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Diffstat (limited to 'DSP_Lib/Source/FastMathFunctions/arm_cos_q31.c')
-rw-r--r-- | DSP_Lib/Source/FastMathFunctions/arm_cos_q31.c | 96 |
1 files changed, 0 insertions, 96 deletions
diff --git a/DSP_Lib/Source/FastMathFunctions/arm_cos_q31.c b/DSP_Lib/Source/FastMathFunctions/arm_cos_q31.c deleted file mode 100644 index 72c51e6..0000000 --- a/DSP_Lib/Source/FastMathFunctions/arm_cos_q31.c +++ /dev/null @@ -1,96 +0,0 @@ -/* ---------------------------------------------------------------------- -* Copyright (C) 2010-2014 ARM Limited. All rights reserved. -* -* $Date: 07. September 2015 -* $Revision: V.1.4.5 a -* -* Project: CMSIS DSP Library -* Title: arm_cos_q31.c -* -* Description: Fast cosine calculation for Q31 values. -* -* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 -* -* Redistribution and use in source and binary forms, with or without -* modification, are permitted provided that the following conditions -* are met: -* - Redistributions of source code must retain the above copyright -* notice, this list of conditions and the following disclaimer. -* - Redistributions in binary form must reproduce the above copyright -* notice, this list of conditions and the following disclaimer in -* the documentation and/or other materials provided with the -* distribution. -* - Neither the name of ARM LIMITED nor the names of its contributors -* may be used to endorse or promote products derived from this -* software without specific prior written permission. -* -* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS -* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE -* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, -* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, -* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; -* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER -* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT -* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN -* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE -* POSSIBILITY OF SUCH DAMAGE. -* -------------------------------------------------------------------- */ - -#include "arm_math.h" -#include "arm_common_tables.h" - -/** - * @ingroup groupFastMath - */ - - /** - * @addtogroup cos - * @{ - */ - -/** - * @brief Fast approximation to the trigonometric cosine function for Q31 data. - * @param[in] x Scaled input value in radians. - * @return cos(x). - * - * The Q31 input value is in the range [0 +0.9999] and is mapped to a radian - * value in the range [0 2*pi). - */ - -q31_t arm_cos_q31( - q31_t x) -{ - q31_t cosVal; /* Temporary variables for input, output */ - int32_t index; /* Index variables */ - q31_t a, b; /* Four nearest output values */ - q31_t fract; /* Temporary values for fractional values */ - - /* add 0.25 (pi/2) to read sine table */ - x = (uint32_t)x + 0x20000000; - if(x < 0) - { /* convert negative numbers to corresponding positive ones */ - x = (uint32_t)x + 0x80000000; - } - - /* Calculate the nearest index */ - index = (uint32_t)x >> FAST_MATH_Q31_SHIFT; - - /* Calculation of fractional value */ - fract = (x - (index << FAST_MATH_Q31_SHIFT)) << 9; - - /* Read two nearest values of input value from the sin table */ - a = sinTable_q31[index]; - b = sinTable_q31[index+1]; - - /* Linear interpolation process */ - cosVal = (q63_t)(0x80000000-fract)*a >> 32; - cosVal = (q31_t)((((q63_t)cosVal << 32) + ((q63_t)fract*b)) >> 32); - - return cosVal << 1; -} - -/** - * @} end of cos group - */ |