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Diffstat (limited to 'Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_f16.c')
| -rw-r--r-- | Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_f16.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_f16.c b/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_f16.c new file mode 100644 index 0000000..b4a03a4 --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_f16.c @@ -0,0 +1,171 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_atan2_f16.c + * Description: float16 Arc tangent of y/x + * + * $Date: 22 April 2022 + * $Revision: V1.10.0 + * + * Target Processor: Cortex-M and Cortex-A cores + * -------------------------------------------------------------------- */ +/* + * Copyright (C) 2010-2022 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/fast_math_functions_f16.h" + +#if defined(ARM_FLOAT16_SUPPORTED) + +/* + +atan for argument between in [0, 1.0] + + +*/ + +#define PIF16 3.14f16 +#define PI16HALF 1.571f16 + +#define ATANHALFF16 0.463648f16 + +#define ATAN2_NB_COEFS_F16 5 + +static const float16_t atan2_coefs_f16[ATAN2_NB_COEFS_F16]={0.f16 +,1.f16 +,0.f16 +,-0.367f16 +,0.152f16 +}; + +__STATIC_FORCEINLINE float16_t arm_atan_limited_f16(float16_t x) +{ + float16_t res=atan2_coefs_f16[ATAN2_NB_COEFS_F16-1]; + int i=1; + for(i=1;i<ATAN2_NB_COEFS_F16;i++) + { + res = (_Float16)x*(_Float16)res + (_Float16)atan2_coefs_f16[ATAN2_NB_COEFS_F16-1-i]; + } + + + return(res); +} + +__STATIC_FORCEINLINE float16_t arm_atan_f16(float16_t x) +{ + int sign=0; + float16_t res=0.0f16; + + if ((_Float16)x < 0.0f16) + { + sign=1; + x=-(_Float16)x; + } + + if ((_Float16)x > 1.0f16) + { + x = 1.0f16 / (_Float16)x; + res = (_Float16)PI16HALF - (_Float16)arm_atan_limited_f16(x); + } + else + { + res += (_Float16)arm_atan_limited_f16(x); + } + + + if (sign) + { + res = -(_Float16)res; + } + + return(res); +} + +/** + @ingroup groupFastMath + */ + + +/** + @addtogroup atan2 + @{ + */ + +/** + @brief Arc Tangent of y/x using sign of y and x to get right quadrant + @param[in] y y coordinate + @param[in] x x coordinate + @param[out] result Result + @return error status. + + @par Compute the Arc tangent of y/x: + The sign of y and x are used to determine the right quadrant + and compute the right angle. + +*/ +arm_status arm_atan2_f16(float16_t y,float16_t x,float16_t *result) +{ + if ((_Float16)x > 0.0f16) + { + *result=arm_atan_f16((_Float16)y/(_Float16)x); + return(ARM_MATH_SUCCESS); + } + if ((_Float16)x < 0.0f16) + { + if ((_Float16)y > 0.0f16) + { + *result=(_Float16)arm_atan_f16((_Float16)y/(_Float16)x) + (_Float16)PIF16; + } + else if ((_Float16)y < 0.0f16) + { + *result=(_Float16)arm_atan_f16((_Float16)y/(_Float16)x) - (_Float16)PIF16; + } + else + { + if (signbit(y)) + { + *result= -(_Float16)PIF16; + } + else + { + *result= PIF16; + } + } + return(ARM_MATH_SUCCESS); + } + if ((_Float16)x == 0.0f16) + { + if ((_Float16)y > 0.0f16) + { + *result=PI16HALF; + return(ARM_MATH_SUCCESS); + } + if ((_Float16)y < 0.0f16) + { + *result=-(_Float16)PI16HALF; + return(ARM_MATH_SUCCESS); + } + } + + + return(ARM_MATH_NANINF); + +} + +#endif /* #if defined(ARM_FLOAT16_SUPPORTED) */ +/** + @} end of atan2 group + */ |