Index: llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
===================================================================
--- llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -29,6 +29,7 @@
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineMemOperand.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/StackProtector.h"
@@ -1672,6 +1673,33 @@
       .addUse(getOrCreateVReg(*CI.getArgOperand(1)));
     return true;
   }
+  case Intrinsic::localescape: {
+    MachineBasicBlock &EntryMBB = MF->front();
+    StringRef EscapedName = GlobalValue::dropLLVMManglingEscape(MF->getName());
+
+    // Directly emit some LOCAL_ESCAPE machine instrs. Label assignment emission
+    // is the same on all targets.
+    for (unsigned Idx = 0, E = CI.getNumArgOperands(); Idx < E; ++Idx) {
+      Value *Arg = CI.getArgOperand(Idx)->stripPointerCasts();
+      if (isa<ConstantPointerNull>(Arg))
+        continue; // Skip null pointers. They represent a hole in index space.
+
+      int FI = getOrCreateFrameIndex(*cast<AllocaInst>(Arg));
+      MCSymbol *FrameAllocSym =
+          MF->getMMI().getContext().getOrCreateFrameAllocSymbol(EscapedName,
+                                                                Idx);
+
+      // This should be inserted at the start of the entry block.
+      auto LocalEscape =
+          MIRBuilder.buildInstrNoInsert(TargetOpcode::LOCAL_ESCAPE)
+              .addSym(FrameAllocSym)
+              .addFrameIndex(FI);
+
+      EntryMBB.insert(EntryMBB.begin(), LocalEscape);
+    }
+
+    return true;
+  }
 #define INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC)  \
   case Intrinsic::INTRINSIC:
 #include "llvm/IR/ConstrainedOps.def"
Index: llvm/lib/CodeGen/GlobalISel/Utils.cpp
===================================================================
--- llvm/lib/CodeGen/GlobalISel/Utils.cpp
+++ llvm/lib/CodeGen/GlobalISel/Utils.cpp
@@ -180,6 +180,14 @@
 
 bool llvm::isTriviallyDead(const MachineInstr &MI,
                            const MachineRegisterInfo &MRI) {
+  // FIXME: This logical is mostly duplicated with
+  // DeadMachineInstructionElim::isDead. Why is LOCAL_ESCAPE not considered in
+  // MachineInstr::isLabel?
+
+  // Don't delete frame allocation labels.
+  if (MI.getOpcode() == TargetOpcode::LOCAL_ESCAPE)
+    return false;
+
   // If we can move an instruction, we can remove it.  Otherwise, it has
   // a side-effect of some sort.
   bool SawStore = false;
Index: llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-localescape.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-localescape.ll
@@ -0,0 +1,70 @@
+; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+; RUN: llc -global-isel -mtriple=arm64-windows -stop-after=irtranslator -o - %s | FileCheck %s
+
+define void @local_escape() {
+  ; CHECK-LABEL: name: local_escape
+  ; CHECK: bb.1 (%ir-block.0):
+  ; CHECK:   LOCAL_ESCAPE <mcsymbol .Llocal_escape$frame_escape_1>, %stack.1.b
+  ; CHECK:   LOCAL_ESCAPE <mcsymbol .Llocal_escape$frame_escape_0>, %stack.0.a
+  ; CHECK:   [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 42
+  ; CHECK:   [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 13
+  ; CHECK:   [[FRAME_INDEX:%[0-9]+]]:_(p0) = G_FRAME_INDEX %stack.0.a
+  ; CHECK:   [[FRAME_INDEX1:%[0-9]+]]:_(p0) = G_FRAME_INDEX %stack.1.b
+  ; CHECK:   G_STORE [[C]](s32), [[FRAME_INDEX]](p0) :: (store 4 into %ir.a)
+  ; CHECK:   G_STORE [[C1]](s32), [[FRAME_INDEX1]](p0) :: (store 4 into %ir.b)
+  ; CHECK:   RET_ReallyLR
+  %a = alloca i32
+  %b = alloca i32, i32 2
+  call void (...) @llvm.localescape(i32* %a, i32* %b)
+  store i32 42, i32* %a
+  store i32 13, i32* %b
+  ret void
+}
+
+; Try some instructions before the localescape, and use a null
+define void @local_escape_insert_point() {
+  ; CHECK-LABEL: name: local_escape_insert_point
+  ; CHECK: bb.1 (%ir-block.0):
+  ; CHECK:   LOCAL_ESCAPE <mcsymbol .Llocal_escape_insert_point$frame_escape_2>, %stack.1.b
+  ; CHECK:   LOCAL_ESCAPE <mcsymbol .Llocal_escape_insert_point$frame_escape_0>, %stack.0.a
+  ; CHECK:   [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 42
+  ; CHECK:   [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 13
+  ; CHECK:   [[FRAME_INDEX:%[0-9]+]]:_(p0) = G_FRAME_INDEX %stack.0.a
+  ; CHECK:   [[FRAME_INDEX1:%[0-9]+]]:_(p0) = G_FRAME_INDEX %stack.1.b
+  ; CHECK:   G_STORE [[C]](s32), [[FRAME_INDEX]](p0) :: (store 4 into %ir.a)
+  ; CHECK:   G_STORE [[C1]](s32), [[FRAME_INDEX1]](p0) :: (store 4 into %ir.b)
+  ; CHECK:   RET_ReallyLR
+  %a = alloca i32
+  %b = alloca i32, i32 2
+  store i32 42, i32* %a
+  store i32 13, i32* %b
+  call void (...) @llvm.localescape(i32* %a, i32* null, i32* %b)
+  ret void
+}
+
+declare void @foo([128 x i32]*)
+
+; Check a cast of an alloca
+define void @local_escape_strip_ptr_cast() {
+  ; CHECK-LABEL: name: local_escape_strip_ptr_cast
+  ; CHECK: bb.1 (%ir-block.0):
+  ; CHECK:   LOCAL_ESCAPE <mcsymbol .Llocal_escape_strip_ptr_cast$frame_escape_0>, %stack.0.a
+  ; CHECK:   [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 42
+  ; CHECK:   [[FRAME_INDEX:%[0-9]+]]:_(p0) = G_FRAME_INDEX %stack.0.a
+  ; CHECK:   G_STORE [[C]](s32), [[FRAME_INDEX]](p0) :: (store 4 into %ir.cast)
+  ; CHECK:   ADJCALLSTACKDOWN 0, 0, implicit-def $sp, implicit $sp
+  ; CHECK:   $x0 = COPY [[FRAME_INDEX]](p0)
+  ; CHECK:   BL @foo, csr_aarch64_aapcs, implicit-def $lr, implicit $sp, implicit $x0
+  ; CHECK:   ADJCALLSTACKUP 0, 0, implicit-def $sp, implicit $sp
+  ; CHECK:   RET_ReallyLR
+  %a = alloca [128 x i32]
+  %cast = bitcast [128 x i32]* %a to i32*
+  store i32 42, i32* %cast
+  call void (...) @llvm.localescape(i32* %cast, i32* null)
+  call void @foo([128 x i32]* %a)
+  ret void
+}
+
+declare void @llvm.localescape(...) #0
+
+attributes #0 = { nounwind }
Index: llvm/test/CodeGen/AArch64/GlobalISel/labels-are-not-dead.mir
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AArch64/GlobalISel/labels-are-not-dead.mir
@@ -0,0 +1,34 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -march=aarch64 -run-pass=legalizer %s -o - | FileCheck %s
+
+# The LOCAL_ESCAPE instructions should not be deleted as dead.
+
+---
+name: no_erase_local_escape
+tracksRegLiveness: true
+stack:
+  - { id: 0, size: 4, alignment: 4 }
+  - { id: 1, size: 8, alignment: 4 }
+body:             |
+  bb.0:
+    ; CHECK-LABEL: name: no_erase_local_escape
+    ; CHECK: LOCAL_ESCAPE <mcsymbol .Llocal_escape$frame_escape_0>, %stack.0
+    ; CHECK: LOCAL_ESCAPE <mcsymbol .Llocal_escape$frame_escape_1>, %stack.1
+    ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 42
+    ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 13
+    ; CHECK: [[FRAME_INDEX:%[0-9]+]]:_(p0) = G_FRAME_INDEX %stack.0
+    ; CHECK: [[FRAME_INDEX1:%[0-9]+]]:_(p0) = G_FRAME_INDEX %stack.1
+    ; CHECK: G_STORE [[C]](s32), [[FRAME_INDEX]](p0) :: (store 4)
+    ; CHECK: G_STORE [[C1]](s32), [[FRAME_INDEX1]](p0) :: (store 4)
+    ; CHECK: RET_ReallyLR
+    LOCAL_ESCAPE <mcsymbol .Llocal_escape$frame_escape_0>, %stack.0
+    LOCAL_ESCAPE <mcsymbol .Llocal_escape$frame_escape_1>, %stack.1
+    %2:_(s32) = G_CONSTANT i32 42
+    %3:_(s32) = G_CONSTANT i32 13
+    %0:_(p0) = G_FRAME_INDEX %stack.0
+    %1:_(p0) = G_FRAME_INDEX %stack.1
+    G_STORE %2(s32), %0(p0) :: (store 4)
+    G_STORE %3(s32), %1(p0) :: (store 4)
+    RET_ReallyLR
+
+...