Fix #650: use a card table to mark dirty sections of mutable arrays

[ghc-hetmet.git] / includes / rts / Constants.h

diff --git a/includes/rts/Constants.h b/includes/rts/Constants.h
index 8ebe16a..0aee60a 100644 (file)
--- a/includes/rts/Constants.h
+++ b/includes/rts/Constants.h
@@ -66,6 +66,13 @@
 #define MAX_CHARLIKE           255
 #define MIN_CHARLIKE           0
 
+/* Each byte in the card table for an StgMutaArrPtrs covers
+ * (1<<MUT_ARR_PTRS_CARD_BITS) elements in the array.  To find a good
+ * value for this, I used the benchmarks nofib/gc/hash,
+ * nofib/gc/graph, and nofib/gc/gc_bench.
+ */
+#define MUT_ARR_PTRS_CARD_BITS 7
+
 /* -----------------------------------------------------------------------------
    STG Registers.