[llvm] Base with add like constant offset (PR #88493)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-selectiondag

Author: fengfeng (fengfeng09)

<details>
<summary>Changes</summary>

Or-disjoint application.

---
Full diff: https://github.com/llvm/llvm-project/pull/88493.diff


2 Files Affected:

- (modified) llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (+3) 
- (added) llvm/test/CodeGen/AVR/base-with-add-like-constant-offset.ll (+20) 


``````````diff
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 1dd0fa49a460f8..67feb47fef076f 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/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;
diff --git a/llvm/test/CodeGen/AVR/base-with-add-like-constant-offset.ll b/llvm/test/CodeGen/AVR/base-with-add-like-constant-offset.ll
new file mode 100644
index 00000000000000..6077f71b5efe06
--- /dev/null
+++ b/llvm/test/CodeGen/AVR/base-with-add-like-constant-offset.ll
@@ -0,0 +1,20 @@
+; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+; RUN: llc -mtriple=avr %s -start-before=avr-isel -o - -stop-after=avr-isel | FileCheck %s
+
+define void @test(i16 %x, ptr addrspace(1) %o) {
+  ; CHECK-LABEL: name: test
+  ; CHECK: bb.0 (%ir-block.0):
+  ; CHECK-NEXT:   liveins: $r25r24, $r23r22
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[COPY:%[0-9]+]]:dregs = COPY $r23r22
+  ; CHECK-NEXT:   [[COPY1:%[0-9]+]]:dregs = COPY $r25r24
+  ; 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
+  %addr = inttoptr i16 %or to ptr addrspace(1)
+  store i16 %x, ptr addrspace(1) %addr
+  ret void
+}
+

``````````

</details>


https://github.com/llvm/llvm-project/pull/88493