pub unsafe fn shift_right_avx2<const OR_ASSIGN: bool>(
bits: &mut [u64],
rhs: usize,
)Examples found in repository?
crates/competitive/src/data_structure/bitset.rs (line 456)
434 fn shift_right<const OR_ASSIGN: bool>(&mut self, rhs: usize) {
435 if rhs == 0 {
436 return;
437 }
438 if rhs >= self.size {
439 if !OR_ASSIGN {
440 self.reset();
441 }
442 return;
443 }
444 #[cfg(target_arch = "x86_64")]
445 if self.bits.len() >= SIMD_MIN_BLOCKS {
446 if avx512_enabled()
447 && is_x86_feature_detected!("avx512f")
448 && is_x86_feature_detected!("avx512vbmi2")
449 {
450 // SAFETY: blocks are aligned and feature detection checked AVX-512F and VBMI2.
451 unsafe { simd::shift_right_avx512::<OR_ASSIGN>(&mut self.bits, rhs) };
452 return;
453 }
454 if is_x86_feature_detected!("avx2") {
455 // SAFETY: feature detection checked AVX2 support.
456 unsafe { simd::shift_right_avx2::<OR_ASSIGN>(self.words_mut(), rhs) };
457 return;
458 }
459 }
460
461 let bits = self.words_mut();
462 let word_shift = rhs >> 6;
463 let bit_shift = rhs & 63;
464 if bit_shift == 0 {
465 for i in word_shift..bits.len() {
466 if OR_ASSIGN {
467 bits[i - word_shift] |= bits[i];
468 } else {
469 bits[i - word_shift] = bits[i];
470 }
471 }
472 } else {
473 for i in word_shift..bits.len() - 1 {
474 let value = (bits[i] >> bit_shift) | (bits[i + 1] << (64 - bit_shift));
475 if OR_ASSIGN {
476 bits[i - word_shift] |= value;
477 } else {
478 bits[i - word_shift] = value;
479 }
480 }
481 if OR_ASSIGN {
482 bits[bits.len() - word_shift - 1] |= bits[bits.len() - 1] >> bit_shift;
483 } else {
484 bits[bits.len() - word_shift - 1] = bits[bits.len() - 1] >> bit_shift;
485 }
486 }
487 if !OR_ASSIGN {
488 let end = bits.len() - word_shift;
489 bits[end..].fill(0);
490 }
491 }