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Change alignment of temporary IDFT buffer in PHY_ofdm_mod

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Alignment of temporary IDFT buffer was changed to 64 bytes. This is in preparation
for possible use of different IDFT implementation which could use AVX-512, requiring
64-byte alignment.
This commit is contained in:
Bartosz Podrygajlo
2024-12-17 23:04:30 +01:00
parent 9e6c0c8c78
commit 55b5e04e8d
1 changed files with 8 additions and 3 deletions
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openair1/PHY/MODULATION/ofdm_mod.c
+8 -3
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@@ -40,6 +40,9 @@ This section deals with basic functions for OFDM Modulation.
#include "PHY/LTE_TRANSPORT/transport_common_proto.h"
//#define DEBUG_OFDM_MOD
// Use 64-byte alignment for IDFT output buffer to ensure no
// runtime error in case IDFT implementation uses AVX-512.
#define IDFT_OUTPUT_BUFFER_ALIGNMENT 64
void normal_prefix_mod(int32_t *txdataF,int32_t *txdata,uint8_t nsymb,LTE_DL_FRAME_PARMS *frame_parms)
{
@@ -163,12 +166,13 @@ void PHY_ofdm_mod(const int *input, /// pointer to complex input
switch (etype) {
case CYCLIC_PREFIX: {
int *output_ptr = &output[(i * fftsize) + ((1 + i) * nb_prefix_samples)];
// Current idft implementation uses AVX-256: Check if buffer is already aligned to 256 bits (32 bytes)
if ((uintptr_t)output_ptr % 32 == 0) {
// output ptr is aligned, do ifft inplace
idft(idft_size, (int16_t *)&input[i * fftsize], (int16_t *)output_ptr, 1);
} else {
// output ptr is not aligned, needs an extra memcpy
c16_t temp[fftsize] __attribute__((aligned(32)));
c16_t temp[fftsize] __attribute__((aligned(IDFT_OUTPUT_BUFFER_ALIGNMENT)));
idft(idft_size, (int16_t *)&input[i * fftsize], (int16_t *)temp, 1);
memcpy((void *)output_ptr, (void *)temp, sizeof(temp));
}
@@ -178,7 +182,8 @@ void PHY_ofdm_mod(const int *input, /// pointer to complex input
}
case CYCLIC_SUFFIX: {
c16_t temp[fftsize] __attribute__((aligned(32)));
// Use alignment of 64 bytes
c16_t temp[fftsize] __attribute__((aligned(IDFT_OUTPUT_BUFFER_ALIGNMENT)));
idft(idft_size, (int16_t *)&input[i * fftsize], (int16_t *)temp, 1);
int *output_ptr = &output[(i * fftsize) + (i * nb_prefix_samples)];
memcpy(output_ptr, temp, sizeof(temp));
@@ -191,7 +196,7 @@ void PHY_ofdm_mod(const int *input, /// pointer to complex input
break;
case NONE: {
c16_t temp[fftsize] __attribute__((aligned(32)));
c16_t temp[fftsize] __attribute__((aligned(IDFT_OUTPUT_BUFFER_ALIGNMENT)));
idft(idft_size, (int16_t *)&input[i * fftsize], (int16_t *)temp, 1);
int *output_ptr = &output[i * fftsize];
memcpy(output_ptr, temp, sizeof(temp));