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>

3 files changed, 2 insertions, 96 deletions

diff --git a/sysdeps/i386/ffs.c b/sysdeps/i386/ffs.c
deleted file mode 100644
index 587d80d..0000000
--- a/sysdeps/i386/ffs.c
+++ /dev/null
@@ -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
diff --git a/sysdeps/i386/i686/ffs.c b/sysdeps/i386/i686/ffs.c
deleted file mode 100644
index 6712730..0000000
--- a/sysdeps/i386/i686/ffs.c
+++ /dev/null
@@ -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
diff --git a/sysdeps/i386/math-use-builtins-ffs.h b/sysdeps/i386/math-use-builtins-ffs.h
new file mode 100644
index 0000000..c0f108c
--- /dev/null
+++ b/sysdeps/i386/math-use-builtins-ffs.h
@@ -0,0 +1,2 @@
+#define USE_FFS_BUILTIN   1
+#define USE_FFSLL_BUILTIN 0