Index: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -211,7 +211,13 @@
     ClWithIfunc("asan-with-ifunc",
                 cl::desc("Access dynamic shadow through an ifunc global on "
                          "platforms that support this"),
-                cl::Hidden, cl::init(false));
+                cl::Hidden, cl::init(true));
+
+static cl::opt<bool> ClWithIfuncSuppressRemat(
+    "asan-with-ifunc-suppress-remat",
+    cl::desc("Suppress rematerialization of dynamic shadow address by passing "
+             "it through inline asm in prologue."),
+    cl::Hidden, cl::init(true));
 
 // This flag limits the number of instructions to be instrumented
 // in any given BB. Normally, this should be set to unlimited (INT_MAX),
@@ -988,8 +994,9 @@
   void visitCallSite(CallSite CS) {
     Instruction *I = CS.getInstruction();
     if (CallInst *CI = dyn_cast<CallInst>(I)) {
-      HasNonEmptyInlineAsm |=
-          CI->isInlineAsm() && !CI->isIdenticalTo(EmptyInlineAsm.get());
+      HasNonEmptyInlineAsm |= CI->isInlineAsm() &&
+                              !CI->isIdenticalTo(EmptyInlineAsm.get()) &&
+                              I != ASan.LocalDynamicShadow;
       HasReturnsTwiceCall |= CI->canReturnTwice();
     }
   }
@@ -1121,11 +1128,6 @@
   if (Mapping.Offset == 0) return Shadow;
   // (Shadow >> scale) | offset
   Value *ShadowBase;
-  if (Mapping.InGlobal)
-    return IRB.CreatePtrToInt(
-        IRB.CreateGEP(AsanShadowGlobal,
-                      {ConstantInt::get(IntptrTy, 0), Shadow}),
-        IntptrTy);
   if (LocalDynamicShadow)
     ShadowBase = LocalDynamicShadow;
   else
@@ -2343,13 +2345,29 @@
 
 void AddressSanitizer::maybeInsertDynamicShadowAtFunctionEntry(Function &F) {
   // Generate code only when dynamic addressing is needed.
-  if (Mapping.Offset != kDynamicShadowSentinel || Mapping.InGlobal)
+  if (Mapping.Offset != kDynamicShadowSentinel)
     return;
 
   IRBuilder<> IRB(&F.front().front());
-  Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
-      kAsanShadowMemoryDynamicAddress, IntptrTy);
-  LocalDynamicShadow = IRB.CreateLoad(GlobalDynamicAddress);
+  if (Mapping.InGlobal) {
+    if (ClWithIfuncSuppressRemat) {
+      // An empty inline asm with input reg == output reg.
+      // An opaque pointer-to-int cast, basically.
+      InlineAsm *Asm = InlineAsm::get(
+          FunctionType::get(IntptrTy, {AsanShadowGlobal->getType()}, false),
+          StringRef(""), StringRef("=r,0"),
+          /*hasSideEffects=*/false);
+      LocalDynamicShadow =
+          IRB.CreateCall(Asm, {AsanShadowGlobal}, ".asan.shadow");
+    } else {
+      LocalDynamicShadow =
+          IRB.CreatePointerCast(AsanShadowGlobal, IntptrTy, ".asan.shadow");
+    }
+  } else {
+    Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
+        kAsanShadowMemoryDynamicAddress, IntptrTy);
+    LocalDynamicShadow = IRB.CreateLoad(GlobalDynamicAddress);
+  }
 }
 
 void AddressSanitizer::markEscapedLocalAllocas(Function &F) {
Index: llvm/trunk/test/Instrumentation/AddressSanitizer/with-ifunc.ll
===================================================================
--- llvm/trunk/test/Instrumentation/AddressSanitizer/with-ifunc.ll
+++ llvm/trunk/test/Instrumentation/AddressSanitizer/with-ifunc.ll
@@ -1,7 +1,11 @@
-; Test -asan-force-dynamic-shadow flag.
+; Test -asan-with-ifunc flag.
 ;
-; RUN: opt -asan -asan-module -S -asan-with-ifunc=1 < %s | FileCheck %s --check-prefixes=CHECK,CHECK-IFUNC
-; RUN: opt -asan -asan-module -S -asan-with-ifunc=0 < %s | FileCheck %s --check-prefixes=CHECK,CHECK-NOIFUNC
+; RUN: opt -asan -asan-module -S -asan-with-ifunc=0 < %s | \
+; RUN:     FileCheck %s --check-prefixes=CHECK,CHECK-NOIFUNC
+; RUN: opt -asan -asan-module -S -asan-with-ifunc=1 -asan-with-ifunc-suppress-remat=0 < %s | \
+; RUN:     FileCheck %s --check-prefixes=CHECK,CHECK-IFUNC
+; RUN: opt -asan -asan-module -S -asan-with-ifunc=1 -asan-with-ifunc-suppress-remat=1 < %s | \
+; RUN:     FileCheck %s --check-prefixes=CHECK,CHECK-IFUNC-NOREMAT
 
 target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
 target triple = "armv7--linux-android"
@@ -17,7 +21,12 @@
 
 ; CHECK-IFUNC-NEXT: %[[A:[^ ]*]] = ptrtoint i32* %a to i32
 ; CHECK-IFUNC-NEXT: %[[B:[^ ]*]] = lshr i32 %[[A]], 3
-; CHECK-IFUNC-NEXT: %[[C:[^ ]*]] = getelementptr [0 x i8], [0 x i8]* @__asan_shadow, i32 0, i32 %[[B]]
+; CHECK-IFUNC-NEXT: %[[C:[^ ]*]] = add i32 %[[B]], ptrtoint ([0 x i8]* @__asan_shadow to i32)
+
+; CHECK-IFUNC-NOREMAT-NEXT: %[[S:[^ ]*]] = call i32 asm "", "=r,0"([0 x i8]* @__asan_shadow)
+; CHECK-IFUNC-NOREMAT-NEXT: %[[A:[^ ]*]] = ptrtoint i32* %a to i32
+; CHECK-IFUNC-NOREMAT-NEXT: %[[B:[^ ]*]] = lshr i32 %[[A]], 3
+; CHECK-IFUNC-NOREMAT-NEXT: %[[C:[^ ]*]] = add i32 %[[B]], %[[S]]
 
 ; CHECK-NOIFUNC-NEXT: %[[SHADOW:[^ ]*]] = load i32, i32* @__asan_shadow_memory_dynamic_address
 ; CHECK-NOIFUNC-NEXT: %[[A:[^ ]*]] = ptrtoint i32* %a to i32