Teach the SelectionDAG ISel how to turn ConstantPacked values into

constant nodes with vector types.  Also teach the asm printer how to print
ConstantPacked constant pool entries.  This allows us to generate altivec
code such as the following, which adds a vector constantto a packed float.

LCPI1_0:  <4 x float> < float 0.0e+0, float 0.0e+0, float 0.0e+0, float 1.0e+0 >
        .space  4
        .space  4
        .space  4
        .long   1065353216      ; float 1
        .text
        .align  4
        .globl  _foo
_foo:
        lis r2, ha16(LCPI1_0)
        la r2, lo16(LCPI1_0)(r2)
        li r4, 0
        lvx v0, r4, r2
        lvx v1, r4, r3
        vaddfp v0, v1, v0
        stvx v0, r4, r3
        blr

For the llvm code:

void %foo(<4 x float> * %a) {
entry:
  %tmp1 = load <4 x float> * %a;
  %tmp2 = add <4 x float> %tmp1, < float 0.0, float 0.0, float 0.0, float 1.0 >
  store <4 x float> %tmp2, <4 x float> *%a
  ret void
}


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24616 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index c02fc9ac69..18da8168a9 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -690,6 +690,32 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
     }
     break;
   }
+  case ISD::ConstantVec: {
+    // We assume that vector constants are not legal, and will be immediately
+    // spilled to the constant pool.
+    //
+    // FIXME: revisit this when we have some kind of mechanism by which targets
+    // can decided legality of vector constants, of which there may be very
+    // many.
+    //
+    // Create a ConstantPacked, and put it in the constant pool.
+    std::vector<Constant*> CV;
+    MVT::ValueType VT = Node->getValueType(0);
+    for (unsigned I = 0, E = Node->getNumOperands(); I < E; ++I) {
+      SDOperand OpN = Node->getOperand(I);
+      const Type* OpNTy = MVT::getTypeForValueType(OpN.getValueType());
+      if (MVT::isFloatingPoint(VT))
+        CV.push_back(ConstantFP::get(OpNTy, 
+                                     cast<ConstantFPSDNode>(OpN)->getValue()));
+      else
+        CV.push_back(ConstantUInt::get(OpNTy,
+                                       cast<ConstantSDNode>(OpN)->getValue()));
+    }
+    Constant *CP = ConstantPacked::get(CV);
+    SDOperand CPIdx = DAG.getConstantPool(CP, Node->getValueType(0));
+    Result = DAG.getLoad(VT, DAG.getEntryNode(), CPIdx, DAG.getSrcValue(NULL));
+    break;
+  }
   case ISD::TokenFactor:
     if (Node->getNumOperands() == 2) {
       bool Changed = false;