From: Julian Seward <jseward@acm.org>
Date: Mon, 21 Mar 2005 11:53:38 +0000 (+0000)
Subject: handleOneStatement: Derive a value for *instrAddr from the IMark in a
X-Git-Tag: svn/VALGRIND_3_0_0~919
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=eaae711c64fbb6ba33bb7f84b0f1e4923523b70e;p=thirdparty%2Fvalgrind.git

handleOneStatement: Derive a value for *instrAddr from the IMark in a
way which is 64-bit clean.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@3399
---

diff --git a/cachegrind/cg_main.c b/cachegrind/cg_main.c
index b4ec110eb7..159051b3de 100644
--- a/cachegrind/cg_main.c
+++ b/cachegrind/cg_main.c
@@ -395,8 +395,17 @@ void handleOneStatement(IRTypeEnv* tyenv, IRBB* bbOut, IRStmt* st,
       break;
 
    case Ist_IMark:
-      *instrAddr = (Addr)st->Ist.IMark.addr;
-      tl_assert(*instrAddr == st->Ist.IMark.addr); // XXX: check no overflow
+      /* st->Ist.IMark.addr is a 64-bit int.  ULong_to_Ptr casts this
+         to the host's native pointer type; if that is 32 bits then it
+         discards the upper 32 bits.  If we are cachegrinding on a
+         32-bit host then we are also ensured that the guest word size
+         is 32 bits, due to the assertion in TL_(instrument) that the
+         host and guest word sizes must be the same.  Hence
+         st->Ist.IMark.addr will have been derived from a 32-bit guest
+         code address and truncation of it is safe.  I believe this
+         assignment should be correct for both 32- and 64-bit
+         machines. */
+      *instrAddr = (Addr)ULong_to_Ptr(st->Ist.IMark.addr);
       *instrLen =        st->Ist.IMark.len;
       addStmtToIRBB( bbOut, st );
       break;