[incubator-nuttx] branch master updated: bug patch for frexpf function

[ac...@apache.org]

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


The following commit(s) were added to refs/heads/master by this push:
     new a310b09  bug patch for frexpf function
a310b09 is described below

commit a310b0952f9329ea483e642c6b55c6e52f041fcb
Author: zouboan <ff...@feedforward.com.cn>
AuthorDate: Fri Jan 21 22:46:34 2022 +0800

    bug patch for frexpf function
---
 libs/libc/math/lib_frexpf.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/libs/libc/math/lib_frexpf.c b/libs/libc/math/lib_frexpf.c
index 76284fd..e8a6b1f 100644
--- a/libs/libc/math/lib_frexpf.c
+++ b/libs/libc/math/lib_frexpf.c
@@ -37,6 +37,21 @@
 
 float frexpf(float x, int *exponent)
 {
-  *exponent = (int)ceilf(log2f(x));
-  return x / ldexpf(1.0F, *exponent);
+  float res;
+
+  *exponent = (int)ceilf(log2f(fabsf(x)));
+  res = x / ldexpf(1.0F, *exponent);
+  if (res >= 1.0)
+    {
+      res -= 0.5;
+      *exponent += 1;
+    }
+
+  if (res <= -1.0)
+    {
+      res += 0.5;
+      *exponent += 1;
+    }
+
+  return res;
 }