gcc/libgo/runtime/go-int-to-string.c

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/* go-int-to-string.c -- convert an integer to a string in Go.
Copyright 2009 The Go Authors. All rights reserved.
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file. */
#include "runtime.h"
#include "arch.h"
#include "malloc.h"
String
__go_int_to_string (intgo v)
{
char buf[4];
int len;
unsigned char *retdata;
String ret;
/* A negative value is not valid UTF-8; turn it into the replacement
character. */
if (v < 0)
v = 0xfffd;
if (v <= 0x7f)
{
buf[0] = v;
len = 1;
}
else if (v <= 0x7ff)
{
buf[0] = 0xc0 + (v >> 6);
buf[1] = 0x80 + (v & 0x3f);
len = 2;
}
else
{
/* If the value is out of range for UTF-8, turn it into the
"replacement character". */
if (v > 0x10ffff)
v = 0xfffd;
/* If the value is a surrogate pair, which is invalid in UTF-8,
turn it into the replacement character. */
if (v >= 0xd800 && v < 0xe000)
v = 0xfffd;
if (v <= 0xffff)
{
buf[0] = 0xe0 + (v >> 12);
buf[1] = 0x80 + ((v >> 6) & 0x3f);
buf[2] = 0x80 + (v & 0x3f);
len = 3;
}
else
{
buf[0] = 0xf0 + (v >> 18);
buf[1] = 0x80 + ((v >> 12) & 0x3f);
buf[2] = 0x80 + ((v >> 6) & 0x3f);
buf[3] = 0x80 + (v & 0x3f);
len = 4;
}
}
retdata = runtime_mallocgc (len, 0, FlagNoScan);
__builtin_memcpy (retdata, buf, len);
ret.str = retdata;
ret.len = len;
return ret;
}