[AIE] Make one more copy in the unrolled dag

This is necessary to try sufficient stages, but makes it very difficult to reach the earlier
NCopies == 1 crash situation.

llvm/lib/Target/AIE/AIEMachineScheduler.cpp

@@ -1235,8 +1235,9 @@ void llvm::AIEPostRASchedStrategy::buildGraph(ScheduleDAGMI &DAG, AAResults *AA,
     assert(BS.getRegions().size() == 1);
     // Try to wrap the linear schedule within II.
     // We virtually unroll the body by the stagecount, computed from rounding
-    // up the length divided by II.
-    NCopies = (BS.getScheduleLength() + II - 1) / II;
+    // up the length divided by II, adding one more stage to account for
+    // the added resource contention
+    NCopies = (BS.getScheduleLength() + II - 1) / II + 1;
   }
   DEBUG_BLOCKS(dbgs() << "    buildGraph, NCopies=" << NCopies << "\n");
   for (int S = 0; S < NCopies; S++) {

llvm/test/CodeGen/AIE/aie2/schedule/postpipeliner/crash.mir

@@ -8,7 +8,7 @@
 # RUN: llc --mtriple=aie2 -O2 --start-before=postmisched %s -o - | FileCheck %s
 
 # This crashed the postpipeliner because it reaches NCopies=1 which causes an out of
-# bound access when setting up LCD heuristics. 
+# bound access when setting up LCD heuristics.
 # The filecheck reference is the unpipelined loop
 
 --- |
@@ -29,13 +29,13 @@
   ; CHECK-NEXT:    .p2align 4
   ; CHECK-NEXT:  .LBB0_1: // %for.body
   ; CHECK-NEXT:    // =>This Inner Loop Header: Depth=1
-  ; CHECK-NEXT:    nopb ; lda r0, [p2, #0]; nops ; nopxm ; nopv
-  ; CHECK-NEXT:    nopx
+  ; CHECK-NEXT:    nopb ; lda r0, [p2, #0]; nops ; nopx ; mov p2, p1; nopv
+  ; CHECK-NEXT:    nopa ; nopx
+  ; CHECK-NEXT:    nop
   ; CHECK-NEXT:    nop
   ; CHECK-NEXT:    nop
   ; CHECK-NEXT:    nop
   ; CHECK-NEXT:    nop
-  ; CHECK-NEXT:    mov p2, p1
   ; CHECK-NEXT:  .L_LEnd0:
   ; CHECK-NEXT:    nopb ; nopa ; st r0, [p0, #0]; nopxm ; nopv
   ; CHECK-NEXT:  // %bb.2: // %for.cond.cleanup