1 files changed, 146 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/DistanceFunctions/arm_chebyshev_distance_f16.c b/Drivers/CMSIS/DSP/Source/DistanceFunctions/arm_chebyshev_distance_f16.c
new file mode 100644
index 0000000..8dec141
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+++ b/Drivers/CMSIS/DSP/Source/DistanceFunctions/arm_chebyshev_distance_f16.c
@@ -0,0 +1,146 @@
+
+/* ----------------------------------------------------------------------
+ * Project:      CMSIS DSP Library
+ * Title:        arm_chebyshev_distance_f16.c
+ * Description:  Chebyshev distance between two vectors
+ *
+ * $Date:        23 April 2021
+ * $Revision:    V1.9.0
+ *
+ * Target Processor: Cortex-M and Cortex-A cores
+ * -------------------------------------------------------------------- */
+/*
+ * Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "dsp/distance_functions_f16.h"
+
+#if defined(ARM_FLOAT16_SUPPORTED)
+
+#include <limits.h>
+#include <math.h>
+
+/**
+  @ingroup FloatDist
+ */
+
+/**
+  @defgroup Chebyshev Chebyshev distance
+
+  Chebyshev distance
+ */
+
+/**
+  @addtogroup Chebyshev
+  @{
+ */
+
+
+/**
+ * @brief        Chebyshev distance between two vectors
+ * @param[in]    pA         First vector
+ * @param[in]    pB         Second vector
+ * @param[in]    blockSize  vector length
+ * @return distance
+ *
+ */
+
+#if defined(ARM_MATH_MVE_FLOAT16) && !defined(ARM_MATH_AUTOVECTORIZE)
+
+#include "arm_helium_utils.h"
+#include "arm_vec_math.h"
+
+float16_t arm_chebyshev_distance_f16(const float16_t *pA,const float16_t *pB, uint32_t blockSize)
+{
+    uint32_t        blkCnt;     /* loop counters */
+    f16x8_t         vecA, vecB;
+    f16x8_t         vecDiff = vdupq_n_f16(0.0);
+    float16_t       maxValue = 0.0f16;
+
+
+    blkCnt = blockSize >> 3;
+    while (blkCnt > 0U) {
+        vecA = vld1q(pA);
+        pA += 8;
+        vecB = vld1q(pB);
+        pB += 8;
+        /*
+         * update per-lane max.
+         */
+        vecDiff = vmaxnmaq(vsubq(vecA, vecB), vecDiff);
+        /*
+         * Decrement the blockSize loop counter
+         */
+        blkCnt--;
+    }
+    /*
+     * tail
+     * (will be merged thru tail predication)
+     */
+    blkCnt = blockSize & 7;
+    if (blkCnt > 0U) {
+        mve_pred16_t    p0 = vctp16q(blkCnt);
+
+        vecA = vldrhq_z_f16(pA, p0);
+        vecB = vldrhq_z_f16(pB, p0);
+
+        /*
+         * Get current max per lane and current index per lane
+         * when a max is selected
+         */
+        vecDiff = vmaxnmaq_m(vecDiff, vsubq(vecA, vecB), p0);
+    }
+    /*
+     * Get max value across the vector
+     */
+    return vmaxnmavq(maxValue, vecDiff);
+}
+
+#else
+float16_t arm_chebyshev_distance_f16(const float16_t *pA,const float16_t *pB, uint32_t blockSize)
+{
+   _Float16 diff=0.0f,  maxVal,tmpA, tmpB;
+
+   tmpA = *pA++;
+   tmpB = *pB++;
+   diff = (_Float16)fabsf((float32_t)((_Float16)tmpA - (_Float16)tmpB));
+   maxVal = diff;
+   blockSize--;
+
+   while(blockSize > 0)
+   {
+      tmpA = *pA++;
+      tmpB = *pB++;
+      diff = (_Float16)fabsf((float32_t)((_Float16)tmpA - (_Float16)tmpB));
+      if ((_Float16)diff > (_Float16)maxVal)
+      {
+        maxVal = diff;
+      }
+      blockSize --;
+   }
+  
+   return(maxVal);
+}
+#endif /* defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE) */
+
+
+/**
+ * @} end of Chebyshev group
+ */
+
+#endif /* #if defined(ARM_FLOAT16_SUPPORTED) */ 
+