Refactor InferAlignment out of DAGCombine.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90917 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 45 deletions

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 204cbc4dc1..7846e3d01c 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4811,49 +4811,6 @@ bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
   return false;
 }
 
-/// InferAlignment - If we can infer some alignment information from this
-/// pointer, return it.
-static unsigned InferAlignment(SDValue Ptr, SelectionDAG &DAG) {
-  // If this is a direct reference to a stack slot, use information about the
-  // stack slot's alignment.
-  int FrameIdx = 1 << 31;
-  int64_t FrameOffset = 0;
-  if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Ptr)) {
-    FrameIdx = FI->getIndex();
-  } else if (Ptr.getOpcode() == ISD::ADD &&
-             isa<ConstantSDNode>(Ptr.getOperand(1)) &&
-             isa<FrameIndexSDNode>(Ptr.getOperand(0))) {
-    FrameIdx = cast<FrameIndexSDNode>(Ptr.getOperand(0))->getIndex();
-    FrameOffset = Ptr.getConstantOperandVal(1);
-  }
-
-  if (FrameIdx != (1 << 31)) {
-    // FIXME: Handle FI+CST.
-    const MachineFrameInfo &MFI = *DAG.getMachineFunction().getFrameInfo();
-    if (MFI.isFixedObjectIndex(FrameIdx)) {
-      int64_t ObjectOffset = MFI.getObjectOffset(FrameIdx) + FrameOffset;
-
-      // The alignment of the frame index can be determined from its offset from
-      // the incoming frame position.  If the frame object is at offset 32 and
-      // the stack is guaranteed to be 16-byte aligned, then we know that the
-      // object is 16-byte aligned.
-      unsigned StackAlign = DAG.getTarget().getFrameInfo()->getStackAlignment();
-      unsigned Align = MinAlign(ObjectOffset, StackAlign);
-
-      // Finally, the frame object itself may have a known alignment.  Factor
-      // the alignment + offset into a new alignment.  For example, if we know
-      // the  FI is 8 byte aligned, but the pointer is 4 off, we really have a
-      // 4-byte alignment of the resultant pointer.  Likewise align 4 + 4-byte
-      // offset = 4-byte alignment, align 4 + 1-byte offset = align 1, etc.
-      unsigned FIInfoAlign = MinAlign(MFI.getObjectAlignment(FrameIdx),
-                                      FrameOffset);
-      return std::max(Align, FIInfoAlign);
-    }
-  }
-
-  return 0;
-}
-
 SDValue DAGCombiner::visitLOAD(SDNode *N) {
   LoadSDNode *LD  = cast<LoadSDNode>(N);
   SDValue Chain = LD->getChain();
@@ -4861,7 +4818,7 @@ SDValue DAGCombiner::visitLOAD(SDNode *N) {
 
   // Try to infer better alignment information than the load already has.
   if (OptLevel != CodeGenOpt::None && LD->isUnindexed()) {
-    if (unsigned Align = InferAlignment(Ptr, DAG)) {
+    if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
       if (Align > LD->getAlignment())
         return DAG.getExtLoad(LD->getExtensionType(), N->getDebugLoc(),
                               LD->getValueType(0),
@@ -5086,7 +5043,7 @@ SDValue DAGCombiner::visitSTORE(SDNode *N) {
 
   // Try to infer better alignment information than the store already has.
   if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
-    if (unsigned Align = InferAlignment(Ptr, DAG)) {
+    if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
       if (Align > ST->getAlignment())
         return DAG.getTruncStore(Chain, N->getDebugLoc(), Value,
                                  Ptr, ST->getSrcValue(),