[Fixed Point Arithmetic] Fix for FixedPointValueToString

- Print negative numbers correctly
- Handle APInts of different sizes
- Add formal unit tests for FixedPointValueToString
- Add tests for checking correct printing when padding is set
- Restrict to printing in radix 10 since that's all we need for now

Differential Revision: https://reviews.llvm.org/D49945

llvm-svn: 339026

1 files changed, 107 insertions, 0 deletions

diff --git a/clang/unittests/Frontend/FixedPointString.cpp b/clang/unittests/Frontend/FixedPointString.cpp
new file mode 100644
index 00000000000..755efd7fcaa
--- /dev/null
+++ b/clang/unittests/Frontend/FixedPointString.cpp
@@ -0,0 +1,107 @@
+#include "clang/AST/Type.h"
+#include "llvm/ADT/APSInt.h"
+#include "llvm/ADT/SmallString.h"
+#include "gtest/gtest.h"
+
+using clang::FixedPointValueToString;
+using llvm::APSInt;
+using llvm::SmallString;
+
+namespace {
+
+TEST(FixedPointString, DifferentTypes) {
+  SmallString<64> S;
+  FixedPointValueToString(S, APSInt::get(320), 7);
+  ASSERT_STREQ(S.c_str(), "2.5");
+
+  S.clear();
+  FixedPointValueToString(S, APSInt::get(0), 7);
+  ASSERT_STREQ(S.c_str(), "0.0");
+
+  // signed short _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(16, /*Unsigned=*/false), 7);
+  ASSERT_STREQ(S.c_str(), "255.9921875");
+
+  // signed _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(32, /*Unsigned=*/false), 15);
+  ASSERT_STREQ(S.c_str(), "65535.999969482421875");
+
+  // signed long _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(64, /*Unsigned=*/false), 31);
+  ASSERT_STREQ(S.c_str(), "4294967295.9999999995343387126922607421875");
+
+  // unsigned short _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(16, /*Unsigned=*/true), 8);
+  ASSERT_STREQ(S.c_str(), "255.99609375");
+
+  // unsigned _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(32, /*Unsigned=*/true), 16);
+  ASSERT_STREQ(S.c_str(), "65535.9999847412109375");
+
+  // unsigned long _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(64, /*Unsigned=*/true), 32);
+  ASSERT_STREQ(S.c_str(), "4294967295.99999999976716935634613037109375");
+
+  // signed short _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(8, /*Unsigned=*/false), 7);
+  ASSERT_STREQ(S.c_str(), "0.9921875");
+
+  // signed _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(16, /*Unsigned=*/false), 15);
+  ASSERT_STREQ(S.c_str(), "0.999969482421875");
+
+  // signed long _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(32, /*Unsigned=*/false), 31);
+  ASSERT_STREQ(S.c_str(), "0.9999999995343387126922607421875");
+
+  // unsigned short _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(8, /*Unsigned=*/true), 8);
+  ASSERT_STREQ(S.c_str(), "0.99609375");
+
+  // unsigned _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(16, /*Unsigned=*/true), 16);
+  ASSERT_STREQ(S.c_str(), "0.9999847412109375");
+
+  // unsigned long _Fract
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMaxValue(32, /*Unsigned=*/true), 32);
+  ASSERT_STREQ(S.c_str(), "0.99999999976716935634613037109375");
+}
+
+TEST(FixedPointString, Negative) {
+  SmallString<64> S;
+  FixedPointValueToString(S, APSInt::get(-320), 7);
+  ASSERT_STREQ(S.c_str(), "-2.5");
+
+  S.clear();
+  FixedPointValueToString(S, APSInt::get(-64), 7);
+  ASSERT_STREQ(S.c_str(), "-0.5");
+
+  // signed short _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMinValue(16, /*Unsigned=*/false), 7);
+  ASSERT_STREQ(S.c_str(), "-256.0");
+
+  // signed _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMinValue(32, /*Unsigned=*/false), 15);
+  ASSERT_STREQ(S.c_str(), "-65536.0");
+
+  // signed long _Accum
+  S.clear();
+  FixedPointValueToString(S, APSInt::getMinValue(64, /*Unsigned=*/false), 31);
+  ASSERT_STREQ(S.c_str(), "-4294967296.0");
+}
+
+} // namespace