[X86]Remove X86-specific dead code in ScheduleDAGRRList.cpp

[XinWang10]

After patch #67288 landed, unfoldMemoryOperand would not return NewMIs whose size ==3. So the removed line is useless.

[llvmbot]

@llvm/pr-subscribers-backend-x86

@llvm/pr-subscribers-llvm-selectiondag

Changes

After patch #67288 landed, unfoldMemoryOperand would not return NewMIs whose size ==3. So the removed line is useless.

---

Full diff: https://github.com/llvm/llvm-project/pull/67629.diff

1 Files Affected:

• (modified) llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp (-5)

diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index 36f68e9363ebd55..47c137d2bcad733 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -986,11 +986,6 @@ SUnit *ScheduleDAGRRList::TryUnfoldSU(SUnit *SU) {
   if (!TII->unfoldMemoryOperand(*DAG, N, NewNodes))
     return nullptr;
 
-  // unfolding an x86 DEC64m operation results in store, dec, load which
-  // can't be handled here so quit
-  if (NewNodes.size() == 3)
-    return nullptr;
-
   assert(NewNodes.size() == 2 && "Expected a load folding node!");
 
   N = NewNodes[1];

[KanRobert]

LGTM for x86 part. I'm fine with the change if it does not affect other targets.

[RKSimon]

LGTM

[XinWang10]

Thank you for reviews!