2 files changed, 149 insertions, 0 deletions
diff --git a/llvm/unittests/Analysis/CMakeLists.txt b/llvm/unittests/Analysis/CMakeLists.txt
index 35a6d92ce17..28d35ceec92 100644
--- a/llvm/unittests/Analysis/CMakeLists.txt
+++ b/llvm/unittests/Analysis/CMakeLists.txt
@@ -13,4 +13,5 @@ add_llvm_unittest(AnalysisTests
   LazyCallGraphTest.cpp
   ScalarEvolutionTest.cpp
   MixedTBAATest.cpp
+  ValueTrackingTest.cpp
   )
diff --git a/llvm/unittests/Analysis/ValueTrackingTest.cpp b/llvm/unittests/Analysis/ValueTrackingTest.cpp
new file mode 100644
index 00000000000..b5ad01968b9
--- /dev/null
+++ b/llvm/unittests/Analysis/ValueTrackingTest.cpp
@@ -0,0 +1,148 @@
+//===- ValueTrackingTest.cpp - ValueTracking tests ------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/AsmParser/Parser.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/InstIterator.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/SourceMgr.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+namespace {
+
+class MatchSelectPatternTest : public testing::Test {
+protected:
+  void parseAssembly(const char *Assembly) {
+    SMDiagnostic Error;
+    M = parseAssemblyString(Assembly, Error, getGlobalContext());
+
+    std::string errMsg;
+    raw_string_ostream os(errMsg);
+    Error.print("", os);
+
+    // A failure here means that the test itself is buggy.
+    if (!M)
+      report_fatal_error(os.str());
+
+    Function *F = M->getFunction("test");
+    if (F == nullptr)
+      report_fatal_error("Test must have a function named @test");
+
+    A = nullptr;
+    for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
+      if (I->hasName()) {
+        if (I->getName() == "A")
+          A = &*I;
+      }
+    }
+    if (A == nullptr)
+      report_fatal_error("@test must have an instruction %A");
+  }
+
+  void expectPattern(const SelectPatternResult &P) {
+    Value *LHS, *RHS;
+    Instruction::CastOps CastOp;
+    SelectPatternResult R = matchSelectPattern(A, LHS, RHS, &CastOp);
+    EXPECT_EQ(P.Flavor, R.Flavor);
+    EXPECT_EQ(P.NaNBehavior, R.NaNBehavior);
+    EXPECT_EQ(P.Ordered, R.Ordered);
+  }
+
+  std::unique_ptr<Module> M;
+  Instruction *A, *B;
+};
+
+}
+
+TEST_F(MatchSelectPatternTest, SimpleFMin) {
+  parseAssembly(
+      "define float @test(float %a) {\n"
+      "  %1 = fcmp ult float %a, 5.0\n"
+      "  %A = select i1 %1, float %a, float 5.0\n"
+      "  ret float %A\n"
+      "}\n");
+  expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, false});
+}
+
+TEST_F(MatchSelectPatternTest, SimpleFMax) {
+  parseAssembly(
+      "define float @test(float %a) {\n"
+      "  %1 = fcmp ogt float %a, 5.0\n"
+      "  %A = select i1 %1, float %a, float 5.0\n"
+      "  ret float %A\n"
+      "}\n");
+  expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true});
+}
+
+TEST_F(MatchSelectPatternTest, SwappedFMax) {
+  parseAssembly(
+      "define float @test(float %a) {\n"
+      "  %1 = fcmp olt float 5.0, %a\n"
+      "  %A = select i1 %1, float %a, float 5.0\n"
+      "  ret float %A\n"
+      "}\n");
+  expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, false});
+}
+
+TEST_F(MatchSelectPatternTest, SwappedFMax2) {
+  parseAssembly(
+      "define float @test(float %a) {\n"
+      "  %1 = fcmp olt float %a, 5.0\n"
+      "  %A = select i1 %1, float 5.0, float %a\n"
+      "  ret float %A\n"
+      "}\n");
+  expectPattern({SPF_FMAXNUM, SPNB_RETURNS_NAN, false});
+}
+
+TEST_F(MatchSelectPatternTest, SwappedFMax3) {
+  parseAssembly(
+      "define float @test(float %a) {\n"
+      "  %1 = fcmp ult float %a, 5.0\n"
+      "  %A = select i1 %1, float 5.0, float %a\n"
+      "  ret float %A\n"
+      "}\n");
+  expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true});
+}
+
+TEST_F(MatchSelectPatternTest, FastFMin) {
+  parseAssembly(
+      "define float @test(float %a) {\n"
+      "  %1 = fcmp nnan olt float %a, 5.0\n"
+      "  %A = select i1 %1, float %a, float 5.0\n"
+      "  ret float %A\n"
+      "}\n");
+  expectPattern({SPF_FMINNUM, SPNB_RETURNS_ANY, false});
+}
+
+TEST_F(MatchSelectPatternTest, FMinConstantZero) {
+  parseAssembly(
+      "define float @test(float %a) {\n"
+      "  %1 = fcmp ole float %a, 0.0\n"
+      "  %A = select i1 %1, float %a, float 0.0\n"
+      "  ret float %A\n"
+      "}\n");
+  // This shouldn't be matched, as %a could be -0.0.
+  expectPattern({SPF_UNKNOWN, SPNB_NA, false});
+}
+
+TEST_F(MatchSelectPatternTest, FMinConstantZeroNsz) {
+  parseAssembly(
+      "define float @test(float %a) {\n"
+      "  %1 = fcmp nsz ole float %a, 0.0\n"
+      "  %A = select i1 %1, float %a, float 0.0\n"
+      "  ret float %A\n"
+      "}\n");
+  // But this should be, because we've ignored signed zeroes.
+  expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, true});
+}