Use sse4.2 CRC32 instructions to hash when available.

tests/ChecksumTest.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
-#include "SkChecksum.h"
+#include "SkOpts.h"
 #include "SkRandom.h"
 #include "Test.h"
 
-
-// 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); }
-
-#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);
-    const algorithmProc kAlgorithms[] = { &murmur_noseed };
-
     // Put 128 random bytes into two identical buffers.  Any multiple of 4 will do.
     const size_t kBytes = SkAlign4(128);
     SkRandom rand;
     uint32_t data[kBytes/4], tweaked[kBytes/4];
     for (size_t i = 0; i < SK_ARRAY_COUNT(tweaked); ++i) {
         data[i] = tweaked[i] = rand.nextU();
     }
 
-    // Test each algorithm.
-    for (size_t i = 0; i < SK_ARRAY_COUNT(kAlgorithms); ++i) {
-        const algorithmProc algorithm = kAlgorithms[i];
+    // Hash of nullptr is always 0.
+    REPORTER_ASSERT(r, SkOpts::hash(nullptr, 0) == 0);
 
-        // Hash of nullptr is always 0.
-        ASSERT(algorithm(nullptr, 0) == 0);
+    const uint32_t hash = SkOpts::hash(data, kBytes);
+    // Should be deterministic.
+    REPORTER_ASSERT(r, hash == SkOpts::hash(data, kBytes));
 
-        const uint32_t hash = algorithm(data, kBytes);
-        // Should be deterministic.
-        ASSERT(hash == algorithm(data, kBytes));
-
-        // Changing any single element should change the hash.
-        for (size_t j = 0; j < SK_ARRAY_COUNT(tweaked); ++j) {
-            const uint32_t saved = tweaked[j];
-            tweaked[j] = rand.nextU();
-            const uint32_t tweakedHash = algorithm(tweaked, kBytes);
-            ASSERT(tweakedHash != hash);
-            ASSERT(tweakedHash == algorithm(tweaked, kBytes));
-            tweaked[j] = saved;
-        }
+    // Changing any single element should change the hash.
+    for (size_t j = 0; j < SK_ARRAY_COUNT(tweaked); ++j) {
+        const uint32_t saved = tweaked[j];
+        tweaked[j] = rand.nextU();
+        const uint32_t tweakedHash = SkOpts::hash(tweaked, kBytes);
+        REPORTER_ASSERT(r, tweakedHash != hash);
+        REPORTER_ASSERT(r, tweakedHash == SkOpts::hash(tweaked, kBytes));
+        tweaked[j] = saved;
     }
 }
 
 DEF_TEST(GoodHash, r) {
-    ASSERT(SkGoodHash()(( int32_t)4) ==  614249093);  // 4 bytes.  Hits SkChecksum::Mix fast path.
-    ASSERT(SkGoodHash()((uint32_t)4) ==  614249093);  // (Ditto)
-
-    // None of these are 4 byte sized, so they use SkChecksum::Murmur3, not SkChecksum::Mix.
-    ASSERT(SkGoodHash()((uint64_t)4) == 3491892518);
-    ASSERT(SkGoodHash()((uint16_t)4) ==  899251846);
-    ASSERT(SkGoodHash()( (uint8_t)4) ==  962700458);
-
-    // Tests SkString is correctly specialized.
-    ASSERT(SkGoodHash()(SkString("Hi")) == 55667557);
+    // 4 bytes --> hits SkChecksum::Mix fast path.
+    REPORTER_ASSERT(r, SkGoodHash()(( int32_t)4) ==  614249093);
+    REPORTER_ASSERT(r, SkGoodHash()((uint32_t)4) ==  614249093);
 }