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author | Noel Gordon <noel@chromium.org> | 2020-04-20 08:26:29 +0000 |
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committer | Commit Bot <commit-bot@chromium.org> | 2020-04-20 08:26:29 +0000 |
commit | 96b8f5aa7875102b1c72a16e09e028ce9a4a6d69 (patch) | |
tree | c5125781604ac9c7d5011c6216e1b1a4f10b1813 /contrib | |
parent | 3479ee01ac33fd7cf12e249a8b3cd907431618bf (diff) | |
download | zlib-96b8f5aa7875102b1c72a16e09e028ce9a4a6d69.tar.gz |
[zlib] Make insert string a little less #ifdef-ie
Remove one level of #ifdef indent to make that part of the code easier
to read. Change the accelerated routine name to end in _simd as is our
way elsewhere in chromium zlib.
Minor: adjust the comments around the performance claims, and move the
important comments re CHROMIUM_ZLIB_NO_CASTAGNOLI into that block.
Bug: 1032721
Change-Id: Icb4044f3b87277d67f0ff004ac70813af0a91f5b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2148893
Reviewed-by: Chris Blume <cblume@chromium.org>
Reviewed-by: Adenilson Cavalcanti <cavalcantii@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#760408}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 4520abf183652950cb4b68701f7bd695d127d1f8
Diffstat (limited to 'contrib')
-rw-r--r-- | contrib/optimizations/insert_string.h | 59 |
1 files changed, 30 insertions, 29 deletions
diff --git a/contrib/optimizations/insert_string.h b/contrib/optimizations/insert_string.h index 1826601..d3bc33c 100644 --- a/contrib/optimizations/insert_string.h +++ b/contrib/optimizations/insert_string.h @@ -4,45 +4,47 @@ * Use of this source code is governed by a BSD-style license that can be * found in the Chromium source repository LICENSE file. */ -#ifdef _MSC_VER + +#if defined(_MSC_VER) #define INLINE __inline #else #define INLINE inline #endif #include "cpu_features.h" -/* Optimized insert_string block */ -#if defined(CRC32_SIMD_SSE42_PCLMUL) || defined(CRC32_ARMV8_CRC32) -#define TARGET_CPU_WITH_CRC + // clang-format off #if defined(CRC32_SIMD_SSE42_PCLMUL) - /* Required to make MSVC bot build pass. */ - #include <smmintrin.h> - #if defined(__GNUC__) || defined(__clang__) - #undef TARGET_CPU_WITH_CRC + #include <smmintrin.h> /* Required to make MSVC bot build pass. */ + + #if defined(__clang__) || defined(__GNUC__) #define TARGET_CPU_WITH_CRC __attribute__((target("sse4.2"))) + #else + #define TARGET_CPU_WITH_CRC #endif #define _cpu_crc32_u32 _mm_crc32_u32 #elif defined(CRC32_ARMV8_CRC32) #if defined(__clang__) - #undef TARGET_CPU_WITH_CRC #define __crc32cw __builtin_arm_crc32cw #endif - #define _cpu_crc32_u32 __crc32cw - #if defined(__aarch64__) #define TARGET_CPU_WITH_CRC __attribute__((target("crc"))) #else // !defined(__aarch64__) #define TARGET_CPU_WITH_CRC __attribute__((target("armv8-a,crc"))) #endif // defined(__aarch64__) + + #define _cpu_crc32_u32 __crc32cw + #endif // clang-format on + +#if defined(TARGET_CPU_WITH_CRC) + TARGET_CPU_WITH_CRC -local INLINE Pos insert_string_optimized(deflate_state* const s, - const Pos str) { +local INLINE Pos insert_string_simd(deflate_state* const s, const Pos str) { Pos ret; unsigned *ip, val, h = 0; @@ -64,7 +66,8 @@ local INLINE Pos insert_string_optimized(deflate_state* const s, s->prev[str & s->w_mask] = ret; return ret; } -#endif /* Optimized insert_string block */ + +#endif // TARGET_CPU_WITH_CRC /* =========================================================================== * Update a hash value with the given input byte @@ -99,24 +102,22 @@ local INLINE Pos insert_string_c(deflate_state* const s, const Pos str) { } local INLINE Pos insert_string(deflate_state* const s, const Pos str) { -/* String dictionary insertion: faster symbol hashing has a positive impact - * on data compression speeds (around 20% on Intel and 36% on Arm Cortex big - * cores). - * A misfeature is that the generated compressed output will differ from - * vanilla zlib (even though it is still valid 'DEFLATE-d' content). +/* insert_string_simd string dictionary insertion: this SIMD symbol hashing + * significantly improves data compression speed. * - * We offer here a way to disable the optimization if there is the expectation - * that compressed content should match when compared to vanilla zlib. + * Note: the generated compressed output is a valid DEFLATE stream but will + * differ from vanilla zlib output ... */ -#if !defined(CHROMIUM_ZLIB_NO_CASTAGNOLI) - /* TODO(cavalcantii): unify CPU features code. */ -#if defined(CRC32_ARMV8_CRC32) - if (arm_cpu_enable_crc32) - return insert_string_optimized(s, str); -#elif defined(CRC32_SIMD_SSE42_PCLMUL) +#if defined(CHROMIUM_ZLIB_NO_CASTAGNOLI) +/* ... so this build-time option can used to disable the SIMD symbol hasher + * if matching vanilla zlib DEFLATE output is required. + */ (;) /* FALLTHOUGH */ +#elif defined(TARGET_CPU_WITH_CRC) && defined(CRC32_SIMD_SSE42_PCLMUL) if (x86_cpu_enable_simd) - return insert_string_optimized(s, str); -#endif + return insert_string_simd(s, str); +#elif defined(TARGET_CPU_WITH_CRC) && defined(CRC32_ARMV8_CRC32) + if (arm_cpu_enable_crc32) + return insert_string_simd(s, str); #endif return insert_string_c(s, str); } |