diff options
| author | Alejandro Colomar <alx@kernel.org> | 2024-03-12 18:25:17 +0100 |
|---|---|---|
| committer | Alejandro Colomar <alx@kernel.org> | 2024-03-12 18:25:19 +0100 |
| commit | a4ea5f76215dcf1d8d017eb65ab12919ccf09f3f (patch) | |
| tree | 1087a6ee27db5639893a1c290ced79ea4c69a0b6 | |
| parent | 347f1ebaaf2495196bbb2efe8a74e87cc797d944 (diff) | |
logb.3: floor(log2(fabs(x))) has rounding errors
Link: <https://inbox.sourceware.org/libc-alpha/20240305150131.GD3653@qaa.vinc17.org/T/#m3ceecda630012995339bcc5448fee451cf277a8b>
Reported-by: Vincent Lefevre <vincent@vinc17.net>
Suggested-by: Vincent Lefevre <vincent@vinc17.net>
Cc: Morten Welinder <mwelinder@gmail.com>
Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
| -rw-r--r-- | man3/logb.3 | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/man3/logb.3 b/man3/logb.3 index 7a1ad2f4a..6d1cb5be8 100644 --- a/man3/logb.3 +++ b/man3/logb.3 @@ -57,9 +57,10 @@ If .B FLT_RADIX is 2, .BI logb( x ) -is equal to +is similar to .BI floor(log2(fabs( x )))\f[R],\f[] -except that it is probably faster. +except that the latter may give an incorrect integer +due to intermediate rounding. .P If .I x |