From: Richard Henderson <rth@twiddle.net>
To: libc-ports@sourceware.org
Cc: joseph@codesourcery.com
Subject: [PATCH v2 11/14] arm: Add optimized ffs for armv6t2
Date: Fri, 01 Mar 2013 17:36:00 -0000 [thread overview]
Message-ID: <1362159320-5934-12-git-send-email-rth@twiddle.net> (raw)
In-Reply-To: <1362159320-5934-1-git-send-email-rth@twiddle.net>
---
* sysdeps/arm/armv6t2/ffs.S: New file.
* sysdeps/arm/armv6t2/ffsll.S: New file.
---
ports/sysdeps/arm/armv6t2/ffs.S | 35 +++++++++++++++++++++++++++
ports/sysdeps/arm/armv6t2/ffsll.S | 50 +++++++++++++++++++++++++++++++++++++++
2 files changed, 85 insertions(+)
create mode 100644 ports/sysdeps/arm/armv6t2/ffs.S
create mode 100644 ports/sysdeps/arm/armv6t2/ffsll.S
diff --git a/ports/sysdeps/arm/armv6t2/ffs.S b/ports/sysdeps/arm/armv6t2/ffs.S
new file mode 100644
index 0000000..b2c88b9
--- /dev/null
+++ b/ports/sysdeps/arm/armv6t2/ffs.S
@@ -0,0 +1,35 @@
+/* ffs -- find first set bit in an int, from least significant end.
+ Copyright (C) 2013 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+ .syntax unified
+ .text
+
+ENTRY (__ffs)
+ cmp r0, #0
+ rbit r0, r0
+ itt ne
+ clzne r0, r0
+ addne r0, r0, #1
+ bx lr
+END (__ffs)
+
+weak_alias (__ffs, ffs)
+weak_alias (__ffs, ffsl)
+libc_hidden_builtin_def (ffs)
diff --git a/ports/sysdeps/arm/armv6t2/ffsll.S b/ports/sysdeps/arm/armv6t2/ffsll.S
new file mode 100644
index 0000000..e49c70f
--- /dev/null
+++ b/ports/sysdeps/arm/armv6t2/ffsll.S
@@ -0,0 +1,50 @@
+/* ffsll -- find first set bit in a long long, from least significant end.
+ Copyright (C) 2013 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+ .syntax unified
+ .text
+
+ENTRY (ffsll)
+ @ If low part is 0, operate on the high part. Ensure that the
+ @ word on which we operate is in r0. Set r2 to the bit offset
+ @ of the word being considered. Set the flags for the word
+ @ being operated on.
+#ifdef __ARMEL__
+ cmp r0, #0
+ itee ne
+ movne r2, #0
+ moveq r2, #32
+ movseq r0, r1
+#else
+ cmp r1, #0
+ ittee ne
+ movne r2, #0
+ movne r0, r1
+ moveq r2, #32
+ cmpeq r0, #0
+#endif
+ @ Perform the ffs on r0.
+ rbit r0, r0
+ ittt ne
+ clzne r0, r0
+ addne r2, r2, #1
+ addne r0, r0, r2
+ bx lr
+END (ffsll)
--
1.8.1.2
next prev parent reply other threads:[~2013-03-01 17:36 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-01 17:36 [PATCH v2 00/14] ARM improvements Richard Henderson
2013-03-01 17:36 ` [PATCH v2 10/14] arm: Implement hard-tp for GET_TLS Richard Henderson
2013-03-01 17:55 ` Roland McGrath
2013-03-05 2:01 ` Joseph S. Myers
2013-03-01 17:36 ` [PATCH v2 08/14] arm: Unless arm4t, pop return address directly into pc Richard Henderson
2013-03-01 17:36 ` [PATCH v2 05/14] arm: Use push/pop mnemonics Richard Henderson
2013-03-01 17:36 ` [PATCH v2 09/14] arm: Tidy architecture selection Richard Henderson
2013-03-01 17:55 ` Roland McGrath
2013-03-05 2:01 ` Joseph S. Myers
2013-03-01 17:36 ` [PATCH v2 14/14] arm: Add optimized add_n and sub_n Richard Henderson
2013-03-01 17:59 ` Roland McGrath
2013-03-06 0:53 ` Joseph S. Myers
2013-03-01 17:36 ` [PATCH v2 06/14] arm: Delete LOADREGS macro Richard Henderson
2013-03-01 17:36 ` Richard Henderson [this message]
2013-03-05 2:08 ` [PATCH v2 11/14] arm: Add optimized ffs for armv6t2 Joseph S. Myers
2013-03-06 15:52 ` Richard Henderson
2013-03-01 17:36 ` [PATCH v2 13/14] arm: Add optimized submul_1 Richard Henderson
2013-03-01 17:58 ` Roland McGrath
2013-03-06 1:14 ` Joseph S. Myers
2013-03-01 17:36 ` [PATCH v2 02/14] arm: Introduce and use NEGOFF series of macros Richard Henderson
2013-03-01 17:57 ` Roland McGrath
2013-03-05 1:42 ` Joseph S. Myers
2013-03-01 17:36 ` [PATCH v2 12/14] arm: Add optimized addmul_1 Richard Henderson
2013-03-01 17:58 ` Roland McGrath
2013-03-01 18:00 ` Roland McGrath
2013-03-06 1:18 ` Joseph S. Myers
2013-10-25 22:13 ` Roland McGrath
2013-03-06 1:11 ` Joseph S. Myers
2013-03-01 17:36 ` [PATCH v2 07/14] arm: Commonize BX conditionals Richard Henderson
2013-03-01 17:36 ` [PATCH v2 03/14] arm: Introduce and use GET_TLS Richard Henderson
2013-03-01 17:57 ` Roland McGrath
2013-03-05 1:45 ` Joseph S. Myers
2013-03-01 17:36 ` [PATCH v2 01/14] arm: Introduce and use LDST_PCREL Richard Henderson
2013-03-04 17:47 ` Joseph S. Myers
2013-03-01 17:36 ` [PATCH v2 04/14] arm: Enable thumb2 mode in assembly files Richard Henderson
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