From: Julian Seward <jseward@acm.org>
Date: Sat, 19 Sep 2020 10:09:54 +0000 (+0200)
Subject: On amd64, use by default the expensive instrumentation scheme for Iop_Add32.
X-Git-Tag: VALGRIND_3_17_0~160
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=913ed1fa179710ada662fbaa84282e5dadd393d1;p=thirdparty%2Fvalgrind.git

On amd64, use by default the expensive instrumentation scheme for Iop_Add32.

This is necessary to avoid some false positives in code compiled by clang 10
at -O2.  Some very crude measurements suggest the increase in generated code
size is around 0.2%, viz, insignificant.
---

diff --git a/memcheck/mc_translate.c b/memcheck/mc_translate.c
index 87b8ac6886..b32c9c9c53 100644
--- a/memcheck/mc_translate.c
+++ b/memcheck/mc_translate.c
@@ -8478,6 +8478,7 @@ IRSB* MC_(instrument) ( VgCallbackClosure* closure,
       mce.dlbo.dl_Add32           = DLauto;
       mce.dlbo.dl_CmpEQ32_CmpNE32 = DLexpensive;
 #     elif defined(VGA_amd64)
+      mce.dlbo.dl_Add32           = DLexpensive;
       mce.dlbo.dl_Add64           = DLauto;
       mce.dlbo.dl_CmpEQ32_CmpNE32 = DLexpensive;
       mce.dlbo.dl_CmpEQ64_CmpNE64 = DLexpensive;