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7 relative randomization + a full random / 8 element

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This commit is contained in:
Richard Thier 2025-10-01 17:12:58 +02:00
parent 603e689de7
commit 27873e06fe
1 changed files with 19 additions and 17 deletions
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36
randominus.h
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@ -3,6 +3,7 @@
/* To randomize an array - hopefully as fast as possible */
#include "fastrand/fastrand.h"
#define RD_REL_WIDTH 16
/** swap */
static void inline rd_swap(uint32_t *a, uint32_t *b) {
@ -24,23 +25,24 @@ static inline void randominus(uint32_t *a, int n, uint32_t seed) {
}
/** Go over the array and randomly swap stuff - hand unrolled with ILP random get! */
for(int i = 0; i < (n - 8); i += 8) {
uint32_t to0 = fastmodlike(lcg_ilp(&rsi, A), n);
uint32_t to1 = fastmodlike(lcg_ilp(&rsi, B), n);
uint32_t to2 = fastmodlike(lcg_ilp(&rsi, C), n);
uint32_t to3 = fastmodlike(lcg_ilp(&rsi, D), n);
uint32_t to4 = fastmodlike(lcg_ilp(&rsi, E), n);
uint32_t to5 = fastmodlike(lcg_ilp(&rsi, F), n);
uint32_t to6 = fastmodlike(lcg_ilp(&rsi, G), n);
uint32_t to7 = fastmodlike(lcg_ilp(&rsi, H), n);
rd_swap(&a[i], &a[to0]);
rd_swap(&a[i + 1], &a[to1]);
rd_swap(&a[i + 2], &a[to2]);
rd_swap(&a[i + 3], &a[to3]);
rd_swap(&a[i + 4], &a[to4]);
rd_swap(&a[i + 5], &a[to5]);
rd_swap(&a[i + 6], &a[to6]);
rd_swap(&a[i + 7], &a[to7]);
#pragma GCC unroll 16
for(int i = (RD_REL_WIDTH/2 + 1); i < (n - 8 - (RD_REL_WIDTH/2 + 1)); i += 8) {
uint32_t to = fastmodlike(lcg_ilp(&rsi, A), n);
uint32_t relto1 = fastmodlike(lcg_ilp(&rsi, B), RD_REL_WIDTH) - (RD_REL_WIDTH / 2);
uint32_t relto2 = fastmodlike(lcg_ilp(&rsi, C), RD_REL_WIDTH) - (RD_REL_WIDTH / 2);
uint32_t relto3 = fastmodlike(lcg_ilp(&rsi, D), RD_REL_WIDTH) - (RD_REL_WIDTH / 2);
uint32_t relto4 = fastmodlike(lcg_ilp(&rsi, E), RD_REL_WIDTH) - (RD_REL_WIDTH / 2);
uint32_t relto5 = fastmodlike(lcg_ilp(&rsi, F), RD_REL_WIDTH) - (RD_REL_WIDTH / 2);
uint32_t relto6 = fastmodlike(lcg_ilp(&rsi, G), RD_REL_WIDTH) - (RD_REL_WIDTH / 2);
uint32_t relto7 = fastmodlike(lcg_ilp(&rsi, H), RD_REL_WIDTH) - (RD_REL_WIDTH / 2);
rd_swap(&a[i], &a[to]);
rd_swap(&a[i + 1], &a[i + relto1]);
rd_swap(&a[i + 2], &a[i + relto2]);
rd_swap(&a[i + 3], &a[i + relto3]);
rd_swap(&a[i + 4], &a[i + relto4]);
rd_swap(&a[i + 5], &a[i + relto5]);
rd_swap(&a[i + 6], &a[i + relto6]);
rd_swap(&a[i + 7], &a[i + relto7]);
}
}