From: Philippe Waroquiers <philippe.waroquiers@skynet.be>
Date: Mon, 11 May 2015 19:41:43 +0000 (+0000)
Subject: Micro-optimisation following helgrind secmap gc
X-Git-Tag: svn/VALGRIND_3_11_0~406
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=73266b0930f7549fafa610f3c03d551288f320c9;p=thirdparty%2Fvalgrind.git

Micro-optimisation following helgrind secmap gc
Checking the range in indexXA can be done with one comparison.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15211
---

diff --git a/coregrind/m_xarray.c b/coregrind/m_xarray.c
index 6a306f8201..e4a6ccec81 100644
--- a/coregrind/m_xarray.c
+++ b/coregrind/m_xarray.c
@@ -127,9 +127,10 @@ void VG_(setCmpFnXA) ( XArray* xa, XACmpFn_t compar )
 
 inline void* VG_(indexXA) ( const XArray* xa, Word n )
 {
-   vg_assert(xa);
-   vg_assert(n >= 0);
-   vg_assert(n < xa->usedsizeE);
+   // vg_assert(xa);
+   // vg_assert(n >= 0); If n negative, the UWord conversion will make
+   // it bigger than usedsizeE.
+   vg_assert((UWord)n < xa->usedsizeE);
    return ((char*)xa->arr) + n * xa->elemSzB;
 }