maki/openairinterface5g
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Change alignment of temporary IDFT buffer in PHY_ofdm_mod

Browse Source 
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
Download Patch File Download Diff File Expand all files Collapse all files
openair1/PHY/MODULATION/ofdm_mod.c
+8 -3
View File
@@ -40,6 +40,9 @@ This section deals with basic functions for OFDM Modulation.
#include "PHY/LTE_TRANSPORT/transport_common_proto.h" #include "PHY/LTE_TRANSPORT/transport_common_proto.h"
//#define DEBUG_OFDM_MOD //#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) 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) { switch (etype) {
case CYCLIC_PREFIX: { case CYCLIC_PREFIX: {
int *output_ptr = &output[(i * fftsize) + ((1 + i) * nb_prefix_samples)]; 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) { if ((uintptr_t)output_ptr % 32 == 0) {
// output ptr is aligned, do ifft inplace // output ptr is aligned, do ifft inplace
idft(idft_size, (int16_t *)&input[i * fftsize], (int16_t *)output_ptr, 1); idft(idft_size, (int16_t *)&input[i * fftsize], (int16_t *)output_ptr, 1);
} else { } else {
// output ptr is not aligned, needs an extra memcpy // 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); idft(idft_size, (int16_t *)&input[i * fftsize], (int16_t *)temp, 1);
memcpy((void *)output_ptr, (void *)temp, sizeof(temp)); 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: { 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); idft(idft_size, (int16_t *)&input[i * fftsize], (int16_t *)temp, 1);
int *output_ptr = &output[(i * fftsize) + (i * nb_prefix_samples)]; int *output_ptr = &output[(i * fftsize) + (i * nb_prefix_samples)];
memcpy(output_ptr, temp, sizeof(temp)); memcpy(output_ptr, temp, sizeof(temp));
@@ -191,7 +196,7 @@ void PHY_ofdm_mod(const int *input, /// pointer to complex input
break; break;
case NONE: { 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); idft(idft_size, (int16_t *)&input[i * fftsize], (int16_t *)temp, 1);
int *output_ptr = &output[i * fftsize]; int *output_ptr = &output[i * fftsize];
memcpy(output_ptr, temp, sizeof(temp)); memcpy(output_ptr, temp, sizeof(temp));