[llvm-exegesis] Add predefined floating point values so we can test impact of special values on latency.

Summary: This will be useful to generate many configurations and test instruction regimes (NaN, Inf, subnormal, normal).

Reviewers: courbet

Subscribers: mgorny, tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D51858

llvm-svn: 342369

2 files changed, 72 insertions, 0 deletions

diff --git a/llvm/unittests/tools/llvm-exegesis/CMakeLists.txt b/llvm/unittests/tools/llvm-exegesis/CMakeLists.txt
index 387f8a58ebd..21459a46ddb 100644
--- a/llvm/unittests/tools/llvm-exegesis/CMakeLists.txt
+++ b/llvm/unittests/tools/llvm-exegesis/CMakeLists.txt
@@ -15,6 +15,7 @@ add_llvm_unittest(LLVMExegesisTests
   BenchmarkRunnerTest.cpp
   ClusteringTest.cpp
   PerfHelperTest.cpp
+  RegisterValueTest.cpp
   )
 target_link_libraries(LLVMExegesisTests PRIVATE LLVMExegesis)
 
diff --git a/llvm/unittests/tools/llvm-exegesis/RegisterValueTest.cpp b/llvm/unittests/tools/llvm-exegesis/RegisterValueTest.cpp
new file mode 100644
index 00000000000..4ade990382d
--- /dev/null
+++ b/llvm/unittests/tools/llvm-exegesis/RegisterValueTest.cpp
@@ -0,0 +1,71 @@
+//===-- RegisterValueTest.cpp -----------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "RegisterValue.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+namespace exegesis {
+
+namespace {
+
+#define CHECK(EXPECTED, ACTUAL)                                                \
+  EXPECT_EQ(llvm::APInt(SizeInBits, EXPECTED, 16),                             \
+            bitcastFloatValue(Semantic, PredefinedValues::ACTUAL))
+
+TEST(RegisterValueTest, Half) {
+  const size_t SizeInBits = 16;
+  const auto &Semantic = llvm::APFloatBase::IEEEhalf();
+  CHECK("0000", POS_ZERO);
+  CHECK("8000", NEG_ZERO);
+  CHECK("3C00", ONE);
+  CHECK("4000", TWO);
+  CHECK("7C00", INF);
+  CHECK("7E00", QNAN);
+  CHECK("7BFF", LARGEST);
+  CHECK("0400", SMALLEST_NORM);
+  CHECK("0001", SMALLEST);
+  CHECK("0001", ULP);
+  CHECK("3C01", ONE_PLUS_ULP);
+}
+
+TEST(RegisterValueTest, Single) {
+  const size_t SizeInBits = 32;
+  const auto &Semantic = llvm::APFloatBase::IEEEsingle();
+  CHECK("00000000", POS_ZERO);
+  CHECK("80000000", NEG_ZERO);
+  CHECK("3F800000", ONE);
+  CHECK("40000000", TWO);
+  CHECK("7F800000", INF);
+  CHECK("7FC00000", QNAN);
+  CHECK("7F7FFFFF", LARGEST);
+  CHECK("00800000", SMALLEST_NORM);
+  CHECK("00000001", SMALLEST);
+  CHECK("00000001", ULP);
+  CHECK("3F800001", ONE_PLUS_ULP);
+}
+
+TEST(RegisterValueTest, Double) {
+  const size_t SizeInBits = 64;
+  const auto &Semantic = llvm::APFloatBase::IEEEdouble();
+  CHECK("0000000000000000", POS_ZERO);
+  CHECK("8000000000000000", NEG_ZERO);
+  CHECK("3FF0000000000000", ONE);
+  CHECK("4000000000000000", TWO);
+  CHECK("7FF0000000000000", INF);
+  CHECK("7FF8000000000000", QNAN);
+  CHECK("7FEFFFFFFFFFFFFF", LARGEST);
+  CHECK("0010000000000000", SMALLEST_NORM);
+  CHECK("0000000000000001", SMALLEST);
+  CHECK("0000000000000001", ULP);
+  CHECK("3FF0000000000001", ONE_PLUS_ULP);
+}
+
+} // namespace
+} // namespace exegesis