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authorYufeng Zhang <yufeng.zhang@arm.com>2014-04-22 17:26:59 +0100
committerMarcus Shawcroft <marcus.shawcroft@arm.com>2014-04-22 17:26:59 +0100
commitea6c92f3be6d59736ee6183a61c538e5d1cc46f8 (patch)
tree0ad25404aa0f39cdbdd7ca401cb0e472f0195893
parent766c4a363d5487dde04bb5e968c3db8b383ec3c2 (diff)
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[AArch64] Use GCC builtins to count leading/tailing zeros.
-rw-r--r--ChangeLog5
-rw-r--r--stdlib/longlong.h16
2 files changed, 21 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 8c0f2a2..c3fa6e5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2014-04-22 Yufeng Zhang <yufeng.zhang@arm.com>
+
+ * stdlib/longlong.h (count_leading_zeros, count_trailing_zeros)
+ (COUNT_LEADING_ZEROS_0): Define for AArch64.
+
2014-04-22 Siddhesh Poyarekar <siddhesh@redhat.com>
* nptl/sysdeps/unix/sysv/linux/sem_trywait.c: Include atomic.h.
diff --git a/stdlib/longlong.h b/stdlib/longlong.h
index 10d76cf..d45dbe2 100644
--- a/stdlib/longlong.h
+++ b/stdlib/longlong.h
@@ -122,6 +122,22 @@ extern const UQItype __clz_tab[256] attribute_hidden;
#define __AND_CLOBBER_CC , "cc"
#endif /* __GNUC__ < 2 */
+#if defined (__aarch64__)
+
+#if W_TYPE_SIZE == 32
+#define count_leading_zeros(COUNT, X) ((COUNT) = __builtin_clz (X))
+#define count_trailing_zeros(COUNT, X) ((COUNT) = __builtin_ctz (X))
+#define COUNT_LEADING_ZEROS_0 32
+#endif /* W_TYPE_SIZE == 32 */
+
+#if W_TYPE_SIZE == 64
+#define count_leading_zeros(COUNT, X) ((COUNT) = __builtin_clzll (X))
+#define count_trailing_zeros(COUNT, X) ((COUNT) = __builtin_ctzll (X))
+#define COUNT_LEADING_ZEROS_0 64
+#endif /* W_TYPE_SIZE == 64 */
+
+#endif /* __aarch64__ */
+
#if defined (__alpha) && W_TYPE_SIZE == 64
#define umul_ppmm(ph, pl, m0, m1) \
do { \