Index: lib/CodeGen/CGExpr.cpp
===================================================================
--- lib/CodeGen/CGExpr.cpp
+++ lib/CodeGen/CGExpr.cpp
@@ -498,18 +498,50 @@
   } else {
     switch (M->getStorageDuration()) {
     case SD_Automatic:
-    case SD_FullExpression:
       if (auto *Size = EmitLifetimeStart(
               CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
               Alloca.getPointer())) {
-        if (M->getStorageDuration() == SD_Automatic)
-          pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
-                                                    Alloca, Size);
-        else
-          pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
-                                               Size);
+        pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
+                                                  Alloca, Size);
       }
       break;
+
+    case SD_FullExpression: {
+      if (!ShouldEmitLifetimeMarkers)
+        break;
+
+      // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end
+      // marker. Instead, start the lifetime of a conditional temporary earlier
+      // so that it's unconditional. Don't do this in ASan's use-after-scope
+      // mode so that it gets the more precise lifetime marks.
+      ConditionalEvaluation *OldConditional = nullptr;
+      CGBuilderTy::InsertPoint OldIP;
+      if (isInConditionalBranch() && !E->getType().isDestructedType() &&
+          CGM.getCodeGenOpts().OptimizationLevel > 0 &&
+          !CGM.getCodeGenOpts().SanitizeAddressUseAfterScope) {
+        OldConditional = OutermostConditional;
+        OutermostConditional = nullptr;
+
+        OldIP = Builder.saveIP();
+        llvm::BasicBlock *Block = OldConditional->getStartingBlock();
+        Builder.restoreIP(CGBuilderTy::InsertPoint(
+            Block, llvm::BasicBlock::iterator(Block->back())));
+      }
+
+      if (auto *Size = EmitLifetimeStart(
+              CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
+              Alloca.getPointer())) {
+        pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
+                                             Size);
+      }
+
+      if (OldConditional) {
+        OutermostConditional = OldConditional;
+        Builder.restoreIP(OldIP);
+      }
+      break;
+    }
+
     default:
       break;
     }
Index: test/CodeGenCXX/conditional-temporaries.cpp
===================================================================
--- test/CodeGenCXX/conditional-temporaries.cpp
+++ test/CodeGenCXX/conditional-temporaries.cpp
@@ -1,6 +1,7 @@
 // REQUIRES: amdgpu-registered-target
-// RUN: %clang_cc1 -emit-llvm %s -o - -triple=x86_64-apple-darwin9 -O3 | FileCheck %s
-// RUN: %clang_cc1 -emit-llvm %s -o - -triple=amdgcn-amd-amdhsa -O3 | FileCheck %s
+// RUN: %clang_cc1 -emit-llvm %s -o - -triple=x86_64-apple-darwin9 -O2 -disable-llvm-passes | FileCheck %s --check-prefixes=CHECK,CHECK-NOOPT
+// RUN: %clang_cc1 -emit-llvm %s -o - -triple=x86_64-apple-darwin9 -O2 | FileCheck %s --check-prefixes=CHECK,CHECK-OPT
+// RUN: %clang_cc1 -emit-llvm %s -o - -triple=amdgcn-amd-amdhsa -O2 | FileCheck %s --check-prefixes=CHECK,CHECK-OPT
 
 namespace {
 
@@ -38,20 +39,167 @@
 
 }
 
-// CHECK-LABEL: define i32 @_Z12getCtorCallsv()
+// CHECK-OPT-LABEL: define i32 @_Z12getCtorCallsv()
 int getCtorCalls() {
-  // CHECK: ret i32 5
+  // CHECK-OPT: ret i32 5
   return ctorcalls;
 }
 
-// CHECK-LABEL: define i32 @_Z12getDtorCallsv()
+// CHECK-OPT-LABEL: define i32 @_Z12getDtorCallsv()
 int getDtorCalls() {
-  // CHECK: ret i32 5
+  // CHECK-OPT: ret i32 5
   return dtorcalls;
 }
 
-// CHECK-LABEL: define zeroext i1 @_Z7successv()
+// CHECK-OPT-LABEL: define zeroext i1 @_Z7successv()
 bool success() {
-  // CHECK: ret i1 true
+  // CHECK-OPT: ret i1 true
   return ctorcalls == dtorcalls;
 }
+
+struct X { ~X(); int f(); };
+int g(int, int, int);
+// CHECK-LABEL: @_Z16lifetime_nontriv
+int lifetime_nontriv(bool cond) {
+  // CHECK-NOOPT: store i1 false,
+  // CHECK-NOOPT: store i1 false,
+  // CHECK-NOOPT: store i1 false,
+  // CHECK-NOOPT: store i1 false,
+  // CHECK-NOOPT: store i1 false,
+  // CHECK-NOOPT: store i1 false,
+  // CHECK-NOOPT: br i1
+  //
+  // CHECK-NOOPT: call void @llvm.lifetime.start
+  // CHECK-NOOPT: store i1 true,
+  // CHECK-NOOPT: store i1 true,
+  // CHECK-NOOPT: call i32 @_ZN1X1fEv(
+  // CHECK-NOOPT: call void @llvm.lifetime.start
+  // CHECK-NOOPT: store i1 true,
+  // CHECK-NOOPT: store i1 true,
+  // CHECK-NOOPT: call i32 @_ZN1X1fEv(
+  // CHECK-NOOPT: call void @llvm.lifetime.start
+  // CHECK-NOOPT: store i1 true,
+  // CHECK-NOOPT: store i1 true,
+  // CHECK-NOOPT: call i32 @_ZN1X1fEv(
+  // CHECK-NOOPT: call i32 @_Z1giii(
+  // CHECK-NOOPT: br label
+  //
+  // CHECK-NOOPT: call i32 @_Z1giii(i32 1, i32 2, i32 3)
+  // CHECK-NOOPT: br label
+  //
+  // CHECK-NOOPT: load i1,
+  // CHECK-NOOPT: br i1
+  // CHECK-NOOPT: call void @_ZN1XD1Ev(
+  // CHECK-NOOPT: br label
+  //
+  // CHECK-NOOPT: load i1,
+  // CHECK-NOOPT: br i1
+  // CHECK-NOOPT: call void @llvm.lifetime.end
+  // CHECK-NOOPT: br label
+  //
+  // CHECK-NOOPT: load i1,
+  // CHECK-NOOPT: br i1
+  // CHECK-NOOPT: call void @_ZN1XD1Ev(
+  // CHECK-NOOPT: br label
+  //
+  // CHECK-NOOPT: load i1,
+  // CHECK-NOOPT: br i1
+  // CHECK-NOOPT: call void @llvm.lifetime.end
+  // CHECK-NOOPT: br label
+  //
+  // CHECK-NOOPT: load i1,
+  // CHECK-NOOPT: br i1
+  // CHECK-NOOPT: call void @_ZN1XD1Ev(
+  // CHECK-NOOPT: br label
+  //
+  // CHECK-NOOPT: load i1,
+  // CHECK-NOOPT: br i1
+  // CHECK-NOOPT: call void @llvm.lifetime.end
+  // CHECK-NOOPT: br label
+  //
+  // CHECK-NOOPT: ret
+
+  // CHECK-OPT: br i1
+  //
+  // CHECK-OPT: call void @llvm.lifetime.start
+  // CHECK-OPT: call i32 @_ZN1X1fEv(
+  // CHECK-OPT: call void @llvm.lifetime.start
+  // CHECK-OPT: call i32 @_ZN1X1fEv(
+  // CHECK-OPT: call void @llvm.lifetime.start
+  // CHECK-OPT: call i32 @_ZN1X1fEv(
+  // CHECK-OPT: call i32 @_Z1giii(
+  // CHECK-OPT: call void @_ZN1XD1Ev(
+  // CHECK-OPT: call void @llvm.lifetime.end
+  // CHECK-OPT: call void @_ZN1XD1Ev(
+  // CHECK-OPT: call void @llvm.lifetime.end
+  // CHECK-OPT: call void @_ZN1XD1Ev(
+  // CHECK-OPT: call void @llvm.lifetime.end
+  // CHECK-OPT: br label
+  return cond ? g(X().f(), X().f(), X().f()) : g(1, 2, 3);
+}
+
+struct Y { int f(); };
+int g(int, int, int);
+// CHECK-LABEL: @_Z13lifetime_triv
+int lifetime_triv(bool cond) {
+  // CHECK-NOOPT: call void @llvm.lifetime.start
+  // CHECK-NOOPT: call void @llvm.lifetime.start
+  // CHECK-NOOPT: call void @llvm.lifetime.start
+  // CHECK-NOOPT: br i1
+  //
+  // CHECK-NOOPT: call i32 @_ZN1Y1fEv(
+  // CHECK-NOOPT: call i32 @_ZN1Y1fEv(
+  // CHECK-NOOPT: call i32 @_ZN1Y1fEv(
+  // CHECK-NOOPT: call i32 @_Z1giii(
+  // CHECK-NOOPT: br label
+  //
+  // CHECK-NOOPT: call i32 @_Z1giii(i32 1, i32 2, i32 3)
+  // CHECK-NOOPT: br label
+  //
+  // CHECK-NOOPT: call void @llvm.lifetime.end
+  // CHECK-NOOPT-NOT: br
+  // CHECK-NOOPT: call void @llvm.lifetime.end
+  // CHECK-NOOPT-NOT: br
+  // CHECK-NOOPT: call void @llvm.lifetime.end
+  //
+  // CHECK-NOOPT: ret
+
+  // FIXME: LLVM isn't smart enough to remove the lifetime markers from the
+  // g(1, 2, 3) path here.
+
+  // CHECK-OPT: call void @llvm.lifetime.start
+  // CHECK-OPT: call void @llvm.lifetime.start
+  // CHECK-OPT: call void @llvm.lifetime.start
+  // CHECK-OPT: br i1
+  //
+  // CHECK-OPT: call i32 @_ZN1Y1fEv(
+  // CHECK-OPT: call i32 @_ZN1Y1fEv(
+  // CHECK-OPT: call i32 @_ZN1Y1fEv(
+  // CHECK-OPT: call i32 @_Z1giii(
+  // CHECK-OPT: br label
+  //
+  // CHECK-OPT: call void @llvm.lifetime.end
+  // CHECK-OPT: call void @llvm.lifetime.end
+  // CHECK-OPT: call void @llvm.lifetime.end
+  return cond ? g(Y().f(), Y().f(), Y().f()) : g(1, 2, 3);
+}
+
+struct Z { ~Z() {} int f(); };
+int g(int, int, int);
+// CHECK-LABEL: @_Z22lifetime_nontriv_empty
+int lifetime_nontriv_empty(bool cond) {
+  // CHECK-OPT: br i1
+  //
+  // CHECK-OPT: call void @llvm.lifetime.start
+  // CHECK-OPT: call i32 @_ZN1Z1fEv(
+  // CHECK-OPT: call void @llvm.lifetime.start
+  // CHECK-OPT: call i32 @_ZN1Z1fEv(
+  // CHECK-OPT: call void @llvm.lifetime.start
+  // CHECK-OPT: call i32 @_ZN1Z1fEv(
+  // CHECK-OPT: call i32 @_Z1giii(
+  // CHECK-OPT: call void @llvm.lifetime.end
+  // CHECK-OPT: call void @llvm.lifetime.end
+  // CHECK-OPT: call void @llvm.lifetime.end
+  // CHECK-OPT: br label
+  return cond ? g(Z().f(), Z().f(), Z().f()) : g(1, 2, 3);
+}