add unittest for sk_memset16 and sk_memset32

git-svn-id: http://skia.googlecode.com/svn/trunk@2985 2bbb7eff-a529-9590-31e7-b0007b416f81

gyp/tests.gyp

@@ -39,6 +39,7 @@
         '../tests/MathTest.cpp',
         '../tests/MatrixTest.cpp',
         '../tests/Matrix44Test.cpp',
+        '../tests/MemsetTest.cpp',
         '../tests/MetaDataTest.cpp',
         '../tests/PackBitsTest.cpp',
         '../tests/PaintTest.cpp',

tests/MemsetTest.cpp

@@ -0,0 +1,91 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "Test.h"
+#include "SkUtils.h"
+
+static void set_zero(void* dst, size_t bytes) {
+    char* ptr = (char*)dst;
+    for (size_t i = 0; i < bytes; ++i) {
+        ptr[i] = 0;
+    }
+}
+
+#define MAX_ALIGNMENT   64
+#define MAX_COUNT       ((MAX_ALIGNMENT) * 32)
+#define PAD             32
+#define TOTAL           (PAD + MAX_ALIGNMENT + MAX_COUNT + PAD)
+
+#define VALUE16         0x1234
+#define VALUE32         0x12345678
+
+static bool compare16(const uint16_t base[], uint16_t value, int count) {
+    for (int i = 0; i < count; ++i) {
+        if (base[i] != value) {
+            SkDebugf("[%d] expected %x found %x\n", i, value, base[i]);
+            return false;
+        }
+    }
+    return true;
+}
+
+static bool compare32(const uint32_t base[], uint32_t value, int count) {
+    for (int i = 0; i < count; ++i) {
+        if (base[i] != value) {
+            SkDebugf("[%d] expected %x found %x\n", i, value, base[i]);
+            return false;
+        }
+    }
+    return true;
+}
+
+static void test_16(skiatest::Reporter* reporter) {
+    uint16_t buffer[TOTAL];
+    
+    for (int count = 0; count < MAX_COUNT; ++count) {
+        for (int alignment = 0; alignment < MAX_ALIGNMENT; ++alignment) {
+            set_zero(buffer, sizeof(buffer));
+            
+            uint16_t* base = &buffer[PAD + alignment];
+            sk_memset16(base, VALUE16, count);
+            
+            compare16(buffer,       0,       PAD + alignment);
+            compare16(base,         VALUE16, count);
+            compare16(base + count, 0,       TOTAL - count - PAD - alignment);
+        }
+    }
+}
+
+static void test_32(skiatest::Reporter* reporter) {
+    uint32_t buffer[TOTAL];
+    
+    for (int count = 0; count < MAX_COUNT; ++count) {
+        for (int alignment = 0; alignment < MAX_ALIGNMENT; ++alignment) {
+            set_zero(buffer, sizeof(buffer));
+            
+            uint32_t* base = &buffer[PAD + alignment];
+            sk_memset32(base, VALUE32, count);
+            
+            compare32(buffer,       0,       PAD + alignment);
+            compare32(base,         VALUE32, count);
+            compare32(base + count, 0,       TOTAL - count - PAD - alignment);
+        }
+    }
+}
+
+/**
+ *  Test sk_memset16 and sk_memset32.
+ *  For performance considerations, implementations may take different paths
+ *  depending on the alignment of the dst, and/or the size of the count.
+ */
+static void TestMemset(skiatest::Reporter* reporter) {
+    test_16(reporter);
+    test_32(reporter);
+};
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("Memset", TestMemsetClass, TestMemset)