authorgravatar for 124872+jedisct1@users.noreply.github.comFrank Denis <124872+jedisct1@users.noreply.github.com> 2025-11-26 10:16:20+01:00
committergravatar for noreply@github.comGitHub <noreply@github.com> 2025-11-26 10:16:20+01:00
log5f73c01368f418bb9b5186ff14bcdacb044fcb86
treeb4d3887a1b1712dffc16b6170ee86a980496f86b
parente23af9d31d79af3636cea5bfb8fc4c9b26f1c854
signaturebadge-check Signed by PGP key B5690EEEBB952194

crypto.blake3: sequentially process larger small tree layers (#26046)

Improves performance by spawning less threads.

1 files changed, 52 insertions(+), 8 deletions(-)

lib/std/crypto/blake3.zig+52-8
...@@ -685,9 +685,9 @@ const ChunkBatch = struct {...@@ -685,9 +685,9 @@ const ChunkBatch = struct {
685685
686 while (chunk_idx < ctx.end_chunk) {686 while (chunk_idx < ctx.end_chunk) {
687 const remaining = ctx.end_chunk - chunk_idx;687 const remaining = ctx.end_chunk - chunk_idx;
688 const batch_size = @min(remaining, max_simd_degree);688 const batch_size: usize = @min(remaining, max_simd_degree);
689 const offset = chunk_idx * chunk_length;689 const offset = chunk_idx * chunk_length;
690 const batch_len = @as(usize, batch_size) * chunk_length;690 const batch_len = batch_size * chunk_length;
691691
692 const num_cvs = compressChunksParallel(692 const num_cvs = compressChunksParallel(
693 ctx.input[offset..][0..batch_len],693 ctx.input[offset..][0..batch_len],
...@@ -723,6 +723,44 @@ fn processParentBatch(ctx: ParentBatchContext) void {...@@ -723,6 +723,44 @@ fn processParentBatch(ctx: ParentBatchContext) void {
723 }723 }
724}724}
725725
726fn processParentBatchSIMD(ctx: ParentBatchContext) void {
727 const num_parents = ctx.end_idx - ctx.start_idx;
728 if (num_parents == 0) return;
729
730 // Convert input CVs to bytes for SIMD processing
731 var input_bytes: [max_simd_degree * 2 * Blake3.digest_length]u8 = undefined;
732 var output_bytes: [max_simd_degree * Blake3.digest_length]u8 = undefined;
733 var parents_array: [max_simd_degree][*]const u8 = undefined;
734
735 var processed: usize = 0;
736 while (processed < num_parents) {
737 const batch_size: usize = @min(num_parents - processed, max_simd_degree);
738
739 // Convert CV pairs to byte blocks for this batch
740 for (0..batch_size) |i| {
741 const pair_idx = ctx.start_idx + processed + i;
742 const left_cv = ctx.input_cvs[pair_idx * 2];
743 const right_cv = ctx.input_cvs[pair_idx * 2 + 1];
744
745 // Write left CV || right CV to form 64-byte parent block
746 for (0..8) |j| {
747 store32(input_bytes[i * 64 + j * 4 ..][0..4], left_cv[j]);
748 store32(input_bytes[i * 64 + 32 + j * 4 ..][0..4], right_cv[j]);
749 }
750 parents_array[i] = input_bytes[i * 64 ..].ptr;
751 }
752
753 hashMany(parents_array[0..batch_size], batch_size, 1, ctx.key, 0, false, ctx.flags.with(.{ .parent = true }), .{}, .{}, output_bytes[0 .. batch_size * Blake3.digest_length]);
754
755 for (0..batch_size) |i| {
756 const output_idx = ctx.start_idx + processed + i;
757 ctx.output_cvs[output_idx] = loadCvWords(output_bytes[i * Blake3.digest_length ..][0..Blake3.digest_length].*);
758 }
759
760 processed += batch_size;
761 }
762}
763
726fn buildMerkleTreeLayerParallel(764fn buildMerkleTreeLayerParallel(
727 input_cvs: [][8]u32,765 input_cvs: [][8]u32,
728 output_cvs: [][8]u32,766 output_cvs: [][8]u32,
...@@ -732,11 +770,17 @@ fn buildMerkleTreeLayerParallel(...@@ -732,11 +770,17 @@ fn buildMerkleTreeLayerParallel(
732) void {770) void {
733 const num_parents = input_cvs.len / 2;771 const num_parents = input_cvs.len / 2;
734772
735 if (num_parents <= 16) {773 // Process sequentially with SIMD for smaller tree layers to avoid thread overhead
736 for (0..num_parents) |i| {774 // Tree layers shrink quickly, so only parallelize the first few large layers
737 const output = parentOutputFromCvs(input_cvs[i * 2], input_cvs[i * 2 + 1], key, flags);775 if (num_parents <= 1024) {
738 output_cvs[i] = output.chainingValue();776 processParentBatchSIMD(ParentBatchContext{
739 }777 .input_cvs = input_cvs,
778 .output_cvs = output_cvs,
779 .start_idx = 0,
780 .end_idx = num_parents,
781 .key = key,
782 .flags = flags,
783 });
740 return;784 return;
741 }785 }
742786
...@@ -748,7 +792,7 @@ fn buildMerkleTreeLayerParallel(...@@ -748,7 +792,7 @@ fn buildMerkleTreeLayerParallel(
748 const start_idx = worker_id * parents_per_worker;792 const start_idx = worker_id * parents_per_worker;
749 if (start_idx >= num_parents) break;793 if (start_idx >= num_parents) break;
750794
751 group.async(io, processParentBatch, .{ParentBatchContext{795 group.async(io, processParentBatchSIMD, .{ParentBatchContext{
752 .input_cvs = input_cvs,796 .input_cvs = input_cvs,
753 .output_cvs = output_cvs,797 .output_cvs = output_cvs,
754 .start_idx = start_idx,798 .start_idx = start_idx,