libgo/go/bytes/indexbyte.c

   1 /* indexbyte.c -- implement bytes.IndexByte for Go.
   2
   3    Copyright 2009 The Go Authors. All rights reserved.
   4    Use of this source code is governed by a BSD-style
   5    license that can be found in the LICENSE file.  */
   6
   7 #include <stddef.h>
   8
   9 #include "array.h"
  10
  11 /* This is in C so that the compiler can optimize it appropriately.
  12    We deliberately don't split the stack in case it does call the
  13    library function, which shouldn't need much stack space.  */
  14
  15 int IndexByte (struct __go_open_array, char)
  16   asm ("libgo_bytes.bytes.IndexByte")
  17   __attribute__ ((no_split_stack));
  18
  19 int
  20 IndexByte (struct __go_open_array s, char b)
  21 {
  22   char *p;
  23
  24   p = __builtin_memchr (s.__values, b, s.__count);
  25   if (p == NULL)
  26     return -1;
  27   return p - (char *) s.__values;
  28 }