[v2,3/5] riscv: vectorized str* functions

diff --git a/sysdeps/riscv/rvv/strcat.S b/sysdeps/riscv/rvv/strcat.S
new file mode 100644
index 0000000000..8a7779fd3c
--- /dev/null
+++ b/sysdeps/riscv/rvv/strcat.S
@@ -0,0 +1,72 @@ 
+/* RVV versions strcat.  RISC-V version.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jerry Shih <jerry.shih@sifive.com>.
+
+   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 pDst a0
+#define pSrc a1
+#define pDstPtr a2
+
+#define iVL a3
+#define iCurrentVL a4
+#define iActiveElemPos a5
+
+#define ELEM_LMUL_SETTING m1
+#define vMask1 v0
+#define vMask2 v1
+#define vStr1 v8
+#define vStr2 v16
+
+ENTRY(strcat)
+
+    mv pDstPtr, pDst
+
+    /* Perform `strlen(dst)`.  */
+L(strlen_loop):
+    vsetvli iVL, zero, e8, ELEM_LMUL_SETTING, ta, ma
+
+    vle8ff.v vStr1, (pDstPtr)
+    vmseq.vx vMask1, vStr1, zero
+    csrr iCurrentVL, vl
+    vfirst.m iActiveElemPos, vMask1
+    add pDstPtr, pDstPtr, iCurrentVL
+    bltz iActiveElemPos, L(strlen_loop)
+
+    sub pDstPtr, pDstPtr, iCurrentVL
+    add pDstPtr, pDstPtr, iActiveElemPos
+
+    /* Perform `strcpy(dst, src)`.  */
+L(strcpy_loop):
+    vsetvli iVL, zero, e8, ELEM_LMUL_SETTING, ta, ma
+
+    vle8ff.v vStr1, (pSrc)
+    vmseq.vx vMask2, vStr1, zero
+    csrr iCurrentVL, vl
+    vfirst.m iActiveElemPos, vMask2
+    vmsif.m vMask1, vMask2
+    add pSrc, pSrc, iCurrentVL
+    vse8.v vStr1, (pDstPtr), vMask1.t
+    add pDstPtr, pDstPtr, iCurrentVL
+    bltz iActiveElemPos, 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..c5f525bbe9
--- /dev/null
+++ b/sysdeps/riscv/rvv/strcmp.S
@@ -0,0 +1,93 @@ 
+// Copyright (c) 2023 SiFive, Inc. -- Proprietary and Confidential All Rights
+// Reserved.
+//
+// NOTICE: All information contained herein is, and remains the property of
+// SiFive, Inc. The intellectual and technical concepts contained herein are
+// proprietary to SiFive, Inc. and may be covered by U.S. and Foreign Patents,
+// patents in process, and are protected by trade secret or copyright law.
+//
+// This work may not be copied, modified, re-published, uploaded, executed, or
+// distributed in any way, in any medium, whether in whole or in part, without
+// prior written permission from SiFive, Inc.
+//
+// The copyright notice above does not evidence any actual or intended
+// publication or disclosure of this source code, which includes information
+// that is confidential and/or proprietary, and is a trade secret, of SiFive,
+// Inc.
+//===----------------------------------------------------------------------===//
+
+// Contributed by: Jerry Shih <jerry.shih@sifive.com>
+
+// Prototype:
+// int strcmp(const char *lhs, const char *rhs)
+
+#include <sysdep.h>
+#include <sys/asm.h>
+
+#define iResult a0
+
+#define pStr1 a0
+#define pStr2 a1
+
+#define iVL a2
+#define iTemp1 a3
+#define iTemp2 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, (pStr1)
+    // check if vStr1[i] == 0
+    vmseq.vx vMask1, vStr1, zero
+
+    vle8ff.v vStr2, (pStr2)
+    // check if vStr1[i] != vStr2[i]
+    vmsne.vv vMask2, vStr1, vStr2
+
+    // find the index x for vStr1[x]==0
+    vfirst.m iTemp1, vMask1
+    // find the index x for vStr1[x]!=vStr2[x]
+    vfirst.m iTemp2, vMask2
+
+    bgez iTemp1, L(check1)
+    bgez iTemp2, L(check2)
+
+    // get the current vl updated by vle8ff.
+    csrr iVL, vl
+    add pStr1, pStr1, iVL
+    add pStr2, pStr2, iVL
+    j L(Loop)
+
+    // iTemp1>=0
+L(check1):
+    bltz iTemp2, 1f
+    blt iTemp2, iTemp1, L(check2)
+1:
+    // iTemp2<0
+    // iTemp2>=0 && iTemp1<iTemp2
+    add pStr1, pStr1, iTemp1
+    add pStr2, pStr2, iTemp1
+    lbu iTemp1, 0(pStr1)
+    lbu iTemp2, 0(pStr2)
+    sub iResult, iTemp1, iTemp2
+    ret
+
+    // iTemp1<0
+    // iTemp2>=0
+L(check2):
+    add pStr1, pStr1, iTemp2
+    add pStr2, pStr2, iTemp2
+    lbu iTemp1, 0(pStr1)
+    lbu iTemp2, 0(pStr2)
+    sub iResult, iTemp1, iTemp2
+    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..8fb754ee23
--- /dev/null
+++ b/sysdeps/riscv/rvv/strcpy.S
@@ -0,0 +1,56 @@ 
+/* RVV versions strcpy.  RISC-V version.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jerry Shih <jerry.shih@sifive.com>.
+
+   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 pDst a0
+#define pSrc a1
+#define pDstPtr a2
+
+#define iVL a3
+#define iCurrentVL a4
+#define iActiveElemPos a5
+
+#define ELEM_LMUL_SETTING m1
+#define vMask1 v0
+#define vMask2 v1
+#define vStr1 v8
+#define vStr2 v16
+
+ENTRY(strcpy)
+
+    mv pDstPtr, pDst
+
+L(strcpy_loop):
+    vsetvli iVL, zero, e8, ELEM_LMUL_SETTING, ta, ma
+    vle8ff.v vStr1, (pSrc)
+    vmseq.vx vMask2, vStr1, zero
+    csrr iCurrentVL, vl
+    vfirst.m iActiveElemPos, vMask2
+    vmsif.m vMask1, vMask2
+    add pSrc, pSrc, iCurrentVL
+    vse8.v vStr1, (pDstPtr), vMask1.t
+    add pDstPtr, pDstPtr, iCurrentVL
+    bltz iActiveElemPos, 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..eb456b094b
--- /dev/null
+++ b/sysdeps/riscv/rvv/strlen.S
@@ -0,0 +1,54 @@ 
+/* RVV versions strlen.  RISC-V version.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jerry Shih <jerry.shih@sifive.com>.
+
+   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 iResult a0
+#define pStr a0
+#define pCopyStr a1
+#define iVL a2
+#define iCurrentVL a2
+#define iEndOffset a3
+
+#define ELEM_LMUL_SETTING m2
+#define vStr v0
+#define vMaskEnd v2
+
+ENTRY(strlen)
+
+    mv pCopyStr, pStr
+L(loop):
+    vsetvli iVL, zero, e8, ELEM_LMUL_SETTING, ta, ma
+    vle8ff.v vStr, (pCopyStr)
+    csrr iCurrentVL, vl
+    vmseq.vi vMaskEnd, vStr, 0
+    vfirst.m iEndOffset, vMaskEnd
+    add pCopyStr, pCopyStr, iCurrentVL
+    bltz iEndOffset, L(loop)
+
+    add pStr, pStr, iCurrentVL
+    add pCopyStr, pCopyStr, iEndOffset
+    sub iResult, pCopyStr, iResult
+
+    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..7847c4f008
--- /dev/null
+++ b/sysdeps/riscv/rvv/strncat.S
@@ -0,0 +1,83 @@ 
+/* RVV versions strncat.  RISC-V version.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jerry Shih <jerry.shih@sifive.com>.
+
+   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 pDst a0
+#define pSrc a1
+#define iLength a2
+#define pDstPtr a3
+
+#define iVL a4
+#define iCurrentVL a5
+#define iActiveElemPos a6
+
+#define ELEM_LMUL_SETTING m1
+#define vMask1 v0
+#define vMask2 v1
+#define vStr1 v8
+#define vStr2 v16
+
+ENTRY(strncat)
+
+    mv pDstPtr, pDst
+
+    /* the strlen of dst.  */
+L(strlen_loop):
+    vsetvli iVL, zero, e8, ELEM_LMUL_SETTING, ta, ma
+
+    vle8ff.v vStr1, (pDstPtr)
+    /* find the '\0'.  */
+    vmseq.vx vMask1, vStr1, zero
+    csrr iCurrentVL, vl
+    vfirst.m iActiveElemPos, vMask1
+    add pDstPtr, pDstPtr, iCurrentVL
+    bltz iActiveElemPos, L(strlen_loop)
+
+    sub pDstPtr, pDstPtr, iCurrentVL
+    add pDstPtr, pDstPtr, iActiveElemPos
+
+    /* copy pSrc to pDstPtr.  */
+L(strcpy_loop):
+    vsetvli zero, iLength, e8, ELEM_LMUL_SETTING, ta, ma
+
+    vle8ff.v vStr1, (pSrc)
+    vmseq.vx vMask2, vStr1, zero
+    csrr iCurrentVL, vl
+    vfirst.m iActiveElemPos, vMask2
+    vmsif.m vMask1, vMask2
+    add pSrc, pSrc, iCurrentVL
+    sub iLength, iLength, iCurrentVL
+    vse8.v vStr1, (pDstPtr), vMask1.t
+    add pDstPtr, pDstPtr, iCurrentVL
+    beqz iLength, L(fill_zero)
+    bltz iActiveElemPos, L(strcpy_loop)
+
+    ret
+
+L(fill_zero):
+    bgez iActiveElemPos, L(fill_zero_end)
+    sb zero, (pDstPtr)
+
+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..168dbb07ce
--- /dev/null
+++ b/sysdeps/riscv/rvv/strncmp.S
@@ -0,0 +1,85 @@ 
+/* RVV versions strncmp.  RISC-V version.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jerry Shih <jerry.shih@sifive.com>.
+
+   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 iResult a0
+
+#define pStr1 a0
+#define pStr2 a1
+#define iLength a2
+
+#define iVL a3
+#define iTemp1 a4
+#define iTemp2 a5
+
+#define ELEM_LMUL_SETTING m1
+#define vStr1 v0
+#define vStr2 v4
+#define vMask1 v8
+#define vMask2 v9
+
+ENTRY(strncmp)
+
+    beqz iLength, L(zero_length)
+
+L(loop):
+    vsetvli zero, iLength, e8, ELEM_LMUL_SETTING, ta, ma
+
+    vle8ff.v vStr1, (pStr1)
+    /* vStr1[i] == 0.  */
+    vmseq.vx vMask1, vStr1, zero
+
+    vle8ff.v vStr2, (pStr2)
+    /* 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 iLength, iLength, iVL
+
+    vfirst.m iTemp1, vMask1
+
+    bgez iTemp1, L(end_loop)
+
+    add pStr1, pStr1, iVL
+    add pStr2, pStr2, iVL
+    bnez iLength, L(loop)
+L(end_loop):
+
+    add pStr1, pStr1, iTemp1
+    add pStr2, pStr2, iTemp1
+    lbu iTemp1, 0(pStr1)
+    lbu iTemp2, 0(pStr2)
+
+    sub iResult, iTemp1, iTemp2
+    ret
+
+L(zero_length):
+    li iResult, 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..e8d9450448
--- /dev/null
+++ b/sysdeps/riscv/rvv/strncpy.S
@@ -0,0 +1,86 @@ 
+/* RVV versions strncpy.  RISC-V version.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jerry Shih <jerry.shih@sifive.com>.
+
+   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 pDst a0
+#define pSrc a1
+#define iLength a2
+#define pDstPtr a3
+
+#define iVL a4
+#define iCurrentVL a5
+#define iActiveElemPos a6
+#define iTemp 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 pDstPtr, pDst
+
+    /* Copy pSrc to pDstPtr.  */
+L(strcpy_loop):
+    vsetvli zero, iLength, e8, ELEM_LMUL_SETTING, ta, ma
+    vle8ff.v vStr1, (pSrc)
+    vmseq.vx vMask2, vStr1, zero
+    csrr iCurrentVL, vl
+    vfirst.m iActiveElemPos, vMask2
+    vmsif.m vMask1, vMask2
+    add pSrc, pSrc, iCurrentVL
+    sub iLength, iLength, iCurrentVL
+    vse8.v vStr1, (pDstPtr), vMask1.t
+    add pDstPtr, pDstPtr, iCurrentVL
+    bgez iActiveElemPos, L(fill_zero)
+    bnez iLength, 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 iLength for zero filling.  */
+    sub iTemp, iCurrentVL, iActiveElemPos
+    addi iTemp, iTemp, -1
+    add iLength, iLength, iTemp
+    /* Have an earily return for `strlen(src) + 1 == count` case.  */
+    bnez iLength, 1f
+    ret
+1:
+    sub pDstPtr, pDstPtr, iTemp
+    vsetvli zero, iLength, e8, ZERO_FILL_ELEM_LMUL_SETTING, ta, ma
+    vmv.v.x vStr2, zero
+
+L(fill_zero_loop):
+    vsetvli iVL, iLength, e8, ZERO_FILL_ELEM_LMUL_SETTING, ta, ma
+    vse8.v vStr2, (pDstPtr)
+    sub iLength, iLength, iVL
+    add pDstPtr, pDstPtr, iVL
+    bnez iLength, L(fill_zero_loop)
+
+    ret
+
+END(strncpy)
+libc_hidden_builtin_def (strncpy)