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[Qemu-devel] [PATCH v2 34/45] host-utils: add ffsl
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH v2 34/45] host-utils: add ffsl |
Date: |
Wed, 26 Sep 2012 17:56:40 +0200 |
We can provide fast versions based on the other functions defined
by host-utils.h. Some care is required on glibc, which provides
ffsl already.
Signed-off-by: Paolo Bonzini <address@hidden>
---
host-utils.h | 26 ++++++++++++++++++++++++++
1 file modificato, 26 inserzioni(+)
diff --git a/host-utils.h b/host-utils.h
index 821db93..2724be0 100644
--- a/host-utils.h
+++ b/host-utils.h
@@ -24,6 +24,7 @@
*/
#include "compiler.h" /* QEMU_GNUC_PREREQ */
+#include <string.h> /* ffsl */
#if defined(__x86_64__)
#define __HAVE_FAST_MULU64__
@@ -234,3 +235,28 @@ static inline int ctpop64(uint64_t val)
return val;
#endif
}
+
+/* glibc does not provide an inline version of ffsl, so always define
+ * ours. We need to give it a different name, however.
+ */
+#ifdef __GLIBC__
+#define ffsl qemu_ffsl
+#endif
+static inline int ffsl(long val)
+{
+ if (!val) {
+ return 0;
+ }
+
+#if QEMU_GNUC_PREREQ(3, 4)
+ return __builtin_ctzl(val) + 1;
+#else
+ if (sizeof(long) == 4) {
+ return ctz32(val) + 1;
+ } else if (sizeof(long) == 8) {
+ return ctz64(val) + 1;
+ } else {
+ abort();
+ }
+#endif
+}
--
1.7.12
- [Qemu-devel] [PATCH v2 37/45] block: make round_to_clusters public, (continued)
- [Qemu-devel] [PATCH v2 37/45] block: make round_to_clusters public, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 39/45] block: return count of dirty sectors, not chunks, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 38/45] mirror: perform COW if the cluster size is bigger than the granularity, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 41/45] mirror: allow customizing the granularity, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 43/45] mirror: add buf-size argument to drive-mirror, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 42/45] mirror: switch mirror_iteration to AIO, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 44/45] mirror: support more than one in-flight AIO operation, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 35/45] add hierarchical bitmap data type and test cases, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 34/45] host-utils: add ffsl,
Paolo Bonzini <=
- [Qemu-devel] [PATCH v2 45/45] mirror: support arbitrarily-sized iterations, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 21/45] block: add bdrv_open_backing_file, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 28/45] mirror: implement completion, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 15/45] stream: add on-error argument, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 30/45] iostatus: forward block_job_iostatus_reset to block job, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 31/45] mirror: add support for on-source-error/on-target-error, Paolo Bonzini, 2012/09/26
- [Qemu-devel] [PATCH v2 29/45] qemu-iotests: add mirroring test case, Paolo Bonzini, 2012/09/26