Diff: TransformFunctions/arm_cfft_radix2_q31.c

Revision:

0:3d9c67d97d6f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TransformFunctions/arm_cfft_radix2_q31.c	Mon Jul 28 15:03:15 2014 +0000
@@ -0,0 +1,350 @@
+/* ----------------------------------------------------------------------   
+* Copyright (C) 2010-2014 ARM Limited. All rights reserved.   
+*   
+* $Date:        12. March 2014  
+* $Revision: 	V1.4.3  
+*   
+* Project: 	    CMSIS DSP Library   
+* Title:	    arm_cfft_radix2_q31.c   
+*   
+* Description:	Radix-2 Decimation in Frequency CFFT & CIFFT Fixed 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_q31(
+  q31_t * pSrc,
+  uint32_t fftLen,
+  q31_t * pCoef,
+  uint16_t twidCoefModifier);
+
+void arm_radix2_butterfly_inverse_q31(
+  q31_t * pSrc,
+  uint32_t fftLen,
+  q31_t * pCoef,
+  uint16_t twidCoefModifier);
+
+void arm_bitreversal_q31(
+  q31_t * pSrc,
+  uint32_t fftLen,
+  uint16_t bitRevFactor,
+  uint16_t * pBitRevTab);
+
+/**   
+* @ingroup groupTransforms   
+*/
+
+/**   
+* @addtogroup ComplexFFT   
+* @{   
+*/
+
+/**   
+* @details   
+* @brief Processing function for the fixed-point CFFT/CIFFT.  
+* @param[in]      *S    points to an instance of the fixed-point 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_q31(
+const arm_cfft_radix2_instance_q31 * S,
+q31_t * pSrc)
+{
+
+   if(S->ifftFlag == 1u)
+   {
+      arm_radix2_butterfly_inverse_q31(pSrc, S->fftLen,
+      S->pTwiddle, S->twidCoefModifier);
+   }
+   else
+   {
+      arm_radix2_butterfly_q31(pSrc, S->fftLen,
+      S->pTwiddle, S->twidCoefModifier);
+   }
+
+   arm_bitreversal_q31(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable);
+}
+
+/**   
+* @} end of ComplexFFT group   
+*/
+
+void arm_radix2_butterfly_q31(
+q31_t * pSrc,
+uint32_t fftLen,
+q31_t * pCoef,
+uint16_t twidCoefModifier)
+{
+
+   unsigned i, j, k, l, m;
+   unsigned n1, n2, ia;
+   q31_t xt, yt, cosVal, sinVal;
+   q31_t p0, p1;
+
+   //N = fftLen; 
+   n2 = fftLen;
+
+   n1 = n2;
+   n2 = n2 >> 1;
+   ia = 0;
+
+   // loop for groups 
+   for (i = 0; i < n2; i++)
+   {
+      cosVal = pCoef[ia * 2];
+      sinVal = pCoef[(ia * 2) + 1];
+      ia = ia + twidCoefModifier;
+
+      l = i + n2;
+      xt = (pSrc[2 * i] >> 1u) - (pSrc[2 * l] >> 1u);
+      pSrc[2 * i] = ((pSrc[2 * i] >> 1u) + (pSrc[2 * l] >> 1u)) >> 1u;
+      
+      yt = (pSrc[2 * i + 1] >> 1u) - (pSrc[2 * l + 1] >> 1u);
+      pSrc[2 * i + 1] =
+        ((pSrc[2 * l + 1] >> 1u) + (pSrc[2 * i + 1] >> 1u)) >> 1u;
+
+      mult_32x32_keep32_R(p0, xt, cosVal);
+      mult_32x32_keep32_R(p1, yt, cosVal);
+      multAcc_32x32_keep32_R(p0, yt, sinVal); 
+      multSub_32x32_keep32_R(p1, xt, sinVal);
+      
+      pSrc[2u * l] = p0;
+      pSrc[2u * l + 1u] = p1;
+
+   }                             // 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 
+      for (j = 0; j < n2; j++)
+      {
+         cosVal = pCoef[ia * 2];
+         sinVal = pCoef[(ia * 2) + 1];
+         ia = ia + twidCoefModifier;
+
+         // loop for butterfly 
+         i = j;
+         m = fftLen / n1;
+         do
+         {
+            l = i + n2;
+            xt = pSrc[2 * i] - pSrc[2 * l];
+            pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u;
+            
+            yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
+            pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u;
+
+            mult_32x32_keep32_R(p0, xt, cosVal);
+            mult_32x32_keep32_R(p1, yt, cosVal);
+            multAcc_32x32_keep32_R(p0, yt, sinVal);
+            multSub_32x32_keep32_R(p1, xt, sinVal);
+            
+            pSrc[2u * l] = p0;
+            pSrc[2u * l + 1u] = p1;
+            i += n1;
+            m--;
+         } while( m > 0);                   // butterfly loop end 
+
+      }                           // groups loop end 
+
+      twidCoefModifier <<= 1u;
+   }                             // stages loop end 
+
+   n1 = n2;
+   n2 = n2 >> 1;
+   ia = 0;
+
+   cosVal = pCoef[ia * 2];
+   sinVal = pCoef[(ia * 2) + 1];
+   ia = ia + twidCoefModifier;
+
+   // loop for butterfly 
+   for (i = 0; i < fftLen; i += n1)
+   {
+      l = i + n2;
+      xt = pSrc[2 * i] - pSrc[2 * l];
+      pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
+
+      yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
+      pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
+
+      pSrc[2u * l] = xt;
+
+      pSrc[2u * l + 1u] = yt;
+
+      i += n1;
+      l = i + n2;
+
+      xt = pSrc[2 * i] - pSrc[2 * l];
+      pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
+
+      yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
+      pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
+
+      pSrc[2u * l] = xt;
+
+      pSrc[2u * l + 1u] = yt;
+
+   }                             // butterfly loop end 
+
+}
+
+
+void arm_radix2_butterfly_inverse_q31(
+q31_t * pSrc,
+uint32_t fftLen,
+q31_t * pCoef,
+uint16_t twidCoefModifier)
+{
+
+   unsigned i, j, k, l;
+   unsigned n1, n2, ia;
+   q31_t xt, yt, cosVal, sinVal;
+   q31_t p0, p1;
+
+   //N = fftLen; 
+   n2 = fftLen;
+
+   n1 = n2;
+   n2 = n2 >> 1;
+   ia = 0;
+
+   // loop for groups 
+   for (i = 0; i < n2; i++)
+   {
+      cosVal = pCoef[ia * 2];
+      sinVal = pCoef[(ia * 2) + 1];
+      ia = ia + twidCoefModifier;
+
+      l = i + n2;
+      xt = (pSrc[2 * i] >> 1u) - (pSrc[2 * l] >> 1u);
+      pSrc[2 * i] = ((pSrc[2 * i] >> 1u) + (pSrc[2 * l] >> 1u)) >> 1u;
+      
+      yt = (pSrc[2 * i + 1] >> 1u) - (pSrc[2 * l + 1] >> 1u);
+      pSrc[2 * i + 1] =
+        ((pSrc[2 * l + 1] >> 1u) + (pSrc[2 * i + 1] >> 1u)) >> 1u;
+
+      mult_32x32_keep32_R(p0, xt, cosVal);
+      mult_32x32_keep32_R(p1, yt, cosVal);
+      multSub_32x32_keep32_R(p0, yt, sinVal);
+      multAcc_32x32_keep32_R(p1, xt, sinVal);
+      
+      pSrc[2u * l] = p0;
+      pSrc[2u * l + 1u] = p1;
+   }                             // groups loop end 
+
+   twidCoefModifier = twidCoefModifier << 1u;
+
+   // loop for stage 
+   for (k = fftLen / 2; k > 2; k = k >> 1)
+   {
+      n1 = n2;
+      n2 = n2 >> 1;
+      ia = 0;
+
+      // loop for groups 
+      for (j = 0; j < n2; j++)
+      {
+         cosVal = pCoef[ia * 2];
+         sinVal = pCoef[(ia * 2) + 1];
+         ia = ia + twidCoefModifier;
+
+         // loop for butterfly 
+         for (i = j; i < fftLen; i += n1)
+         {
+            l = i + n2;
+            xt = pSrc[2 * i] - pSrc[2 * l];
+            pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u;
+      
+            yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
+            pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u;
+
+            mult_32x32_keep32_R(p0, xt, cosVal);
+            mult_32x32_keep32_R(p1, yt, cosVal);
+            multSub_32x32_keep32_R(p0, yt, sinVal);
+            multAcc_32x32_keep32_R(p1, xt, sinVal);
+            
+            pSrc[2u * l] = p0;
+            pSrc[2u * l + 1u] = p1;
+         }                         // butterfly loop end 
+
+      }                           // groups loop end 
+
+      twidCoefModifier = twidCoefModifier << 1u;
+   }                             // stages loop end 
+
+   n1 = n2;
+   n2 = n2 >> 1;
+   ia = 0;
+
+   cosVal = pCoef[ia * 2];
+   sinVal = pCoef[(ia * 2) + 1];
+   ia = ia + twidCoefModifier;
+
+   // loop for butterfly 
+   for (i = 0; i < fftLen; i += n1)
+   {
+      l = i + n2;
+      xt = pSrc[2 * i] - pSrc[2 * l];
+      pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
+
+      yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
+      pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
+
+      pSrc[2u * l] = xt;
+
+      pSrc[2u * l + 1u] = yt;
+
+      i += n1;
+      l = i + n2;
+
+      xt = pSrc[2 * i] - pSrc[2 * l];
+      pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
+
+      yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
+      pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
+
+      pSrc[2u * l] = xt;
+
+      pSrc[2u * l + 1u] = yt;
+
+   }                             // butterfly loop end 
+
+}