2 files changed, 59 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 200d6b8abec..f1cb5c0ad02 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -126,6 +126,7 @@ llvm::createLibcall(MachineIRBuilder &MIRBuilder, RTLIB::Libcall Libcall,
   return LegalizerHelper::Legalized;
 }
 
+// Useful for libcalls where all operands have the same type.
 static LegalizerHelper::LegalizeResult
 simpleLibcall(MachineInstr &MI, MachineIRBuilder &MIRBuilder, unsigned Size,
               Type *OpType) {
@@ -138,6 +139,28 @@ simpleLibcall(MachineInstr &MI, MachineIRBuilder &MIRBuilder, unsigned Size,
                        Args);
 }
 
+static RTLIB::Libcall getConvRTLibDesc(unsigned Opcode, Type *ToType,
+                                       Type *FromType) {
+  auto ToMVT = MVT::getVT(ToType);
+  auto FromMVT = MVT::getVT(FromType);
+
+  switch (Opcode) {
+  case TargetOpcode::G_FPEXT:
+    return RTLIB::getFPEXT(FromMVT, ToMVT);
+  case TargetOpcode::G_FPTRUNC:
+    return RTLIB::getFPROUND(FromMVT, ToMVT);
+  }
+  llvm_unreachable("Unsupported libcall function");
+}
+
+static LegalizerHelper::LegalizeResult
+conversionLibcall(MachineInstr &MI, MachineIRBuilder &MIRBuilder, Type *ToType,
+                  Type *FromType) {
+  RTLIB::Libcall Libcall = getConvRTLibDesc(MI.getOpcode(), ToType, FromType);
+  return createLibcall(MIRBuilder, Libcall, {MI.getOperand(0).getReg(), ToType},
+                       {{MI.getOperand(1).getReg(), FromType}});
+}
+
 LegalizerHelper::LegalizeResult
 LegalizerHelper::libcall(MachineInstr &MI) {
   LLT LLTy = MRI.getType(MI.getOperand(0).getReg());
@@ -172,6 +195,30 @@ LegalizerHelper::libcall(MachineInstr &MI) {
       return Status;
     break;
   }
+  case TargetOpcode::G_FPEXT: {
+    // FIXME: Support other floating point types (half, fp128 etc)
+    unsigned FromSize = MRI.getType(MI.getOperand(1).getReg()).getSizeInBits();
+    unsigned ToSize = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
+    if (ToSize != 64 || FromSize != 32)
+      return UnableToLegalize;
+    LegalizeResult Status = conversionLibcall(
+        MI, MIRBuilder, Type::getDoubleTy(Ctx), Type::getFloatTy(Ctx));
+    if (Status != Legalized)
+      return Status;
+    break;
+  }
+  case TargetOpcode::G_FPTRUNC: {
+    // FIXME: Support other floating point types (half, fp128 etc)
+    unsigned FromSize = MRI.getType(MI.getOperand(1).getReg()).getSizeInBits();
+    unsigned ToSize = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
+    if (ToSize != 32 || FromSize != 64)
+      return UnableToLegalize;
+    LegalizeResult Status = conversionLibcall(
+        MI, MIRBuilder, Type::getFloatTy(Ctx), Type::getDoubleTy(Ctx));
+    if (Status != Legalized)
+      return Status;
+    break;
+  }
   }
 
   MI.eraseFromParent();
diff --git a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
index 3e694b80f80..7b560088510 100644
--- a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
@@ -178,6 +178,12 @@ ARMLegalizerInfo::ARMLegalizerInfo(const ARMSubtarget &ST) {
     setAction({G_MERGE_VALUES, 1, s32}, Legal);
     setAction({G_UNMERGE_VALUES, s32}, Legal);
     setAction({G_UNMERGE_VALUES, 1, s64}, Legal);
+
+    setAction({G_FPEXT, s64}, Legal);
+    setAction({G_FPEXT, 1, s32}, Legal);
+
+    setAction({G_FPTRUNC, s32}, Legal);
+    setAction({G_FPTRUNC, 1, s64}, Legal);
   } else {
     for (unsigned BinOp : {G_FADD, G_FSUB, G_FMUL, G_FDIV})
       for (auto Ty : {s32, s64})
@@ -192,6 +198,12 @@ ARMLegalizerInfo::ARMLegalizerInfo(const ARMSubtarget &ST) {
     setAction({G_FCMP, 1, s32}, Custom);
     setAction({G_FCMP, 1, s64}, Custom);
 
+    setAction({G_FPEXT, s64}, Legal);
+    setAction({G_FPEXT, 1, s32}, Libcall);
+
+    setAction({G_FPTRUNC, s32}, Legal);
+    setAction({G_FPTRUNC, 1, s64}, Libcall);
+
     if (AEABI(ST))
       setFCmpLibcallsAEABI();
     else