Handle load/store of misaligned vectors that are the

same size as an int type by doing a bitconvert of
load/store of the int type (same algorithm as floating point).
This makes them work for ppc Altivec.  There was some
code that purported to handle loads of (some) vectors
by splitting them into two smaller vectors, but getExtLoad
rejects subvector loads, so this could never have worked;
the patch removes it.

llvm-svn: 47696

1 files changed, 30 insertions, 19 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 7df4c3f2acc..ff4ddf373f1 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -569,22 +569,32 @@ SDOperand ExpandUnalignedStore(StoreSDNode *ST, SelectionDAG &DAG,
   MVT::ValueType VT = Val.getValueType();
   int Alignment = ST->getAlignment();
   int SVOffset = ST->getSrcValueOffset();
-  if (MVT::isFloatingPoint(ST->getMemoryVT())) {
+  if (MVT::isFloatingPoint(ST->getMemoryVT()) || 
+      MVT::isVector(ST->getMemoryVT())) {
     // Expand to a bitconvert of the value to the integer type of the 
     // same size, then a (misaligned) int store.
     MVT::ValueType intVT;
-    if (VT==MVT::f64)
+    if (VT == MVT::v8i16 || VT == MVT::v4i32 ||
+        VT == MVT::v2i64 || VT == MVT::v2f64 ||
+        VT == MVT::v4f32 || VT == MVT::v16i8 ||
+        VT == MVT::ppcf128)
+      intVT = MVT::i128;
+    else if (VT==MVT::f64 ||
+        VT == MVT::v8i8 || VT == MVT::v4i16 ||
+        VT == MVT::v2i32 || VT == MVT::v1i64 ||
+        VT == MVT::v2f32)
       intVT = MVT::i64;
     else if (VT==MVT::f32)
       intVT = MVT::i32;
     else
-      assert(0 && "Unaligned load of unsupported floating point type");
+      assert(0 && "Unaligned load of unsupported type");
 
     SDOperand Result = DAG.getNode(ISD::BIT_CONVERT, intVT, Val);
     return DAG.getStore(Chain, Result, Ptr, ST->getSrcValue(),
                         SVOffset, ST->isVolatile(), Alignment);
   }
   assert(MVT::isInteger(ST->getMemoryVT()) &&
+         !MVT::isVector(ST->getMemoryVT()) &&
          "Unaligned store of unknown type.");
   // Get the half-size VT
   MVT::ValueType NewStoredVT = ST->getMemoryVT() - 1;
@@ -620,43 +630,44 @@ SDOperand ExpandUnalignedLoad(LoadSDNode *LD, SelectionDAG &DAG,
   SDOperand Ptr = LD->getBasePtr();
   MVT::ValueType VT = LD->getValueType(0);
   MVT::ValueType LoadedVT = LD->getMemoryVT();
-  if (MVT::isFloatingPoint(VT) && !MVT::isVector(VT)) {
+  if (MVT::isFloatingPoint(VT) || MVT::isVector(VT)) {
     // Expand to a (misaligned) integer load of the same size,
-    // then bitconvert to floating point.
+    // then bitconvert to floating point or vector.
     MVT::ValueType intVT;
-    if (LoadedVT == MVT::f64)
+    if (LoadedVT == MVT::v8i16 || LoadedVT == MVT::v4i32 ||
+        LoadedVT == MVT::v2i64 || LoadedVT == MVT::v2f64 ||
+        LoadedVT == MVT::v4f32 || LoadedVT == MVT::v16i8 ||
+        LoadedVT == MVT::ppcf128)
+      intVT = MVT::i128;
+    else if (LoadedVT == MVT::f64 || 
+             LoadedVT == MVT::v8i8 || LoadedVT == MVT::v4i16 ||
+             LoadedVT == MVT::v2i32 || LoadedVT == MVT::v1i64 ||
+             LoadedVT == MVT::v2f32)
       intVT = MVT::i64;
     else if (LoadedVT == MVT::f32)
       intVT = MVT::i32;
     else
-      assert(0 && "Unaligned load of unsupported floating point type");
+      assert(0 && "Unaligned load of unsupported type");
 
     SDOperand newLoad = DAG.getLoad(intVT, Chain, Ptr, LD->getSrcValue(),
                                     SVOffset, LD->isVolatile(), 
                                     LD->getAlignment());
     SDOperand Result = DAG.getNode(ISD::BIT_CONVERT, LoadedVT, newLoad);
-    if (LoadedVT != VT)
+    if (MVT::isFloatingPoint(VT) && LoadedVT != VT)
       Result = DAG.getNode(ISD::FP_EXTEND, VT, Result);
 
     SDOperand Ops[] = { Result, Chain };
     return DAG.getNode(ISD::MERGE_VALUES, DAG.getVTList(VT, MVT::Other), 
                        Ops, 2);
   }
-  assert((MVT::isInteger(LoadedVT) || MVT::isVector(LoadedVT)) &&
+  assert(MVT::isInteger(LoadedVT) && !MVT::isVector(LoadedVT) &&
          "Unaligned load of unsupported type.");
 
-  // Compute the new VT that is half the size of the old one.  We either have an
-  // integer MVT or we have a vector MVT.
+  // Compute the new VT that is half the size of the old one.  This is an
+  // integer MVT.
   unsigned NumBits = MVT::getSizeInBits(LoadedVT);
   MVT::ValueType NewLoadedVT;
-  if (!MVT::isVector(LoadedVT)) {
-    NewLoadedVT = MVT::getIntegerType(NumBits/2);
-  } else {
-    // FIXME: This is not right for <1 x anything> it is also not right for
-    // non-power-of-two vectors.
-    NewLoadedVT = MVT::getVectorType(MVT::getVectorElementType(LoadedVT),
-                                     MVT::getVectorNumElements(LoadedVT)/2);
-  }
+  NewLoadedVT = MVT::getIntegerType(NumBits/2);
   NumBits >>= 1;
   
   unsigned Alignment = LD->getAlignment();