Index: lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
===================================================================
--- lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
+++ lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
@@ -26,6 +26,7 @@
 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/Analysis/MemorySSA.h"
 #include "llvm/Analysis/MemorySSAUpdater.h"
+#include "llvm/Analysis/ScalarEvolutionExpander.h"
 #include "llvm/Analysis/Utils/Local.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Constant.h"
@@ -47,6 +48,7 @@
 #include "llvm/Transforms/Scalar/SimpleLoopUnswitch.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
 #include "llvm/Transforms/Utils/ValueMapper.h"
 #include <algorithm>
@@ -364,7 +366,9 @@
   // some input conditions to the branch.
   bool FullUnswitch = false;
 
-  if (L.isLoopInvariant(BI.getCondition())) {
+  if (L.isLoopInvariant(BI.getCondition()) ||
+      (SE->isLoopInvariant(SE->getSCEV(BI.getCondition()), &L) &&
+       isSafeToExpand(SE->getSCEV(BI.getCondition()), *SE))) {
     Invariants.push_back(BI.getCondition());
     FullUnswitch = true;
   } else {
@@ -417,6 +421,28 @@
     }
   });
 
+  if (!L.isLoopInvariant(BI.getCondition()) &&
+      SE->isLoopInvariant(SE->getSCEV(BI.getCondition()), &L)) {
+    auto &DL = LoopExitBB->getParent()->getParent()->getDataLayout();
+    auto *PHTerm = L.getLoopPreheader()->getTerminator();
+    // TODO: Do we need a SCEVHoister?
+    SCEVExpander Expander(*SE, DL, "");
+    auto *OldCond = BI.getCondition();
+    auto *NewCond = Expander.expandCodeFor(SE->getSCEV(OldCond),
+                                           OldCond->getType(),
+                                           PHTerm);
+    BI.setCondition(NewCond);
+    assert(Invariants.size() == 1 &&
+           Invariants[0] == OldCond);
+    TinyPtrVector<Value *> NewInvariants;
+    NewInvariants.push_back(NewCond);
+    Invariants = NewInvariants;
+
+    // FIXME: This can walk out of our current loop.
+    RecursivelyDeleteTriviallyDeadInstructions(OldCond, nullptr, MSSAU);
+  }
+
+  
   // If we have scalar evolutions, we need to invalidate them including this
   // loop and the loop containing the exit block.
   if (SE) {
Index: test/Transforms/SimpleLoopUnswitch/trivial-unswitch.ll
===================================================================
--- test/Transforms/SimpleLoopUnswitch/trivial-unswitch.ll
+++ test/Transforms/SimpleLoopUnswitch/trivial-unswitch.ll
@@ -1243,3 +1243,49 @@
 ; CHECK:       loopexit:
 ; CHECK-NEXT:    ret
 }
+
+define i32 @test_iterative_scev_hoist(i32* %var, i32 %cond1.i32,
+                                      i32 %cond2.i32) {
+; CHECK-LABEL: @test_iterative_scev_hoist(
+entry:
+  br label %loop_begin
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    trunc
+; CHECK-NEXT:    br i1 %{{.*}}, label %entry.split, label %loop_exit.split
+;
+; CHECK:       entry.split:
+; CHECK-NEXT:    trunc
+; CHECK-NEXT:    br i1 %{{.*}}, label %entry.split.split, label %loop_exit
+;
+; CHECK:       entry.split.split:
+; CHECK-NEXT:    br label %loop_begin
+
+loop_begin:
+  %cond1 = trunc i32 %cond1.i32 to i1
+  br i1 %cond1, label %continue, label %loop_exit	; first trivial condition
+; CHECK:       loop_begin:
+; CHECK-NEXT:    br label %continue
+
+continue:
+  %var_val = load i32, i32* %var
+  %cond2 = trunc i32 %cond2.i32 to i1
+  br i1 %cond2, label %do_something, label %loop_exit	; second trivial condition
+; CHECK:       continue:
+; CHECK-NEXT:    load
+; CHECK-NEXT:    br label %do_something
+
+do_something:
+  call void @some_func() noreturn nounwind
+  br label %loop_begin
+; CHECK:       do_something:
+; CHECK-NEXT:    call
+; CHECK-NEXT:    br label %loop_begin
+
+loop_exit:
+  ret i32 0
+; CHECK:       loop_exit:
+; CHECK-NEXT:    br label %loop_exit.split
+;
+; CHECK:       loop_exit.split:
+; CHECK-NEXT:    ret
+}