Loongarch: Add ifunc support and add different versions of strlen

strlen-lasx is implemeted by LASX simd instructions(256bit)
strlen-lsx is implemeted by LSX simd instructions(128bit)
strlen-align is implemented by LA basic instructions and never use unaligned memory acess

7 files changed, 359 insertions, 0 deletions

diff --git a/sysdeps/loongarch/lp64/multiarch/Makefile b/sysdeps/loongarch/lp64/multiarch/Makefile
new file mode 100644
index 0000000000..76c506c966
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/Makefile
@@ -0,0 +1,7 @@
+ifeq ($(subdir),string)
+sysdep_routines += \
+  strlen-aligned \
+  strlen-lsx \
+  strlen-lasx \
+# sysdep_routines
+endif
diff --git a/sysdeps/loongarch/lp64/multiarch/ifunc-impl-list.c b/sysdeps/loongarch/lp64/multiarch/ifunc-impl-list.c
new file mode 100644
index 0000000000..1a2a576fcd
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/ifunc-impl-list.c
@@ -0,0 +1,41 @@
+/* Enumerate available IFUNC implementations of a function LoongArch64 version.
+   Copyright (C) 2023 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 <assert.h>
+#include <string.h>
+#include <wchar.h>
+#include <ldsodefs.h>
+#include <ifunc-impl-list.h>
+#include <stdio.h>
+
+size_t
+__libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
+			size_t max)
+{
+
+  size_t i = max;
+
+  IFUNC_IMPL (i, name, strlen,
+#if !defined __loongarch_soft_float
+	      IFUNC_IMPL_ADD (array, i, strlen, SUPPORT_LASX, __strlen_lasx)
+	      IFUNC_IMPL_ADD (array, i, strlen, SUPPORT_LSX, __strlen_lsx)
+#endif
+	      IFUNC_IMPL_ADD (array, i, strlen, 1, __strlen_aligned)
+	      )
+  return i;
+}
diff --git a/sysdeps/loongarch/lp64/multiarch/ifunc-strlen.h b/sysdeps/loongarch/lp64/multiarch/ifunc-strlen.h
new file mode 100644
index 0000000000..6258bb76c3
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/ifunc-strlen.h
@@ -0,0 +1,40 @@
+/* Common definition for strlen ifunc selections.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 2023 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 <ldsodefs.h>
+#include <ifunc-init.h>
+
+#if !defined __loongarch_soft_float
+extern __typeof (REDIRECT_NAME) OPTIMIZE (lasx) attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (lsx) attribute_hidden;
+#endif
+extern __typeof (REDIRECT_NAME) OPTIMIZE (aligned) attribute_hidden;
+
+static inline void *
+IFUNC_SELECTOR (void)
+{
+#if !defined __loongarch_soft_float
+  if (SUPPORT_LASX)
+    return OPTIMIZE (lasx);
+  else if (SUPPORT_LSX)
+    return OPTIMIZE (lsx);
+  else
+#endif
+    return OPTIMIZE (aligned);
+}
diff --git a/sysdeps/loongarch/lp64/multiarch/strlen-aligned.S b/sysdeps/loongarch/lp64/multiarch/strlen-aligned.S
new file mode 100644
index 0000000000..e9e1d2fc04
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strlen-aligned.S
@@ -0,0 +1,100 @@
+/* Optimized strlen implementation using basic Loongarch instructions.
+   Copyright (C) 2023 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>
+#include <sys/regdef.h>
+#include <sys/asm.h>
+
+#if IS_IN (libc)
+# define STRLEN __strlen_aligned
+#else
+# define STRLEN strlen
+#endif
+
+LEAF(STRLEN, 6)
+    move        a1, a0
+    bstrins.d   a0, zero, 2, 0
+    lu12i.w     a2, 0x01010
+    li.w        t0, -1
+
+    ld.d        t2, a0, 0
+    andi        t1, a1, 0x7
+    ori         a2, a2, 0x101
+    slli.d      t1, t1, 3
+
+    bstrins.d   a2, a2, 63, 32
+    sll.d       t1, t0, t1
+    slli.d      t3, a2, 7
+    nor         a3, zero, t3
+
+    orn         t2, t2, t1
+    sub.d       t0, t2, a2
+    nor         t1, t2, a3
+    and         t0, t0, t1
+
+
+    bnez        t0, L(count_pos)
+    addi.d      a0, a0, 8
+L(loop_16_7bit):
+    ld.d        t2, a0, 0
+    sub.d       t1, t2, a2
+
+    and         t0, t1, t3
+    bnez        t0, L(more_check)
+    ld.d        t2, a0, 8
+    sub.d       t1, t2, a2
+
+    and         t0, t1, t3
+    addi.d      a0, a0, 16
+    beqz        t0, L(loop_16_7bit)
+    addi.d      a0, a0, -8
+
+L(more_check):
+    nor         t0, t2, a3
+    and         t0, t1, t0
+    bnez        t0, L(count_pos)
+    addi.d      a0, a0, 8
+
+
+L(loop_16_8bit):
+    ld.d        t2, a0, 0
+    sub.d       t1, t2, a2
+    nor         t0, t2, a3
+    and         t0, t0, t1
+
+    bnez        t0, L(count_pos)
+    ld.d        t2, a0, 8
+    addi.d      a0, a0, 16
+    sub.d       t1, t2, a2
+
+    nor         t0, t2, a3
+    and         t0, t0, t1
+    beqz        t0, L(loop_16_8bit)
+    addi.d      a0, a0, -8
+
+L(count_pos):
+    ctz.d       t1, t0
+    sub.d       a0, a0, a1
+    srli.d      t1, t1, 3
+    add.d       a0, a0, t1
+
+    jr          ra
+END(STRLEN)
+
+libc_hidden_builtin_def (STRLEN)
diff --git a/sysdeps/loongarch/lp64/multiarch/strlen-lasx.S b/sysdeps/loongarch/lp64/multiarch/strlen-lasx.S
new file mode 100644
index 0000000000..258c47cea0
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strlen-lasx.S
@@ -0,0 +1,63 @@
+/* Optimized strlen implementation using loongarch LASX SIMD instructions.
+   Copyright (C) 2023 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>
+#include <sys/regdef.h>
+#include <sys/asm.h>
+
+#if IS_IN (libc) && !defined __loongarch_soft_float
+
+# define STRLEN __strlen_lasx
+
+LEAF(STRLEN, 6)
+    move            a1, a0
+    bstrins.d       a0, zero, 4, 0
+    li.d            t1, -1
+    xvld            xr0, a0, 0
+
+    xvmsknz.b       xr0, xr0
+    xvpickve.w      xr1, xr0, 4
+    vilvl.h         vr0, vr1, vr0
+    movfr2gr.s      t0, fa0  # sign extend
+
+    sra.w           t0, t0, a1
+    beq             t0, t1, L(loop)
+    cto.w           a0, t0
+    jr              ra
+
+L(loop):
+    xvld            xr0, a0, 32
+    addi.d          a0, a0, 32
+    xvsetanyeqz.b   fcc0, xr0
+    bceqz           fcc0, L(loop)
+
+
+    xvmsknz.b       xr0, xr0
+    sub.d           a0, a0, a1
+    xvpickve.w      xr1, xr0, 4
+    vilvl.h         vr0, vr1, vr0
+
+    movfr2gr.s      t0, fa0
+    cto.w           t0, t0
+    add.d           a0, a0, t0
+    jr              ra
+END(STRLEN)
+
+libc_hidden_builtin_def (STRLEN)
+#endif
diff --git a/sysdeps/loongarch/lp64/multiarch/strlen-lsx.S b/sysdeps/loongarch/lp64/multiarch/strlen-lsx.S
new file mode 100644
index 0000000000..b194355e7b
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strlen-lsx.S
@@ -0,0 +1,71 @@
+/* Optimized strlen implementation using Loongarch LSX SIMD instructions.
+   Copyright (C) 2023 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>
+#include <sys/regdef.h>
+#include <sys/asm.h>
+
+#if IS_IN (libc) && !defined __loongarch_soft_float
+
+# define STRLEN __strlen_lsx
+
+LEAF(STRLEN, 6)
+    move            a1, a0
+    bstrins.d       a0, zero, 4, 0
+    vld             vr0, a0, 0
+    vld             vr1, a0, 16
+
+    li.d            t1, -1
+    vmsknz.b        vr0, vr0
+    vmsknz.b        vr1, vr1
+    vilvl.h         vr0, vr1, vr0
+
+    movfr2gr.s      t0, fa0
+    sra.w           t0, t0, a1
+    beq             t0, t1, L(loop)
+    cto.w           a0, t0
+
+    jr              ra
+    nop
+    nop
+    nop
+
+
+L(loop):
+    vld             vr0, a0, 32
+    vld             vr1, a0, 48
+    addi.d          a0, a0, 32
+    vmin.bu         vr2, vr0, vr1
+
+    vsetanyeqz.b    fcc0, vr2
+    bceqz           fcc0, L(loop)
+    vmsknz.b        vr0, vr0
+    vmsknz.b        vr1, vr1
+
+    vilvl.h         vr0, vr1, vr0
+    sub.d           a0, a0, a1
+    movfr2gr.s      t0, fa0
+    cto.w           t0, t0
+
+    add.d           a0, a0, t0
+    jr              ra
+END(STRLEN)
+
+libc_hidden_builtin_def (STRLEN)
+#endif
diff --git a/sysdeps/loongarch/lp64/multiarch/strlen.c b/sysdeps/loongarch/lp64/multiarch/strlen.c
new file mode 100644
index 0000000000..381c2daa86
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strlen.c
@@ -0,0 +1,37 @@
+/* Multiple versions of strlen.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 2023 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 multiple versions only for the definition in libc.  */
+
+#if IS_IN (libc)
+# define strlen __redirect_strlen
+# include <string.h>
+# undef strlen
+
+# define SYMBOL_NAME strlen
+# include "ifunc-strlen.h"
+
+libc_ifunc_redirected (__redirect_strlen, strlen, IFUNC_SELECTOR ());
+
+# ifdef SHARED
+__hidden_ver1 (strlen, __GI_strlen, __redirect_strlen)
+  __attribute__ ((visibility ("hidden"))) __attribute_copy__ (strlen);
+# endif
+
+#endif