Rebased onto upstream/develop (6cfa7d52) and re-measured. Upstream has since introduced
MAX_LEN_ROOT_BITS, so the change is now a one-macro bump plus ENOUGH_LENS, with a second
commit adding an adaptive gate.
Apple M5, 4 P-cores + 6 E-cores, 32 GB, macOS 26.5.2, Apple clang 21.0.0.
Release build, BUILD_SHARED_LIBS=OFF, WITH_MAINTAINER_WARNINGS=ON.
| /* benchmark_compress_block.cc -- benchmark the compress_block emit loop in isolation | |
| * Copyright (C) 2026 Nathan Moinvaziri | |
| * For conditions of distribution and use, see copyright notice in zlib.h | |
| */ | |
| #include <stdio.h> | |
| #include <cstring> | |
| #include <benchmark/benchmark.h> |
Packing up to 3 consecutive literals into a single send_bits makes deflate 1% to 4.5% faster on
most data types, with byte-identical output and no regressions.
compress_block emits one symbol at a time. Each symbol ORs its Huffman code into the 64-bit bit
buffer at the running bit position, then updates that position. bi_buf/bi_valid are therefore a
loop-carried dependency: symbol N+1 cannot be placed until symbol N's length is known. That chain,
Follow-up to PR #1977. Enables the disabled (#if 0) adler32_copy_avx2_vnni copy variant by
rebuilding it on the same structure as the shipping checksum-only path.
The author left adler32_copy_avx2_vnni under #if 0 with a note about a "data dependency
bubble," faster on Gracemont E-cores but slower on Raptor Cove P-cores, and a conversation
comment: "I think there may need to be more unrolling."
Follow-up idea spun off from PR #1977 (AVX2-VNNI adler32).
adler32_avx512_vnni uses only 2 VPDPBUSD accumulators (vs2, vs2_1). VPDPBUSD
has ~5-cycle latency, so two in-flight dot products can't cover it and the 128-byte loop is
latency-bound at ~5c/128B — the same ceiling as the AVX2-VNNI path.
| name: nathan | |
| description: Configuration files synced by config-sync | |
| url: https://github.com/nmoinvaz/gcs | |
| files: | |
| - path: .claude/skills/security-evidence/SKILL.md | |
| gist: nathan_.claude_skills_security-evidence_SKILL.md | |
| updated_at: 2026-06-12T01:39:34.319047220Z | |
| - path: .claude/skills/security-evidence/scripts/ss-capture.sh | |
| gist: nathan_.claude_skills_security-evidence_scripts_ss-capture.sh | |
| updated_at: 2026-06-12T01:38:43.526802792Z |
Follow-up to PR #2291 (nv/develop/deflate-strategy-locals-hoist). After the scalar-local hoist landed, tried two variants in deflate_quick.c to see whether packing the two uint32_t fields into a struct could coax the compiler into 64-bit load/store transfers.
CMAKE_OSX_ARCHITECTURES=x86_64-D BUILD_SHARED_LIBS=OFF
Branch: nv/develop/deflate-struct-hoist
Commit: c435d01e — "Hoist deflate bit-emit state into deflate_emit_hot local"
Base: upstream/develop (48087450)
Introduces a deflate_emit_hot struct (bi_buf, bi_valid, pending_buf, pending) and DEFLATE_EMIT_HOT_LOAD/STORE macros that cache bit-emit state in a local at the top of hot loops and write it back once on exit. Converts put_byte/put_short/put_short_msb/put_uint32/put_uint32_msb/put_uint64 from macros to static inline functions taking a deflate_emit_hot *. Cold-path callers in deflate.c (zlib/gzip header and trailer writers, name/comment loops) and deflate_stored.c bracket their put_* clusters with LOAD/STORE.
| /* benchmark_chunkmemset.cc -- benchmark chunkmemset_safe variants | |
| * Copyright (C) 2026 Nathan Moinvaziri | |
| * For conditions of distribution and use, see copyright notice in zlib.h | |
| */ | |
| #include <benchmark/benchmark.h> | |
| extern "C" { | |
| # include "zbuild.h" | |
| # include "zutil_p.h" |
| /* benchmark_dist1.cc -- compare strategies for the dist=1 path in CHUNKMEMSET */ | |
| #include <benchmark/benchmark.h> | |
| extern "C" { | |
| # include "zbuild.h" | |
| # include "zutil.h" | |
| } | |
| #if defined(__ARM_NEON) || defined(__ARM_NEON__) |