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 6a306f820142a15d50a0ba95f74f9eac0a5f64d0..e4a6ccec81c99937cbb3bcd11bd40eb6483d5e4b 100644 (file)
--- 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;
 }