[PATCH] Cygwin: fix return value of sqrtl on negative infinity
Ken Brown
kbrown@cornell.edu
Tue Oct 27 14:10:37 GMT 2020
The return value is now -NaN.
This fixes a bug in the mingw-w64 code that was imported into Cygwin.
The fix is consistent with Posix and Linux. It is also consistent
with the current mingw-w64 code, with one exception: The mingw-w64
code sets errno to EDOM if the input is -NaN, but this appears to
differ from Posix and Linux.
Addresses: https://cygwin.com/pipermail/cygwin/2020-October/246606.html
---
winsup/cygwin/math/sqrt.def.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/winsup/cygwin/math/sqrt.def.h b/winsup/cygwin/math/sqrt.def.h
index cf8b5cbe6..3d1a00908 100644
--- a/winsup/cygwin/math/sqrt.def.h
+++ b/winsup/cygwin/math/sqrt.def.h
@@ -73,8 +73,11 @@ __FLT_ABI (sqrt) (__FLT_TYPE x)
if (x_class == FP_ZERO)
return __FLT_CST (-0.0);
+ if (x_class == FP_NAN)
+ return x;
+
errno = EDOM;
- return x;
+ return -__FLT_NAN;
}
else if (x_class == FP_ZERO)
return __FLT_CST (0.0);
--
2.28.0
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