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-rw-r--r--src/util.c42
1 files changed, 3 insertions, 39 deletions
diff --git a/src/util.c b/src/util.c
index 938b6a9fb..31c88046e 100644
--- a/src/util.c
+++ b/src/util.c
@@ -58,47 +58,11 @@ int sqlite3FaultSim(int iTest){
#ifndef SQLITE_OMIT_FLOATING_POINT
/*
** Return true if the floating point value is Not a Number (NaN).
-**
-** Use the math library isnan() function if compiled with SQLITE_HAVE_ISNAN.
-** Otherwise, we have our own implementation that works on most systems.
*/
int sqlite3IsNaN(double x){
- int rc; /* The value return */
-#if !SQLITE_HAVE_ISNAN && !HAVE_ISNAN
- /*
- ** Systems that support the isnan() library function should probably
- ** make use of it by compiling with -DSQLITE_HAVE_ISNAN. But we have
- ** found that many systems do not have a working isnan() function so
- ** this implementation is provided as an alternative.
- **
- ** This NaN test sometimes fails if compiled on GCC with -ffast-math.
- ** On the other hand, the use of -ffast-math comes with the following
- ** warning:
- **
- ** This option [-ffast-math] should never be turned on by any
- ** -O option since it can result in incorrect output for programs
- ** which depend on an exact implementation of IEEE or ISO
- ** rules/specifications for math functions.
- **
- ** Under MSVC, this NaN test may fail if compiled with a floating-
- ** point precision mode other than /fp:precise. From the MSDN
- ** documentation:
- **
- ** The compiler [with /fp:precise] will properly handle comparisons
- ** involving NaN. For example, x != x evaluates to true if x is NaN
- ** ...
- */
-#ifdef __FAST_MATH__
-# error SQLite will not work correctly with the -ffast-math option of GCC.
-#endif
- volatile double y = x;
- volatile double z = y;
- rc = (y!=z);
-#else /* if HAVE_ISNAN */
- rc = isnan(x);
-#endif /* HAVE_ISNAN */
- testcase( rc );
- return rc;
+ u64 y;
+ memcpy(&y,&x,sizeof(y));
+ return IsNaN(y);
}
#endif /* SQLITE_OMIT_FLOATING_POINT */