Jason Merrill <ja...@redhat.com> writes:
> I think a better fix to your binary search algorithm would be to change
>
> mn = md;
>
> to be
>
> mn = md + 1;
>
> since you've eliminated md as a possibility. And then change the test to
>
> (mn < mx).
>
Right, thanks.
Here the updated patch, bootstrapped and tested on
x86_64-unknown-linux-gnu against trunk.
From: Dodji Seketeli <do...@redhat.com>
Date: Fri, 21 Oct 2011 16:47:07 +0200
Subject: [PATCH 2/2] Fix lookup of macro maps
* line-map.c (linemap_macro_map_lookup): Fix logic.
---
libcpp/line-map.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/libcpp/line-map.c b/libcpp/line-map.c
index 4af3782..97075e1 100644
--- a/libcpp/line-map.c
+++ b/libcpp/line-map.c
@@ -588,14 +588,14 @@ linemap_macro_map_lookup (struct line_maps *set,
source_location line)
mn = 0;
}
- do
+ while (mn < mx)
{
md = (mx + mn) / 2;
if (MAP_START_LOCATION (LINEMAPS_MACRO_MAP_AT (set, md)) > line)
- mn = md;
+ mn = md + 1;
else
mx = md;
- } while (mx - mn > 1);
+ }
LINEMAPS_MACRO_CACHE (set) = mx;
result = LINEMAPS_MACRO_MAP_AT (set, LINEMAPS_MACRO_CACHE (set));
--
1.7.6.4
--
Dodji
