libm: cherry-pick one patch from freebsd to fix logb() denormals issue

Oops, fix the fix in rev.1.10.  logb() and logbf() were broken on
 denormals, and logb() remained broken after 1.10 because the fix for
 logbf() was incompletely translated.

Convert to __FBSDID().

Change-Id: I54f33648db7c421b06eee1ea8e63c57a179fae0d
Signed-off-by: Jack Ren <>
Signed-off-by: Jin Wei <>
Signed-off-by: Bruce Beare <>
1 file changed