1ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown
2ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown#include <stdio.h>
3ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown#include <config.h>
4ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown
5ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brownstatic
6ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brownint try_mtocrf ( int x )
7ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown{
8ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  int base = 0x31415927;
9ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  int res;
10ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown#ifdef HAVE_AS_PPC_MFTOCRF
11ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  /* pre-set CR */
12ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  __asm__ __volatile__(
13ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown     "mtcr %0"
14ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown     : /*w*/ : /*r*/ "b"(base) : /*trash*/"cc" );
15ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown
16ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  /* do it */
17ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  __asm__ __volatile__(
18ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown     "mtocrf 4, %0"
19ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown     : /*w*/ : /*r*/ "b"(x) : /*trash*/"cc" );
20ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown
21ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  /* get CR */
22ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  __asm__ __volatile__(
23ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown     "mfcr %0"
24ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown     : /*w*/"=b"(res) : /*r*/ );
25ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown#else
26ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  res = 42;
27ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown#endif
28ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  return res;
29ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown}
30ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown
31ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brownstatic
32ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brownint try_mfocrf ( int x )
33ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown{
34ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown   int res;
35ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown#ifdef HAVE_AS_PPC_MFTOCRF
36ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown   /* CR = x */
37ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown   __asm__ __volatile__(
38ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown     "mtcr %0"
39ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown     : /*w*/ : /*r*/ "b"(x) : /*trash*/"cc" );
40ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown
41ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  /* do it */
42ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  __asm__ __volatile__(
43ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown     "li %0,0\n\t"
44ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown     "mfocrf %0,64"
45ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown     : /*w*/"=b"(res) : /*r*/ );
46ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown#else
47ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  res = 42;
48ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown#endif
49ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  return res;
50ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown}
51ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown
52ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown/* This is a bit of a kludge since mfocrf reads the spec'd CR field,
53ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown   but the remaining returned bits are undefined.  It seems like on
54ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown   MPC7447A (Apple Mac Mini) mfocrf just reads the entire CR, which is
55ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown   an acceptable implementation, but is not necessarily what other
56ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown   implementations are going to do. */
57ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown
58ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brownint main ( void )
59ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown{
60ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  int i, j;
61ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  for (i = 0; i < 32; i++) {
62ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown    printf("0x%08x\n", try_mtocrf( 1<<i ));
63ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  }
64ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  printf("\n");
65ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  j = 1;
66ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  for (i = 0; i < 32; i++) {
67ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown    printf("0x%08x\n", try_mfocrf( j ));
68ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown    j *= 3;
69ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  }
70ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown
71ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown  return 0;
72ed07e00d438c74b7a23c01bfffde77e3968305e4Jeff Brown}
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