diff --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index 6299deca08c9..2981c149acad 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -2717,6 +2717,24 @@ bool IndVarSimplify::optimizeLoopExits(Loop *L, SCEVExpander &Rewriter) {
   if (isa<SCEVCouldNotCompute>(MaxExitCount))
     return false;
 
+  // Visit our exit blocks in order of dominance.  We know from the fact that
+  // all exits (left) are analyzeable that the must be a total dominance order
+  // between them as each must dominate the latch.  The visit order only
+  // matters for the provably equal case.  
+  llvm::sort(ExitingBlocks,
+             [&](BasicBlock *A, BasicBlock *B) {
+               // std::sort sorts in ascending order, so we want the inverse of
+               // the normal dominance relation.
+               if (DT->properlyDominates(A, B)) return true;
+               if (DT->properlyDominates(B, A)) return false;
+               llvm_unreachable("expected total dominance order!");
+             });
+#ifdef ASSERT
+  for (unsigned i = 1; i < ExitingBlocks.size(); i++) {
+    assert(DT->dominates(ExitingBlocks[i-1], ExitingBlocks[i]));
+  }
+#endif
+  
   auto FoldExit = [&](BasicBlock *ExitingBB, bool IsTaken) {
     BranchInst *BI = cast<BranchInst>(ExitingBB->getTerminator());
     bool ExitIfTrue = !L->contains(*succ_begin(ExitingBB));
@@ -2729,6 +2747,7 @@ bool IndVarSimplify::optimizeLoopExits(Loop *L, SCEVExpander &Rewriter) {
   };
 
   bool Changed = false;
+  SmallSet<const SCEV*, 8> DominatingExitCounts;
   for (BasicBlock *ExitingBB : ExitingBlocks) {
     const SCEV *ExitCount = SE->getExitCount(L, ExitingBB);
     assert(!isa<SCEVCouldNotCompute>(ExitCount) && "checked above");
@@ -2766,10 +2785,15 @@ bool IndVarSimplify::optimizeLoopExits(Loop *L, SCEVExpander &Rewriter) {
       continue;
     }
 
-    // TODO: If we can prove that the exiting iteration is equal to the exit
-    // count for this exit and that no previous exit oppurtunities exist within
-    // the loop, then we can discharge all other exits.  (May fall out of
-    // previous TODO.)
+    // As we run, keep track of which exit counts we've encountered.  If we
+    // find a duplicate, we've found an exit which would have exited on the
+    // exiting iteration, but (from the visit order) strictly follows another
+    // which does the same and is thus dead. 
+    if (!DominatingExitCounts.insert(ExitCount).second) {
+      FoldExit(ExitingBB, false);
+      Changed = true;
+      continue;
+    }
   }
   return Changed;
 }
diff --git a/llvm/test/Transforms/IndVarSimplify/eliminate-exit.ll b/llvm/test/Transforms/IndVarSimplify/eliminate-exit.ll
index b1c6c4d2ade8..726f3cd7f2f2 100644
--- a/llvm/test/Transforms/IndVarSimplify/eliminate-exit.ll
+++ b/llvm/test/Transforms/IndVarSimplify/eliminate-exit.ll
@@ -185,5 +185,39 @@ exit:
   ret void
 }
 
+define void @mixed_width(i32 %len) {
+; CHECK-LABEL: @mixed_width(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[LEN_ZEXT:%.*]] = zext i32 [[LEN:%.*]] to i64
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i64 [[IV]], [[LEN_ZEXT]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[BACKEDGE]], label [[EXIT:%.*]]
+; CHECK:       backedge:
+; CHECK-NEXT:    call void @side_effect()
+; CHECK-NEXT:    br i1 true, label [[LOOP]], label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %len.zext = zext i32 %len to i64
+  br label %loop
+loop:
+  %iv = phi i64 [0, %entry], [%iv.next, %backedge]
+  %iv2 = phi i32 [0, %entry], [%iv2.next, %backedge]
+  %iv.next = add i64 %iv, 1
+  %iv2.next = add i32 %iv2, 1
+  %cmp1 = icmp ult i64 %iv, %len.zext
+  br i1 %cmp1, label %backedge, label %exit
+
+backedge:
+  call void @side_effect()
+  %cmp2 = icmp ult i32 %iv2, %len
+  br i1 %cmp2, label %loop, label %exit
+exit:
+  ret void
+}
 
 declare void @side_effect()
diff --git a/llvm/test/Transforms/IndVarSimplify/loop-predication.ll b/llvm/test/Transforms/IndVarSimplify/loop-predication.ll
index 94363706b5b1..77c18ef23d7d 100644
--- a/llvm/test/Transforms/IndVarSimplify/loop-predication.ll
+++ b/llvm/test/Transforms/IndVarSimplify/loop-predication.ll
@@ -464,7 +464,6 @@ define i32 @duplicate_checks(i32* %array.1, i32* %array.2, i32* %array.3, i32 %l
 ; CHECK-NEXT:    [[TMP2:%.*]] = icmp ult i32 [[LENGTH:%.*]], [[TMP1]]
 ; CHECK-NEXT:    [[UMIN:%.*]] = select i1 [[TMP2]], i32 [[LENGTH]], i32 [[TMP1]]
 ; CHECK-NEXT:    [[TMP3:%.*]] = icmp ne i32 [[LENGTH]], [[UMIN]]
-; CHECK-NEXT:    [[TMP4:%.*]] = icmp ne i32 [[LENGTH]], [[UMIN]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED1:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
@@ -478,7 +477,7 @@ define i32 @duplicate_checks(i32* %array.1, i32* %array.2, i32* %array.3, i32 %l
 ; CHECK-NEXT:    [[ARRAY_1_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_1:%.*]], i64 [[I_I64]]
 ; CHECK-NEXT:    [[ARRAY_1_I:%.*]] = load i32, i32* [[ARRAY_1_I_PTR]], align 4
 ; CHECK-NEXT:    [[LOOP_ACC_1:%.*]] = add i32 [[LOOP_ACC]], [[ARRAY_1_I]]
-; CHECK-NEXT:    br i1 [[TMP4]], label [[GUARDED1]], label [[DEOPT2:%.*]], !prof !0
+; CHECK-NEXT:    br i1 true, label [[GUARDED1]], label [[DEOPT2:%.*]], !prof !0
 ; CHECK:       deopt2:
 ; CHECK-NEXT:    call void @prevent_merging()
 ; CHECK-NEXT:    ret i32 -1
@@ -784,7 +783,7 @@ exit:
 ; If we have a dominating exit (exit1) which can't be itself rewritten, we
 ; can't rewrite a later exit (exit2).  Doing so would cause the loop to exit
 ; from the exit2 when it should have exited from exit1.
-define i32 @neg_dominating_exit(i32* %array, i32 %length, i32 %n) {
+define i32 @neg_dominating_exit(i32* %array, i32 %length, i32 %length2, i32 %n) {
 ; CHECK-LABEL: @neg_dominating_exit(
 ; CHECK-NEXT:  loop.preheader:
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
@@ -798,7 +797,7 @@ define i32 @neg_dominating_exit(i32* %array, i32 %length, i32 %n) {
 ; CHECK-NEXT:    call void @prevent_merging()
 ; CHECK-NEXT:    ret i32 [[RESULT]]
 ; CHECK:       guarded:
-; CHECK-NEXT:    [[WITHIN_BOUNDS2:%.*]] = icmp ult i32 [[I]], [[LENGTH]]
+; CHECK-NEXT:    [[WITHIN_BOUNDS2:%.*]] = icmp ult i32 [[I]], [[LENGTH2:%.*]]
 ; CHECK-NEXT:    br i1 [[WITHIN_BOUNDS2]], label [[GUARDED2]], label [[DEOPT2:%.*]], !prof !0
 ; CHECK:       deopt2:
 ; CHECK-NEXT:    call void @prevent_merging()
@@ -830,7 +829,7 @@ deopt:                                            ; preds = %loop
   ret i32 %result
 
 guarded:                                          ; preds = %loop
-  %within.bounds2 = icmp ult i32 %i, %length
+  %within.bounds2 = icmp ult i32 %i, %length2
   br i1 %within.bounds2, label %guarded2, label %deopt2, !prof !0
 
 deopt2:                                            ; preds = %loop
diff --git a/llvm/test/Transforms/IndVarSimplify/pr38674.ll b/llvm/test/Transforms/IndVarSimplify/pr38674.ll
index 1c839ffd2acb..390a68d7cbbe 100644
--- a/llvm/test/Transforms/IndVarSimplify/pr38674.ll
+++ b/llvm/test/Transforms/IndVarSimplify/pr38674.ll
@@ -14,10 +14,9 @@ define i32 @test_01() {
 ; CHECK-NEXT:    [[ZEXT:%.*]] = zext i16 1 to i32
 ; CHECK-NEXT:    br label [[FOR_BODY6:%.*]]
 ; CHECK:       for.cond4:
-; CHECK-NEXT:    [[CMP5:%.*]] = icmp ult i32 [[INC:%.*]], 2
-; CHECK-NEXT:    br i1 [[CMP5]], label [[FOR_BODY6]], label [[FOR_END:%.*]]
+; CHECK-NEXT:    br i1 true, label [[FOR_BODY6]], label [[FOR_END:%.*]]
 ; CHECK:       for.body6:
-; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, [[FOR_COND4_PREHEADER]] ], [ [[INC]], [[FOR_COND4:%.*]] ]
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, [[FOR_COND4_PREHEADER]] ], [ [[INC:%.*]], [[FOR_COND4:%.*]] ]
 ; CHECK-NEXT:    [[TMP0:%.*]] = icmp eq i32 [[IV]], [[ZEXT]]
 ; CHECK-NEXT:    [[INC]] = add nuw nsw i32 [[IV]], 1
 ; CHECK-NEXT:    br i1 [[TMP0]], label [[RETURN_LOOPEXIT:%.*]], label [[FOR_COND4]]