[Commit-gnuradio] [gnuradio] 05/14: volk: Added avx proto-kernel for fast exp.

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commit 43934eb5896cf6261c3d9b7662e2ee95fb344dfd
Author: Abhishek Bhowmick <address@hidden>
Date:   Thu Jun 12 18:03:56 2014 +0530

    volk: Added avx proto-kernel for fast exp.
---
 volk/kernels/volk/volk_32f_expfast_32f.h | 78 ++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/volk/kernels/volk/volk_32f_expfast_32f.h 
b/volk/kernels/volk/volk_32f_expfast_32f.h
index 0826527..01ed79a 100644
--- a/volk/kernels/volk/volk_32f_expfast_32f.h
+++ b/volk/kernels/volk/volk_32f_expfast_32f.h
@@ -12,6 +12,45 @@
 #ifndef INCLUDED_volk_32f_expfast_32f_a_H
 #define INCLUDED_volk_32f_expfast_32f_a_H
 
+#ifdef LV_HAVE_AVX
+#include <immintrin.h>
+/*!
+  \brief Computes fast exp (max 7% error) of input vector and stores results 
in output vector
+  \param bVector The vector where results will be stored
+  \param aVector The input vector of floats
+  \param num_points Number of points for which log is to be computed
+*/
+static inline void volk_32f_expfast_32f_a_avx(float* bVector, const float* 
aVector, unsigned int num_points){
+
+       float* bPtr = bVector;
+       const float* aPtr = aVector;
+    
+       unsigned int number = 0;
+        const unsigned int eighthPoints = num_points / 8;
+
+       __m256 aVal, bVal, a, b;
+       __m256i exp;
+        a = _mm256_set1_ps(A/Mln2);
+        b = _mm256_set1_ps(B-C);
+
+       for(;number < eighthPoints; number++){    
+       aVal = _mm256_load_ps(aPtr); 
+       exp = _mm256_cvtps_epi32(_mm256_add_ps(_mm256_mul_ps(a,aVal), b));
+       bVal = _mm256_castsi256_ps(exp);
+
+       _mm256_store_ps(bPtr, bVal);
+       aPtr += 8;
+       bPtr += 8;
+       }
+ 
+       number = eighthPoints * 8;
+       for(;number < num_points; number++){
+          *bPtr++ = expf(*aPtr++);
+       }
+}
+
+#endif /* LV_HAVE_AVX for aligned */
+
 #ifdef LV_HAVE_SSE4_1
 #include <smmintrin.h>
 /*!
@@ -76,6 +115,45 @@ static inline void volk_32f_expfast_32f_a_generic(float* 
bVector, const float* a
 #ifndef INCLUDED_volk_32f_expfast_32f_u_H
 #define INCLUDED_volk_32f_expfast_32f_u_H
 
+#ifdef LV_HAVE_AVX
+#include <immintrin.h>
+/*!
+  \brief Computes fast exp (max 7% error) of input vector and stores results 
in output vector
+  \param bVector The vector where results will be stored
+  \param aVector The input vector of floats
+  \param num_points Number of points for which log is to be computed
+*/
+static inline void volk_32f_expfast_32f_u_avx(float* bVector, const float* 
aVector, unsigned int num_points){
+
+       float* bPtr = bVector;
+       const float* aPtr = aVector;
+    
+       unsigned int number = 0;
+        const unsigned int eighthPoints = num_points / 8;
+
+       __m256 aVal, bVal, a, b;
+       __m256i exp;
+        a = _mm256_set1_ps(A/Mln2);
+        b = _mm256_set1_ps(B-C);
+
+       for(;number < eighthPoints; number++){    
+       aVal = _mm256_loadu_ps(aPtr); 
+       exp = _mm256_cvtps_epi32(_mm256_add_ps(_mm256_mul_ps(a,aVal), b));
+       bVal = _mm256_castsi256_ps(exp);
+
+       _mm256_storeu_ps(bPtr, bVal);
+       aPtr += 8;
+       bPtr += 8;
+       }
+ 
+       number = eighthPoints * 8;
+       for(;number < num_points; number++){
+          *bPtr++ = expf(*aPtr++);
+       }
+}
+
+#endif /* LV_HAVE_AVX for aligned */
+
 #ifdef LV_HAVE_SSE4_1
 #include <smmintrin.h>
 /*!