S390: Optimize utf8-utf16 module.
authorStefan Liebler <stli@linux.vnet.ibm.com>
Wed, 25 May 2016 15:18:05 +0000 (17:18 +0200)
committerStefan Liebler <stli@linux.vnet.ibm.com>
Wed, 25 May 2016 15:18:05 +0000 (17:18 +0200)
This patch reworks the s390 specific module to convert between utf8 and utf16.
Now ifunc is used to choose either the c or etf3eh (with convert utf instruction)
variants at runtime. Furthermore a new vector variant for z13 is introduced
which will be build and chosen if vector support is available at build / runtime.

In case of converting utf 8 to utf16, the vector variant optimizes input of
1byte utf8 characters. The convert utf instruction is used if a multibyte utf8
character is found.

For the other direction utf16 to utf8, the cu21 instruction can't be re-enabled,
because it does not report an error, if the input-stream consists of a single
low surrogate utf16 char (e.g. 0xdc00). This applies to the newest z13, too.
Thus there is only the c or the new vector variant, which can handle 1..4 byte
utf8 characters.

The c variant from utf16 to utf8 has beed fixed. If a high surrogate was at the
end of the input-buffer, then errno was set to EINVAL and the input-pointer
pointed just after the high surrogate. Now it points to the beginning of the
high surrogate.

This patch also fixes some whitespace errors. The c variant from utf8 to utf16
is now checking that tail-bytes starts with 0b10... and the value is not in
range of an utf16 surrogate.

Furthermore, the etf3eh variants are handling the "UTF-xx//IGNORE" case now.
Before they ignored the ignore-case and always stopped at an error.

ChangeLog:

* sysdeps/s390/s390-64/utf8-utf16-z9.c: Use ifunc to select c,
etf3eh or new vector loop-variant.

ChangeLog
sysdeps/s390/s390-64/utf8-utf16-z9.c

index 42e37fd..c201dd1 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2016-05-25  Stefan Liebler  <stli@linux.vnet.ibm.com>
 
+       * sysdeps/s390/s390-64/utf8-utf16-z9.c: Use ifunc to select c,
+       etf3eh or new vector loop-variant.
+
+2016-05-25  Stefan Liebler  <stli@linux.vnet.ibm.com>
+
        * sysdeps/s390/s390-64/utf8-utf32-z9.c: Use ifunc to select c, etf3eh
        or new vector loop-variant.
 
index 4148ed7..7520ef2 100644 (file)
 #include <dl-procinfo.h>
 #include <gconv.h>
 
-/* UTF-16 big endian byte order mark.  */
-#define BOM_UTF16      0xfeff
+#if defined HAVE_S390_VX_GCC_SUPPORT
+# define ASM_CLOBBER_VR(NR) , NR
+#else
+# define ASM_CLOBBER_VR(NR)
+#endif
 
+/* Defines for skeleton.c.  */
 #define DEFINE_INIT            0
 #define DEFINE_FINI            0
 #define MIN_NEEDED_FROM                1
 #define MAX_NEEDED_FROM                4
 #define MIN_NEEDED_TO          2
 #define MAX_NEEDED_TO          4
-#define FROM_LOOP              from_utf8_loop
-#define TO_LOOP                        to_utf8_loop
+#define FROM_LOOP              __from_utf8_loop
+#define TO_LOOP                        __to_utf8_loop
 #define FROM_DIRECTION         (dir == from_utf8)
 #define ONE_DIRECTION           0
-#define PREPARE_LOOP                                                   \
-  enum direction dir = ((struct utf8_data *) step->__data)->dir;       \
-  int emit_bom = ((struct utf8_data *) step->__data)->emit_bom;                \
-                                                                       \
-  if (emit_bom && !data->__internal_use                                        \
-      && data->__invocation_counter == 0)                              \
-    {                                                                  \
-      /* Emit the UTF-16 Byte Order Mark.  */                          \
-      if (__glibc_unlikely (outbuf + 2 > outend))                            \
-       return __GCONV_FULL_OUTPUT;                                     \
-                                                                       \
-      put16u (outbuf, BOM_UTF16);                                      \
-      outbuf += 2;                                                     \
-    }
+
+
+/* UTF-16 big endian byte order mark.  */
+#define BOM_UTF16      0xfeff
 
 /* Direction of the transformation.  */
 enum direction
@@ -151,16 +145,16 @@ gconv_end (struct __gconv_step *data)
     register unsigned long long outlen __asm__("11") = outend - outptr;        \
     uint64_t cc = 0;                                                   \
                                                                        \
-    __asm__ volatile (".machine push       \n\t"                       \
-                     ".machine \"z9-109\" \n\t"                        \
-                     "0: " INSTRUCTION "  \n\t"                        \
-                     ".machine pop        \n\t"                        \
-                     "   jo     0b        \n\t"                        \
-                     "   ipm    %2        \n"                          \
-                     : "+a" (pOutput), "+a" (pInput), "+d" (cc),       \
-                       "+d" (outlen), "+d" (inlen)                     \
-                     :                                                 \
-                     : "cc", "memory");                                \
+    __asm__ __volatile__ (".machine push       \n\t"                   \
+                         ".machine \"z9-109\" \n\t"                    \
+                         "0: " INSTRUCTION "  \n\t"                    \
+                         ".machine pop        \n\t"                    \
+                         "   jo     0b        \n\t"                    \
+                         "   ipm    %2        \n"                      \
+                         : "+a" (pOutput), "+a" (pInput), "+d" (cc),   \
+                           "+d" (outlen), "+d" (inlen)                 \
+                         :                                             \
+                         : "cc", "memory");                            \
                                                                        \
     inptr = pInput;                                                    \
     outptr = pOutput;                                                  \
@@ -169,50 +163,135 @@ gconv_end (struct __gconv_step *data)
     if (cc == 1)                                                       \
       {                                                                        \
        result = __GCONV_FULL_OUTPUT;                                   \
-       break;                                                          \
       }                                                                        \
     else if (cc == 2)                                                  \
       {                                                                        \
        result = __GCONV_ILLEGAL_INPUT;                                 \
-       break;                                                          \
       }                                                                        \
   }
 
+#define PREPARE_LOOP                                                   \
+  enum direction dir = ((struct utf8_data *) step->__data)->dir;       \
+  int emit_bom = ((struct utf8_data *) step->__data)->emit_bom;                \
+                                                                       \
+  if (emit_bom && !data->__internal_use                                        \
+      && data->__invocation_counter == 0)                              \
+    {                                                                  \
+      /* Emit the UTF-16 Byte Order Mark.  */                          \
+      if (__glibc_unlikely (outbuf + 2 > outend))                      \
+       return __GCONV_FULL_OUTPUT;                                     \
+                                                                       \
+      put16u (outbuf, BOM_UTF16);                                      \
+      outbuf += 2;                                                     \
+    }
+
 /* Conversion function from UTF-8 to UTF-16.  */
+#define BODY_FROM_HW(ASM)                                              \
+  {                                                                    \
+    ASM;                                                               \
+    if (__glibc_likely (inptr == inend)                                        \
+       || result == __GCONV_FULL_OUTPUT)                               \
+      break;                                                           \
+                                                                       \
+    int i;                                                             \
+    for (i = 1; inptr + i < inend && i < 5; ++i)                       \
+      if ((inptr[i] & 0xc0) != 0x80)                                   \
+       break;                                                          \
+                                                                       \
+    if (__glibc_likely (inptr + i == inend                             \
+                       && result == __GCONV_EMPTY_INPUT))              \
+      {                                                                        \
+       result = __GCONV_INCOMPLETE_INPUT;                              \
+       break;                                                          \
+      }                                                                        \
+    STANDARD_FROM_LOOP_ERR_HANDLER (i);                                        \
+  }
+
+#define BODY_FROM_ETF3EH BODY_FROM_HW (HARDWARE_CONVERT ("cu12 %0, %1, 1"))
+
+#define HW_FROM_VX                                                     \
+  {                                                                    \
+    register const unsigned char* pInput asm ("8") = inptr;            \
+    register size_t inlen asm ("9") = inend - inptr;                   \
+    register unsigned char* pOutput asm ("10") = outptr;               \
+    register size_t outlen asm("11") = outend - outptr;                        \
+    unsigned long tmp, tmp2, tmp3;                                     \
+    asm volatile (".machine push\n\t"                                  \
+                 ".machine \"z13\"\n\t"                                \
+                 ".machinemode \"zarch_nohighgprs\"\n\t"               \
+                 "    vrepib %%v30,0x7f\n\t" /* For compare > 0x7f.  */ \
+                 "    vrepib %%v31,0x20\n\t"                           \
+                 /* Loop which handles UTF-8 chars <=0x7f.  */         \
+                 "0:  clgijl %[R_INLEN],16,20f\n\t"                    \
+                 "    clgijl %[R_OUTLEN],32,20f\n\t"                   \
+                 "1:  vl %%v16,0(%[R_IN])\n\t"                         \
+                 "    vstrcbs %%v17,%%v16,%%v30,%%v31\n\t"             \
+                 "    jno 10f\n\t" /* Jump away if not all bytes are 1byte \
+                                      UTF8 chars.  */                  \
+                 /* Enlarge to UTF-16.  */                             \
+                 "    vuplhb %%v18,%%v16\n\t"                          \
+                 "    la %[R_IN],16(%[R_IN])\n\t"                      \
+                 "    vupllb %%v19,%%v16\n\t"                          \
+                 "    aghi %[R_INLEN],-16\n\t"                         \
+                 /* Store 32 bytes to buf_out.  */                     \
+                 "    vstm %%v18,%%v19,0(%[R_OUT])\n\t"                \
+                 "    aghi %[R_OUTLEN],-32\n\t"                        \
+                 "    la %[R_OUT],32(%[R_OUT])\n\t"                    \
+                 "    clgijl %[R_INLEN],16,20f\n\t"                    \
+                 "    clgijl %[R_OUTLEN],32,20f\n\t"                   \
+                 "    j 1b\n\t"                                        \
+                 "10:\n\t"                                             \
+                 /* At least one byte is > 0x7f.                       \
+                    Store the preceding 1-byte chars.  */              \
+                 "    vlgvb %[R_TMP],%%v17,7\n\t"                      \
+                 "    sllk %[R_TMP2],%[R_TMP],1\n\t" /* Compute highest \
+                                                        index to store. */ \
+                 "    llgfr %[R_TMP3],%[R_TMP2]\n\t"                   \
+                 "    ahi %[R_TMP2],-1\n\t"                            \
+                 "    jl 20f\n\t"                                      \
+                 "    vuplhb %%v18,%%v16\n\t"                          \
+                 "    vstl %%v18,%[R_TMP2],0(%[R_OUT])\n\t"            \
+                 "    ahi %[R_TMP2],-16\n\t"                           \
+                 "    jl 11f\n\t"                                      \
+                 "    vupllb %%v19,%%v16\n\t"                          \
+                 "    vstl %%v19,%[R_TMP2],16(%[R_OUT])\n\t"           \
+                 "11: \n\t" /* Update pointers.  */                    \
+                 "    la %[R_IN],0(%[R_TMP],%[R_IN])\n\t"              \
+                 "    slgr %[R_INLEN],%[R_TMP]\n\t"                    \
+                 "    la %[R_OUT],0(%[R_TMP3],%[R_OUT])\n\t"           \
+                 "    slgr %[R_OUTLEN],%[R_TMP3]\n\t"                  \
+                 /* Handle multibyte utf8-char with convert instruction. */ \
+                 "20: cu12 %[R_OUT],%[R_IN],1\n\t"                     \
+                 "    jo 0b\n\t" /* Try vector implemenation again.  */ \
+                 "    lochil %[R_RES],%[RES_OUT_FULL]\n\t" /* cc == 1.  */ \
+                 "    lochih %[R_RES],%[RES_IN_ILL]\n\t" /* cc == 2.  */ \
+                 ".machine pop"                                        \
+                 : /* outputs */ [R_IN] "+a" (pInput)                  \
+                   , [R_INLEN] "+d" (inlen), [R_OUT] "+a" (pOutput)    \
+                   , [R_OUTLEN] "+d" (outlen), [R_TMP] "=a" (tmp)      \
+                   , [R_TMP2] "=d" (tmp2), [R_TMP3] "=a" (tmp3)        \
+                   , [R_RES] "+d" (result)                             \
+                 : /* inputs */                                        \
+                   [RES_OUT_FULL] "i" (__GCONV_FULL_OUTPUT)            \
+                   , [RES_IN_ILL] "i" (__GCONV_ILLEGAL_INPUT)          \
+                 : /* clobber list */ "memory", "cc"                   \
+                   ASM_CLOBBER_VR ("v16") ASM_CLOBBER_VR ("v17")       \
+                   ASM_CLOBBER_VR ("v18") ASM_CLOBBER_VR ("v19")       \
+                   ASM_CLOBBER_VR ("v30") ASM_CLOBBER_VR ("v31")       \
+                 );                                                    \
+    inptr = pInput;                                                    \
+    outptr = pOutput;                                                  \
+  }
+#define BODY_FROM_VX BODY_FROM_HW (HW_FROM_VX)
+
 
-#define MIN_NEEDED_INPUT       MIN_NEEDED_FROM
-#define MAX_NEEDED_INPUT       MAX_NEEDED_FROM
-#define MIN_NEEDED_OUTPUT      MIN_NEEDED_TO
-#define MAX_NEEDED_OUTPUT      MAX_NEEDED_TO
-#define LOOPFCT                        FROM_LOOP
 /* The software implementation is based on the code in gconv_simple.c.  */
-#define BODY                                                           \
+#define BODY_FROM_C                                                    \
   {                                                                    \
-    if (GLRO (dl_hwcap) & HWCAP_S390_ETF3EH)                           \
-      {                                                                        \
-       HARDWARE_CONVERT ("cu12 %0, %1, 1");                            \
-                                                                       \
-       if (inptr != inend)                                             \
-         {                                                             \
-           int i;                                                      \
-           for (i = 1; inptr + i < inend; ++i)                         \
-             if ((inptr[i] & 0xc0) != 0x80)                            \
-               break;                                                  \
-                                                               \
-           if (__glibc_likely (inptr + i == inend))                          \
-             {                                                         \
-               result = __GCONV_INCOMPLETE_INPUT;                      \
-               break;                                                  \
-             }                                                         \
-           STANDARD_FROM_LOOP_ERR_HANDLER (i);                         \
-         }                                                             \
-       continue;                                                       \
-    }                                                                  \
-                                                                       \
     /* Next input byte.  */                                            \
     uint16_t ch = *inptr;                                              \
                                                                        \
-    if (__glibc_likely (ch < 0x80))                                          \
+    if (__glibc_likely (ch < 0x80))                                    \
       {                                                                        \
        /* One byte sequence.  */                                       \
        ++inptr;                                                        \
@@ -230,13 +309,13 @@ gconv_end (struct __gconv_step *data)
            cnt = 2;                                                    \
            ch &= 0x1f;                                                 \
          }                                                             \
-        else if (__glibc_likely ((ch & 0xf0) == 0xe0))                       \
+       else if (__glibc_likely ((ch & 0xf0) == 0xe0))                  \
          {                                                             \
            /* We expect three bytes.  */                               \
            cnt = 3;                                                    \
            ch &= 0x0f;                                                 \
          }                                                             \
-       else if (__glibc_likely ((ch & 0xf8) == 0xf0))                        \
+       else if (__glibc_likely ((ch & 0xf8) == 0xf0))                  \
          {                                                             \
            /* We expect four bytes.  */                                \
            cnt = 4;                                                    \
@@ -257,7 +336,7 @@ gconv_end (struct __gconv_step *data)
            STANDARD_FROM_LOOP_ERR_HANDLER (i);                         \
          }                                                             \
                                                                        \
-       if (__glibc_unlikely (inptr + cnt > inend))                           \
+       if (__glibc_unlikely (inptr + cnt > inend))                     \
          {                                                             \
            /* We don't have enough input.  But before we report        \
               that check that all the bytes are correct.  */           \
@@ -265,7 +344,7 @@ gconv_end (struct __gconv_step *data)
              if ((inptr[i] & 0xc0) != 0x80)                            \
                break;                                                  \
                                                                        \
-           if (__glibc_likely (inptr + i == inend))                          \
+           if (__glibc_likely (inptr + i == inend))                    \
              {                                                         \
                result = __GCONV_INCOMPLETE_INPUT;                      \
                break;                                                  \
@@ -280,23 +359,31 @@ gconv_end (struct __gconv_step *data)
               low) are needed.  */                                     \
            uint16_t zabcd, high, low;                                  \
                                                                        \
-           if (__glibc_unlikely (outptr + 4 > outend))                       \
+           if (__glibc_unlikely (outptr + 4 > outend))                 \
              {                                                         \
                /* Overflow in the output buffer.  */                   \
                result = __GCONV_FULL_OUTPUT;                           \
                break;                                                  \
              }                                                         \
                                                                        \
+           /* Check if tail-bytes >= 0x80, < 0xc0.  */                 \
+           for (i = 1; i < cnt; ++i)                                   \
+             {                                                         \
+               if ((inptr[i] & 0xc0) != 0x80)                          \
+                 /* This is an illegal encoding.  */                   \
+                 goto errout;                                          \
+             }                                                         \
+                                                                       \
            /* See Principles of Operations cu12.  */                   \
            zabcd = (((inptr[0] & 0x7) << 2) |                          \
-                     ((inptr[1] & 0x30) >> 4)) - 1;                    \
+                    ((inptr[1] & 0x30) >> 4)) - 1;                     \
                                                                        \
            /* z-bit must be zero after subtracting 1.  */              \
            if (zabcd & 0x10)                                           \
              STANDARD_FROM_LOOP_ERR_HANDLER (4)                        \
                                                                        \
            high = (uint16_t)(0xd8 << 8);       /* high surrogate id */ \
-           high |= zabcd << 6;                         /* abcd bits */ \
+           high |= zabcd << 6;                         /* abcd bits */ \
            high |= (inptr[1] & 0xf) << 2;              /* efgh bits */ \
            high |= (inptr[2] & 0x30) >> 4;               /* ij bits */ \
                                                                        \
@@ -326,8 +413,19 @@ gconv_end (struct __gconv_step *data)
                ch <<= 6;                                               \
                ch |= byte & 0x3f;                                      \
              }                                                         \
-           inptr += cnt;                                               \
                                                                        \
+           /* If i < cnt, some trail byte was not >= 0x80, < 0xc0.     \
+              If cnt > 2 and ch < 2^(5*cnt-4), the wide character ch could \
+              have been represented with fewer than cnt bytes.  */     \
+           if (i < cnt || (cnt > 2 && (ch >> (5 * cnt - 4)) == 0)      \
+               /* Do not accept UTF-16 surrogates.  */                 \
+               || (ch >= 0xd800 && ch <= 0xdfff))                      \
+             {                                                         \
+               /* This is an illegal encoding.  */                     \
+               goto errout;                                            \
+             }                                                         \
+                                                                       \
+           inptr += cnt;                                               \
          }                                                             \
       }                                                                        \
     /* Now adjust the pointers and store the result.  */               \
@@ -335,43 +433,70 @@ gconv_end (struct __gconv_step *data)
     outptr += sizeof (uint16_t);                                       \
   }
 
+/* Generate loop-function with software implementation.  */
+#define MIN_NEEDED_INPUT       MIN_NEEDED_FROM
+#define MAX_NEEDED_INPUT       MAX_NEEDED_FROM
+#define MIN_NEEDED_OUTPUT      MIN_NEEDED_TO
+#define MAX_NEEDED_OUTPUT      MAX_NEEDED_TO
+#define LOOPFCT                        __from_utf8_loop_c
+#define LOOP_NEED_FLAGS
+#define BODY                   BODY_FROM_C
+#include <iconv/loop.c>
+
+/* Generate loop-function with hardware utf-convert instruction.  */
+#define MIN_NEEDED_INPUT       MIN_NEEDED_FROM
+#define MAX_NEEDED_INPUT       MAX_NEEDED_FROM
+#define MIN_NEEDED_OUTPUT      MIN_NEEDED_TO
+#define MAX_NEEDED_OUTPUT      MAX_NEEDED_TO
+#define LOOPFCT                        __from_utf8_loop_etf3eh
 #define LOOP_NEED_FLAGS
+#define BODY                   BODY_FROM_ETF3EH
 #include <iconv/loop.c>
 
+#if defined HAVE_S390_VX_ASM_SUPPORT
+/* Generate loop-function with hardware vector and utf-convert instructions.  */
+# define MIN_NEEDED_INPUT      MIN_NEEDED_FROM
+# define MAX_NEEDED_INPUT      MAX_NEEDED_FROM
+# define MIN_NEEDED_OUTPUT     MIN_NEEDED_TO
+# define MAX_NEEDED_OUTPUT     MAX_NEEDED_TO
+# define LOOPFCT               __from_utf8_loop_vx
+# define LOOP_NEED_FLAGS
+# define BODY                  BODY_FROM_VX
+# include <iconv/loop.c>
+#endif
+
+
+/* Generate ifunc'ed loop function.  */
+__typeof(__from_utf8_loop_c)
+__attribute__ ((ifunc ("__from_utf8_loop_resolver")))
+__from_utf8_loop;
+
+static void *
+__from_utf8_loop_resolver (unsigned long int dl_hwcap)
+{
+#if defined HAVE_S390_VX_ASM_SUPPORT
+  if (dl_hwcap & HWCAP_S390_VX)
+    return __from_utf8_loop_vx;
+  else
+#endif
+  if (dl_hwcap & HWCAP_S390_ETF3EH)
+    return __from_utf8_loop_etf3eh;
+  else
+    return __from_utf8_loop_c;
+}
+
+strong_alias (__from_utf8_loop_c_single, __from_utf8_loop_single)
+
 /* Conversion from UTF-16 to UTF-8.  */
 
-#define MIN_NEEDED_INPUT       MIN_NEEDED_TO
-#define MAX_NEEDED_INPUT       MAX_NEEDED_TO
-#define MIN_NEEDED_OUTPUT      MIN_NEEDED_FROM
-#define MAX_NEEDED_OUTPUT      MAX_NEEDED_FROM
-#define LOOPFCT                        TO_LOOP
 /* The software routine is based on the functionality of the S/390
    hardware instruction (cu21) as described in the Principles of
    Operation.  */
-#define BODY                                                           \
+#define BODY_TO_C                                                      \
   {                                                                    \
-    /* The hardware instruction currently fails to report an error for \
-       isolated low surrogates so we have to disable the instruction   \
-       until this gets resolved.  */                                   \
-    if (0) /* (GLRO (dl_hwcap) & HWCAP_S390_ETF3EH) */                 \
-      {                                                                        \
-       HARDWARE_CONVERT ("cu21 %0, %1, 1");                            \
-       if (inptr != inend)                                             \
-         {                                                             \
-           /* Check if the third byte is                               \
-              a valid start of a UTF-16 surrogate.  */                 \
-           if (inend - inptr == 3 && (inptr[3] & 0xfc) != 0xdc)        \
-             STANDARD_TO_LOOP_ERR_HANDLER (3);                         \
-                                                                       \
-           result = __GCONV_INCOMPLETE_INPUT;                          \
-           break;                                                      \
-         }                                                             \
-       continue;                                                       \
-      }                                                                        \
-                                                                       \
     uint16_t c = get16 (inptr);                                                \
                                                                        \
-    if (__glibc_likely (c <= 0x007f))                                        \
+    if (__glibc_likely (c <= 0x007f))                                  \
       {                                                                        \
        /* Single byte UTF-8 char.  */                                  \
        *outptr = c & 0xff;                                             \
@@ -379,20 +504,20 @@ gconv_end (struct __gconv_step *data)
       }                                                                        \
     else if (c >= 0x0080 && c <= 0x07ff)                               \
       {                                                                        \
-        /* Two byte UTF-8 char.  */                                    \
+       /* Two byte UTF-8 char.  */                                     \
                                                                        \
-       if (__glibc_unlikely (outptr + 2 > outend))                           \
+       if (__glibc_unlikely (outptr + 2 > outend))                     \
          {                                                             \
            /* Overflow in the output buffer.  */                       \
            result = __GCONV_FULL_OUTPUT;                               \
            break;                                                      \
          }                                                             \
                                                                        \
-        outptr[0] = 0xc0;                                              \
-        outptr[0] |= c >> 6;                                           \
+       outptr[0] = 0xc0;                                               \
+       outptr[0] |= c >> 6;                                            \
                                                                        \
-        outptr[1] = 0x80;                                              \
-        outptr[1] |= c & 0x3f;                                         \
+       outptr[1] = 0x80;                                               \
+       outptr[1] |= c & 0x3f;                                          \
                                                                        \
        outptr += 2;                                                    \
       }                                                                        \
@@ -400,7 +525,7 @@ gconv_end (struct __gconv_step *data)
       {                                                                        \
        /* Three byte UTF-8 char.  */                                   \
                                                                        \
-       if (__glibc_unlikely (outptr + 3 > outend))                           \
+       if (__glibc_unlikely (outptr + 3 > outend))                     \
          {                                                             \
            /* Overflow in the output buffer.  */                       \
            result = __GCONV_FULL_OUTPUT;                               \
@@ -419,22 +544,22 @@ gconv_end (struct __gconv_step *data)
       }                                                                        \
     else if (c >= 0xd800 && c <= 0xdbff)                               \
       {                                                                        \
-        /* Four byte UTF-8 char.  */                                   \
+       /* Four byte UTF-8 char.  */                                    \
        uint16_t low, uvwxy;                                            \
                                                                        \
-       if (__glibc_unlikely (outptr + 4 > outend))                           \
+       if (__glibc_unlikely (outptr + 4 > outend))                     \
          {                                                             \
            /* Overflow in the output buffer.  */                       \
            result = __GCONV_FULL_OUTPUT;                               \
            break;                                                      \
          }                                                             \
-       inptr += 2;                                                     \
-       if (__glibc_unlikely (inptr + 2 > inend))                             \
+       if (__glibc_unlikely (inptr + 4 > inend))                       \
          {                                                             \
            result = __GCONV_INCOMPLETE_INPUT;                          \
            break;                                                      \
          }                                                             \
                                                                        \
+       inptr += 2;                                                     \
        low = get16 (inptr);                                            \
                                                                        \
        if ((low & 0xfc00) != 0xdc00)                                   \
@@ -461,11 +586,221 @@ gconv_end (struct __gconv_step *data)
       }                                                                        \
     else                                                               \
       {                                                                        \
-        STANDARD_TO_LOOP_ERR_HANDLER (2);                              \
+       STANDARD_TO_LOOP_ERR_HANDLER (2);                               \
       }                                                                        \
     inptr += 2;                                                                \
   }
-#define LOOP_NEED_FLAGS
-#include <iconv/loop.c>
+
+#define BODY_TO_VX                                                     \
+  {                                                                    \
+    size_t inlen  = inend - inptr;                                     \
+    size_t outlen  = outend - outptr;                                  \
+    unsigned long tmp, tmp2, tmp3;                                     \
+    asm volatile (".machine push\n\t"                                  \
+                 ".machine \"z13\"\n\t"                                \
+                 ".machinemode \"zarch_nohighgprs\"\n\t"               \
+                 /* Setup to check for values <= 0x7f.  */             \
+                 "    larl %[R_TMP],9f\n\t"                            \
+                 "    vlm %%v30,%%v31,0(%[R_TMP])\n\t"                 \
+                 /* Loop which handles UTF-16 chars <=0x7f.  */        \
+                 "0:  clgijl %[R_INLEN],32,2f\n\t"                     \
+                 "    clgijl %[R_OUTLEN],16,2f\n\t"                    \
+                 "1:  vlm %%v16,%%v17,0(%[R_IN])\n\t"                  \
+                 "    lghi %[R_TMP2],0\n\t"                            \
+                 /* Check for > 1byte UTF-8 chars.  */                 \
+                 "    vstrchs %%v19,%%v16,%%v30,%%v31\n\t"             \
+                 "    jno 10f\n\t" /* Jump away if not all bytes are 1byte \
+                                      UTF8 chars.  */                  \
+                 "    vstrchs %%v19,%%v17,%%v30,%%v31\n\t"             \
+                 "    jno 11f\n\t" /* Jump away if not all bytes are 1byte \
+                                      UTF8 chars.  */                  \
+                 /* Shorten to UTF-8.  */                              \
+                 "    vpkh %%v18,%%v16,%%v17\n\t"                      \
+                 "    la %[R_IN],32(%[R_IN])\n\t"                      \
+                 "    aghi %[R_INLEN],-32\n\t"                         \
+                 /* Store 16 bytes to buf_out.  */                     \
+                 "    vst %%v18,0(%[R_OUT])\n\t"                       \
+                 "    aghi %[R_OUTLEN],-16\n\t"                        \
+                 "    la %[R_OUT],16(%[R_OUT])\n\t"                    \
+                 "    clgijl %[R_INLEN],32,2f\n\t"                     \
+                 "    clgijl %[R_OUTLEN],16,2f\n\t"                    \
+                 "    j 1b\n\t"                                        \
+                 /* Setup to check for ch > 0x7f. (v30, v31)  */       \
+                 "9:  .short 0x7f,0x7f,0x0,0x0,0x0,0x0,0x0,0x0\n\t"    \
+                 "    .short 0x2000,0x2000,0x0,0x0,0x0,0x0,0x0,0x0\n\t" \
+                 /* At least one byte is > 0x7f.                       \
+                    Store the preceding 1-byte chars.  */              \
+                 "11: lghi %[R_TMP2],16\n\t" /* match was found in v17.  */ \
+                 "10:\n\t"                                             \
+                 "    vlgvb %[R_TMP],%%v19,7\n\t"                      \
+                 /* Shorten to UTF-8.  */                              \
+                 "    vpkh %%v18,%%v16,%%v17\n\t"                      \
+                 "    ar %[R_TMP],%[R_TMP2]\n\t" /* Number of in bytes.  */ \
+                 "    srlg %[R_TMP3],%[R_TMP],1\n\t" /* Number of out bytes.  */ \
+                 "    ahik %[R_TMP2],%[R_TMP3],-1\n\t" /* Highest index to store.  */ \
+                 "    jl 13f\n\t"                                      \
+                 "    vstl %%v18,%[R_TMP2],0(%[R_OUT])\n\t"            \
+                 /* Update pointers.  */                               \
+                 "    la %[R_IN],0(%[R_TMP],%[R_IN])\n\t"              \
+                 "    slgr %[R_INLEN],%[R_TMP]\n\t"                    \
+                 "    la %[R_OUT],0(%[R_TMP3],%[R_OUT])\n\t"           \
+                 "    slgr %[R_OUTLEN],%[R_TMP3]\n\t"                  \
+                 "13: \n\t"                                            \
+                 /* Calculate remaining uint16_t values in loaded vrs.  */ \
+                 "    lghi %[R_TMP2],16\n\t"                           \
+                 "    slgr %[R_TMP2],%[R_TMP3]\n\t"                    \
+                 "    llh %[R_TMP],0(%[R_IN])\n\t"                     \
+                 "    aghi %[R_INLEN],-2\n\t"                          \
+                 "    j 22f\n\t"                                       \
+                 /* Handle remaining bytes.  */                        \
+                 "2:  \n\t"                                            \
+                 /* Zero, one or more bytes available?  */             \
+                 "    clgfi %[R_INLEN],1\n\t"                          \
+                 "    locghie %[R_RES],%[RES_IN_FULL]\n\t" /* Only one byte.  */ \
+                 "    jle 99f\n\t" /* End if less than two bytes.  */  \
+                 /* Calculate remaining uint16_t values in inptr.  */  \
+                 "    srlg %[R_TMP2],%[R_INLEN],1\n\t"                 \
+                 /* Handle multibyte utf8-char. */                     \
+                 "20: llh %[R_TMP],0(%[R_IN])\n\t"                     \
+                 "    aghi %[R_INLEN],-2\n\t"                          \
+                 /* Test if ch is 1-byte UTF-8 char.  */               \
+                 "21: clijh %[R_TMP],0x7f,22f\n\t"                     \
+                 /* Handle 1-byte UTF-8 char.  */                      \
+                 "31: slgfi %[R_OUTLEN],1\n\t"                         \
+                 "    jl 90f \n\t"                                     \
+                 "    stc %[R_TMP],0(%[R_OUT])\n\t"                    \
+                 "    la %[R_IN],2(%[R_IN])\n\t"                       \
+                 "    la %[R_OUT],1(%[R_OUT])\n\t"                     \
+                 "    brctg %[R_TMP2],20b\n\t"                         \
+                 "    j 0b\n\t" /* Switch to vx-loop.  */              \
+                 /* Test if ch is 2-byte UTF-8 char.  */               \
+                 "22: clfi %[R_TMP],0x7ff\n\t"                         \
+                 "    jh 23f\n\t"                                      \
+                 /* Handle 2-byte UTF-8 char.  */                      \
+                 "32: slgfi %[R_OUTLEN],2\n\t"                         \
+                 "    jl 90f \n\t"                                     \
+                 "    llill %[R_TMP3],0xc080\n\t"                      \
+                 "    la %[R_IN],2(%[R_IN])\n\t"                       \
+                 "    risbgn %[R_TMP3],%[R_TMP],51,55,2\n\t" /* 1. byte.   */ \
+                 "    risbgn %[R_TMP3],%[R_TMP],58,63,0\n\t" /* 2. byte.   */ \
+                 "    sth %[R_TMP3],0(%[R_OUT])\n\t"                   \
+                 "    la %[R_OUT],2(%[R_OUT])\n\t"                     \
+                 "    brctg %[R_TMP2],20b\n\t"                         \
+                 "    j 0b\n\t" /* Switch to vx-loop.  */              \
+                 /* Test if ch is 3-byte UTF-8 char.  */               \
+                 "23: clfi %[R_TMP],0xd7ff\n\t"                        \
+                 "    jh 24f\n\t"                                      \
+                 /* Handle 3-byte UTF-8 char.  */                      \
+                 "33: slgfi %[R_OUTLEN],3\n\t"                         \
+                 "    jl 90f \n\t"                                     \
+                 "    llilf %[R_TMP3],0xe08080\n\t"                    \
+                 "    la %[R_IN],2(%[R_IN])\n\t"                       \
+                 "    risbgn %[R_TMP3],%[R_TMP],44,47,4\n\t" /* 1. byte.  */ \
+                 "    risbgn %[R_TMP3],%[R_TMP],50,55,2\n\t" /* 2. byte.  */ \
+                 "    risbgn %[R_TMP3],%[R_TMP],58,63,0\n\t" /* 3. byte.  */ \
+                 "    stcm %[R_TMP3],7,0(%[R_OUT])\n\t"                \
+                 "    la %[R_OUT],3(%[R_OUT])\n\t"                     \
+                 "    brctg %[R_TMP2],20b\n\t"                         \
+                 "    j 0b\n\t" /* Switch to vx-loop.  */              \
+                 /* Test if ch is 4-byte UTF-8 char.  */               \
+                 "24: clfi %[R_TMP],0xdfff\n\t"                        \
+                 "    jh 33b\n\t" /* Handle this 3-byte UTF-8 char.  */ \
+                 "    clfi %[R_TMP],0xdbff\n\t"                        \
+                 "    locghih %[R_RES],%[RES_IN_ILL]\n\t"              \
+                 "    jh 99f\n\t" /* Jump away if this is a low surrogate \
+                                     without a preceding high surrogate.  */ \
+                 /* Handle 4-byte UTF-8 char.  */                      \
+                 "34: slgfi %[R_OUTLEN],4\n\t"                         \
+                 "    jl 90f \n\t"                                     \
+                 "    slgfi %[R_INLEN],2\n\t"                          \
+                 "    locghil %[R_RES],%[RES_IN_FULL]\n\t"             \
+                 "    jl 99f\n\t" /* Jump away if low surrogate is missing.  */ \
+                 "    llilf %[R_TMP3],0xf0808080\n\t"                  \
+                 "    aghi %[R_TMP],0x40\n\t"                          \
+                 "    risbgn %[R_TMP3],%[R_TMP],37,39,16\n\t" /* 1. byte: uvw  */ \
+                 "    risbgn %[R_TMP3],%[R_TMP],42,43,14\n\t" /* 2. byte: xy  */ \
+                 "    risbgn %[R_TMP3],%[R_TMP],44,47,14\n\t" /* 2. byte: efgh  */ \
+                 "    risbgn %[R_TMP3],%[R_TMP],50,51,12\n\t" /* 3. byte: ij */ \
+                 "    llh %[R_TMP],2(%[R_IN])\n\t" /* Load low surrogate.  */ \
+                 "    risbgn %[R_TMP3],%[R_TMP],52,55,2\n\t" /* 3. byte: klmn  */ \
+                 "    risbgn %[R_TMP3],%[R_TMP],58,63,0\n\t" /* 4. byte: opqrst  */ \
+                 "    nilf %[R_TMP],0xfc00\n\t"                        \
+                 "    clfi %[R_TMP],0xdc00\n\t" /* Check if it starts with 0xdc00.  */ \
+                 "    locghine %[R_RES],%[RES_IN_ILL]\n\t"             \
+                 "    jne 99f\n\t" /* Jump away if low surrogate is invalid.  */ \
+                 "    st %[R_TMP3],0(%[R_OUT])\n\t"                    \
+                 "    la %[R_IN],4(%[R_IN])\n\t"                       \
+                 "    la %[R_OUT],4(%[R_OUT])\n\t"                     \
+                 "    aghi %[R_TMP2],-2\n\t"                           \
+                 "    jh 20b\n\t"                                      \
+                 "    j 0b\n\t" /* Switch to vx-loop.  */              \
+                 /* Exit with __GCONV_FULL_OUTPUT.  */                 \
+                 "90: lghi %[R_RES],%[RES_OUT_FULL]\n\t"               \
+                 "99: \n\t"                                            \
+                 ".machine pop"                                        \
+                 : /* outputs */ [R_IN] "+a" (inptr)                   \
+                   , [R_INLEN] "+d" (inlen), [R_OUT] "+a" (outptr)     \
+                   , [R_OUTLEN] "+d" (outlen), [R_TMP] "=a" (tmp)      \
+                   , [R_TMP2] "=d" (tmp2), [R_TMP3] "=a" (tmp3)        \
+                   , [R_RES] "+d" (result)                             \
+                 : /* inputs */                                        \
+                   [RES_OUT_FULL] "i" (__GCONV_FULL_OUTPUT)            \
+                   , [RES_IN_ILL] "i" (__GCONV_ILLEGAL_INPUT)          \
+                   , [RES_IN_FULL] "i" (__GCONV_INCOMPLETE_INPUT)      \
+                 : /* clobber list */ "memory", "cc"                   \
+                   ASM_CLOBBER_VR ("v16") ASM_CLOBBER_VR ("v17")       \
+                   ASM_CLOBBER_VR ("v18") ASM_CLOBBER_VR ("v19")       \
+                   ASM_CLOBBER_VR ("v30") ASM_CLOBBER_VR ("v31")       \
+                 );                                                    \
+    if (__glibc_likely (inptr == inend)                                        \
+       || result != __GCONV_ILLEGAL_INPUT)                             \
+      break;                                                           \
+                                                                       \
+    STANDARD_TO_LOOP_ERR_HANDLER (2);                                  \
+  }
+
+/* Generate loop-function with software implementation.  */
+#define MIN_NEEDED_INPUT       MIN_NEEDED_TO
+#define MAX_NEEDED_INPUT       MAX_NEEDED_TO
+#define MIN_NEEDED_OUTPUT      MIN_NEEDED_FROM
+#define MAX_NEEDED_OUTPUT      MAX_NEEDED_FROM
+#if defined HAVE_S390_VX_ASM_SUPPORT
+# define LOOPFCT               __to_utf8_loop_c
+# define BODY                   BODY_TO_C
+# define LOOP_NEED_FLAGS
+# include <iconv/loop.c>
+
+/* Generate loop-function with software implementation.  */
+# define MIN_NEEDED_INPUT      MIN_NEEDED_TO
+# define MAX_NEEDED_INPUT      MAX_NEEDED_TO
+# define MIN_NEEDED_OUTPUT     MIN_NEEDED_FROM
+# define MAX_NEEDED_OUTPUT     MAX_NEEDED_FROM
+# define LOOPFCT               __to_utf8_loop_vx
+# define BODY                   BODY_TO_VX
+# define LOOP_NEED_FLAGS
+# include <iconv/loop.c>
+
+/* Generate ifunc'ed loop function.  */
+__typeof(__to_utf8_loop_c)
+__attribute__ ((ifunc ("__to_utf8_loop_resolver")))
+__to_utf8_loop;
+
+static void *
+__to_utf8_loop_resolver (unsigned long int dl_hwcap)
+{
+  if (dl_hwcap & HWCAP_S390_VX)
+    return __to_utf8_loop_vx;
+  else
+    return __to_utf8_loop_c;
+}
+
+strong_alias (__to_utf8_loop_c_single, __to_utf8_loop_single)
+
+#else
+# define LOOPFCT               TO_LOOP
+# define BODY                   BODY_TO_C
+# define LOOP_NEED_FLAGS
+# include <iconv/loop.c>
+#endif /* !HAVE_S390_VX_ASM_SUPPORT  */
 
 #include <iconv/skeleton.c>