Enable expensive handling of CmpEQ64/CmpNE64 for amd64 by default.

This has unfortunately become necessary because optimising compilers are
generating 64-bit equality comparisons on partially defined values on this
target.  There will shortly be two followup commits which partially mitigate
the resulting performance loss.

diff --git a/memcheck/mc_translate.c b/memcheck/mc_translate.c
index bd29ea09f9c0719924edff52ad161e22728ae64c..87b8ac6886cec5b4902128c3d01d3f8104bddf40 100644 (file)
--- a/memcheck/mc_translate.c
+++ b/memcheck/mc_translate.c
@@ -8480,6 +8480,7 @@ IRSB* MC_(instrument) ( VgCallbackClosure* closure,
 #     elif defined(VGA_amd64)
       mce.dlbo.dl_Add64           = DLauto;
       mce.dlbo.dl_CmpEQ32_CmpNE32 = DLexpensive;
+      mce.dlbo.dl_CmpEQ64_CmpNE64 = DLexpensive;
 #     elif defined(VGA_ppc64le)
       // Needed by (at least) set_AV_CR6() in the front end.
       mce.dlbo.dl_CmpEQ64_CmpNE64 = DLexpensive;