[CRT]

[reactos.git] / reactos / lib / sdk / crt / misc / i10output.c

diff --git a/reactos/lib/sdk/crt/misc/i10output.c b/reactos/lib/sdk/crt/misc/i10output.c
index b44d03a..ba291a7 100644 (file)
--- a/reactos/lib/sdk/crt/misc/i10output.c
+++ b/reactos/lib/sdk/crt/misc/i10output.c
@@ -11,7 +11,7 @@ struct _I10_OUTPUT_DATA {
 
 /*********************************************************************
  *              $I10_OUTPUT (MSVCRT.@)
- * ld - long double to be printed to data
+ * ld80 - long double (Intel 80 bit FP in 12 bytes) to be printed to data
  * prec - precision of part, we're interested in
  * flag - 0 for first prec digits, 1 for fractional part
  * data - data to be populated
@@ -24,16 +24,22 @@ struct _I10_OUTPUT_DATA {
  *      Native sets last byte of data->str to '0' or '9', I don't know what
  *      it means. Current implementation sets it always to '0'.
  */
-int CDECL MSVCRT_I10_OUTPUT(long double ld, int prec, int flag, struct _I10_OUTPUT_DATA *data)
+int CDECL MSVCRT_I10_OUTPUT(_LDOUBLE ld80, int prec, int flag, struct _I10_OUTPUT_DATA *data)
 {
     static const char inf_str[] = "1#INF";
     static const char nan_str[] = "1#QNAN";
 
-    double d = ld;
+    /* MS' long double type wants 12 bytes for Intel's 80 bit FP format.
+     * Some UNIX have sizeof(long double) == 16, yet only 80 bit are used.
+     * Assume long double uses 80 bit FP, never seen 128 bit FP. */
+    long double ld = 0;
+    double d;
     char format[8];
     char buf[I10_OUTPUT_MAX_PREC+9]; /* 9 = strlen("0.e+0000") + '\0' */
     char *p;
 
+    memcpy(&ld, &ld80, 10);
+    d = ld;
     TRACE("(%lf %d %x %p)\n", d, prec, flag, data);
 
     if(d<0) {