When building with Zbb enabled, strchrnul benefits from using orc.b in
find_zero_all(). This patch changes the build system such, that a
non-Zbb version as well as a Zbb version of this routine is built.
Further, a ifunc resolver is provided that selects the right routine
based on the outcome of extension probing via hwprobe().
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
---
sysdeps/riscv/multiarch/strchrnul-generic.c | 26 ++++++++
sysdeps/riscv/multiarch/strchrnul-zbb.c | 30 +++++++++
.../unix/sysv/linux/riscv/multiarch/Makefile | 3 +
.../linux/riscv/multiarch/ifunc-impl-list.c | 4 ++
.../sysv/linux/riscv/multiarch/strchrnul.c | 61 +++++++++++++++++++
5 files changed, 124 insertions(+)
create mode 100644 sysdeps/riscv/multiarch/strchrnul-generic.c
create mode 100644 sysdeps/riscv/multiarch/strchrnul-zbb.c
create mode 100644 sysdeps/unix/sysv/linux/riscv/multiarch/strchrnul.c
new file mode 100644
@@ -0,0 +1,26 @@
+/* Re-include the default strchrnul implementation.
+ Copyright (C) 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 <string.h>
+
+#if IS_IN(libc)
+# define STRCHRNUL __strchrnul_generic
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(x)
+#endif
+#include <string/strchrnul.c>
new file mode 100644
@@ -0,0 +1,30 @@
+/* Re-include the default strchrnul implementation for Zbb.
+ Copyright (C) 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 <string.h>
+
+#if IS_IN(libc)
+# define STRCHRNUL __strchrnul_zbb
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(x)
+#endif
+/* Convince preprocessor to have Zbb instructions. */
+#ifndef __riscv_zbb
+# define __riscv_zbb
+#endif
+#include <string/strchrnul.c>
@@ -9,6 +9,9 @@ sysdep_routines += \
memrchr \
memrchr-generic \
memrchr-zbb \
+ strchrnul \
+ strchrnul-generic \
+ strchrnul-zbb \
# sysdep_routines
CFLAGS-memcpy_noalignment.c += -mno-strict-align
@@ -64,5 +64,9 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL_ADD (array, i, memrchr, has_zbb, __memrchr_zbb)
IFUNC_IMPL_ADD (array, i, memrchr, 1, __memrchr_generic))
+ IFUNC_IMPL (i, name, strchrnul,
+ IFUNC_IMPL_ADD (array, i, strchrnul, has_zbb, __strchrnul_zbb)
+ IFUNC_IMPL_ADD (array, i, strchrnul, 1, __strchrnul_generic))
+
return 0;
}
new file mode 100644
@@ -0,0 +1,61 @@
+/* Multiple versions of strchrnul.
+ All versions must be listed in ifunc-impl-list.c.
+ Copyright (C) 2017-2024 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/>. */
+
+#if IS_IN (libc)
+/* Redefine strchrnul so that the compiler won't complain about the type
+ mismatch with the IFUNC selector in strong_alias, below. */
+# undef strchrnul
+# undef __strchrnul
+# define strchrnul __redirect_strchrnul
+# define __strchrnul __redirect_strchrnul
+# include <stdint.h>
+# include <string.h>
+# include <ifunc-init.h>
+# include <riscv-ifunc.h>
+# include <sys/hwprobe.h>
+
+extern __typeof (__redirect_strchrnul) __libc_strchrnul;
+
+extern __typeof (__redirect_strchrnul) __strchrnul_generic attribute_hidden;
+extern __typeof (__redirect_strchrnul) __strchrnul_zbb attribute_hidden;
+
+static inline __typeof (__redirect_strchrnul) *
+select_strchrnul_ifunc (uint64_t dl_hwcap, __riscv_hwprobe_t hwprobe_func)
+{
+ unsigned long long int v;
+ if (__riscv_hwprobe_one (hwprobe_func, RISCV_HWPROBE_KEY_IMA_EXT_0, &v) == 0
+ && (v & RISCV_HWPROBE_EXT_ZBB))
+ return __strchrnul_zbb;
+
+ return __strchrnul_generic;
+}
+
+riscv_libc_ifunc (__libc_strchrnul, select_strchrnul_ifunc);
+
+# undef strchrnul
+# undef __strchrnul
+strong_alias (__libc_strchrnul, __strchrnul);
+weak_alias (__strchrnul, strchrnul)
+# ifdef SHARED
+__hidden_ver1 (strchrnul, __GI___strchrnul, __redirect_strchrnul)
+ __attribute__ ((visibility ("hidden"))) __attribute_copy__ (strchrnul);
+# endif
+#else
+# include <string/strchrnul.c>
+#endif