From: Sebastian Huber <sebastian.huber@embedded-brains.de>
To: newlib@sourceware.org
Subject: [PATCH] Workaround for ffs() on LP64 targets
Date: Thu, 27 Jul 2017 08:06:00 -0000 [thread overview]
Message-ID: <20170727080624.24818-1-sebastian.huber@embedded-brains.de> (raw)
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
---
newlib/libc/misc/ffs.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/newlib/libc/misc/ffs.c b/newlib/libc/misc/ffs.c
index ba5700920..a09cbd3bb 100644
--- a/newlib/libc/misc/ffs.c
+++ b/newlib/libc/misc/ffs.c
@@ -31,6 +31,17 @@ No supporting OS subroutines are required. */
int
ffs(int i)
{
+#ifdef __LP64__
+ /* GCC would expand the __builtin_ffs() to ffs() in this case */
+ int bit;
+
+ if (i == 0)
+ return (0);
+ for (bit = 1; !(i & 1); bit++)
+ i = (unsigned int)i >> 1;
+ return (bit);
+#else
return (__builtin_ffs(i));
+#endif
}
--
2.12.3
next reply other threads:[~2017-07-27 8:06 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-27 8:06 Sebastian Huber [this message]
2017-07-27 8:29 ` Kito Cheng
2017-07-27 8:40 ` Sebastian Huber
2017-07-27 9:01 ` Kito Cheng
2017-07-27 11:13 ` Eric Blake
2017-07-27 11:25 ` Sebastian Huber
2017-07-27 12:27 ` Corinna Vinschen
2017-07-27 12:34 ` Sebastian Huber
2017-07-27 12:49 ` Corinna Vinschen
2017-07-27 12:53 ` Sebastian Huber
2017-07-27 21:03 ` Brian Inglis
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