diff options
author | mtklein <mtklein@chromium.org> | 2014-07-10 14:10:45 -0700 |
---|---|---|
committer | Commit bot <commit-bot@chromium.org> | 2014-07-10 14:10:47 -0700 |
commit | 53d435990bdb4d14df78013da45a9364d0287ebe (patch) | |
tree | 52ba2dff9d429e069fe07c63a8cfa6960c32327e | |
parent | b17c764f852c04d84f8fbbc3c82eefb8c7665217 (diff) |
Slim Skia down to just one murmur3 implementation.
BUG=skia:
Committed: https://skia.googlesource.com/skia/+/6ac0037b70410ff7d5ce5788bc89314223e1a587
Committed: https://skia.googlesource.com/skia/+/67a3271f0de9ccc32d559b042b862528272047cc
R=reed@google.com, mtklein@google.com
Author: mtklein@chromium.org
Review URL: https://codereview.chromium.org/376183004
-rw-r--r-- | src/core/SkChecksum.h | 8 | ||||
-rw-r--r-- | src/core/SkImageFilter.cpp | 28 | ||||
-rw-r--r-- | tests/ChecksumTest.cpp | 6 |
3 files changed, 12 insertions, 30 deletions
diff --git a/src/core/SkChecksum.h b/src/core/SkChecksum.h index fe1e9584a2..daf87cf62e 100644 --- a/src/core/SkChecksum.h +++ b/src/core/SkChecksum.h @@ -51,6 +51,10 @@ public: return hash; } + // Remind compiler that our users will be intentionally violating strict aliasing by casting + // their data to const uint32_t*, so don't apply any strict-aliasing-based optimizations. + typedef uint32_t SK_ATTRIBUTE(may_alias) FourByteAligned; + /** * Calculate 32-bit Murmur hash (murmur3). * This should take 2-3x longer than SkChecksum::Compute, but is a considerably better hash. @@ -61,7 +65,7 @@ public: * @param seed Initial hash seed. (optional) * @return hash result */ - static uint32_t Murmur3(const uint32_t* data, size_t bytes, uint32_t seed=0) { + static uint32_t Murmur3(const FourByteAligned* data, size_t bytes, uint32_t seed=0) { SkASSERTF(SkIsAlign4(bytes), "Expected 4-byte multiple, got %zu", bytes); const size_t words = bytes/4; @@ -94,7 +98,7 @@ public: * @param size Size of the data block in bytes. Must be a multiple of 4. * @return checksum result */ - static uint32_t Compute(const uint32_t* data, size_t size) { + static uint32_t Compute(const FourByteAligned* data, size_t size) { SkASSERT(SkIsAlign4(size)); /* diff --git a/src/core/SkImageFilter.cpp b/src/core/SkImageFilter.cpp index 64603b4cb5..8a0e734b24 100644 --- a/src/core/SkImageFilter.cpp +++ b/src/core/SkImageFilter.cpp @@ -8,6 +8,7 @@ #include "SkImageFilter.h" #include "SkBitmap.h" +#include "SkChecksum.h" #include "SkDevice.h" #include "SkReadBuffer.h" #include "SkWriteBuffer.h" @@ -334,31 +335,6 @@ bool SkImageFilter::getInputResultGPU(SkImageFilter::Proxy* proxy, } #endif -static uint32_t compute_hash(const uint32_t* data, int count) { - uint32_t hash = 0; - - for (int i = 0; i < count; ++i) { - uint32_t k = data[i]; - k *= 0xcc9e2d51; - k = (k << 15) | (k >> 17); - k *= 0x1b873593; - - hash ^= k; - hash = (hash << 13) | (hash >> 19); - hash *= 5; - hash += 0xe6546b64; - } - - // hash ^= size; - hash ^= hash >> 16; - hash *= 0x85ebca6b; - hash ^= hash >> 13; - hash *= 0xc2b2ae35; - hash ^= hash >> 16; - - return hash; -} - class CacheImpl : public SkImageFilter::Cache { public: explicit CacheImpl(int minChildren) : fMinChildren(minChildren) { @@ -381,7 +357,7 @@ private: return v.fKey; } static uint32_t Hash(Key key) { - return compute_hash(reinterpret_cast<const uint32_t*>(&key), sizeof(Key) / sizeof(uint32_t)); + return SkChecksum::Murmur3(reinterpret_cast<const uint32_t*>(&key), sizeof(Key)); } }; SkTDynamicHash<Value, Key> fData; diff --git a/tests/ChecksumTest.cpp b/tests/ChecksumTest.cpp index 6248678043..923f303509 100644 --- a/tests/ChecksumTest.cpp +++ b/tests/ChecksumTest.cpp @@ -11,13 +11,15 @@ // Murmur3 has an optional third seed argument, so we wrap it to fit a uniform type. -static uint32_t murmur_noseed(const uint32_t* d, size_t l) { return SkChecksum::Murmur3(d, l); } +static uint32_t murmur_noseed(const SkChecksum::FourByteAligned* d, size_t l) { + return SkChecksum::Murmur3(d, l); +} #define ASSERT(x) REPORTER_ASSERT(r, x) DEF_TEST(Checksum, r) { // Algorithms to test. They're currently all uint32_t(const uint32_t*, size_t). - typedef uint32_t(*algorithmProc)(const uint32_t*, size_t); + typedef uint32_t(*algorithmProc)(const SkChecksum::FourByteAligned*, size_t); const algorithmProc kAlgorithms[] = { &SkChecksum::Compute, &murmur_noseed }; // Put 128 random bytes into two identical buffers. Any multiple of 4 will do. |