Make it possible to indicate relaxed floating point requirements at the IR level

through the use of 'fpmath' metadata.  Currently this only provides a 'fpaccuracy'
value, which may be a number in ULPs or the keyword 'fast', however the intent is
that this will be extended with additional information about NaN's, infinities
etc later.  No optimizations have been hooked up to this so far.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154822 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 25 insertions, 0 deletions

diff --git a/unittests/VMCore/InstructionsTest.cpp b/unittests/VMCore/InstructionsTest.cpp
index 218a9a0..9c0cb44 100644
--- a/unittests/VMCore/InstructionsTest.cpp
+++ b/unittests/VMCore/InstructionsTest.cpp
@@ -12,8 +12,11 @@
 #include "llvm/Constants.h"
 #include "llvm/DerivedTypes.h"
 #include "llvm/LLVMContext.h"
+#include "llvm/Operator.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Analysis/ValueTracking.h"
+#include "llvm/Support/MDBuilder.h"
+#include "llvm/Support/IRBuilder.h"
 #include "llvm/Target/TargetData.h"
 #include "gtest/gtest.h"
 
@@ -226,5 +229,27 @@ TEST(InstructionsTest, VectorGep) {
   delete PtrVecB;
 }
 
+TEST(InstructionsTest, FPMathOperator) {
+  LLVMContext &Context = getGlobalContext();
+  IRBuilder<> Builder(Context);
+  MDBuilder MDHelper(Context);
+  Instruction *I = Builder.CreatePHI(Builder.getDoubleTy(), 0);
+  MDNode *MD1 = MDHelper.createFPMath(1.0);
+  MDNode *MDF = MDHelper.createFastFPMath();
+  Value *V1 = Builder.CreateFAdd(I, I, "", MD1);
+  Value *VF = Builder.CreateFAdd(I, I, "", MDF);
+  EXPECT_TRUE(isa<FPMathOperator>(V1));
+  EXPECT_TRUE(isa<FPMathOperator>(VF));
+  FPMathOperator *O1 = cast<FPMathOperator>(V1);
+  FPMathOperator *OF = cast<FPMathOperator>(VF);
+  EXPECT_FALSE(O1->isFastFPAccuracy());
+  EXPECT_TRUE(OF->isFastFPAccuracy());
+  EXPECT_EQ(O1->getFPAccuracy(), 1.0);
+  EXPECT_GT(OF->getFPAccuracy(), 999.0);
+  delete V1;
+  delete VF;
+  delete I;
+}
+
 }  // end anonymous namespace
 }  // end namespace llvm