1 files changed, 132 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index 459969b58b9..67fcb26ee27 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -895,6 +895,138 @@ bool TargetLoweringBase::canOpTrap(unsigned Op, EVT VT) const {
   }
 }
 
+TargetLoweringBase::LegalizeKind
+TargetLoweringBase::getTypeConversion(LLVMContext &Context, EVT VT) const {
+  // If this is a simple type, use the ComputeRegisterProp mechanism.
+  if (VT.isSimple()) {
+    MVT SVT = VT.getSimpleVT();
+    assert((unsigned)SVT.SimpleTy < array_lengthof(TransformToType));
+    MVT NVT = TransformToType[SVT.SimpleTy];
+    LegalizeTypeAction LA = ValueTypeActions.getTypeAction(SVT);
+
+    assert((LA == TypeLegal || LA == TypeSoftenFloat ||
+            ValueTypeActions.getTypeAction(NVT) != TypePromoteInteger) &&
+           "Promote may not follow Expand or Promote");
+
+    if (LA == TypeSplitVector)
+      return LegalizeKind(LA,
+                          EVT::getVectorVT(Context, SVT.getVectorElementType(),
+                                           SVT.getVectorNumElements() / 2));
+    if (LA == TypeScalarizeVector)
+      return LegalizeKind(LA, SVT.getVectorElementType());
+    return LegalizeKind(LA, NVT);
+  }
+
+  // Handle Extended Scalar Types.
+  if (!VT.isVector()) {
+    assert(VT.isInteger() && "Float types must be simple");
+    unsigned BitSize = VT.getSizeInBits();
+    // First promote to a power-of-two size, then expand if necessary.
+    if (BitSize < 8 || !isPowerOf2_32(BitSize)) {
+      EVT NVT = VT.getRoundIntegerType(Context);
+      assert(NVT != VT && "Unable to round integer VT");
+      LegalizeKind NextStep = getTypeConversion(Context, NVT);
+      // Avoid multi-step promotion.
+      if (NextStep.first == TypePromoteInteger)
+        return NextStep;
+      // Return rounded integer type.
+      return LegalizeKind(TypePromoteInteger, NVT);
+    }
+
+    return LegalizeKind(TypeExpandInteger,
+                        EVT::getIntegerVT(Context, VT.getSizeInBits() / 2));
+  }
+
+  // Handle vector types.
+  unsigned NumElts = VT.getVectorNumElements();
+  EVT EltVT = VT.getVectorElementType();
+
+  // Vectors with only one element are always scalarized.
+  if (NumElts == 1)
+    return LegalizeKind(TypeScalarizeVector, EltVT);
+
+  // Try to widen vector elements until the element type is a power of two and
+  // promote it to a legal type later on, for example:
+  // <3 x i8> -> <4 x i8> -> <4 x i32>
+  if (EltVT.isInteger()) {
+    // Vectors with a number of elements that is not a power of two are always
+    // widened, for example <3 x i8> -> <4 x i8>.
+    if (!VT.isPow2VectorType()) {
+      NumElts = (unsigned)NextPowerOf2(NumElts);
+      EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts);
+      return LegalizeKind(TypeWidenVector, NVT);
+    }
+
+    // Examine the element type.
+    LegalizeKind LK = getTypeConversion(Context, EltVT);
+
+    // If type is to be expanded, split the vector.
+    //  <4 x i140> -> <2 x i140>
+    if (LK.first == TypeExpandInteger)
+      return LegalizeKind(TypeSplitVector,
+                          EVT::getVectorVT(Context, EltVT, NumElts / 2));
+
+    // Promote the integer element types until a legal vector type is found
+    // or until the element integer type is too big. If a legal type was not
+    // found, fallback to the usual mechanism of widening/splitting the
+    // vector.
+    EVT OldEltVT = EltVT;
+    while (1) {
+      // Increase the bitwidth of the element to the next pow-of-two
+      // (which is greater than 8 bits).
+      EltVT = EVT::getIntegerVT(Context, 1 + EltVT.getSizeInBits())
+                  .getRoundIntegerType(Context);
+
+      // Stop trying when getting a non-simple element type.
+      // Note that vector elements may be greater than legal vector element
+      // types. Example: X86 XMM registers hold 64bit element on 32bit
+      // systems.
+      if (!EltVT.isSimple())
+        break;
+
+      // Build a new vector type and check if it is legal.
+      MVT NVT = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
+      // Found a legal promoted vector type.
+      if (NVT != MVT() && ValueTypeActions.getTypeAction(NVT) == TypeLegal)
+        return LegalizeKind(TypePromoteInteger,
+                            EVT::getVectorVT(Context, EltVT, NumElts));
+    }
+
+    // Reset the type to the unexpanded type if we did not find a legal vector
+    // type with a promoted vector element type.
+    EltVT = OldEltVT;
+  }
+
+  // Try to widen the vector until a legal type is found.
+  // If there is no wider legal type, split the vector.
+  while (1) {
+    // Round up to the next power of 2.
+    NumElts = (unsigned)NextPowerOf2(NumElts);
+
+    // If there is no simple vector type with this many elements then there
+    // cannot be a larger legal vector type.  Note that this assumes that
+    // there are no skipped intermediate vector types in the simple types.
+    if (!EltVT.isSimple())
+      break;
+    MVT LargerVector = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
+    if (LargerVector == MVT())
+      break;
+
+    // If this type is legal then widen the vector.
+    if (ValueTypeActions.getTypeAction(LargerVector) == TypeLegal)
+      return LegalizeKind(TypeWidenVector, LargerVector);
+  }
+
+  // Widen odd vectors to next power of two.
+  if (!VT.isPow2VectorType()) {
+    EVT NVT = VT.getPow2VectorType(Context);
+    return LegalizeKind(TypeWidenVector, NVT);
+  }
+
+  // Vectors with illegal element types are expanded.
+  EVT NVT = EVT::getVectorVT(Context, EltVT, VT.getVectorNumElements() / 2);
+  return LegalizeKind(TypeSplitVector, NVT);
+}
 
 static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
                                           unsigned &NumIntermediates,