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Diffstat (limited to 'DSP_Lib/Source/TransformFunctions/arm_cfft_radix2_f32.c')
-rw-r--r-- | DSP_Lib/Source/TransformFunctions/arm_cfft_radix2_f32.c | 485 |
1 files changed, 485 insertions, 0 deletions
diff --git a/DSP_Lib/Source/TransformFunctions/arm_cfft_radix2_f32.c b/DSP_Lib/Source/TransformFunctions/arm_cfft_radix2_f32.c new file mode 100644 index 0000000..8e3b77c --- /dev/null +++ b/DSP_Lib/Source/TransformFunctions/arm_cfft_radix2_f32.c @@ -0,0 +1,485 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2014 ARM Limited. All rights reserved. +* +* $Date: 19. March 2015 +* $Revision: V.1.4.5 +* +* Project: CMSIS DSP Library +* Title: arm_cfft_radix2_f32.c +* +* Description: Radix-2 Decimation in Frequency CFFT & CIFFT Floating point processing function +* +* +* 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" + +void arm_radix2_butterfly_f32( + float32_t * pSrc, + uint32_t fftLen, + float32_t * pCoef, + uint16_t twidCoefModifier); + +void arm_radix2_butterfly_inverse_f32( + float32_t * pSrc, + uint32_t fftLen, + float32_t * pCoef, + uint16_t twidCoefModifier, + float32_t onebyfftLen); + +extern void arm_bitreversal_f32( + float32_t * pSrc, + uint16_t fftSize, + uint16_t bitRevFactor, + uint16_t * pBitRevTab); + +/** +* @ingroup groupTransforms +*/ + +/** +* @addtogroup ComplexFFT +* @{ +*/ + +/** +* @details +* @brief Radix-2 CFFT/CIFFT. +* @deprecated Do not use this function. It has been superseded by \ref arm_cfft_f32 and will be removed +* in the future. +* @param[in] *S points to an instance of the floating-point Radix-2 CFFT/CIFFT structure. +* @param[in, out] *pSrc points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place. +* @return none. +*/ + +void arm_cfft_radix2_f32( +const arm_cfft_radix2_instance_f32 * S, +float32_t * pSrc) +{ + + if(S->ifftFlag == 1u) + { + /* Complex IFFT radix-2 */ + arm_radix2_butterfly_inverse_f32(pSrc, S->fftLen, S->pTwiddle, + S->twidCoefModifier, S->onebyfftLen); + } + else + { + /* Complex FFT radix-2 */ + arm_radix2_butterfly_f32(pSrc, S->fftLen, S->pTwiddle, + S->twidCoefModifier); + } + + if(S->bitReverseFlag == 1u) + { + /* Bit Reversal */ + arm_bitreversal_f32(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable); + } + +} + + +/** +* @} end of ComplexFFT group +*/ + + + +/* ---------------------------------------------------------------------- +** Internal helper function used by the FFTs +** ------------------------------------------------------------------- */ + +/* +* @brief Core function for the floating-point CFFT butterfly process. +* @param[in, out] *pSrc points to the in-place buffer of floating-point data type. +* @param[in] fftLen length of the FFT. +* @param[in] *pCoef points to the twiddle coefficient buffer. +* @param[in] twidCoefModifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table. +* @return none. +*/ + +void arm_radix2_butterfly_f32( +float32_t * pSrc, +uint32_t fftLen, +float32_t * pCoef, +uint16_t twidCoefModifier) +{ + + uint32_t i, j, k, l; + uint32_t n1, n2, ia; + float32_t xt, yt, cosVal, sinVal; + float32_t p0, p1, p2, p3; + float32_t a0, a1; + +#ifndef ARM_MATH_CM0_FAMILY + + /* Initializations for the first stage */ + n2 = fftLen >> 1; + ia = 0; + i = 0; + + // loop for groups + for (k = n2; k > 0; k--) + { + cosVal = pCoef[ia * 2]; + sinVal = pCoef[(ia * 2) + 1]; + + /* Twiddle coefficients index modifier */ + ia += twidCoefModifier; + + /* index calculation for the input as, */ + /* pSrc[i + 0], pSrc[i + fftLen/1] */ + l = i + n2; + + /* Butterfly implementation */ + a0 = pSrc[2 * i] + pSrc[2 * l]; + xt = pSrc[2 * i] - pSrc[2 * l]; + + yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; + a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; + + p0 = xt * cosVal; + p1 = yt * sinVal; + p2 = yt * cosVal; + p3 = xt * sinVal; + + pSrc[2 * i] = a0; + pSrc[2 * i + 1] = a1; + + pSrc[2 * l] = p0 + p1; + pSrc[2 * l + 1] = p2 - p3; + + i++; + } // groups loop end + + twidCoefModifier <<= 1u; + + // loop for stage + for (k = n2; k > 2; k = k >> 1) + { + n1 = n2; + n2 = n2 >> 1; + ia = 0; + + // loop for groups + j = 0; + do + { + cosVal = pCoef[ia * 2]; + sinVal = pCoef[(ia * 2) + 1]; + ia += twidCoefModifier; + + // loop for butterfly + i = j; + do + { + l = i + n2; + a0 = pSrc[2 * i] + pSrc[2 * l]; + xt = pSrc[2 * i] - pSrc[2 * l]; + + yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; + a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; + + p0 = xt * cosVal; + p1 = yt * sinVal; + p2 = yt * cosVal; + p3 = xt * sinVal; + + pSrc[2 * i] = a0; + pSrc[2 * i + 1] = a1; + + pSrc[2 * l] = p0 + p1; + pSrc[2 * l + 1] = p2 - p3; + + i += n1; + } while( i < fftLen ); // butterfly loop end + j++; + } while( j < n2); // groups loop end + twidCoefModifier <<= 1u; + } // stages loop end + + // loop for butterfly + for (i = 0; i < fftLen; i += 2) + { + a0 = pSrc[2 * i] + pSrc[2 * i + 2]; + xt = pSrc[2 * i] - pSrc[2 * i + 2]; + + yt = pSrc[2 * i + 1] - pSrc[2 * i + 3]; + a1 = pSrc[2 * i + 3] + pSrc[2 * i + 1]; + + pSrc[2 * i] = a0; + pSrc[2 * i + 1] = a1; + pSrc[2 * i + 2] = xt; + pSrc[2 * i + 3] = yt; + } // groups loop end + +#else + + n2 = fftLen; + + // loop for stage + for (k = fftLen; k > 1; k = k >> 1) + { + n1 = n2; + n2 = n2 >> 1; + ia = 0; + + // loop for groups + j = 0; + do + { + cosVal = pCoef[ia * 2]; + sinVal = pCoef[(ia * 2) + 1]; + ia += twidCoefModifier; + + // loop for butterfly + i = j; + do + { + l = i + n2; + a0 = pSrc[2 * i] + pSrc[2 * l]; + xt = pSrc[2 * i] - pSrc[2 * l]; + + yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; + a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; + + p0 = xt * cosVal; + p1 = yt * sinVal; + p2 = yt * cosVal; + p3 = xt * sinVal; + + pSrc[2 * i] = a0; + pSrc[2 * i + 1] = a1; + + pSrc[2 * l] = p0 + p1; + pSrc[2 * l + 1] = p2 - p3; + + i += n1; + } while(i < fftLen); + j++; + } while(j < n2); + twidCoefModifier <<= 1u; + } + +#endif // #ifndef ARM_MATH_CM0_FAMILY + +} + + +void arm_radix2_butterfly_inverse_f32( +float32_t * pSrc, +uint32_t fftLen, +float32_t * pCoef, +uint16_t twidCoefModifier, +float32_t onebyfftLen) +{ + + uint32_t i, j, k, l; + uint32_t n1, n2, ia; + float32_t xt, yt, cosVal, sinVal; + float32_t p0, p1, p2, p3; + float32_t a0, a1; + +#ifndef ARM_MATH_CM0_FAMILY + + n2 = fftLen >> 1; + ia = 0; + + // loop for groups + for (i = 0; i < n2; i++) + { + cosVal = pCoef[ia * 2]; + sinVal = pCoef[(ia * 2) + 1]; + ia += twidCoefModifier; + + l = i + n2; + a0 = pSrc[2 * i] + pSrc[2 * l]; + xt = pSrc[2 * i] - pSrc[2 * l]; + + yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; + a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; + + p0 = xt * cosVal; + p1 = yt * sinVal; + p2 = yt * cosVal; + p3 = xt * sinVal; + + pSrc[2 * i] = a0; + pSrc[2 * i + 1] = a1; + + pSrc[2 * l] = p0 - p1; + pSrc[2 * l + 1] = p2 + p3; + } // groups loop end + + twidCoefModifier <<= 1u; + + // loop for stage + for (k = fftLen / 2; k > 2; k = k >> 1) + { + n1 = n2; + n2 = n2 >> 1; + ia = 0; + + // loop for groups + j = 0; + do + { + cosVal = pCoef[ia * 2]; + sinVal = pCoef[(ia * 2) + 1]; + ia += twidCoefModifier; + + // loop for butterfly + i = j; + do + { + l = i + n2; + a0 = pSrc[2 * i] + pSrc[2 * l]; + xt = pSrc[2 * i] - pSrc[2 * l]; + + yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; + a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; + + p0 = xt * cosVal; + p1 = yt * sinVal; + p2 = yt * cosVal; + p3 = xt * sinVal; + + pSrc[2 * i] = a0; + pSrc[2 * i + 1] = a1; + + pSrc[2 * l] = p0 - p1; + pSrc[2 * l + 1] = p2 + p3; + + i += n1; + } while( i < fftLen ); // butterfly loop end + j++; + } while(j < n2); // groups loop end + + twidCoefModifier <<= 1u; + } // stages loop end + + // loop for butterfly + for (i = 0; i < fftLen; i += 2) + { + a0 = pSrc[2 * i] + pSrc[2 * i + 2]; + xt = pSrc[2 * i] - pSrc[2 * i + 2]; + + a1 = pSrc[2 * i + 3] + pSrc[2 * i + 1]; + yt = pSrc[2 * i + 1] - pSrc[2 * i + 3]; + + p0 = a0 * onebyfftLen; + p2 = xt * onebyfftLen; + p1 = a1 * onebyfftLen; + p3 = yt * onebyfftLen; + + pSrc[2 * i] = p0; + pSrc[2 * i + 1] = p1; + pSrc[2 * i + 2] = p2; + pSrc[2 * i + 3] = p3; + } // butterfly loop end + +#else + + n2 = fftLen; + + // loop for stage + for (k = fftLen; k > 2; k = k >> 1) + { + n1 = n2; + n2 = n2 >> 1; + ia = 0; + + // loop for groups + j = 0; + do + { + cosVal = pCoef[ia * 2]; + sinVal = pCoef[(ia * 2) + 1]; + ia = ia + twidCoefModifier; + + // loop for butterfly + i = j; + do + { + l = i + n2; + a0 = pSrc[2 * i] + pSrc[2 * l]; + xt = pSrc[2 * i] - pSrc[2 * l]; + + yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; + a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; + + p0 = xt * cosVal; + p1 = yt * sinVal; + p2 = yt * cosVal; + p3 = xt * sinVal; + + pSrc[2 * i] = a0; + pSrc[2 * i + 1] = a1; + + pSrc[2 * l] = p0 - p1; + pSrc[2 * l + 1] = p2 + p3; + + i += n1; + } while( i < fftLen ); // butterfly loop end + j++; + } while( j < n2 ); // groups loop end + + twidCoefModifier = twidCoefModifier << 1u; + } // stages loop end + + n1 = n2; + n2 = n2 >> 1; + + // loop for butterfly + for (i = 0; i < fftLen; i += n1) + { + l = i + n2; + + a0 = pSrc[2 * i] + pSrc[2 * l]; + xt = pSrc[2 * i] - pSrc[2 * l]; + + a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; + yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; + + p0 = a0 * onebyfftLen; + p2 = xt * onebyfftLen; + p1 = a1 * onebyfftLen; + p3 = yt * onebyfftLen; + + pSrc[2 * i] = p0; + pSrc[2u * l] = p2; + + pSrc[2 * i + 1] = p1; + pSrc[2u * l + 1u] = p3; + } // butterfly loop end + +#endif // #ifndef ARM_MATH_CM0_FAMILY + +} |