(nuttx) branch master updated: libm: prevent atanf() yielding NaN for high inputs values.

[acassis]

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acassis pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 23a9ff1196b libm: prevent atanf() yielding NaN for high inputs values.
23a9ff1196b is described below

commit 23a9ff1196b6fc14fe85eeddb819a016d55af798
Author: Carlos Sanchez <carlossanc...@geotab.com>
AuthorDate: Wed Jan 14 12:25:35 2026 +0100

    libm: prevent atanf() yielding NaN for high inputs values.
    
    Without this fix, values of x where x * x + 1 are rounded
    down could make asin() argument to be out of range.
    
    Signed-off-by: Carlos Sanchez <carlossanc...@geotab.com>
---
 libs/libm/libm/lib_atanf.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libs/libm/libm/lib_atanf.c b/libs/libm/libm/lib_atanf.c
index 08547152c46..65376153f79 100644
--- a/libs/libm/libm/lib_atanf.c
+++ b/libs/libm/libm/lib_atanf.c
@@ -31,12 +31,15 @@
 #include <math.h>
 #include <stddef.h>
 #include <stdint.h>
+#include <sys/param.h>
 
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
 
+#define ABS(a) ((a) > 0 ? (a) : -(a))
+
 float atanf(float x)
 {
-  return asinf(x / sqrtf(x * x + 1.0F));
+  return asinf(x / MAX(ABS(x), sqrtf(x * x + 1.0F)));
 }