Drop ISD::MEMSET, ISD::MEMMOVE, and ISD::MEMCPY, which are not Legal

on any current target and aren't optimized in DAGCombiner. Instead
of using intermediate nodes, expand the operations, choosing between
simple loads/stores, target-specific code, and library calls,
immediately.

Previously, the code to emit optimized code for these operations
was only used at initial SelectionDAG construction time; now it is
used at all times. This fixes some cases where rep;movs was being
used for small copies where simple loads/stores would be better.

This also cleans up code that checks for alignments less than 4;
let the targets make that decision instead of doing it in
target-independent code. This allows x86 to use rep;movs in
low-alignment cases.

Also, this fixes a bug that resulted in the use of rep;stos for
memsets of 0 with non-constant memory size when the alignment was
at least 4. It's better to use the library in this case, which
can be significantly faster when the size is large.

This also preserves more SourceValue information when memory
intrinsics are lowered into simple loads/stores.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49572 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 45 deletions

diff --git a/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
index 6511cff1c6..380c42220c 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
@@ -439,51 +439,6 @@ SDOperand DAGTypeLegalizer::CreateStackStoreLoad(SDOperand Op,
   return DAG.getLoad(DestVT, Store, FIPtr, NULL, 0);
 }
 
-/// HandleMemIntrinsic - This handles memcpy/memset/memmove with invalid
-/// operands.  This promotes or expands the operands as required.
-SDOperand DAGTypeLegalizer::HandleMemIntrinsic(SDNode *N) {
-  // The chain and pointer [operands #0 and #1] are always valid types.
-  SDOperand Chain = N->getOperand(0);
-  SDOperand Ptr   = N->getOperand(1);
-  SDOperand Op2   = N->getOperand(2);
-  
-  // Op #2 is either a value (memset) or a pointer.  Promote it if required.
-  switch (getTypeAction(Op2.getValueType())) {
-  default: assert(0 && "Unknown action for pointer/value operand");
-  case Legal: break;
-  case Promote: Op2 = GetPromotedOp(Op2); break;
-  }
-
-  // The length could have any action required.
-  SDOperand Length = N->getOperand(3);
-  switch (getTypeAction(Length.getValueType())) {
-  default: assert(0 && "Unknown action for memop operand");
-  case Legal: break;
-  case Promote: Length = GetPromotedZExtOp(Length); break;
-  case Expand:
-    SDOperand Dummy;  // discard the high part.
-    GetExpandedOp(Length, Length, Dummy);
-    break;
-  }
-
-  SDOperand Align = N->getOperand(4);
-  switch (getTypeAction(Align.getValueType())) {
-  default: assert(0 && "Unknown action for memop operand");
-  case Legal: break;
-  case Promote: Align = GetPromotedZExtOp(Align); break;
-  }
-
-  SDOperand AlwaysInline = N->getOperand(5);
-  switch (getTypeAction(AlwaysInline.getValueType())) {
-  default: assert(0 && "Unknown action for memop operand");
-  case Legal: break;
-  case Promote: AlwaysInline = GetPromotedZExtOp(AlwaysInline); break;
-  }
-
-  SDOperand Ops[] = { Chain, Ptr, Op2, Length, Align, AlwaysInline };
-  return DAG.UpdateNodeOperands(SDOperand(N, 0), Ops, 6);
-}
-
 /// JoinIntegers - Build an integer with low bits Lo and high bits Hi.
 SDOperand DAGTypeLegalizer::JoinIntegers(SDOperand Lo, SDOperand Hi) {
   MVT::ValueType LVT = Lo.getValueType();