[v3,3/5] riscv: vectorized str* functions

diff --git a/sysdeps/riscv/rvv/strcat.S b/sysdeps/riscv/rvv/strcat.S
new file mode 100644
index 0000000000..fb5858fa82
--- /dev/null
+++ b/sysdeps/riscv/rvv/strcat.S
@@ -0,0 +1,71 @@ 
+/* RVV versions strcat.  RISC-V 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 <sysdep.h>
+#include <sys/asm.h>
+
+#define dst a0
+#define src a1
+#define dst_ptr a2
+
+#define ivl a3
+#define cur_vl a4
+#define active_elem_pos a5
+
+#define ELEM_LMUL_SETTING m1
+#define vmask1 v0
+#define vmask2 v1
+#define vstr1 v8
+#define vstr2 v16
+
+ENTRY(strcat)
+
+    mv dst_ptr, dst
+
+    /* Perform `strlen(dst)`.  */
+L(strlen_loop):
+    vsetvli ivl, zero, e8, ELEM_LMUL_SETTING, ta, ma
+
+    vle8ff.v vstr1, (dst_ptr)
+    vmseq.vx vmask1, vstr1, zero
+    csrr cur_vl, vl
+    vfirst.m active_elem_pos, vmask1
+    add dst_ptr, dst_ptr, cur_vl
+    bltz active_elem_pos, L(strlen_loop)
+
+    sub dst_ptr, dst_ptr, cur_vl
+    add dst_ptr, dst_ptr, active_elem_pos
+
+    /* Perform `strcpy(dst, src)`.  */
+L(strcpy_loop):
+    vsetvli ivl, zero, e8, ELEM_LMUL_SETTING, ta, ma
+
+    vle8ff.v vstr1, (src)
+    vmseq.vx vmask2, vstr1, zero
+    csrr cur_vl, vl
+    vfirst.m active_elem_pos, vmask2
+    vmsif.m vmask1, vmask2
+    add src, src, cur_vl
+    vse8.v vstr1, (dst_ptr), vmask1.t
+    add dst_ptr, dst_ptr, cur_vl
+    bltz active_elem_pos, L(strcpy_loop)
+
+    ret
+
+END(strcat)
+libc_hidden_builtin_def (strcat)
diff --git a/sysdeps/riscv/rvv/strcmp.S b/sysdeps/riscv/rvv/strcmp.S
new file mode 100644
index 0000000000..2e60d76dc8
--- /dev/null
+++ b/sysdeps/riscv/rvv/strcmp.S
@@ -0,0 +1,88 @@ 
+/* RVV versions strcmp.  RISC-V 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 <sysdep.h>
+#include <sys/asm.h>
+
+#define result a0
+
+#define str1 a0
+#define str2 a1
+
+#define ivl a2
+#define temp1 a3
+#define temp2 a4
+
+#define vstr1 v0
+#define vstr2 v8
+#define vmask1 v16
+#define vmask2 v17
+
+ENTRY(strcmp)
+    /* lmul=1 */
+
+L(Loop):
+    vsetvli ivl, zero, e8, m1, ta, ma
+    vle8ff.v vstr1, (str1)
+    /* check if vstr1[i] == 0 */
+    vmseq.vx vmask1, vstr1, zero
+
+    vle8ff.v vstr2, (str2)
+    /* check if vstr1[i] != vstr2[i] */
+    vmsne.vv vmask2, vstr1, vstr2
+
+    /* find the index x for vstr1[x]==0 */
+    vfirst.m temp1, vmask1
+    /* find the index x for vstr1[x]!=vstr2[x] */
+    vfirst.m temp2, vmask2
+
+    bgez temp1, L(check1)
+    bgez temp2, L(check2)
+
+    /* get the current vl updated by vle8ff. */
+    csrr ivl, vl
+    add str1, str1, ivl
+    add str2, str2, ivl
+    j L(Loop)
+
+    /* temp1>=0 */
+L(check1):
+    bltz temp2, 1f
+    blt temp2, temp1, L(check2)
+1:
+    /* temp2<0 */
+    /* temp2>=0 && temp1<temp2 */
+    add str1, str1, temp1
+    add str2, str2, temp1
+    lbu temp1, 0(str1)
+    lbu temp2, 0(str2)
+    sub result, temp1, temp2
+    ret
+
+    /* temp1<0 */
+    /* temp2>=0 */
+L(check2):
+    add str1, str1, temp2
+    add str2, str2, temp2
+    lbu temp1, 0(str1)
+    lbu temp2, 0(str2)
+    sub result, temp1, temp2
+    ret
+
+END(strcmp)
+libc_hidden_builtin_def (strcmp)
diff --git a/sysdeps/riscv/rvv/strcpy.S b/sysdeps/riscv/rvv/strcpy.S
new file mode 100644
index 0000000000..1ad433f5f3
--- /dev/null
+++ b/sysdeps/riscv/rvv/strcpy.S
@@ -0,0 +1,55 @@ 
+/* RVV versions strcpy.  RISC-V 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 <sysdep.h>
+#include <sys/asm.h>
+
+#define dst a0
+#define src a1
+#define dst_ptr a2
+
+#define ivl a3
+#define cur_vl a4
+#define active_elem_pos a5
+
+#define ELEM_LMUL_SETTING m1
+#define vmask1 v0
+#define vmask2 v1
+#define vstr1 v8
+#define vstr2 v16
+
+ENTRY(strcpy)
+
+    mv dst_ptr, dst
+
+L(strcpy_loop):
+    vsetvli ivl, zero, e8, ELEM_LMUL_SETTING, ta, ma
+    vle8ff.v vstr1, (src)
+    vmseq.vx vmask2, vstr1, zero
+    csrr cur_vl, vl
+    vfirst.m active_elem_pos, vmask2
+    vmsif.m vmask1, vmask2
+    add src, src, cur_vl
+    vse8.v vstr1, (dst_ptr), vmask1.t
+    add dst_ptr, dst_ptr, cur_vl
+    bltz active_elem_pos, L(strcpy_loop)
+
+    ret
+
+END(strcpy)
+libc_hidden_builtin_def (strcpy)
diff --git a/sysdeps/riscv/rvv/strlen.S b/sysdeps/riscv/rvv/strlen.S
new file mode 100644
index 0000000000..cf3698f52a
--- /dev/null
+++ b/sysdeps/riscv/rvv/strlen.S
@@ -0,0 +1,53 @@ 
+/* RVV versions strlen.  RISC-V 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 <sysdep.h>
+#include <sys/asm.h>
+
+#define result a0
+#define str a0
+#define copy_str a1
+#define ivl a2
+#define cur_vl a2
+#define end_offset a3
+
+#define ELEM_LMUL_SETTING m2
+#define vstr v0
+#define vmask_end v2
+
+ENTRY(strlen)
+
+    mv copy_str, str
+L(loop):
+    vsetvli ivl, zero, e8, ELEM_LMUL_SETTING, ta, ma
+    vle8ff.v vstr, (copy_str)
+    csrr cur_vl, vl
+    vmseq.vi vmask_end, vstr, 0
+    vfirst.m end_offset, vmask_end
+    add copy_str, copy_str, cur_vl
+    bltz end_offset, L(loop)
+
+    add str, str, cur_vl
+    add copy_str, copy_str, end_offset
+    sub result, copy_str, result
+
+    ret
+
+END(strlen)
+
+libc_hidden_builtin_def (strlen)
diff --git a/sysdeps/riscv/rvv/strncat.S b/sysdeps/riscv/rvv/strncat.S
new file mode 100644
index 0000000000..d30a6533a3
--- /dev/null
+++ b/sysdeps/riscv/rvv/strncat.S
@@ -0,0 +1,82 @@ 
+/* RVV versions strncat.  RISC-V 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 <sysdep.h>
+#include <sys/asm.h>
+
+#define dst a0
+#define src a1
+#define length a2
+#define dst_ptr a3
+
+#define ivl a4
+#define cur_vl a5
+#define activate_elem_pos a6
+
+#define ELEM_LMUL_SETTING m1
+#define vmask1 v0
+#define vmask2 v1
+#define vstr1 v8
+#define vstr2 v16
+
+ENTRY(strncat)
+
+    mv dst_ptr, dst
+
+    /* the strlen of dst.  */
+L(strlen_loop):
+    vsetvli ivl, zero, e8, ELEM_LMUL_SETTING, ta, ma
+
+    vle8ff.v vstr1, (dst_ptr)
+    /* find the '\0'.  */
+    vmseq.vx vmask1, vstr1, zero
+    csrr cur_vl, vl
+    vfirst.m activate_elem_pos, vmask1
+    add dst_ptr, dst_ptr, cur_vl
+    bltz activate_elem_pos, L(strlen_loop)
+
+    sub dst_ptr, dst_ptr, cur_vl
+    add dst_ptr, dst_ptr, activate_elem_pos
+
+    /* copy src to dst_ptr.  */
+L(strcpy_loop):
+    vsetvli zero, length, e8, ELEM_LMUL_SETTING, ta, ma
+
+    vle8ff.v vstr1, (src)
+    vmseq.vx vmask2, vstr1, zero
+    csrr cur_vl, vl
+    vfirst.m activate_elem_pos, vmask2
+    vmsif.m vmask1, vmask2
+    add src, src, cur_vl
+    sub length, length, cur_vl
+    vse8.v vstr1, (dst_ptr), vmask1.t
+    add dst_ptr, dst_ptr, cur_vl
+    beqz length, L(fill_zero)
+    bltz activate_elem_pos, L(strcpy_loop)
+
+    ret
+
+L(fill_zero):
+    bgez activate_elem_pos, L(fill_zero_end)
+    sb zero, (dst_ptr)
+
+L(fill_zero_end):
+    ret
+
+END(strncat)
+libc_hidden_builtin_def (strncat)
diff --git a/sysdeps/riscv/rvv/strncmp.S b/sysdeps/riscv/rvv/strncmp.S
new file mode 100644
index 0000000000..2b6ab1f233
--- /dev/null
+++ b/sysdeps/riscv/rvv/strncmp.S
@@ -0,0 +1,84 @@ 
+/* RVV versions strncmp.  RISC-V 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 <sysdep.h>
+#include <sys/asm.h>
+
+#define result a0
+
+#define str1 a0
+#define str2 a1
+#define length a2
+
+#define ivl a3
+#define temp1 a4
+#define temp2 a5
+
+#define ELEM_LMUL_SETTING m1
+#define vstr1 v0
+#define vstr2 v4
+#define vmask1 v8
+#define vmask2 v9
+
+ENTRY(strncmp)
+
+    beqz length, L(zero_length)
+
+L(loop):
+    vsetvli zero, length, e8, ELEM_LMUL_SETTING, ta, ma
+
+    vle8ff.v vstr1, (str1)
+    /* vstr1[i] == 0.  */
+    vmseq.vx vmask1, vstr1, zero
+
+    vle8ff.v vstr2, (str2)
+    /* vstr1[i] != vstr2[i].  */
+    vmsne.vv vmask2, vstr1, vstr2
+
+    csrr ivl, vl
+
+    /* r = mask1 | mask2
+       We could use vfirst.m to get the first zero char or the
+       first different char between str1 and str2.  */
+    vmor.mm vmask1, vmask1, vmask2
+
+    sub length, length, ivl
+
+    vfirst.m temp1, vmask1
+
+    bgez temp1, L(end_loop)
+
+    add str1, str1, ivl
+    add str2, str2, ivl
+    bnez length, L(loop)
+L(end_loop):
+
+    add str1, str1, temp1
+    add str2, str2, temp1
+    lbu temp1, 0(str1)
+    lbu temp2, 0(str2)
+
+    sub result, temp1, temp2
+    ret
+
+L(zero_length):
+    li result, 0
+    ret
+
+END(strncmp)
+libc_hidden_builtin_def (strncmp)
diff --git a/sysdeps/riscv/rvv/strncpy.S b/sysdeps/riscv/rvv/strncpy.S
new file mode 100644
index 0000000000..53fb8cdec7
--- /dev/null
+++ b/sysdeps/riscv/rvv/strncpy.S
@@ -0,0 +1,85 @@ 
+/* RVV versions strncpy.  RISC-V 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 <sysdep.h>
+#include <sys/asm.h>
+
+#define dst a0
+#define src a1
+#define length a2
+#define dst_ptr a3
+
+#define ivl a4
+#define cur_vl a5
+#define active_elem_pos a6
+#define temp a7
+
+#define ELEM_LMUL_SETTING m1
+#define vmask1 v0
+#define vmask2 v1
+#define ZERO_FILL_ELEM_LMUL_SETTING m8
+#define vstr1 v8
+#define vstr2 v16
+
+ENTRY(strncpy)
+
+    mv dst_ptr, dst
+
+    /* Copy src to dst_ptr.  */
+L(strcpy_loop):
+    vsetvli zero, length, e8, ELEM_LMUL_SETTING, ta, ma
+    vle8ff.v vstr1, (src)
+    vmseq.vx vmask2, vstr1, zero
+    csrr cur_vl, vl
+    vfirst.m active_elem_pos, vmask2
+    vmsif.m vmask1, vmask2
+    add src, src, cur_vl
+    sub length, length, cur_vl
+    vse8.v vstr1, (dst_ptr), vmask1.t
+    add dst_ptr, dst_ptr, cur_vl
+    bgez active_elem_pos, L(fill_zero)
+    bnez length, L(strcpy_loop)
+    ret
+
+    /* Fill the tail zero.  */
+L(fill_zero):
+    /* We already copy the `\0` to dst. But we use `vfirst.m` to
+       get the `index` of `\0` position. We need to adjust `-1`
+       to get the correct remaining length for zero filling.  */
+    sub temp, cur_vl, active_elem_pos
+    addi temp, temp, -1
+    add length, length, temp
+    /* Have an earily return for `strlen(src) + 1 == count` case.  */
+    bnez length, 1f
+    ret
+1:
+    sub dst_ptr, dst_ptr, temp
+    vsetvli zero, length, e8, ZERO_FILL_ELEM_LMUL_SETTING, ta, ma
+    vmv.v.x vstr2, zero
+
+L(fill_zero_loop):
+    vsetvli ivl, length, e8, ZERO_FILL_ELEM_LMUL_SETTING, ta, ma
+    vse8.v vstr2, (dst_ptr)
+    sub length, length, ivl
+    add dst_ptr, dst_ptr, ivl
+    bnez length, L(fill_zero_loop)
+
+    ret
+
+END(strncpy)
+libc_hidden_builtin_def (strncpy)