[SelectionDAG] Disjoint Or could be also constant offset.

If the addr base of a Load/Store Inst is an Or-disjoint with a constant,
it could be selected to an MI with constans offset if the target have.

Signed-off-by: feng.feng <[email protected]>

Author: fengfeng09

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -5191,6 +5191,9 @@ bool SelectionDAG::isADDLike(SDValue Op) const {
 }
 
 bool SelectionDAG::isBaseWithConstantOffset(SDValue Op) const {
+  if (isADDLike(Op) && isa<ConstantSDNode>(Op.getOperand(1)))
+    return true;
+
   if ((Op.getOpcode() != ISD::ADD && Op.getOpcode() != ISD::OR) ||
       !isa<ConstantSDNode>(Op.getOperand(1)))
     return false;

llvm/test/CodeGen/AVR/base-with-add-like-constant-offset.ll

@@ -6,11 +6,10 @@ define void @test(i16 %x, ptr addrspace(1) %o) {
   ; CHECK: bb.0 (%ir-block.0):
   ; CHECK-NEXT:   liveins: $r25r24, $r23r22
   ; CHECK-NEXT: {{  $}}
-  ; CHECK-NEXT:   [[COPY:%[0-9]+]]:dldregs = COPY $r23r22
+  ; CHECK-NEXT:   [[COPY:%[0-9]+]]:dregs = COPY $r23r22
   ; CHECK-NEXT:   [[COPY1:%[0-9]+]]:dregs = COPY $r25r24
-  ; CHECK-NEXT:   [[ORIWRdK:%[0-9]+]]:dldregs = ORIWRdK [[COPY]], 10, implicit-def dead $sreg
-  ; CHECK-NEXT:   [[COPY2:%[0-9]+]]:ptrdispregs = COPY [[ORIWRdK]]
-  ; CHECK-NEXT:   STWPtrRr killed [[COPY2]], [[COPY1]] :: (store (s16) into %ir.addr, align 1, addrspace 1)
+  ; CHECK-NEXT:   [[COPY2:%[0-9]+]]:ptrdispregs = COPY [[COPY]]
+  ; CHECK-NEXT:   STDWPtrQRr [[COPY2]], 10, [[COPY1]] :: (store (s16) into %ir.addr, align 1, addrspace 1)
   ; CHECK-NEXT:   RET implicit $r1
   %int = ptrtoint ptr addrspace(1) %o to i16
   %or = or disjoint i16 %int, 10