LoongArch: Add ifunc support for strnlen{aligned, lsx, lasx}

Based on the glibc microbenchmark, strnlen-aligned implementation could
reduce the runtime more than 10%, strnlen-lsx implementation could reduce
the runtime about 50%-78%, strnlen-lasx implementation could reduce the
runtime about 50%-88%.

7 files changed, 382 insertions, 0 deletions

diff --git a/sysdeps/loongarch/lp64/multiarch/Makefile b/sysdeps/loongarch/lp64/multiarch/Makefile
index afa5104..c4dd314 100644
--- a/sysdeps/loongarch/lp64/multiarch/Makefile
+++ b/sysdeps/loongarch/lp64/multiarch/Makefile
@@ -3,6 +3,9 @@ sysdep_routines += \
   strlen-aligned \
   strlen-lsx \
   strlen-lasx \
+  strnlen-aligned \
+  strnlen-lsx \
+  strnlen-lasx \
   strchr-aligned \
   strchr-lsx \
   strchr-lasx \
diff --git a/sysdeps/loongarch/lp64/multiarch/ifunc-impl-list.c b/sysdeps/loongarch/lp64/multiarch/ifunc-impl-list.c
index 25eb96b..7cec0b7 100644
--- a/sysdeps/loongarch/lp64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/loongarch/lp64/multiarch/ifunc-impl-list.c
@@ -38,6 +38,14 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 	      IFUNC_IMPL_ADD (array, i, strlen, 1, __strlen_aligned)
 	      )
 
+  IFUNC_IMPL (i, name, strnlen,
+#if !defined __loongarch_soft_float
+	      IFUNC_IMPL_ADD (array, i, strnlen, SUPPORT_LASX, __strnlen_lasx)
+	      IFUNC_IMPL_ADD (array, i, strnlen, SUPPORT_LSX, __strnlen_lsx)
+#endif
+	      IFUNC_IMPL_ADD (array, i, strnlen, 1, __strnlen_aligned)
+	      )
+
   IFUNC_IMPL (i, name, strchr,
 #if !defined __loongarch_soft_float
 	      IFUNC_IMPL_ADD (array, i, strchr, SUPPORT_LASX, __strchr_lasx)
diff --git a/sysdeps/loongarch/lp64/multiarch/ifunc-strnlen.h b/sysdeps/loongarch/lp64/multiarch/ifunc-strnlen.h
new file mode 100644
index 0000000..5cf8981
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/ifunc-strnlen.h
@@ -0,0 +1,41 @@
+/* Common definition for strnlen 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/strnlen-aligned.S b/sysdeps/loongarch/lp64/multiarch/strnlen-aligned.S
new file mode 100644
index 0000000..b900430
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strnlen-aligned.S
@@ -0,0 +1,102 @@
+/* Optimized strnlen 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 STRNLEN __strnlen_aligned
+#else
+# define STRNLEN __strnlen
+#endif
+
+LEAF(STRNLEN, 6)
+    beqz        a1, L(out)
+    lu12i.w     a2, 0x01010
+    andi        t1, a0, 0x7
+    move        t4, a0
+
+    bstrins.d   a0, zero, 2, 0
+    ori         a2, a2, 0x101
+    li.w        t0, -1
+    ld.d        t2, a0, 0
+
+    slli.d      t3, t1, 3
+    bstrins.d   a2, a2, 63, 32
+    li.w        t5, 8
+    slli.d      a3, a2, 7
+
+    sub.w       t1, t5, t1
+    sll.d       t0, t0, t3
+    orn         t2, t2, t0
+    sub.d       t0, t2, a2
+
+
+    andn        t3, a3, t2
+    and         t0, t0, t3
+    bnez        t0, L(count_pos)
+    sub.d       t5, a1, t1
+
+    bgeu        t1, a1, L(out)
+    addi.d      a0, a0, 8
+L(loop):
+    ld.d        t2, a0, 0
+    sub.d       t0, t2, a2
+
+    andn        t1, a3, t2
+    sltui       t6, t5, 9
+    and         t0, t0, t1
+    or          t7, t0, t6
+
+    bnez        t7, L(count_pos)
+    ld.d        t2, a0, 8
+    addi.d      a0, a0, 16
+    sub.d       t0, t2, a2
+
+
+    andn        t1, a3, t2
+    sltui       t6, t5, 17
+    and         t0, t0, t1
+    addi.d      t5, t5, -16
+
+    or          t7, t0, t6
+    beqz        t7, L(loop)
+    addi.d      a0, a0, -8
+L(count_pos):
+    ctz.d       t1, t0
+
+    sub.d       a0, a0, t4
+    srli.d      t1, t1, 3
+    add.d       a0, t1, a0
+    sltu        t0, a0, a1
+
+    masknez     t1, a1, t0
+    maskeqz     a0, a0, t0
+    or          a0, a0, t1
+    jr          ra
+
+
+L(out):
+    move        a0, a1
+    jr          ra
+END(STRNLEN)
+
+weak_alias (STRNLEN, strnlen)
+libc_hidden_builtin_def (STRNLEN)
diff --git a/sysdeps/loongarch/lp64/multiarch/strnlen-lasx.S b/sysdeps/loongarch/lp64/multiarch/strnlen-lasx.S
new file mode 100644
index 0000000..2c03d3d
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strnlen-lasx.S
@@ -0,0 +1,100 @@
+/* Optimized strnlen implementation using loongarch LASX 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 STRNLEN __strnlen_lasx
+
+LEAF(STRNLEN, 6)
+    beqz            a1, L(ret0)
+    andi            t1, a0, 0x3f
+    li.d            t3, 65
+    sub.d           a2, a0, t1
+
+    xvld            xr0, a2, 0
+    xvld            xr1, a2, 32
+    sub.d           t1, t3, t1
+    move            a3, a0
+
+    sltu            t1, a1, t1
+    xvmsknz.b       xr0, xr0
+    xvmsknz.b       xr1, xr1
+    xvpickve.w      xr2, xr0, 4
+
+    xvpickve.w      xr3, xr1, 4
+    vilvl.h         vr0, vr2, vr0
+    vilvl.h         vr1, vr3, vr1
+    vilvl.w         vr0, vr1, vr0
+
+
+    movfr2gr.d      t0, fa0
+    sra.d           t0, t0, a0
+    orn             t1, t1, t0
+    bnez            t1, L(end)
+
+    add.d           a4, a0, a1
+    move            a0, a2
+    addi.d          a4, a4, -1
+    bstrins.d       a4, zero, 5, 0
+
+L(loop):
+    xvld            xr0, a0, 64
+    xvld            xr1, a0, 96
+    addi.d          a0, a0, 64
+    beq             a0, a4, L(out)
+
+    xvmin.bu        xr2, xr0, xr1
+    xvsetanyeqz.b   fcc0, xr2
+    bceqz           fcc0, L(loop)
+L(out):
+    xvmsknz.b       xr0, xr0
+
+
+    xvmsknz.b       xr1, xr1
+    xvpickve.w      xr2, xr0, 4
+    xvpickve.w      xr3, xr1, 4
+    vilvl.h         vr0, vr2, vr0
+
+    vilvl.h         vr1, vr3, vr1
+    vilvl.w         vr0, vr1, vr0
+    movfr2gr.d      t0, fa0
+L(end):
+    sub.d           a0, a0, a3
+
+    cto.d           t0, t0
+    add.d           a0, a0, t0
+    sltu            t1, a0, a1
+    masknez         t0, a1, t1
+
+    maskeqz         t1, a0, t1
+    or              a0, t0, t1
+    jr              ra
+L(ret0):
+    move            a0, zero
+
+
+    jr              ra
+END(STRNLEN)
+
+libc_hidden_def (STRNLEN)
+#endif
diff --git a/sysdeps/loongarch/lp64/multiarch/strnlen-lsx.S b/sysdeps/loongarch/lp64/multiarch/strnlen-lsx.S
new file mode 100644
index 0000000..b769a89
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strnlen-lsx.S
@@ -0,0 +1,89 @@
+/* Optimized strnlen implementation using loongarch LSX 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 STRNLEN __strnlen_lsx
+
+LEAF(STRNLEN, 6)
+    beqz            a1, L(ret0)
+    andi            t1, a0, 0x1f
+    li.d            t3, 33
+    sub.d           a2, a0, t1
+
+    vld             vr0, a2, 0
+    vld             vr1, a2, 16
+    sub.d           t1, t3, t1
+    move            a3, a0
+
+    sltu            t1, a1, t1
+    vmsknz.b        vr0, vr0
+    vmsknz.b        vr1, vr1
+    vilvl.h         vr0, vr1, vr0
+
+    movfr2gr.s      t0, fa0
+    sra.w           t0, t0, a0
+    orn             t1, t1, t0
+    bnez            t1, L(end)
+
+
+    add.d           a4, a0, a1
+    move            a0, a2
+    addi.d          a4, a4, -1
+    bstrins.d       a4, zero, 4, 0
+
+L(loop):
+    vld             vr0, a0, 32
+    vld             vr1, a0, 48
+    addi.d          a0, a0, 32
+    beq             a0, a4, L(out)
+
+    vmin.bu         vr2, vr0, vr1
+    vsetanyeqz.b    fcc0, vr2
+    bceqz           fcc0, L(loop)
+L(out):
+    vmsknz.b        vr0, vr0
+
+    vmsknz.b        vr1, vr1
+    vilvl.h         vr0, vr1, vr0
+    movfr2gr.s      t0, fa0
+L(end):
+    sub.d           a0, a0, a3
+
+
+    cto.w           t0, t0
+    add.d           a0, a0, t0
+    sltu            t1, a0, a1
+    masknez         t0, a1, t1
+
+    maskeqz         t1, a0, t1
+    or              a0, t0, t1
+    jr              ra
+L(ret0):
+    move            a0, zero
+
+    jr              ra
+END(STRNLEN)
+
+libc_hidden_builtin_def (STRNLEN)
+#endif
diff --git a/sysdeps/loongarch/lp64/multiarch/strnlen.c b/sysdeps/loongarch/lp64/multiarch/strnlen.c
new file mode 100644
index 0000000..38b7a25
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strnlen.c
@@ -0,0 +1,39 @@
+/* Multiple versions of strnlen.
+   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 strnlen __redirect_strnlen
+# define __strnlen __redirect___strnlen
+# include <string.h>
+# undef __strnlen
+# undef strnlen
+
+# define SYMBOL_NAME strnlen
+# include "ifunc-strnlen.h"
+
+libc_ifunc_redirected (__redirect_strnlen, __strnlen, IFUNC_SELECTOR ());
+weak_alias (__strnlen, strnlen);
+# ifdef SHARED
+__hidden_ver1 (__strnlen, __GI___strnlen, __redirect___strnlen)
+  __attribute__((visibility ("hidden"))) __attribute_copy__ (strnlen);
+__hidden_ver1 (strnlen, __GI_strnlen, __redirect_strnlen)
+  __attribute__((weak, visibility ("hidden"))) __attribute_copy__ (strnlen);
+# endif
+#endif