diff --git a/llvm/lib/Target/AVR/AVRAsmPrinter.cpp b/llvm/lib/Target/AVR/AVRAsmPrinter.cpp
--- a/llvm/lib/Target/AVR/AVRAsmPrinter.cpp
+++ b/llvm/lib/Target/AVR/AVRAsmPrinter.cpp
@@ -14,6 +14,7 @@
 #include "AVR.h"
 #include "AVRMCInstLower.h"
 #include "AVRSubtarget.h"
+#include "AVRTargetMachine.h"
 #include "MCTargetDesc/AVRInstPrinter.h"
 #include "MCTargetDesc/AVRMCExpr.h"
 #include "TargetInfo/AVRTargetInfo.h"
@@ -21,6 +22,7 @@
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/TargetRegisterInfo.h"
 #include "llvm/CodeGen/TargetSubtargetInfo.h"
 #include "llvm/IR/Mangler.h"
@@ -60,6 +62,8 @@
 
   bool doFinalization(Module &M) override;
 
+  void emitStartOfAsmFile(Module &M) override;
+
 private:
   const MCRegisterInfo &MRI;
   bool EmittedStructorSymbolAttrs = false;
@@ -236,6 +240,45 @@
   return AsmPrinter::doFinalization(M);
 }
 
+void AVRAsmPrinter::emitStartOfAsmFile(Module &M) {
+  const AVRTargetMachine &TM = (const AVRTargetMachine &)MMI->getTarget();
+  const AVRSubtarget *SubTM = (const AVRSubtarget *)TM.getSubtargetImpl();
+  if (!SubTM)
+    return;
+
+  // Emit __tmp_reg__.
+  OutStreamer->emitAssignment(
+      MMI->getContext().getOrCreateSymbol(StringRef("__tmp_reg__")),
+      MCConstantExpr::create(SubTM->getRegTmpIndex(), MMI->getContext()));
+  // Emit __zero_reg__.
+  OutStreamer->emitAssignment(
+      MMI->getContext().getOrCreateSymbol(StringRef("__zero_reg__")),
+      MCConstantExpr::create(SubTM->getRegZeroIndex(), MMI->getContext()));
+  // Emit __SREG__.
+  OutStreamer->emitAssignment(
+      MMI->getContext().getOrCreateSymbol(StringRef("__SREG__")),
+      MCConstantExpr::create(SubTM->getIORegSREG(), MMI->getContext()));
+  // Emit __SP_H__ if available.
+  if (!SubTM->hasSmallStack())
+    OutStreamer->emitAssignment(
+        MMI->getContext().getOrCreateSymbol(StringRef("__SP_H__")),
+        MCConstantExpr::create(SubTM->getIORegSPH(), MMI->getContext()));
+  // Emit __SP_L__.
+  OutStreamer->emitAssignment(
+      MMI->getContext().getOrCreateSymbol(StringRef("__SP_L__")),
+      MCConstantExpr::create(SubTM->getIORegSPL(), MMI->getContext()));
+  // Emit __EIND__ if available.
+  if (SubTM->hasEIJMPCALL())
+    OutStreamer->emitAssignment(
+        MMI->getContext().getOrCreateSymbol(StringRef("__EIND__")),
+        MCConstantExpr::create(SubTM->getIORegEIND(), MMI->getContext()));
+  // Emit __RAMPZ__ if available.
+  if (SubTM->hasELPM())
+    OutStreamer->emitAssignment(
+        MMI->getContext().getOrCreateSymbol(StringRef("__RAMPZ__")),
+        MCConstantExpr::create(SubTM->getIORegRAMPZ(), MMI->getContext()));
+}
+
 } // end of namespace llvm
 
 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAVRAsmPrinter() {
diff --git a/llvm/lib/Target/AVR/AVRDevices.td b/llvm/lib/Target/AVR/AVRDevices.td
--- a/llvm/lib/Target/AVR/AVRDevices.td
+++ b/llvm/lib/Target/AVR/AVRDevices.td
@@ -174,15 +174,13 @@
     : Family<"avr35",
              [FamilyAVR3, FeatureMOVW, FeatureLPMX, FeatureSPM, FeatureBREAK]>;
 
-def FamilyAVR4 : Family<"avr4", [
-  FamilyAVR2, FeatureMultiplication, FeatureMOVW, FeatureLPMX, FeatureSPM,
-  FeatureBREAK
-]>;
+def FamilyAVR4 : Family<"avr4",
+                        [FamilyAVR2, FeatureMultiplication, FeatureMOVW,
+                         FeatureLPMX, FeatureSPM, FeatureBREAK]>;
 
-def FamilyAVR5 : Family<"avr5", [
-  FamilyAVR3, FeatureMultiplication, FeatureMOVW, FeatureLPMX, FeatureSPM,
-  FeatureBREAK
-]>;
+def FamilyAVR5 : Family<"avr5",
+                        [FamilyAVR3, FeatureMultiplication, FeatureMOVW,
+                         FeatureLPMX, FeatureSPM, FeatureBREAK]>;
 
 def FamilyAVR51 : Family<"avr51", [FamilyAVR5, FeatureELPM, FeatureELPMX]>;
 
@@ -190,14 +188,15 @@
 
 def FamilyTiny
     : Family<"avrtiny",
-             [FamilyAVR0, FeatureBREAK, FeatureSRAM, FeatureTinyEncoding]>;
+             [FamilyAVR0, FeatureBREAK, FeatureSRAM, FeatureTinyEncoding,
+              FeatureSmallStack]>;
 
-def FamilyXMEGA : Family<"xmega", [
-  FamilyAVR0, FeatureLPM, FeatureIJMPCALL, FeatureADDSUBIW, FeatureSRAM,
-  FeatureJMPCALL, FeatureMultiplication, FeatureMOVW, FeatureLPMX, FeatureSPM,
-  FeatureBREAK, FeatureEIJMPCALL, FeatureSPMX, FeatureDES, FeatureELPM,
-  FeatureELPMX
-]>;
+def FamilyXMEGA : Family<"xmega",
+                         [FamilyAVR0, FeatureLPM, FeatureIJMPCALL,
+                          FeatureADDSUBIW, FeatureSRAM, FeatureJMPCALL,
+                          FeatureMultiplication, FeatureMOVW, FeatureLPMX,
+                          FeatureSPM, FeatureBREAK, FeatureEIJMPCALL,
+                          FeatureSPMX, FeatureDES, FeatureELPM, FeatureELPMX]>;
 
 def FamilyXMEGAU : Family<"xmegau", [FamilyXMEGA, FeatureRMW]>;
 
@@ -246,41 +245,42 @@
 
 // Specific MCUs
 // NOTE: This list has been synchronized with gcc-avr 5.4.0 and avr-libc 2.0.0.
-def : Device<"at90s1200", FamilyAVR0, ELFArchAVR1>;
-def : Device<"attiny11", FamilyAVR1, ELFArchAVR1>;
-def : Device<"attiny12", FamilyAVR1, ELFArchAVR1>;
-def : Device<"attiny15", FamilyAVR1, ELFArchAVR1>;
-def : Device<"attiny28", FamilyAVR1, ELFArchAVR1>;
-def : Device<"at90s2313", FamilyAVR2, ELFArchAVR2>;
-def : Device<"at90s2323", FamilyAVR2, ELFArchAVR2>;
-def : Device<"at90s2333", FamilyAVR2, ELFArchAVR2>;
-def : Device<"at90s2343", FamilyAVR2, ELFArchAVR2>;
-def : Device<"attiny22", FamilyAVR2, ELFArchAVR2>;
-def : Device<"attiny26", FamilyAVR2, ELFArchAVR2, [FeatureLPMX]>;
+def : Device<"at90s1200", FamilyAVR0, ELFArchAVR1, [FeatureSmallStack]>;
+def : Device<"attiny11", FamilyAVR1, ELFArchAVR1, [FeatureSmallStack]>;
+def : Device<"attiny12", FamilyAVR1, ELFArchAVR1, [FeatureSmallStack]>;
+def : Device<"attiny15", FamilyAVR1, ELFArchAVR1, [FeatureSmallStack]>;
+def : Device<"attiny28", FamilyAVR1, ELFArchAVR1, [FeatureSmallStack]>;
+def : Device<"at90s2313", FamilyAVR2, ELFArchAVR2, [FeatureSmallStack]>;
+def : Device<"at90s2323", FamilyAVR2, ELFArchAVR2, [FeatureSmallStack]>;
+def : Device<"at90s2333", FamilyAVR2, ELFArchAVR2, [FeatureSmallStack]>;
+def : Device<"at90s2343", FamilyAVR2, ELFArchAVR2, [FeatureSmallStack]>;
+def : Device<"attiny22", FamilyAVR2, ELFArchAVR2, [FeatureSmallStack]>;
+def : Device<"attiny26", FamilyAVR2, ELFArchAVR2,
+             [FeatureLPMX, FeatureSmallStack]>;
 def : Device<"at86rf401", FamilyAVR2, ELFArchAVR25, [FeatureMOVW, FeatureLPMX]>;
-def : Device<"at90s4414", FamilyAVR2, ELFArchAVR2>;
-def : Device<"at90s4433", FamilyAVR2, ELFArchAVR2>;
-def : Device<"at90s4434", FamilyAVR2, ELFArchAVR2>;
+def : Device<"at90s4414", FamilyAVR2, ELFArchAVR2, [FeatureSmallStack]>;
+def : Device<"at90s4433", FamilyAVR2, ELFArchAVR2, [FeatureSmallStack]>;
+def : Device<"at90s4434", FamilyAVR2, ELFArchAVR2, [FeatureSmallStack]>;
 def : Device<"at90s8515", FamilyAVR2, ELFArchAVR2>;
 def : Device<"at90c8534", FamilyAVR2, ELFArchAVR2>;
 def : Device<"at90s8535", FamilyAVR2, ELFArchAVR2>;
 def : Device<"ata5272", FamilyAVR25, ELFArchAVR25>;
-def : Device<"attiny13", FamilyAVR25, ELFArchAVR25>;
-def : Device<"attiny13a", FamilyAVR25, ELFArchAVR25>;
-def : Device<"attiny2313", FamilyAVR25, ELFArchAVR25>;
-def : Device<"attiny2313a", FamilyAVR25, ELFArchAVR25>;
-def : Device<"attiny24", FamilyAVR25, ELFArchAVR25>;
-def : Device<"attiny24a", FamilyAVR25, ELFArchAVR25>;
+def : Device<"attiny13", FamilyAVR25, ELFArchAVR25, [FeatureSmallStack]>;
+def : Device<"attiny13a", FamilyAVR25, ELFArchAVR25, [FeatureSmallStack]>;
+def : Device<"attiny2313", FamilyAVR25, ELFArchAVR25, [FeatureSmallStack]>;
+def : Device<"attiny2313a", FamilyAVR25, ELFArchAVR25, [FeatureSmallStack]>;
+def : Device<"attiny24", FamilyAVR25, ELFArchAVR25, [FeatureSmallStack]>;
+def : Device<"attiny24a", FamilyAVR25, ELFArchAVR25, [FeatureSmallStack]>;
 def : Device<"attiny4313", FamilyAVR25, ELFArchAVR25>;
 def : Device<"attiny44", FamilyAVR25, ELFArchAVR25>;
 def : Device<"attiny44a", FamilyAVR25, ELFArchAVR25>;
 def : Device<"attiny84", FamilyAVR25, ELFArchAVR25>;
 def : Device<"attiny84a", FamilyAVR25, ELFArchAVR25>;
-def : Device<"attiny25", FamilyAVR25, ELFArchAVR25>;
+def : Device<"attiny25", FamilyAVR25, ELFArchAVR25, [FeatureSmallStack]>;
 def : Device<"attiny45", FamilyAVR25, ELFArchAVR25>;
 def : Device<"attiny85", FamilyAVR25, ELFArchAVR25>;
-def : Device<"attiny261", FamilyAVR25, ELFArchAVR25>;
-def : Device<"attiny261a", FamilyAVR25, ELFArchAVR25>;
+def : Device<"attiny261", FamilyAVR25, ELFArchAVR25, [FeatureSmallStack]>;
+def : Device<"attiny261a", FamilyAVR25, ELFArchAVR25, [FeatureSmallStack]>;
 def : Device<"attiny441", FamilyAVR25, ELFArchAVR25>;
 def : Device<"attiny461", FamilyAVR25, ELFArchAVR25>;
 def : Device<"attiny461a", FamilyAVR25, ELFArchAVR25>;
diff --git a/llvm/lib/Target/AVR/AVRSubtarget.h b/llvm/lib/Target/AVR/AVRSubtarget.h
--- a/llvm/lib/Target/AVR/AVRSubtarget.h
+++ b/llvm/lib/Target/AVR/AVRSubtarget.h
@@ -91,10 +91,17 @@
     return ELFArch;
   }
 
-  /// Get I/O register address.
-  int getIORegRAMPZ(void) const { return 0x3b; }
+  /// Get I/O register addresses.
+  int getIORegRAMPZ(void) const { return hasELPM() ? 0x3b : -1; }
+  int getIORegEIND(void) const { return hasEIJMPCALL() ? 0x3c : -1; }
+  int getIORegSPL(void) const { return 0x3d; }
+  int getIORegSPH(void) const { return hasSmallStack() ? -1 : 0x3e; }
   int getIORegSREG(void) const { return 0x3f; }
 
+  /// Get GPR aliases.
+  int getRegTmpIndex(void) const { return hasTinyEncoding() ? 16 : 0; }
+  int getRegZeroIndex(void) const { return hasTinyEncoding() ? 17 : 1; }
+
 private:
   /// The ELF e_flags architecture.
   unsigned ELFArch;
diff --git a/llvm/test/CodeGen/AVR/global-aliases.ll b/llvm/test/CodeGen/AVR/global-aliases.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/AVR/global-aliases.ll
@@ -0,0 +1,18 @@
+; RUN: llc < %s -mtriple=avr -mcpu=atxmega384c3 | FileCheck %s --check-prefixes=MEGA
+; RUN: llc < %s -mtriple=avr -mcpu=attiny40 | FileCheck %s --check-prefixes=TINY
+
+; MEGA: .set __tmp_reg__, 0
+; MEGA: .set __zero_reg__, 1
+; MEGA: .set __SREG__, 63
+; MEGA: .set __SP_H__, 62
+; MEGA: .set __SP_L__, 61
+; MEGA: .set __EIND__, 60
+; MEGA: .set __RAMPZ__, 59
+
+; TINY:     .set __tmp_reg__, 16
+; TINY:     .set __zero_reg__, 17
+; TINY:     .set __SREG__, 63
+; TINY-NOT: .set __SP_H__, 62
+; TINY:     .set __SP_L__, 61
+; TINY-NOT: .set __EIND__, 60
+; TINY-NOT: .set __RAMPZ__, 59