Index: llvm/lib/Transforms/Scalar/LoopInterchange.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopInterchange.cpp
+++ llvm/lib/Transforms/Scalar/LoopInterchange.cpp
@@ -1661,15 +1661,19 @@
   // replaced by Inners'.
   OuterLoopLatchSuccessor->replacePhiUsesWith(OuterLoopLatch, InnerLoopLatch);
 
+  auto &OuterInnerReductions = LIL.getOuterInnerReductions();
   // Now update the reduction PHIs in the inner and outer loop headers.
   SmallVector<PHINode *, 4> InnerLoopPHIs, OuterLoopPHIs;
-  for (PHINode &PHI : drop_begin(InnerLoopHeader->phis()))
+  for (PHINode &PHI : InnerLoopHeader->phis()) {
+    if (OuterInnerReductions.find(&PHI) == OuterInnerReductions.end())
+      continue;
     InnerLoopPHIs.push_back(cast<PHINode>(&PHI));
-  for (PHINode &PHI : drop_begin(OuterLoopHeader->phis()))
+  }
+  for (PHINode &PHI : OuterLoopHeader->phis()) {
+    if (OuterInnerReductions.find(&PHI) == OuterInnerReductions.end())
+      continue;
     OuterLoopPHIs.push_back(cast<PHINode>(&PHI));
-
-  auto &OuterInnerReductions = LIL.getOuterInnerReductions();
-  (void)OuterInnerReductions;
+  }
 
   // Now move the remaining reduction PHIs from outer to inner loop header and
   // vice versa. The PHI nodes must be part of a reduction across the inner and
Index: llvm/test/Transforms/LoopInterchange/pr43326.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/LoopInterchange/pr43326.ll
@@ -0,0 +1,86 @@
+; RUN: opt < %s -basic-aa -loop-interchange -pass-remarks-missed='loop-interchange' -pass-remarks-output=%t -S \
+; RUN:     -verify-dom-info -verify-loop-info -verify-loop-lcssa -stats 2>&1
+; RUN: FileCheck --input-file=%t --check-prefix=REMARKS %s
+
+@a = global i32 0
+@b = global i8 0
+@c = global i32 0
+@d = global i32 0
+@e = global [1 x [1 x i32]] zeroinitializer
+
+; REMARKS: --- !Passed
+; REMARKS-NEXT: Pass:            loop-interchange
+; REMARKS-NEXT: Name:            Interchanged
+; REMARKS-NEXT: Function:        pr43326
+
+define void @pr43326() {
+entry:
+  %0 = load i32, i32* @a
+  %tobool.not2 = icmp eq i32 %0, 0
+  br i1 %tobool.not2, label %for.end14, label %for.body.lr.ph
+
+for.body.lr.ph:                                   ; preds = %entry
+  %d.promoted = load i32, i32* @d
+  %a.promoted = load i32, i32* @a
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.inc12
+  %inc1312 = phi i32 [ %a.promoted, %for.body.lr.ph ], [ %inc13, %for.inc12 ]
+  %xor.lcssa.lcssa11 = phi i32 [ %d.promoted, %for.body.lr.ph ], [ %xor.lcssa.lcssa, %for.inc12 ]
+  br label %for.body3
+
+for.body3:                                        ; preds = %for.body, %for.inc10
+  %xor.lcssa9 = phi i32 [ %xor.lcssa.lcssa11, %for.body ], [ %xor.lcssa, %for.inc10 ]
+  %dec7 = phi i8 [ 0, %for.body ], [ %dec, %for.inc10 ]
+  %idxprom8 = sext i8 %dec7 to i64
+  br label %for.body7
+
+for.body7:                                        ; preds = %for.body3, %for.inc
+  %xor5 = phi i32 [ %xor.lcssa9, %for.body3 ], [ %xor, %for.inc ]
+  %inc4 = phi i32 [ 0, %for.body3 ], [ %inc, %for.inc ]
+  %idxprom = sext i32 %inc4 to i64
+  %arrayidx9 = getelementptr inbounds [1 x [1 x i32]], [1 x [1 x i32]]* @e, i64 0, i64 %idxprom, i64 %idxprom8
+  %1 = load i32, i32* %arrayidx9
+  %xor = xor i32 %xor5, %1
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body7
+  %inc = add nsw i32 %inc4, 1
+  %cmp5 = icmp slt i32 %inc, 1
+  br i1 %cmp5, label %for.body7, label %for.end
+
+for.end:                                          ; preds = %for.inc
+  %xor.lcssa = phi i32 [ %xor, %for.inc ]
+  %inc.lcssa = phi i32 [ %inc, %for.inc ]
+  br label %for.inc10
+
+for.inc10:                                        ; preds = %for.end
+  %dec = add i8 %dec7, -1
+  %cmp = icmp sgt i8 %dec, -1
+  br i1 %cmp, label %for.body3, label %for.end11
+
+for.end11:                                        ; preds = %for.inc10
+  %xor.lcssa.lcssa = phi i32 [ %xor.lcssa, %for.inc10 ]
+  %dec.lcssa = phi i8 [ %dec, %for.inc10 ]
+  %inc.lcssa.lcssa = phi i32 [ %inc.lcssa, %for.inc10 ]
+  br label %for.inc12
+
+for.inc12:                                        ; preds = %for.end11
+  %inc13 = add nsw i32 %inc1312, 1
+  %tobool.not = icmp eq i32 %inc13, 0
+  br i1 %tobool.not, label %for.cond.for.end14_crit_edge, label %for.body
+
+for.cond.for.end14_crit_edge:                     ; preds = %for.inc12
+  %inc13.lcssa = phi i32 [ %inc13, %for.inc12 ]
+  %inc.lcssa.lcssa.lcssa = phi i32 [ %inc.lcssa.lcssa, %for.inc12 ]
+  %xor.lcssa.lcssa.lcssa = phi i32 [ %xor.lcssa.lcssa, %for.inc12 ]
+  %dec.lcssa.lcssa = phi i8 [ %dec.lcssa, %for.inc12 ]
+  store i8 %dec.lcssa.lcssa, i8* @b
+  store i32 %xor.lcssa.lcssa.lcssa, i32* @d
+  store i32 %inc.lcssa.lcssa.lcssa, i32* @c
+  store i32 %inc13.lcssa, i32* @a
+  br label %for.end14
+
+for.end14:                                        ; preds = %for.cond.for.end14_crit_edge, %entry
+  ret void
+}
Index: llvm/test/Transforms/LoopInterchange/pr48212.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/LoopInterchange/pr48212.ll
@@ -0,0 +1,54 @@
+; RUN: opt < %s -basic-aa -loop-interchange -pass-remarks-missed='loop-interchange' -pass-remarks-output=%t -S \
+; RUN:     -verify-dom-info -verify-loop-info -verify-loop-lcssa 2>&1
+; RUN: FileCheck --input-file=%t --check-prefix=REMARKS %s
+
+; REMARKS: --- !Passed
+; REMARKS-NEXT: Pass:            loop-interchange
+; REMARKS-NEXT: Name:            Interchanged
+; REMARKS-NEXT: Function:        pr48212
+
+define void @pr48212([5 x i32]* %filter) #0 {
+entry:
+  br label %L1
+
+L1:                                               ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %L1, %for.inc6
+  %temp.04 = phi i32 [ undef, %L1 ], [ %temp.1.lcssa, %for.inc6 ]
+  %k1.03 = phi i32 [ 0, %L1 ], [ %inc7, %for.inc6 ]
+  br label %L2
+
+L2:                                               ; preds = %for.body
+  br label %for.body3
+
+for.body3:                                        ; preds = %L2, %for.inc
+  %temp.12 = phi i32 [ %temp.04, %L2 ], [ %add, %for.inc ]
+  %k2.01 = phi i32 [ 0, %L2 ], [ %inc, %for.inc ]
+  %idxprom = sext i32 %k2.01 to i64
+  %arrayidx = getelementptr inbounds [5 x i32], [5 x i32]* %filter, i64 %idxprom
+  %idxprom4 = sext i32 %k1.03 to i64
+  %arrayidx5 = getelementptr inbounds [5 x i32], [5 x i32]* %arrayidx, i64 0, i64 %idxprom4
+  %0 = load i32, i32* %arrayidx5
+  %add = add nsw i32 %temp.12, %0
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body3
+  %inc = add nsw i32 %k2.01, 1
+  %cmp2 = icmp slt i32 %inc, 3
+  br i1 %cmp2, label %for.body3, label %for.end
+
+for.end:                                          ; preds = %for.inc
+  %temp.1.lcssa = phi i32 [ %add, %for.inc ]
+  br label %for.inc6
+
+for.inc6:                                         ; preds = %for.end
+  %inc7 = add nsw i32 %k1.03, 1
+  %cmp = icmp slt i32 %inc7, 5
+  br i1 %cmp, label %for.body, label %for.end8
+
+for.end8:                                         ; preds = %for.inc6
+  ret void
+}
+
+