From 7cd38dca6a3e636131797266b43b980280999789 Mon Sep 17 00:00:00 2001
From: yanghuatao <yanghuatao@xiaomi.com>
Date: Fri, 15 Dec 2023 14:35:20 +0800
Subject: [PATCH] nuttx/libm: Fix powf wrong if first parameter is negative

Signed-off-by: yanghuatao <yanghuatao@xiaomi.com>
---
 libs/libm/libm/lib_powf.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/libs/libm/libm/lib_powf.c b/libs/libm/libm/lib_powf.c
index 27d5f30d49..60e7b33fb6 100644
--- a/libs/libm/libm/lib_powf.c
+++ b/libs/libm/libm/lib_powf.c
@@ -37,5 +37,21 @@
 
 float powf(float b, float e)
 {
-  return expf(e * logf(b));
+  if (b > 0.0)
+    {
+      return expf(e * logf(b));
+    }
+  else if (b < 0.0 && e == (int)e)
+    {
+      if ((int)e % 2 == 0)
+        {
+          return expf(e * logf(fabsf(b)));
+        }
+      else
+        {
+          return -expf(e * logf(fabsf(b)));
+        }
+    }
+
+  return 0.0;
 }