libmath: Add HashCombine
Add a helper function to combine hashes and
make half and mat/vec std::hashable.
Bug: 158790260
Test: libmath unit tests
Change-Id: I11eb70152ce5a35a6d833cd108732e5b21704fe1
diff --git a/libs/math/tests/Android.bp b/libs/math/tests/Android.bp
index 0184f56..472d337 100644
--- a/libs/math/tests/Android.bp
+++ b/libs/math/tests/Android.bp
@@ -41,3 +41,10 @@
static_libs: ["libmath"],
cflags: ["-Wall", "-Werror"],
}
+
+cc_test {
+ name: "hashcombine_test",
+ srcs: ["hashcombine_test.cpp"],
+ static_libs: ["libmath"],
+ cflags: ["-Wall", "-Werror"],
+}
diff --git a/libs/math/tests/half_test.cpp b/libs/math/tests/half_test.cpp
index 604072e..a514d98 100644
--- a/libs/math/tests/half_test.cpp
+++ b/libs/math/tests/half_test.cpp
@@ -94,4 +94,13 @@
EXPECT_EQ(f4.xy, h2);
}
+
+TEST_F(HalfTest, Hash) {
+ float4 f4a(1,2,3,4);
+ float4 f4b(2,2,3,4);
+ half4 h4a(f4a), h4b(f4b);
+
+ EXPECT_NE(std::hash<half4>{}(h4a), std::hash<half4>{}(h4b));
+}
+
}; // namespace android
diff --git a/libs/math/tests/hashcombine_test.cpp b/libs/math/tests/hashcombine_test.cpp
new file mode 100644
index 0000000..96c6e81
--- /dev/null
+++ b/libs/math/tests/hashcombine_test.cpp
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "HashCombineTest"
+
+#include <math.h>
+#include <stdlib.h>
+
+#include <math/half.h>
+#include <math/vec4.h>
+
+#include <gtest/gtest.h>
+
+namespace android {
+
+class HashCombineTest : public testing::Test {
+protected:
+};
+
+TEST_F(HashCombineTest, Basics) {
+ char a = 40;
+ int b = 32;
+ int c = 55;
+ float d = 42.f;
+ float d_ = 42.1f;
+
+ EXPECT_NE(hashCombine(a, b, c, d), hashCombine(a, b, c, d_));
+}
+
+}; // namespace android