Math: Rename square root function sqrt_int16() to sofm_sqrt_int16()

The rename is done to avoid possible conflict with other math
libraries. The change is done to prepare add of 32 bit square root
function.

Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>

Author: singalsu

src/audio/tdfb/tdfb_direction.c

@@ -108,7 +108,7 @@ static inline int16_t tdfb_mic_distance_sqrt(int32_t x)
 
 	xs = Q_SHIFT_RND(x, 24, 12);
 	xs = MIN(xs, UINT16_MAX);
-	return sqrt_int16((uint16_t)xs);
+	return sofm_sqrt_int16((uint16_t)xs);
 }
 
 static int16_t max_mic_distance(struct tdfb_comp_data *cd)

src/include/sof/math/sqrt.h

@@ -1,15 +1,20 @@
 /* SPDX-License-Identifier: BSD-3-Clause
  *
- * Copyright(c) 2021 Intel Corporation. All rights reserved.
+ * Copyright(c) 2021-2026 Intel Corporation.
  *
  * Author: Shriram Shastry <malladi.sastry@linux.intel.com>
  *
  */
 
-#ifndef __SOF_MATH__SQRTLOOKUP__H
-#define __SOF_MATH__SQRTLOOKUP__H
+#ifndef __SOF_MATH_SQRT_H__
+#define __SOF_MATH_SQRT_H__
 
 #include <stdint.h>
 
-uint16_t sqrt_int16(uint16_t u);
-#endif
+/**
+ * sofm_sqrt_int16() - Calculate 16-bit fractional square root function.
+ * @param u Input value in Q4.12 format, from 0 to 16.0.
+ * @return Calculated square root of n in Q4.12 format, from 0 to 4.0.
+ */
+uint16_t sofm_sqrt_int16(uint16_t u);
+#endif /* __SOF_MATH_SQRT_H__ */

src/math/dct.c

@@ -58,7 +58,7 @@ int mod_dct_initialize_16(struct processing_module *mod, struct dct_plan_16 *dct
 
 	c1 = PI_Q29 / dct->num_in;
 	arg = Q_SHIFT_RND(TWO_Q29 / dct->num_in, 29, 12);
-	c2 = sqrt_int16(arg); /* Q4.12 */
+	c2 = sofm_sqrt_int16(arg); /* Q4.12 */
 	for (n = 0; n < dct->num_in; n++) {
 		for (k = 0; k < dct->num_out; k++) {
 			/* Note: Current int16_t nk works up to DCT_MATRIX_SIZE_MAX = 91 */

src/math/sqrt_int16.c

@@ -29,7 +29,7 @@
  * Arguments	: uint16_t u
  * Return Type	: int32_t
  */
-uint16_t sqrt_int16(uint16_t u)
+uint16_t sofm_sqrt_int16(uint16_t u)
 {
 	static const int32_t iv1[193] = {
 	    46341, 46702, 47059, 47415, 47767, 48117, 48465, 48809, 49152, 49492, 49830, 50166,
@@ -146,4 +146,4 @@ uint16_t sqrt_int16(uint16_t u)
 
 	return y;
 }
-EXPORT_SYMBOL(sqrt_int16);
+EXPORT_SYMBOL(sofm_sqrt_int16);

test/cmocka/src/math/arithmetic/square_root.c

@@ -139,7 +139,7 @@ static void test_math_arithmetic_sqrt_fixed(void **state)
 
 	memcpy_s((void *)&u[0], sizeof(u), (void *)&uv[0], 252U * sizeof(uint32_t));
 	for (i = 0; i < ARRAY_SIZE(sqrt_ref_table); i++) {
-		y = Q_CONVERT_QTOF(sqrt_int16(u[i]), 12);
+		y = Q_CONVERT_QTOF(sofm_sqrt_int16(u[i]), 12);
 		diff = fabs(sqrt_ref_table[i] - y);
 
 		if (diff > CMP_TOLERANCE) {