Refactor to expose RTLIB calls to targets.

fp128 is almost but not quite completely illegal as a type on AArch64. As a
result it needs to have a register class (for argument passing mainly), but all
operations need to be lowered to runtime calls. Currently there's no way for
targets to do this (without duplicating code), as the relevant functions are
hidden in SelectionDAG. This patch changes that.

llvm-svn: 171971

1 files changed, 1 insertions, 21 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 5eaf67ef0c7..db3abafcba8 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1841,26 +1841,6 @@ SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
   return ExpandVectorBuildThroughStack(Node);
 }
 
-static bool isInTailCallPosition(SelectionDAG &DAG, SDNode *Node,
-                                SDValue &Chain, const TargetLowering &TLI) {
-  const Function *F = DAG.getMachineFunction().getFunction();
-
-  // Conservatively require the attributes of the call to match those of
-  // the return. Ignore noalias because it doesn't affect the call sequence.
-  Attribute CallerRetAttr = F->getAttributes().getRetAttributes();
-  if (AttrBuilder(CallerRetAttr)
-      .removeAttribute(Attribute::NoAlias).hasAttributes())
-    return false;
-
-  // It's not safe to eliminate the sign / zero extension of the return value.
-  if (CallerRetAttr.hasAttribute(Attribute::ZExt) ||
-      CallerRetAttr.hasAttribute(Attribute::SExt))
-    return false;
-
-  // Check if the only use is a function return node.
-  return TLI.isUsedByReturnOnly(Node, Chain);
-}
-
 // ExpandLibCall - Expand a node into a call to a libcall.  If the result value
 // does not fit into a register, return the lo part and set the hi part to the
 // by-reg argument.  If it does fit into a single register, return the result
@@ -1891,7 +1871,7 @@ SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
   // isTailCall may be true since the callee does not reference caller stack
   // frame. Check if it's in the right position.
   SDValue TCChain = InChain;
-  bool isTailCall = isInTailCallPosition(DAG, Node, TCChain, TLI);
+  bool isTailCall = TLI.isInTailCallPosition(DAG, Node, TCChain);
   if (isTailCall)
     InChain = TCChain;