diff --git a/lib/Analysis/BranchProbabilityInfo.cpp b/lib/Analysis/BranchProbabilityInfo.cpp
index f9461c0b853..2730ce6c63b 100644
--- a/lib/Analysis/BranchProbabilityInfo.cpp
+++ b/lib/Analysis/BranchProbabilityInfo.cpp
@@ -65,8 +65,9 @@ static const uint32_t UR_TAKEN_WEIGHT = 1;
 ///
 /// This is the weight for a branch not being taken toward a block that
 /// terminates (eventually) in unreachable. Such a branch is essentially never
-/// taken.
-static const uint32_t UR_NONTAKEN_WEIGHT = 1023;
+/// taken. Set the weight to an absurdly high value so that nested loops don't
+/// easily subsume it.
+static const uint32_t UR_NONTAKEN_WEIGHT = 1024*1024 - 1;
 
 static const uint32_t PH_TAKEN_WEIGHT = 20;
 static const uint32_t PH_NONTAKEN_WEIGHT = 12;
diff --git a/test/Analysis/BranchProbabilityInfo/noreturn.ll b/test/Analysis/BranchProbabilityInfo/noreturn.ll
index c53c1ed113e..8b9ae11f7d3 100644
--- a/test/Analysis/BranchProbabilityInfo/noreturn.ll
+++ b/test/Analysis/BranchProbabilityInfo/noreturn.ll
@@ -8,8 +8,8 @@ define i32 @test1(i32 %a, i32 %b) {
 entry:
   %cond = icmp eq i32 %a, 42
   br i1 %cond, label %exit, label %abort
-; CHECK: edge entry -> exit probability is 1023 / 1024
-; CHECK: edge entry -> abort probability is 1 / 1024
+; CHECK: edge entry -> exit probability is 1048575 / 1048576
+; CHECK: edge entry -> abort probability is 1 / 1048576
 
 abort:
   call void @abort() noreturn
@@ -26,11 +26,11 @@ entry:
                               i32 2, label %case_b
                               i32 3, label %case_c
                               i32 4, label %case_d]
-; CHECK: edge entry -> exit probability is 1023 / 1027
-; CHECK: edge entry -> case_a probability is 1 / 1027
-; CHECK: edge entry -> case_b probability is 1 / 1027
-; CHECK: edge entry -> case_c probability is 1 / 1027
-; CHECK: edge entry -> case_d probability is 1 / 1027
+; CHECK: edge entry -> exit probability is 1048575 / 1048579
+; CHECK: edge entry -> case_a probability is 1 / 1048579
+; CHECK: edge entry -> case_b probability is 1 / 1048579
+; CHECK: edge entry -> case_c probability is 1 / 1048579
+; CHECK: edge entry -> case_d probability is 1 / 1048579
 
 case_a:
   br label %case_b
@@ -55,8 +55,8 @@ define i32 @test3(i32 %a, i32 %b) {
 entry:
   %cond1 = icmp eq i32 %a, 42
   br i1 %cond1, label %exit, label %dom
-; CHECK: edge entry -> exit probability is 1023 / 1024
-; CHECK: edge entry -> dom probability is 1 / 1024
+; CHECK: edge entry -> exit probability is 1048575 / 1048576
+; CHECK: edge entry -> dom probability is 1 / 1048576
 
 dom:
   %cond2 = icmp ult i32 %a, 42