_IN(W_) words, where
         // BITS_IN(W_) is the word size in bits.
         for (i = 0; i < BLOCK_SIZE_W / BITS_IN(W_); i++)