Support: Add Endian.h

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117057 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 74 insertions, 1 deletions

diff --git a/unittests/CMakeLists.txt b/unittests/CMakeLists.txt
index d37b8906b4..df51bf821f 100644
--- a/unittests/CMakeLists.txt
+++ b/unittests/CMakeLists.txt
@@ -92,12 +92,13 @@ add_llvm_unittest(Support
   Support/Casting.cpp
   Support/CommandLineTest.cpp
   Support/ConstantRangeTest.cpp
+  Support/EndianTest.cpp
   Support/LeakDetectorTest.cpp
   Support/MathExtrasTest.cpp
   Support/raw_ostream_test.cpp
   Support/RegexTest.cpp
-  Support/System.cpp
   Support/SwapByteOrderTest.cpp
+  Support/System.cpp
   Support/TypeBuilderTest.cpp
   Support/ValueHandleTest.cpp
   )
diff --git a/unittests/Support/EndianTest.cpp b/unittests/Support/EndianTest.cpp
new file mode 100644
index 0000000000..d9172935d6
--- /dev/null
+++ b/unittests/Support/EndianTest.cpp
@@ -0,0 +1,72 @@
+//===- unittests/Support/EndianTest.cpp - Endian.h tests ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "gtest/gtest.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/System/DataTypes.h"
+#include <cstdlib>
+#include <ctime>
+using namespace llvm;
+using namespace support;
+
+#undef max
+
+namespace {
+
+TEST(Endian, Read) {
+  // These are 5 bytes so we can be sure at least one of the reads is unaligned.
+  unsigned char big[] = {0x00, 0x01, 0x02, 0x03, 0x04};
+  unsigned char little[] = {0x00, 0x04, 0x03, 0x02, 0x01};
+  int32_t BigAsHost = 0x00010203;
+  EXPECT_EQ(BigAsHost, (endian::read_be<int32_t, unaligned>(big)));
+  int32_t LittleAsHost = 0x02030400;
+  EXPECT_EQ(LittleAsHost, (endian::read_le<int32_t, unaligned>(little)));
+
+  EXPECT_EQ((endian::read_be<int32_t, unaligned>(big + 1)),
+            (endian::read_le<int32_t, unaligned>(little + 1)));
+}
+
+TEST(Endian, Write) {
+  unsigned char data[5];
+  endian::write_be<int32_t, unaligned>(data, -1362446643);
+  EXPECT_EQ(data[0], 0xAE);
+  EXPECT_EQ(data[1], 0xCA);
+  EXPECT_EQ(data[2], 0xB6);
+  EXPECT_EQ(data[3], 0xCD);
+  endian::write_be<int32_t, unaligned>(data + 1, -1362446643);
+  EXPECT_EQ(data[1], 0xAE);
+  EXPECT_EQ(data[2], 0xCA);
+  EXPECT_EQ(data[3], 0xB6);
+  EXPECT_EQ(data[4], 0xCD);
+
+  endian::write_le<int32_t, unaligned>(data, -1362446643);
+  EXPECT_EQ(data[0], 0xCD);
+  EXPECT_EQ(data[1], 0xB6);
+  EXPECT_EQ(data[2], 0xCA);
+  EXPECT_EQ(data[3], 0xAE);
+  endian::write_le<int32_t, unaligned>(data + 1, -1362446643);
+  EXPECT_EQ(data[1], 0xCD);
+  EXPECT_EQ(data[2], 0xB6);
+  EXPECT_EQ(data[3], 0xCA);
+  EXPECT_EQ(data[4], 0xAE);
+}
+
+TEST(Endian, PackedEndianSpecificIntegral) {
+  // These are 5 bytes so we can be sure at least one of the reads is unaligned.
+  unsigned char big[] = {0x00, 0x01, 0x02, 0x03, 0x04};
+  unsigned char little[] = {0x00, 0x04, 0x03, 0x02, 0x01};
+  big32_t    *big_val    =
+    reinterpret_cast<big32_t *>(big + 1);
+  little32_t *little_val =
+    reinterpret_cast<little32_t *>(little + 1);
+
+  EXPECT_EQ(*big_val, *little_val);
+}
+
+}