Add default constructor to android::half.

This allows the use of android::half in dynamically allocated
arrays, which I need in a device driver I am working on.

Bug: 155932921
Test: presubmit, atest
Change-Id: Ia3e0e404454186240433652d6d1cf6705ced2dce

2 files changed, 2 insertions, 0 deletions

diff --git a/libs/math/include/math/half.h b/libs/math/include/math/half.h
index 76829734a4..617a0ab5d2 100644
--- a/libs/math/include/math/half.h
+++ b/libs/math/include/math/half.h
@@ -82,6 +82,7 @@ class half {
     };
 
 public:
+    CONSTEXPR half() noexcept { }
     CONSTEXPR half(float v) noexcept : mBits(ftoh(v)) { }
     CONSTEXPR operator float() const noexcept { return htof(mBits); }
 
diff --git a/libs/math/tests/half_test.cpp b/libs/math/tests/half_test.cpp
index 496a7ef56d..604072e557 100644
--- a/libs/math/tests/half_test.cpp
+++ b/libs/math/tests/half_test.cpp
@@ -35,6 +35,7 @@ TEST_F(HalfTest, Basics) {
     EXPECT_EQ(2UL, sizeof(half));
 
     // test +/- zero
+    EXPECT_EQ(0x0000, half().getBits());
     EXPECT_EQ(0x0000, half( 0.0f).getBits());
     EXPECT_EQ(0x8000, half(-0.0f).getBits());