fix fp16 bug (#1249)

* fix fp16 bug

* apply code-format changes
Co-authored-by: Nroot <root@ddzhao.openailab.local>
Co-authored-by: Nxiguadong <xiguadong@users.noreply.github.com>

source/utility/float.c

@@ -23,7 +23,6 @@
  */
 
 #include "utility/float.h"
-#include <math.h>
 
 #define BF16_EXP_MAX (256 - 1)  //  2^8 - 1
 #define FP16_EXP_MAX (32 - 1)   //  2^5 - 1
@@ -37,7 +36,8 @@
 #define FP32_NAN ((FP32_EXP_MAX << 23) + 1)
 #define FP32_INF ((FP32_EXP_MAX << 23) + 0)
 
-#ifndef __ARM_ARCH
+#if !defined(__ARM_ARCH) || (defined(__ARM_ARCH) && (0 == __ARM_FEATURE_FP16_VECTOR_ARITHMETIC))
+
 fp32_t fp16_to_fp32(fp16_t package)
 {
     fp32_pack_t data;
@@ -100,7 +100,7 @@ fp32_t fp16_to_fp32(fp16_t package)
         return data.value;
     }
 
-    return NAN;
+    return data.value;
 }
 
 fp16_t fp32_to_fp16(fp32_t value)

source/utility/float.h

@@ -121,10 +121,14 @@ typedef union fp64_pack
 #endif
 
 #ifdef __ARM_ARCH
+#if __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
 typedef __fp16 fp16_t;
 #else
 typedef fp16_pack_t fp16_t;
 #endif
+#else
+typedef fp16_pack_t fp16_t;
+#endif
 typedef bf16_pack_t bf16_t;
 typedef float fp32_t;
 typedef double fp64_t;
@@ -168,6 +172,28 @@ fp32_t bf16_to_fp32(bf16_t package);
 bf16_t fp32_to_bf16(fp32_t package);
 
 #ifdef __ARM_ARCH
+
+#if __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
 #define fp16_to_fp32(data) ({ float f = data; f; })
 #define fp32_to_fp16(data) ({ __fp16 f = data; f; })
+#else
+/*!
+* @brief  Convert a number from float16 to float32.
+*
+* @param [in]  package: Input float16 precision number.
+*
+* @return  The converted float32 precision number.
+*/
+fp32_t fp16_to_fp32(fp16_t package);
+
+/*!
+* @brief  Convert a number from float32 to float16.
+*
+* @param [in]  package: Input float32 precision number.
+*
+* @return  The converted float16 precision number.
+*/
+fp16_t fp32_to_fp16(fp32_t package);
+#endif
+
 #endif