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authorPaul Eggert <eggert@cs.ucla.edu>2012-03-16 02:57:35 -0700
committerPaul Eggert <eggert@cs.ucla.edu>2012-05-23 14:36:24 -0700
commit03cf7fe31be5964707a54ed82969b9c181f8dd99 (patch)
tree0bc872aba029ef45e274a05a4e6e6c6ef2367007
parentf04dfbc244efb683e395d40c08c86fb93e679167 (diff)
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mktime: check signed shifts on long_int and time_t, too
* time/mktime.c (SHR): Check that shifts work as desired on the types long_int and time_t too, as SHR is used on such types.
-rw-r--r--ChangeLog5
-rw-r--r--time/mktime.c8
2 files changed, 10 insertions, 3 deletions
diff --git a/ChangeLog b/ChangeLog
index 5b99dac..b5cf376 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
2012-05-23 Paul Eggert <eggert@cs.ucla.edu>
+ mktime: check signed shifts on long_int and time_t, too
+ * time/mktime.c (SHR): Check that shifts work as desired
+ on the types long_int and time_t too, as SHR is used on
+ such types.
+
mktime: do not assume 'long' is wide enough
* time/mktime.c (verify): Move decl up.
(long_int): New type.
diff --git a/time/mktime.c b/time/mktime.c
index 6d4db69..5144987 100644
--- a/time/mktime.c
+++ b/time/mktime.c
@@ -89,9 +89,11 @@ verify (long_int_is_wide_enough, INT_MAX == INT_MAX * (long_int) 2 / 2);
implementations (e.g., UNICOS 9.0 on a Cray Y-MP EL) don't shift
right in the usual way when A < 0, so SHR falls back on division if
ordinary A >> B doesn't seem to be the usual signed shift. */
-#define SHR(a, b) \
- (-1 >> 1 == -1 \
- ? (a) >> (b) \
+#define SHR(a, b) \
+ ((-1 >> 1 == -1 \
+ && (long_int) -1 >> 1 == -1 \
+ && ((time_t) -1 >> 1 == -1 || ! TYPE_SIGNED (time_t))) \
+ ? (a) >> (b) \
: (a) / (1 << (b)) - ((a) % (1 << (b)) < 0))
/* The extra casts in the following macros work around compiler bugs,