string: Use builtins for ffs and ffsll

It allows to remove a lot of arch-specific implementations.

Checked on x86_64, aarch64, powerpc64.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This commit is contained in:
Adhemerval Zanella Netto 2023-08-25 13:30:58 -03:00 committed by Adhemerval Zanella
parent 26d01172f5
commit ae4b8d6a0e
28 changed files with 48 additions and 651 deletions

View File

@ -18,13 +18,16 @@
#include <limits.h>
#define ffsl __something_else
#include <string.h>
#undef ffs
#include <math-use-builtins.h>
/* Find the first bit set in I. */
int
__ffs (int i)
{
#if USE_FFS_BUILTIN
return __builtin_ffs (i);
#else
static const unsigned char table[] =
{
0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
@ -42,6 +45,7 @@ __ffs (int i)
a = x <= 0xffff ? (x <= 0xff ? 0 : 8) : (x <= 0xffffff ? 16 : 24);
return table[x >> a] + a;
#endif
}
weak_alias (__ffs, ffs)
libc_hidden_def (__ffs)

View File

@ -18,20 +18,26 @@
#include <limits.h>
#define ffsl __something_else
#include <string.h>
#undef ffsll
#include <math-use-builtins.h>
#include <libc-diag.h>
/* Find the first bit set in I. */
int
ffsll (long long int i)
__ffsll (long long int i)
{
#if USE_FFSLL_BUILTIN
return __builtin_ffsll (i);
#else
unsigned long long int x = i & -i;
if (x <= 0xffffffff)
return ffs (i);
else
return 32 + ffs (i >> 32);
#endif
}
weak_alias (__ffsll, ffsll)
#if ULONG_MAX != UINT_MAX
#undef ffsl

View File

@ -0,0 +1,2 @@
#define USE_FFS_BUILTIN 1
#define USE_FFSLL_BUILTIN 1

View File

@ -1,51 +0,0 @@
/* Copyright (C) 2000-2024 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
<https://www.gnu.org/licenses/>. */
/* Finds the first bit set in an integer. */
#include <sysdep.h>
.arch ev6
.set noreorder
.set noat
ENTRY(__ffs)
#ifdef PROF
ldgp gp, 0(pv)
lda AT, _mcount
jsr AT, (AT), _mcount
.prologue 1
#else
.prologue 0
#endif
zap $16, 0xF0, $16
cttz $16, $0
addq $0, 1, $0
cmoveq $16, 0, $0
nop
nop
nop
ret
END(__ffs)
weak_alias (__ffs, ffs)
libc_hidden_def (__ffs)
libc_hidden_builtin_def (ffs)

View File

@ -1,44 +0,0 @@
/* Copyright (C) 2000-2024 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
<https://www.gnu.org/licenses/>. */
/* Finds the first bit set in a long. */
#include <sysdep.h>
.arch ev6
.set noreorder
.set noat
ENTRY(ffsl)
#ifdef PROF
ldgp gp, 0(pv)
lda AT, _mcount
jsr AT, (AT), _mcount
.prologue 1
#else
.prologue 0
#endif
cttz $16, $0
addq $0, 1, $0
cmoveq $16, 0, $0
ret
END(ffsl)
weak_extern (ffsl)
weak_alias (ffsl, ffsll)

View File

@ -1,90 +0,0 @@
/* Copyright (C) 1996-2024 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
<https://www.gnu.org/licenses/>. */
/* Finds the first bit set in an integer. Optimized for the Alpha
architecture. */
#include <sysdep.h>
.set noreorder
.set noat
ENTRY(__ffs)
#ifdef PROF
ldgp gp, 0(pv)
lda AT, _mcount
jsr AT, (AT), _mcount
.prologue 1
zap $16, 0xF0, $16
br $ffsl..ng
#else
.prologue 0
zap $16, 0xF0, $16
# FALLTHRU
#endif
END(__ffs)
.align 4
ENTRY(ffsl)
#ifdef PROF
ldgp gp, 0(pv)
lda AT, _mcount
jsr AT, (AT), _mcount
.prologue 1
$ffsl..ng:
#else
.prologue 0
#endif
not $16, $1 # e0 :
ldi $2, -1 # .. e1 :
cmpbge $1, $2, $3 # e0 : bit N == 1 for byte N == 0
clr $0 # .. e1 :
addq $3, 1, $4 # e0 :
bic $4, $3, $3 # e1 : bit N == 1 for first byte N != 0
and $3, 0xF0, $4 # e0 :
and $3, 0xCC, $5 # .. e1 :
and $3, 0xAA, $6 # e0 :
cmovne $4, 4, $0 # .. e1 :
cmovne $5, 2, $5 # e0 :
cmovne $6, 1, $6 # .. e1 :
addl $0, $5, $0 # e0 :
addl $0, $6, $0 # e1 : $0 == N
extbl $16, $0, $1 # e0 : $1 == byte N
ldi $2, 1 # .. e1 :
negq $1, $3 # e0 :
and $3, $1, $3 # e1 : bit N == least bit set of byte N
and $3, 0xF0, $4 # e0 :
and $3, 0xCC, $5 # .. e1 :
and $3, 0xAA, $6 # e0 :
cmovne $4, 5, $2 # .. e1 :
cmovne $5, 2, $5 # e0 :
cmovne $6, 1, $6 # .. e1 :
s8addl $0, $2, $0 # e0 : mult byte ofs by 8 and sum
addl $5, $6, $5 # .. e1 :
addl $0, $5, $0 # e0 :
nop # .. e1 :
cmoveq $16, 0, $0 # e0 : trap input == 0 case.
ret # .. e1 : 18
END(ffsl)
weak_alias (__ffs, ffs)
libc_hidden_def (__ffs)
libc_hidden_builtin_def (ffs)
weak_extern (ffsl)
weak_alias (ffsl, ffsll)

View File

@ -1 +0,0 @@
/* This function is defined in ffs.S. */

View File

@ -0,0 +1,7 @@
#ifdef __alpha_cix__
# define USE_FFS_BUILTIN 1
# define USE_FFSLL_BUILTIN 1
#else
# define USE_FFS_BUILTIN 0
# define USE_FFSLL_BUILTIN 0
#endif

View File

@ -0,0 +1,2 @@
#define USE_FFS_BUILTIN 1
#define USE_FFSLL_BUILTIN 0

View File

@ -1,36 +0,0 @@
/* ffs -- find first set bit in an int, from least significant end.
Copyright (C) 2013-2024 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
<https://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_def (__ffs)
libc_hidden_builtin_def (ffs)

View File

@ -1,50 +0,0 @@
/* ffsll -- find first set bit in a long long, from least significant end.
Copyright (C) 2013-2024 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
<https://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)

View File

@ -0,0 +1,2 @@
#define USE_FFS_BUILTIN 1
#define USE_FFSLL_BUILTIN 0

View File

@ -0,0 +1,2 @@
#define USE_FFS_BUILTIN 0
#define USE_FFSLL_BUILTIN 0

View File

@ -40,5 +40,6 @@
#include <math-use-builtins-lrint.h>
#include <math-use-builtins-llrint.h>
#include <math-use-builtins-logb.h>
#include <math-use-builtins-ffs.h>
#endif /* MATH_USE_BUILTINS_H */

View File

@ -1,49 +0,0 @@
/* ffs -- find first set bit in a word, counted from least significant end.
For Intel 80x86, x>=3.
This file is part of the GNU C Library.
Copyright (C) 1991-2024 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
#define ffsl __something_else
#include <string.h>
#undef ffs
#ifdef __GNUC__
int
__ffs (int x)
{
int cnt;
int tmp;
asm ("xorl %0,%0\n" /* Set CNT to zero. */
"bsfl %2,%1\n" /* Count low bits in X and store in %1. */
"jz 1f\n" /* Jump if OK, i.e. X was non-zero. */
"leal 1(%1),%0\n" /* Return bsfl-result plus one on %0. */
"1:" : "=&a" (cnt), "=r" (tmp) : "rm" (x));
return cnt;
}
weak_alias (__ffs, ffs)
libc_hidden_def (__ffs)
libc_hidden_builtin_def (ffs)
#undef ffsl
weak_alias (__ffs, ffsl)
#else
#include <string/ffs.c>
#endif

View File

@ -1,47 +0,0 @@
/* ffs -- find first set bit in a word, counted from least significant end.
For Intel 80x86, x>=6.
This file is part of the GNU C Library.
Copyright (C) 1991-2024 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
#define ffsl __something_else
#include <string.h>
#undef ffs
#ifdef __GNUC__
int
__ffs (int x)
{
int cnt;
int tmp;
asm ("bsfl %2,%0\n" /* Count low bits in X and store in %1. */
"cmovel %1,%0\n" /* If number was zero, use -1 as result. */
: "=&r" (cnt), "=r" (tmp) : "rm" (x), "1" (-1));
return cnt + 1;
}
weak_alias (__ffs, ffs)
libc_hidden_def (__ffs)
libc_hidden_builtin_def (ffs)
#undef ffsl
weak_alias (__ffs, ffsl)
#else
#include <string/ffs.c>
#endif

View File

@ -0,0 +1,2 @@
#define USE_FFS_BUILTIN 1
#define USE_FFSLL_BUILTIN 0

View File

@ -0,0 +1,2 @@
#define USE_FFS_BUILTIN 1
#define USE_FFSLL_BUILTIN 1

View File

@ -1,46 +0,0 @@
/* ffs -- find first set bit in a word, counted from least significant end.
For mc68020, mc68030, mc68040.
This file is part of the GNU C Library.
Copyright (C) 1991-2024 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
#define ffsl __something_else
#include <string.h>
#undef ffs
#if defined (__GNUC__) && defined (__mc68020__)
int
__ffs (int x)
{
int cnt;
asm ("bfffo %1{#0:#0},%0" : "=d" (cnt) : "dm" (x & -x));
return 32 - cnt;
}
weak_alias (__ffs, ffs)
libc_hidden_def (__ffs)
libc_hidden_builtin_def (ffs)
#undef ffsl
weak_alias (__ffs, ffsl)
#else
#include <string/ffs.c>
#endif

View File

@ -0,0 +1,7 @@
#if defined __mc68020__ || defined __mc68030__ || defined __mc68040__ \
|| defined __mc68060__
# define USE_FFS_BUILTIN 1
#else
# define USE_FFS_BUILTIN 0
#endif
#define USE_FFSLL_BUILTIN 0

View File

@ -1,46 +0,0 @@
/* Find first set bit in a word, counted from least significant end.
For PowerPC.
Copyright (C) 1991-2024 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
<https://www.gnu.org/licenses/>. */
#define ffsl __something_else
#include <limits.h>
#include <string.h>
#undef ffs
#ifdef __GNUC__
int
__ffs (int x)
{
int cnt;
asm ("cntlzw %0,%1" : "=r" (cnt) : "r" (x & -x));
return 32 - cnt;
}
weak_alias (__ffs, ffs)
libc_hidden_def (__ffs)
libc_hidden_builtin_def (ffs)
#if ULONG_MAX == UINT_MAX
#undef ffsl
weak_alias (__ffs, ffsl)
#endif
#else
#include <string/ffs.c>
#endif

View File

@ -0,0 +1,6 @@
#define USE_FFS_BUILTIN 1
#ifdef __powerpc64__
# define USE_FFSLL_BUILTIN 1
#else
# define USE_FFSLL_BUILTIN 0
#endif

View File

@ -1,36 +0,0 @@
/* Find first set bit in a word, counted from least significant end.
For PowerPC.
Copyright (C) 1991-2024 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
<https://www.gnu.org/licenses/>. */
#define ffsl __something_else
#include <limits.h>
#include <string.h>
#undef ffs
int
__ffsll (long long int x)
{
int cnt;
asm ("cntlzd %0,%1" : "=r" (cnt) : "r" (x & -x));
return 64 - cnt;
}
weak_alias (__ffsll, ffsll)
#undef ffsl
weak_alias (__ffsll, ffsl)

View File

@ -1,69 +0,0 @@
/* ffs -- find first set bit in a word, counted from least significant end.
S/390 version.
Copyright (C) 2000-2024 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
<https://www.gnu.org/licenses/>. */
#include <limits.h>
#define ffsl __something_else
#include <string.h>
#undef ffs
/* ffs: find first bit set. This is defined the same way as
the libc and compiler builtin ffs routines, therefore
differs in spirit from the above ffz (man ffs). */
int
__ffs (int x)
{
int r;
if (x == 0)
return 0;
__asm__(" lr %%r1,%1\n"
" sr %0,%0\n"
" tml %%r1,0xFFFF\n"
" jnz 0f\n"
" ahi %0,16\n"
" srl %%r1,16\n"
"0: tml %%r1,0x00FF\n"
" jnz 1f\n"
" ahi %0,8\n"
" srl %%r1,8\n"
"1: tml %%r1,0x000F\n"
" jnz 2f\n"
" ahi %0,4\n"
" srl %%r1,4\n"
"2: tml %%r1,0x0003\n"
" jnz 3f\n"
" ahi %0,2\n"
" srl %%r1,2\n"
"3: tml %%r1,0x0001\n"
" jnz 4f\n"
" ahi %0,1\n"
"4:"
: "=&d" (r) : "d" (x) : "cc", "1" );
return r+1;
}
weak_alias (__ffs, ffs)
libc_hidden_def (__ffs)
libc_hidden_builtin_def (ffs)
#if ULONG_MAX == UINT_MAX
#undef ffsl
weak_alias (__ffs, ffsl)
#endif

View File

@ -1,38 +0,0 @@
/* ffs -- find first set bit in a word, counted from least significant end.
For AMD x86-64.
This file is part of the GNU C Library.
Copyright (C) 1991-2024 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
#include <string.h>
#undef ffs
int
__ffs (int x)
{
int cnt;
int tmp;
asm ("bsfl %2,%0\n" /* Count low bits in X and store in %1. */
"cmovel %1,%0\n" /* If number was zero, use -1 as result. */
: "=&r" (cnt), "=r" (tmp) : "rm" (x), "1" (-1));
return cnt + 1;
}
weak_alias (__ffs, ffs)
libc_hidden_def (__ffs)
libc_hidden_builtin_def (ffs)

View File

@ -1,41 +0,0 @@
/* ffsll -- find first set bit in a word, counted from least significant end.
For AMD x86-64.
This file is part of the GNU C Library.
Copyright (C) 1991-2024 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
#define ffsl __something_else
#include <string.h>
#undef ffsll
int
ffsll (long long int x)
{
long long int cnt;
asm ("mov $-1,%k0\n" /* Initialize cnt to -1. */
"bsf %1,%0\n" /* Count low bits in x and store in cnt. */
"inc %k0\n" /* Increment cnt by 1. */
: "=&r" (cnt) : "r" (x));
return cnt;
}
#ifndef __ILP32__
#undef ffsl
weak_alias (ffsll, ffsl)
#endif

View File

@ -0,0 +1,2 @@
#define USE_FFS_BUILTIN 1
#define USE_FFSLL_BUILTIN 1

View File

@ -1,4 +0,0 @@
#define ffsl __something_else
#include <sysdeps/x86_64/ffs.c>
#undef ffsl
weak_alias (__ffs, ffsl)