none/tests/amd64/nan80and64.c

   1
   2 /* Test conversions between 64- and 80- bit quiet NaNs.  Uses
   3    "canonical forms" for qNaNs.  It also tests sNaNs but it's not
   4    clear what the canonical form of them should be, so the results are
   5    pretty much irrelevant.  Failure to do this right is the cause
   6    of https://bugzilla.mozilla.org/show_bug.cgi?id=738117
   7 */
   8
   9 #include <assert.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13
  14 typedef  unsigned char  UChar;
  15
  16
  17 void do_64_to_80 ( UChar* dst, UChar* src )
  18 {
  19    __asm__ __volatile__(
  20       "fldl (%0); fstpt (%1)"
  21       : : "r"(src), "r"(dst) : "memory"
  22    );
  23 }
  24
  25 void do_80_to_64 ( UChar* dst, UChar* src )
  26 {
  27    __asm__ __volatile__(
  28       "fldt (%0); fstpl (%1)"
  29       : : "r"(src), "r"(dst) : "memory"
  30    );
  31 }
  32
  33 void print80 ( char* s, UChar* v )
  34 {
  35    int i;
  36    printf("%s", s);
  37    for (i = 9; i >= 0; i--)
  38       printf("%02x", (unsigned int)v[i]);
  39    printf("\n");
  40 }
  41
  42 void print64 ( char* s, UChar* v )
  43 {
  44    int i;
  45    printf("%s", s);
  46    for (i = 7; i >= 0; i--) {
  47       printf("%02x", (unsigned int)v[i]);
  48    }
  49    printf("\n");
  50 }
  51
  52 #if 0
  53 void gen_qnan_64 ( UChar* dst )
  54 {
  55
  56 }
  57 #endif
  58
  59 #define SWAPC(_xx,_yy) { UChar tmp = _xx; _xx = _yy; _yy = tmp; }
  60
  61 static void rev64 ( UChar* f64 )
  62 {
  63    SWAPC( f64[0], f64[7] );
  64    SWAPC( f64[1], f64[6] );
  65    SWAPC( f64[2], f64[5] );
  66    SWAPC( f64[3], f64[4] );
  67 }
  68
  69 static void rev80 ( UChar* f80 )
  70 {
  71    SWAPC( f80[0], f80[9] );
  72    SWAPC( f80[1], f80[8] );
  73    SWAPC( f80[2], f80[7] );
  74    SWAPC( f80[3], f80[6] );
  75    SWAPC( f80[4], f80[5] );
  76 }
  77
  78 #undef SWAPC
  79
  80 int main ( void )
  81 {
  82   UChar ref_qnan64[8]
  83         = { 0x7f, 0xf8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
  84
  85   UChar ref_snan64[8]
  86         = { 0x7f, 0xf4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
  87
  88   UChar ref_qnan80[10]
  89         = { 0x7f, 0xff, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
  90
  91   UChar ref_snan80[10]
  92         = { 0x7f, 0xff, 0xa0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
  93
  94   rev64( ref_qnan64 );
  95   rev64( ref_snan64 );
  96   rev80( ref_qnan80 );
  97   rev80( ref_snan80 );
  98
  99   UChar* res = malloc(10);
 100 #define ZAP memset(res, 0x55, 10)
 101
 102
 103   int pass;
 104   for (pass = 1; pass <= 2; pass++) {
 105
 106   ZAP; do_64_to_80( res, ref_qnan64 );
 107   print64( "src = qnan64: ", ref_qnan64 );
 108   print80( "dst = qnan80: ", res );
 109   printf("\n");
 110
 111   ZAP; do_64_to_80( res, ref_snan64 );
 112   print64( "src = snan64: ", ref_snan64 );
 113   print80( "dst = snan80: ", res );
 114   printf("\n");
 115
 116   ZAP; do_80_to_64( res, ref_qnan80 );
 117   print80( "src = qnan80: ", ref_qnan80 );
 118   print64( "dst = qnan64: ", res );
 119   printf("\n");
 120
 121   ZAP; do_80_to_64( res, ref_snan80 );
 122   print80( "src = snan80: ", ref_snan80 );
 123   print64( "dst = snan64: ", res );
 124   printf("\n");
 125
 126   /* now make all the reference inputs negative and do it again */
 127
 128   ref_qnan64[7] ^= 0x80;
 129   ref_snan64[7] ^= 0x80;
 130
 131   ref_qnan80[9] ^= 0x80;
 132   ref_snan80[9] ^= 0x80;
 133
 134   }
 135
 136 #undef ZAP
 137
 138   free(res);
 139   return 0;
 140 }