[llvm] r366477 - [FPEnv] Teach the IRBuilder about constrained FPTrunc and FPExt

[Kevin P. Neal via llvm-commits]

Author: kpn
Date: Thu Jul 18 11:01:57 2019
New Revision: 366477

URL: http://llvm.org/viewvc/llvm-project?rev=366477&view=rev
Log:
[FPEnv] Teach the IRBuilder about constrained FPTrunc and FPExt

The IRBuilder doesn't know that FPTrunc and FPExt have constrained
equivalents. Add the support by building on the strict FP mode now
present in the IRBuilder.

Reviewed by:	John McCall
Approved by:	John McCall
Differential Revision:	https://reviews.llvm.org/D64934

Modified:
    llvm/trunk/include/llvm/IR/IRBuilder.h
    llvm/trunk/unittests/IR/IRBuilderTest.cpp

Modified: llvm/trunk/include/llvm/IR/IRBuilder.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/IRBuilder.h?rev=366477&r1=366476&r2=366477&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/IRBuilder.h (original)
+++ llvm/trunk/include/llvm/IR/IRBuilder.h Thu Jul 18 11:01:57 2019
@@ -1931,10 +1931,17 @@ public:
 
   Value *CreateFPTrunc(Value *V, Type *DestTy,
                        const Twine &Name = "") {
+    if (IsFPConstrained)
+      return CreateConstrainedFPCast(
+          Intrinsic::experimental_constrained_fptrunc, V, DestTy, nullptr,
+          Name);
     return CreateCast(Instruction::FPTrunc, V, DestTy, Name);
   }
 
   Value *CreateFPExt(Value *V, Type *DestTy, const Twine &Name = "") {
+    if (IsFPConstrained)
+      return CreateConstrainedFPCast(Intrinsic::experimental_constrained_fpext,
+                                     V, DestTy, nullptr, Name);
     return CreateCast(Instruction::FPExt, V, DestTy, Name);
   }
 
@@ -2046,6 +2053,29 @@ public:
     return Insert(CastInst::CreateFPCast(V, DestTy), Name);
   }
 
+  CallInst *CreateConstrainedFPCast(
+      Intrinsic::ID ID, Value *V, Type *DestTy,
+      Instruction *FMFSource = nullptr, const Twine &Name = "",
+      MDNode *FPMathTag = nullptr,
+      Optional<ConstrainedFPIntrinsic::RoundingMode> Rounding = None,
+      Optional<ConstrainedFPIntrinsic::ExceptionBehavior> Except = None) {
+    Value *RoundingV = getConstrainedFPRounding(Rounding);
+    Value *ExceptV = getConstrainedFPExcept(Except);
+
+    FastMathFlags UseFMF = FMF;
+    if (FMFSource)
+      UseFMF = FMFSource->getFastMathFlags();
+
+    CallInst *C;
+    if (ID == Intrinsic::experimental_constrained_fpext)
+      C = CreateIntrinsic(ID, {DestTy, V->getType()}, {V, ExceptV}, nullptr,
+                          Name);
+    else
+      C = CreateIntrinsic(ID, {DestTy, V->getType()}, {V, RoundingV, ExceptV},
+                          nullptr, Name);
+    return cast<CallInst>(setFPAttrs(C, FPMathTag, UseFMF));
+  }
+
   // Provided to resolve 'CreateIntCast(Ptr, Ptr, "...")', giving a
   // compile time error, instead of converting the string to bool for the
   // isSigned parameter.

Modified: llvm/trunk/unittests/IR/IRBuilderTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/IR/IRBuilderTest.cpp?rev=366477&r1=366476&r2=366477&view=diff
==============================================================================
--- llvm/trunk/unittests/IR/IRBuilderTest.cpp (original)
+++ llvm/trunk/unittests/IR/IRBuilderTest.cpp Thu Jul 18 11:01:57 2019
@@ -125,10 +125,14 @@ TEST_F(IRBuilderTest, Intrinsics) {
 TEST_F(IRBuilderTest, ConstrainedFP) {
   IRBuilder<> Builder(BB);
   Value *V;
+  Value *VDouble;
   CallInst *Call;
   IntrinsicInst *II;
+  GlobalVariable *GVDouble = new GlobalVariable(*M, Type::getDoubleTy(Ctx),
+                            true, GlobalValue::ExternalLinkage, nullptr);
 
   V = Builder.CreateLoad(GV->getValueType(), GV);
+  VDouble = Builder.CreateLoad(GVDouble->getValueType(), GVDouble);
 
   // See if we get constrained intrinsics instead of non-constrained
   // instructions.
@@ -159,6 +163,16 @@ TEST_F(IRBuilderTest, ConstrainedFP) {
   II = cast<IntrinsicInst>(V);
   EXPECT_EQ(II->getIntrinsicID(), Intrinsic::experimental_constrained_frem);
 
+  V = Builder.CreateFPTrunc(VDouble, Type::getFloatTy(Ctx));
+  ASSERT_TRUE(isa<IntrinsicInst>(V));
+  II = cast<IntrinsicInst>(V);
+  EXPECT_EQ(II->getIntrinsicID(), Intrinsic::experimental_constrained_fptrunc);
+
+  VDouble = Builder.CreateFPExt(V, Type::getDoubleTy(Ctx));
+  ASSERT_TRUE(isa<IntrinsicInst>(VDouble));
+  II = cast<IntrinsicInst>(VDouble);
+  EXPECT_EQ(II->getIntrinsicID(), Intrinsic::experimental_constrained_fpext);
+
   // Verify the codepaths for setting and overriding the default metadata.
   V = Builder.CreateFAdd(V, V);
   ASSERT_TRUE(isa<ConstrainedFPIntrinsic>(V));