diff options
| author | Nathan West <nathan.west@okstate.edu> | 2014-10-22 14:39:40 -0500 |
|---|---|---|
| committer | Nathan West <nathan.west@okstate.edu> | 2014-10-22 14:39:40 -0500 |
| commit | cb32b70b79f430456208a2cd521d028e0ece5d5b (patch) | |
| tree | fe57644e195baca365fee6ee4485798a39c8bb5e /volk | |
| parent | 2c4c371885c31222362f70a1cd714415d1398021 (diff) | |
volk: add a neon table version of 16u_byteswap
Diffstat (limited to 'volk')
| -rw-r--r-- | volk/kernels/volk/volk_16u_byteswap.h | 52 | ||||
| -rw-r--r-- | volk/kernels/volk/volk_16u_byteswappuppet_16u.h | 9 |
2 files changed, 61 insertions, 0 deletions
diff --git a/volk/kernels/volk/volk_16u_byteswap.h b/volk/kernels/volk/volk_16u_byteswap.h index bffdeed185..3b2f9e2c91 100644 --- a/volk/kernels/volk/volk_16u_byteswap.h +++ b/volk/kernels/volk/volk_16u_byteswap.h @@ -158,6 +158,58 @@ static inline void volk_16u_byteswap_neon(uint16_t* intsToSwap, unsigned int num } #endif /* LV_HAVE_NEON */ +#ifdef LV_HAVE_NEON +#include <arm_neon.h> +/*! + \brief Byteswaps (in-place) an aligned vector of int32_t's. + \param intsToSwap The vector of data to byte swap + \param numDataPoints The number of data points +*/ +static inline void volk_16u_byteswap_neon_table(uint16_t* intsToSwap, unsigned int num_points){ + uint16_t* inputPtr = intsToSwap; + unsigned int number = 0; + unsigned int n16points = num_points / 16; + + uint8x8x4_t input_table; + uint8x8_t int_lookup01, int_lookup23, int_lookup45, int_lookup67; + uint8x8_t swapped_int01, swapped_int23, swapped_int45, swapped_int67; + + /* these magic numbers are used as byte-indeces in the LUT. + they are pre-computed to save time. A simple C program + can calculate them; for example for lookup01: + uint8_t chars[8] = {24, 16, 8, 0, 25, 17, 9, 1}; + for(ii=0; ii < 8; ++ii) { + index += ((uint64_t)(*(chars+ii))) << (ii*8); + } + */ + int_lookup01 = vcreate_u8(1232017111498883080); + int_lookup23 = vcreate_u8(1376697457175036426); + int_lookup45 = vcreate_u8(1521377802851189772); + int_lookup67 = vcreate_u8(1666058148527343118); + + for(number = 0; number < n16points; ++number){ + input_table = vld4_u8((uint8_t*) inputPtr); + swapped_int01 = vtbl4_u8(input_table, int_lookup01); + swapped_int23 = vtbl4_u8(input_table, int_lookup23); + swapped_int45 = vtbl4_u8(input_table, int_lookup45); + swapped_int67 = vtbl4_u8(input_table, int_lookup67); + vst1_u8((uint8_t*)inputPtr, swapped_int01); + vst1_u8((uint8_t*)(inputPtr+4), swapped_int23); + vst1_u8((uint8_t*)(inputPtr+8), swapped_int45); + vst1_u8((uint8_t*)(inputPtr+12), swapped_int67); + + inputPtr += 16; + } + + for(number = n16points * 16; number < num_points; ++number){ + uint16_t output = *inputPtr; + output = (((output >> 8) & 0xff) | ((output << 8) & 0xff00)); + *inputPtr = output; + inputPtr++; + } +} +#endif /* LV_HAVE_NEON */ + #ifdef LV_HAVE_GENERIC /*! \brief Byteswaps (in-place) an aligned vector of int16_t's. diff --git a/volk/kernels/volk/volk_16u_byteswappuppet_16u.h b/volk/kernels/volk/volk_16u_byteswappuppet_16u.h index 699a7586bd..c636e2f579 100644 --- a/volk/kernels/volk/volk_16u_byteswappuppet_16u.h +++ b/volk/kernels/volk/volk_16u_byteswappuppet_16u.h @@ -24,6 +24,15 @@ static inline void volk_16u_byteswappuppet_16u_neon(uint16_t*output, uint16_t* i } #endif +#ifdef LV_HAVE_NEON +static inline void volk_16u_byteswappuppet_16u_neon_table(uint16_t*output, uint16_t* intsToSwap, unsigned int num_points){ + + volk_16u_byteswap_neon_table((uint16_t*)intsToSwap, num_points); + memcpy((void*)output, (void*)intsToSwap, num_points * sizeof(uint16_t)); + +} +#endif + #ifdef LV_HAVE_SSE2 static inline void volk_16u_byteswappuppet_16u_u_sse2(uint16_t* intsToSwap, unsigned int num_points){ |