diff --git a/llvm/lib/Analysis/CodeMetrics.cpp b/llvm/lib/Analysis/CodeMetrics.cpp
index 1f7c6aa3..bdffdd8 100644
--- a/llvm/lib/Analysis/CodeMetrics.cpp
+++ b/llvm/lib/Analysis/CodeMetrics.cpp
@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Analysis/AssumptionCache.h"
 #include "llvm/Analysis/CodeMetrics.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
@@ -70,31 +71,45 @@
 
 // Find all ephemeral values.
 void CodeMetrics::collectEphemeralValues(
-    const Loop *L, SmallPtrSetImpl<const Value *> &EphValues) {
+    const Loop *L, AssumptionCache *AC,
+    SmallPtrSetImpl<const Value *> &EphValues) {
   SmallPtrSet<const Value *, 32> Visited;
   SmallVector<const Value *, 16> Worklist;
 
-  for (auto &B : L->blocks())
-    for (auto &I : *B)
-      if (auto *II = dyn_cast<IntrinsicInst>(&I))
-        if (II->getIntrinsicID() == Intrinsic::assume &&
-            EphValues.insert(II).second)
-          appendSpeculatableOperands(II, Visited, Worklist);
+  for (auto &AssumeVH : AC->assumptions()) {
+    if (!AssumeVH)
+      continue;
+    Instruction *I = cast<Instruction>(AssumeVH);
+
+    // Filter out call sites outside of the loop so we don't do a function's
+    // worth of work for each of its loops (and, in the common case, ephemeral
+    // values in the loop are likely due to @llvm.assume calls in the loop).
+    if (!L->contains(I->getParent()))
+      continue;
+
+    if (EphValues.insert(I).second)
+      appendSpeculatableOperands(I, Visited, Worklist);
+  }
 
   completeEphemeralValues(Visited, Worklist, EphValues);
 }
 
 void CodeMetrics::collectEphemeralValues(
-    const Function *F, SmallPtrSetImpl<const Value *> &EphValues) {
+    const Function *F, AssumptionCache *AC,
+    SmallPtrSetImpl<const Value *> &EphValues) {
   SmallPtrSet<const Value *, 32> Visited;
   SmallVector<const Value *, 16> Worklist;
 
-  for (auto &B : *F)
-    for (auto &I : B)
-      if (auto *II = dyn_cast<IntrinsicInst>(&I))
-        if (II->getIntrinsicID() == Intrinsic::assume &&
-            EphValues.insert(II).second)
-          appendSpeculatableOperands(II, Visited, Worklist);
+  for (auto &AssumeVH : AC->assumptions()) {
+    if (!AssumeVH)
+      continue;
+    Instruction *I = cast<Instruction>(AssumeVH);
+    assert(I->getParent()->getParent() == F &&
+           "Found assumption for the wrong function!");
+
+    if (EphValues.insert(I).second)
+      appendSpeculatableOperands(I, Visited, Worklist);
+  }
 
   completeEphemeralValues(Visited, Worklist, EphValues);
 }