mark recordMutableCap() with [R1] to avoid saving all regs across it

diff --git a/ghc/rts/Updates.h b/ghc/rts/Updates.h
index 62473b3..5872157 100644 (file)
--- a/ghc/rts/Updates.h
+++ b/ghc/rts/Updates.h
@@ -278,7 +278,7 @@ FILL_SLOP(StgClosure *p)
     if (bdescr_gen_no(bd) != 0 :: CInt) {                      \
       foreign "C" recordMutableCap(p1 "ptr",                   \
                                   MyCapability() "ptr",        \
-                                  bdescr_gen_no(bd));          \
+                                  bdescr_gen_no(bd)) [R1];     \
       SET_INFO(p1, stg_IND_OLDGEN_info);                       \
       LDV_RECORD_CREATE(p1);                                   \
       TICK_UPD_OLD_IND();                                      \