From 5695fc848fb3cd25fb528dada44f8bbdd113c04a Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 13 Feb 2013 12:06:42 -0800 Subject: arm: Add optimized ffs for armv6t2 --- ports/ChangeLog.arm | 3 +++ ports/sysdeps/arm/armv6t2/ffs.S | 35 +++++++++++++++++++++++++++ ports/sysdeps/arm/armv6t2/ffsll.S | 50 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 88 insertions(+) create mode 100644 ports/sysdeps/arm/armv6t2/ffs.S create mode 100644 ports/sysdeps/arm/armv6t2/ffsll.S (limited to 'ports') diff --git a/ports/ChangeLog.arm b/ports/ChangeLog.arm index 288dfb4c09..55e63fa368 100644 --- a/ports/ChangeLog.arm +++ b/ports/ChangeLog.arm @@ -1,5 +1,8 @@ 2013-03-06 Richard Henderson + * sysdeps/arm/armv6t2/ffs.S: New file. + * sysdeps/arm/armv6t2/ffsll.S: New file. + * sysdeps/arm/sysdep.h (ARCH_HAS_HARD_TP): New macro. (GET_TLS): Use hard-tp if ARCH_HAS_HARD_TP. * sysdeps/unix/sysv/linux/arm/aeabi_read_tp.S: Likewise. diff --git a/ports/sysdeps/arm/armv6t2/ffs.S b/ports/sysdeps/arm/armv6t2/ffs.S new file mode 100644 index 0000000000..b2c88b9460 --- /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 + . */ + +#include + + .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 0000000000..e49c70fdf1 --- /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 + . */ + +#include + + .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) -- cgit 1.4.1