diff --git a/llvm/lib/Target/X86/X86FastISel.cpp b/llvm/lib/Target/X86/X86FastISel.cpp
@@ -972,6 +972,21 @@ bool X86FastISel::X86SelectStore(const Instruction *I) {
   if (S->isAtomic())
     return false;
 
+  const Value *PtrV = I->getOperand(1);
+  if (TLI.supportSwiftError()) {
+    // Swifterror values can come from either a function parameter with
+    // swifterror attribute or an alloca with swifterror attribute.
+    if (const Argument *Arg = dyn_cast<Argument>(PtrV)) {
+      if (Arg->hasSwiftErrorAttr())
+        return false;
+    }
+
+    if (const AllocaInst *Alloca = dyn_cast<AllocaInst>(PtrV)) {
+      if (Alloca->isSwiftError())
+        return false;
+    }
+  }
+
   const Value *Val = S->getValueOperand();
   const Value *Ptr = S->getPointerOperand();
 
@@ -1002,6 +1017,10 @@ bool X86FastISel::X86SelectRet(const Instruction *I) {
   if (!FuncInfo.CanLowerReturn)
     return false;
 
+  if (TLI.supportSwiftError() &&
+      F.getAttributes().hasAttrSomewhere(Attribute::SwiftError))
+    return false;
+
   if (TLI.supportSplitCSR(FuncInfo.MF))
     return false;
 
@@ -1133,6 +1152,21 @@ bool X86FastISel::X86SelectLoad(const Instruction *I) {
   if (LI->isAtomic())
     return false;
 
+  const Value *SV = I->getOperand(0);
+  if (TLI.supportSwiftError()) {
+    // Swifterror values can come from either a function parameter with
+    // swifterror attribute or an alloca with swifterror attribute.
+    if (const Argument *Arg = dyn_cast<Argument>(SV)) {
+      if (Arg->hasSwiftErrorAttr())
+        return false;
+    }
+
+    if (const AllocaInst *Alloca = dyn_cast<AllocaInst>(SV)) {
+      if (Alloca->isSwiftError())
+        return false;
+    }
+  }
+
   MVT VT;
   if (!isTypeLegal(LI->getType(), VT, /*AllowI1=*/true))
     return false;
@@ -2745,6 +2779,7 @@ bool X86FastISel::fastLowerArguments() {
         F->getAttributes().hasAttribute(Idx, Attribute::InReg) ||
         F->getAttributes().hasAttribute(Idx, Attribute::StructRet) ||
         F->getAttributes().hasAttribute(Idx, Attribute::SwiftSelf) ||
+        F->getAttributes().hasAttribute(Idx, Attribute::SwiftError) ||
         F->getAttributes().hasAttribute(Idx, Attribute::Nest))
       return false;
 
@@ -2877,6 +2912,10 @@ bool X86FastISel::fastLowerCall(CallLoweringInfo &CLI) {
   if (CLI.CS && CLI.CS->hasInAllocaArgument())
     return false;
 
+  for (auto Flag : CLI.OutFlags)
+    if (Flag.isSwiftError())
+      return false;
+
   // Fast-isel doesn't know about callee-pop yet.
   if (X86::isCalleePop(CC, Subtarget->is64Bit(), IsVarArg,
                        TM.Options.GuaranteedTailCallOpt))

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -2227,7 +2227,26 @@ X86TargetLowering::LowerReturn(SDValue Chain,
   // false, then an sret argument may be implicitly inserted in the SelDAG. In
   // either case FuncInfo->setSRetReturnReg() will have been called.
   if (unsigned SRetReg = FuncInfo->getSRetReturnReg()) {
-    SDValue Val = DAG.getCopyFromReg(Chain, dl, SRetReg,
+    // When we have both sret and another return value, we should use the
+    // original Chain stored in RetOps[0], instead of the current Chain updated
+    // in the above loop. If we only have sret, RetOps[0] equals to Chain.
+
+    // For the case of sret and another return value, we have
+    //   Chain_0 at the function entry
+    //   Chain_1 = getCopyToReg(Chain_0) in the above loop
+    // If we use Chain_1 in getCopyFromReg, we will have
+    //   Val = getCopyFromReg(Chain_1)
+    //   Chain_2 = getCopyToReg(Chain_1, Val) from below
+
+    // getCopyToReg(Chain_0) will be glued together with
+    // getCopyToReg(Chain_1, Val) into Unit A, getCopyFromReg(Chain_1) will be
+    // in Unit B, and we will have cyclic dependency between Unit A and Unit B:
+    //   Data dependency from Unit B to Unit A due to usage of Val in
+    //     getCopyToReg(Chain_1, Val)
+    //   Chain dependency from Unit A to Unit B
+
+    // So here, we use RetOps[0] (i.e Chain_0) for getCopyFromReg.
+    SDValue Val = DAG.getCopyFromReg(RetOps[0], dl, SRetReg,
                                      getPointerTy(MF.getDataLayout()));
 
     unsigned RetValReg

diff --git a/llvm/lib/Target/X86/X86ISelLowering.h b/llvm/lib/Target/X86/X86ISelLowering.h
@@ -984,6 +984,10 @@ namespace llvm {
 
     bool isIntDivCheap(EVT VT, AttributeSet Attr) const override;
 
+    bool supportSwiftError() const override {
+      return true;
+    }
+
   protected:
     std::pair<const TargetRegisterClass *, uint8_t>
     findRepresentativeClass(const TargetRegisterInfo *TRI,

diff --git a/llvm/lib/Target/X86/X86RegisterInfo.cpp b/llvm/lib/Target/X86/X86RegisterInfo.cpp
@@ -299,6 +299,10 @@ X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
       return CSR_Win64_SaveList;
     if (CallsEHReturn)
       return CSR_64EHRet_SaveList;
+    if (Subtarget.getTargetLowering()->supportSwiftError() &&
+        MF->getFunction()->getAttributes().hasAttrSomewhere(
+            Attribute::SwiftError))
+      return CSR_64_SwiftError_SaveList;
     return CSR_64_SaveList;
   }
   if (CallsEHReturn)
@@ -385,6 +389,10 @@ X86RegisterInfo::getCallPreservedMask(const MachineFunction &MF,
   if (Is64Bit) {
     if (IsWin64)
       return CSR_Win64_RegMask;
+    if (Subtarget.getTargetLowering()->supportSwiftError() &&
+        MF.getFunction()->getAttributes().hasAttrSomewhere(
+            Attribute::SwiftError))
+      return CSR_64_SwiftError_RegMask;
     return CSR_64_RegMask;
   }
   return CSR_32_RegMask;

diff --git a/llvm/test/CodeGen/AArch64/swifterror.ll b/llvm/test/CodeGen/AArch64/swifterror.ll
@@ -0,0 +1,385 @@
+; RUN: llc -verify-machineinstrs < %s -mtriple=aarch64-apple-ios -disable-post-ra | FileCheck --check-prefix=CHECK-APPLE %s
+; RUN: llc -verify-machineinstrs -O0 < %s -mtriple=aarch64-apple-ios -disable-post-ra | FileCheck --check-prefix=CHECK-O0 %s
+
+declare i8* @malloc(i64)
+declare void @free(i8*)
+%swift_error = type {i64, i8}
+
+; This tests the basic usage of a swifterror parameter. "foo" is the function
+; that takes a swifterror parameter and "caller" is the caller of "foo".
+define float @foo(%swift_error** swifterror %error_ptr_ref) {
+; CHECK-APPLE-LABEL: foo:
+; CHECK-APPLE: orr w0, wzr, #0x10
+; CHECK-APPLE: malloc
+; CHECK-APPLE: orr [[ID:w[0-9]+]], wzr, #0x1
+; CHECK-APPLE: strb [[ID]], [x0, #8]
+; CHECK-APPLE: mov x19, x0
+; CHECK-APPLE-NOT: x19
+
+; CHECK-O0-LABEL: foo:
+; CHECK-O0: orr w{{.*}}, wzr, #0x10
+; CHECK-O0: malloc
+; CHECK-O0: mov [[ID2:x[0-9]+]], x0
+; CHECK-O0: orr [[ID:w[0-9]+]], wzr, #0x1
+; CHECK-O0: strb [[ID]], [x0, #8]
+; CHECK-O0: mov x19, [[ID2]]
+; CHECK-O0-NOT: x19
+entry:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  ret float 1.0
+}
+
+; "caller" calls "foo" that takes a swifterror parameter.
+define float @caller(i8* %error_ref) {
+; CHECK-APPLE-LABEL: caller:
+; CHECK-APPLE: mov [[ID:x[0-9]+]], x0
+; CHECK-APPLE: mov x19, xzr
+; CHECK-APPLE: bl {{.*}}foo
+; CHECK-APPLE: cbnz x19
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: ldrb [[CODE:w[0-9]+]], [x19, #8]
+; CHECK-APPLE: strb [[CODE]], [{{.*}}[[ID]]]
+; CHECK-APPLE: mov x0, x19
+; CHECK_APPLE: bl {{.*}}free
+
+; CHECK-O0-LABEL: caller:
+; CHECK-O0: mov x19
+; CHECK-O0: bl {{.*}}foo
+; CHECK-O0: mov [[ID:x[0-9]+]], x19
+; CHECK-O0: cbnz [[ID]]
+entry:
+  %error_ptr_ref = alloca swifterror %swift_error*
+  store %swift_error* null, %swift_error** %error_ptr_ref
+  %call = call float @foo(%swift_error** swifterror %error_ptr_ref)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+cont:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+  ret float 1.0
+}
+
+; "caller2" is the caller of "foo", it calls "foo" inside a loop.
+define float @caller2(i8* %error_ref) {
+; CHECK-APPLE-LABEL: caller2:
+; CHECK-APPLE: mov [[ID:x[0-9]+]], x0
+; CHECK-APPLE: fmov [[CMP:s[0-9]+]], #1.0
+; CHECK-APPLE: mov x19, xzr
+; CHECK-APPLE: bl {{.*}}foo
+; CHECK-APPLE: cbnz x19
+; CHECK-APPLE: fcmp s0, [[CMP]]
+; CHECK-APPLE: b.le
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: ldrb [[CODE:w[0-9]+]], [x19, #8]
+; CHECK-APPLE: strb [[CODE]], [{{.*}}[[ID]]]
+; CHECK-APPLE: mov x0, x19
+; CHECK_APPLE: bl {{.*}}free
+
+; CHECK-O0-LABEL: caller2:
+; CHECK-O0: mov x19
+; CHECK-O0: bl {{.*}}foo
+; CHECK-O0: mov [[ID:x[0-9]+]], x19
+; CHECK-O0: cbnz [[ID]]
+entry:
+  %error_ptr_ref = alloca swifterror %swift_error*
+  br label %bb_loop
+bb_loop:
+  store %swift_error* null, %swift_error** %error_ptr_ref
+  %call = call float @foo(%swift_error** swifterror %error_ptr_ref)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+cont:
+  %cmp = fcmp ogt float %call, 1.000000e+00
+  br i1 %cmp, label %bb_end, label %bb_loop
+bb_end:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+  ret float 1.0
+}
+
+; "foo_if" is a function that takes a swifterror parameter, it sets swifterror
+; under a certain condition.
+define float @foo_if(%swift_error** swifterror %error_ptr_ref, i32 %cc) {
+; CHECK-APPLE-LABEL: foo_if:
+; CHECK-APPLE: cbz w0
+; CHECK-APPLE: orr w0, wzr, #0x10
+; CHECK-APPLE: malloc
+; CHECK-APPLE: orr [[ID:w[0-9]+]], wzr, #0x1
+; CHECK-APPLE: strb [[ID]], [x0, #8]
+; CHECK-APPLE: mov x19, x0
+; CHECK-APPLE-NOT: x19
+; CHECK-APPLE: ret
+
+; CHECK-O0-LABEL: foo_if:
+; spill x19
+; CHECK-O0: str x19
+; CHECK-O0: cbz w0
+; CHECK-O0: orr w{{.*}}, wzr, #0x10
+; CHECK-O0: malloc
+; CHECK-O0: mov [[ID:x[0-9]+]], x0
+; CHECK-O0: orr [[ID2:w[0-9]+]], wzr, #0x1
+; CHECK-O0: strb [[ID2]], [x0, #8]
+; CHECK-O0: mov x19, [[ID]]
+; CHECK-O0: ret
+; reload from stack
+; CHECK-O0: ldr x19
+; CHECK-O0: ret
+entry:
+  %cond = icmp ne i32 %cc, 0
+  br i1 %cond, label %gen_error, label %normal
+
+gen_error:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  ret float 1.0
+
+normal:
+  ret float 0.0
+}
+
+; "foo_loop" is a function that takes a swifterror parameter, it sets swifterror
+; under a certain condition inside a loop.
+define float @foo_loop(%swift_error** swifterror %error_ptr_ref, i32 %cc, float %cc2) {
+; CHECK-APPLE-LABEL: foo_loop:
+; CHECK-APPLE: mov x0, x19
+; CHECK-APPLE: cbz
+; CHECK-APPLE: orr w0, wzr, #0x10
+; CHECK-APPLE: malloc
+; CHECK-APPLE: strb w{{.*}}, [x0, #8]
+; CHECK-APPLE: fcmp
+; CHECK-APPLE: b.le
+; CHECK-APPLE: mov x19, x0
+; CHECK-APPLE: ret
+
+; CHECK-O0-LABEL: foo_loop:
+; spill x19
+; CHECK-O0: str x19
+; CHECk-O0: cbz
+; CHECK-O0: orr w{{.*}}, wzr, #0x10
+; CHECK-O0: malloc
+; CHECK-O0: mov [[ID:x[0-9]+]], x0
+; CHECK-O0: strb w{{.*}}, [{{.*}}[[ID]], #8]
+; spill x0
+; CHECK-O0: str x0
+; CHECK-O0: fcmp
+; CHECK-O0: b.le
+; reload from stack
+; CHECK-O0: ldr x19
+; CHECK-O0: ret
+entry:
+  br label %bb_loop
+
+bb_loop:
+  %cond = icmp ne i32 %cc, 0
+  br i1 %cond, label %gen_error, label %bb_cont
+
+gen_error:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  br label %bb_cont
+
+bb_cont:
+  %cmp = fcmp ogt float %cc2, 1.000000e+00
+  br i1 %cmp, label %bb_end, label %bb_loop
+bb_end:
+  ret float 0.0
+}
+
+%struct.S = type { i32, i32, i32, i32, i32, i32 }
+
+; "foo_sret" is a function that takes a swifterror parameter, it also has a sret
+; parameter.
+define void @foo_sret(%struct.S* sret %agg.result, i32 %val1, %swift_error** swifterror %error_ptr_ref) {
+; CHECK-APPLE-LABEL: foo_sret:
+; CHECK-APPLE: mov [[SRET:x[0-9]+]], x8
+; CHECK-APPLE: orr w0, wzr, #0x10
+; CHECK-APPLE: malloc
+; CHECK-APPLE: orr [[ID:w[0-9]+]], wzr, #0x1
+; CHECK-APPLE: strb [[ID]], [x0, #8]
+; CHECK-APPLE: str w{{.*}}, [{{.*}}[[SRET]], #4]
+; CHECK-APPLE: mov x19, x0
+; CHECK-APPLE-NOT: x19
+
+; CHECK-O0-LABEL: foo_sret:
+; CHECK-O0: orr w{{.*}}, wzr, #0x10
+; spill x8
+; CHECK-O0-DAG: str x8
+; spill x19
+; CHECK-O0-DAG: str x19
+; CHECK-O0: malloc
+; CHECK-O0: orr [[ID:w[0-9]+]], wzr, #0x1
+; CHECK-O0: strb [[ID]], [x0, #8]
+; reload from stack
+; CHECK-O0: ldr [[SRET:x[0-9]+]]
+; CHECK-O0: str w{{.*}}, [{{.*}}[[SRET]], #4]
+; CHECK-O0: mov x19
+; CHECK-O0-NOT: x19
+entry:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  %v2 = getelementptr inbounds %struct.S, %struct.S* %agg.result, i32 0, i32 1
+  store i32 %val1, i32* %v2
+  ret void
+}
+
+; "caller3" calls "foo_sret" that takes a swifterror parameter.
+define float @caller3(i8* %error_ref) {
+; CHECK-APPLE-LABEL: caller3:
+; CHECK-APPLE: mov [[ID:x[0-9]+]], x0
+; CHECK-APPLE: mov x19, xzr
+; CHECK-APPLE: bl {{.*}}foo_sret
+; CHECK-APPLE: cbnz x19
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: ldrb [[CODE:w[0-9]+]], [x19, #8]
+; CHECK-APPLE: strb [[CODE]], [{{.*}}[[ID]]]
+; CHECK-APPLE: mov x0, x19
+; CHECK_APPLE: bl {{.*}}free
+
+; CHECK-O0-LABEL: caller3:
+; spill x0
+; CHECK-O0: str x0
+; CHECK-O0: mov x19
+; CHECK-O0: bl {{.*}}foo_sret
+; CHECK-O0: mov [[ID2:x[0-9]+]], x19
+; CHECK-O0: cbnz [[ID2]]
+; Access part of the error object and save it to error_ref
+; reload from stack
+; CHECK-O0: ldrb [[CODE:w[0-9]+]]
+; CHECK-O0: ldr [[ID:x[0-9]+]]
+; CHECK-O0: strb [[CODE]], [{{.*}}[[ID]]]
+; CHECK_O0: bl {{.*}}free
+entry:
+  %s = alloca %struct.S, align 8
+  %error_ptr_ref = alloca swifterror %swift_error*
+  store %swift_error* null, %swift_error** %error_ptr_ref
+  call void @foo_sret(%struct.S* sret %s, i32 1, %swift_error** swifterror %error_ptr_ref)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+cont:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+  ret float 1.0
+}
+
+; "foo_vararg" is a function that takes a swifterror parameter, it also has
+; variable number of arguments.
+declare void @llvm.va_start(i8*) nounwind
+define float @foo_vararg(%swift_error** swifterror %error_ptr_ref, ...) {
+; CHECK-APPLE-LABEL: foo_vararg:
+; CHECK-APPLE: orr w0, wzr, #0x10
+; CHECK-APPLE: malloc
+; CHECK-APPLE: orr [[ID:w[0-9]+]], wzr, #0x1
+; CHECK-FIXMEAPPLE: add [[ARGS:x[0-9]+]], [[TMP:x[0-9]+]], #16
+; CHECK-APPLE: strb [[ID]], [x0, #8]
+
+; First vararg
+; CHECK-FIXMEAPPLE-DAG: orr {{x[0-9]+}}, [[ARGS]], #0x8
+; CHECK-FIXMEAPPLE-DAG: ldr {{w[0-9]+}}, [{{.*}}[[TMP]], #16]
+; CHECK-APPLE: add {{x[0-9]+}}, {{x[0-9]+}}, #8
+; Second vararg
+; CHECK-APPLE: ldr {{w[0-9]+}}, [{{x[0-9]+}}]
+; CHECK-APPLE: add {{x[0-9]+}}, {{x[0-9]+}}, #8
+; Third vararg
+; CHECK-APPLE: ldr {{w[0-9]+}}, [{{x[0-9]+}}]
+
+; CHECK-APPLE: mov x19, x0
+; CHECK-APPLE-NOT: x19
+entry:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+
+  %args = alloca i8*, align 8
+  %a10 = alloca i32, align 4
+  %a11 = alloca i32, align 4
+  %a12 = alloca i32, align 4
+  %v10 = bitcast i8** %args to i8*
+  call void @llvm.va_start(i8* %v10)
+  %v11 = va_arg i8** %args, i32
+  store i32 %v11, i32* %a10, align 4
+  %v12 = va_arg i8** %args, i32
+  store i32 %v12, i32* %a11, align 4
+  %v13 = va_arg i8** %args, i32
+  store i32 %v13, i32* %a12, align 4
+
+  ret float 1.0
+}
+
+; "caller4" calls "foo_vararg" that takes a swifterror parameter.
+define float @caller4(i8* %error_ref) {
+; CHECK-APPLE-LABEL: caller4:
+
+; CHECK-APPLE: mov [[ID:x[0-9]+]], x0
+; CHECK-APPLE: stp {{x[0-9]+}}, {{x[0-9]+}}, [sp, #8]
+; CHECK-APPLE: str {{x[0-9]+}}, [sp]
+
+; CHECK-APPLE: mov x19, xzr
+; CHECK-APPLE: bl {{.*}}foo_vararg
+; CHECK-APPLE: cbnz x19
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: ldrb [[CODE:w[0-9]+]], [x19, #8]
+; CHECK-APPLE: strb [[CODE]], [{{.*}}[[ID]]]
+; CHECK-APPLE: mov x0, x19
+; CHECK_APPLE: bl {{.*}}free
+entry:
+  %error_ptr_ref = alloca swifterror %swift_error*
+  store %swift_error* null, %swift_error** %error_ptr_ref
+
+  %a10 = alloca i32, align 4
+  %a11 = alloca i32, align 4
+  %a12 = alloca i32, align 4
+  store i32 10, i32* %a10, align 4
+  store i32 11, i32* %a11, align 4
+  store i32 12, i32* %a12, align 4
+  %v10 = load i32, i32* %a10, align 4
+  %v11 = load i32, i32* %a11, align 4
+  %v12 = load i32, i32* %a12, align 4
+
+  %call = call float (%swift_error**, ...) @foo_vararg(%swift_error** swifterror %error_ptr_ref, i32 %v10, i32 %v11, i32 %v12)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+
+cont:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+  ret float 1.0
+}
diff --git a/llvm/test/CodeGen/ARM/swifterror.ll b/llvm/test/CodeGen/ARM/swifterror.ll
@@ -0,0 +1,381 @@
+; RUN: llc -verify-machineinstrs < %s -mtriple=armv7-apple-ios | FileCheck --check-prefix=CHECK-APPLE %s
+; RUN: llc -verify-machineinstrs -O0 < %s -mtriple=armv7-apple-ios | FileCheck --check-prefix=CHECK-O0 %s
+
+declare i8* @malloc(i64)
+declare void @free(i8*)
+%swift_error = type { i64, i8 }
+%struct.S = type { i32, i32, i32, i32, i32, i32 }
+
+; This tests the basic usage of a swifterror parameter. "foo" is the function
+; that takes a swifterror parameter and "caller" is the caller of "foo".
+define float @foo(%swift_error** swifterror %error_ptr_ref) {
+; CHECK-APPLE-LABEL: foo:
+; CHECK-APPLE: mov r0, #16
+; CHECK-APPLE: malloc
+; CHECK-APPLE-DAG: mov [[ID:r[0-9]+]], #1
+; CHECK-APPLE-DAG: mov r6, r{{.*}}
+; CHECK-APPLE-DAG: strb [[ID]], [r{{.*}}, #8]
+
+; CHECK-O0-LABEL: foo:
+; CHECK-O0: mov r{{.*}}, #16
+; CHECK-O0: malloc
+; CHECK-O0: mov [[ID2:r[0-9]+]], r0
+; CHECK-O0: mov [[ID:r[0-9]+]], #1
+; CHECK-O0: strb [[ID]], [r0, #8]
+; CHECK-O0: mov r6, [[ID2]]
+entry:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  ret float 1.0
+}
+
+; "caller" calls "foo" that takes a swifterror parameter.
+define float @caller(i8* %error_ref) {
+; CHECK-APPLE-LABEL: caller:
+; CHECK-APPLE-DAG: mov [[ID:r[0-9]+]], r0
+; CHECK-APPLE-DAG: mov r6, #0
+; CHECK-APPLE: bl {{.*}}foo
+; CHECK-APPLE: cmp r6, #0
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: ldrbeq [[CODE:r[0-9]+]], [r6, #8]
+; CHECK-APPLE: strbeq [[CODE]], [{{.*}}[[ID]]]
+; CHECK-APPLE: mov r0, r6
+; CHECK_APPLE: bl {{.*}}free
+
+; CHECK-O0-LABEL: caller:
+; spill r0
+; CHECK-O0-DAG: str r0,
+; CHECK-O0-DAG: mov r6, #0
+; CHECK-O0: bl {{.*}}foo
+; CHECK-O0: mov r{{.*}}, r6
+; CHECK-O0: bne
+; CHECK-O0: ldrb [[CODE:r[0-9]+]], [r0, #8]
+; reload r0
+; CHECK-O0: ldr [[ID:r[0-9]+]],
+; CHECK-O0: strb [[CODE]], [{{.*}}[[ID]]]
+; CHECK-O0: mov r0,
+; CHECK-O0: free
+entry:
+  %error_ptr_ref = alloca swifterror %swift_error*
+  store %swift_error* null, %swift_error** %error_ptr_ref
+  %call = call float @foo(%swift_error** swifterror %error_ptr_ref)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+cont:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+  ret float 1.0
+}
+
+; "caller2" is the caller of "foo", it calls "foo" inside a loop.
+define float @caller2(i8* %error_ref) {
+; CHECK-APPLE-LABEL: caller2:
+; CHECK-APPLE-DAG: mov [[ID:r[0-9]+]], r0
+; CHECK-APPLE-DAG: mov r6, #0
+; CHECK-APPLE: bl {{.*}}foo
+; CHECK-APPLE: cmp r6, #0
+; CHECK-APPLE: bne
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: ldrb [[CODE:r[0-9]+]], [r6, #8]
+; CHECK-APPLE: strb [[CODE]], [{{.*}}[[ID]]]
+; CHECK-APPLE: mov r0, r6
+; CHECK_APPLE: bl {{.*}}free
+
+; CHECK-O0-LABEL: caller2:
+; spill r0
+; CHECK-O0-DAG: str r0,
+; CHECK-O0-DAG: mov r6, #0
+; CHECK-O0: bl {{.*}}foo
+; CHECK-O0: mov r{{.*}}, r6
+; CHECK-O0: bne
+; CHECK-O0: ble
+; CHECK-O0: ldrb [[CODE:r[0-9]+]], [r0, #8]
+; reload r0
+; CHECK-O0: ldr [[ID:r[0-9]+]],
+; CHECK-O0: strb [[CODE]], [{{.*}}[[ID]]]
+; CHECK-O0: mov r0,
+; CHECK-O0: free
+entry:
+  %error_ptr_ref = alloca swifterror %swift_error*
+  br label %bb_loop
+bb_loop:
+  store %swift_error* null, %swift_error** %error_ptr_ref
+  %call = call float @foo(%swift_error** swifterror %error_ptr_ref)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+cont:
+  %cmp = fcmp ogt float %call, 1.000000e+00
+  br i1 %cmp, label %bb_end, label %bb_loop
+bb_end:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+  ret float 1.0
+}
+
+; "foo_if" is a function that takes a swifterror parameter, it sets swifterror
+; under a certain condition.
+define float @foo_if(%swift_error** swifterror %error_ptr_ref, i32 %cc) {
+; CHECK-APPLE-LABEL: foo_if:
+; CHECK-APPLE: cmp r0, #0
+; CHECK-APPLE: eq
+; CHECK-APPLE: mov r0, #16
+; CHECK-APPLE: malloc
+; CHECK-APPLE: mov [[ID:r[0-9]+]], #1
+; CHECK-APPLE-DAG: mov r6, r{{.*}}
+; CHECK-APPLE-DAG: strb [[ID]], [r{{.*}}, #8]
+
+; CHECK-O0-LABEL: foo_if:
+; CHECK-O0: cmp r0, #0
+; spill to stack
+; CHECK-O0: str r6
+; CHECK-O0: beq
+; CHECK-O0: mov r0, #16
+; CHECK-O0: malloc
+; CHECK-O0: mov [[ID:r[0-9]+]], r0
+; CHECK-O0: mov [[ID2:[a-z0-9]+]], #1
+; CHECK-O0: strb [[ID2]], [r0, #8]
+; CHECK-O0: mov r6, [[ID]]
+; reload from stack
+; CHECK-O0: ldr r6
+entry:
+  %cond = icmp ne i32 %cc, 0
+  br i1 %cond, label %gen_error, label %normal
+
+gen_error:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  ret float 1.0
+
+normal:
+  ret float 0.0
+}
+
+; "foo_loop" is a function that takes a swifterror parameter, it sets swifterror
+; under a certain condition inside a loop.
+define float @foo_loop(%swift_error** swifterror %error_ptr_ref, i32 %cc, float %cc2) {
+; CHECK-APPLE-LABEL: foo_loop:
+; CHECK-APPLE: mov [[CODE:r[0-9]+]], r0
+; swifterror is kept in a register
+; CHECK-APPLE: mov [[ID:r[0-9]+]], r6
+; CHECK-APPLE: cmp [[CODE]], #0
+; CHECK-APPLE: beq
+; CHECK-APPLE: mov r0, #16
+; CHECK-APPLE: malloc
+; CHECK-APPLE: strb r{{.*}}, [{{.*}}[[ID]], #8]
+; CHECK-APPLE: ble
+; CHECK-APPLE: mov r6, [[ID]]
+
+; CHECK-O0-LABEL: foo_loop:
+; CHECK-O0: mov r{{.*}}, r6
+; CHECK-O0: cmp r{{.*}}, #0
+; CHECK-O0: beq
+; CHECK-O0-DAG: movw r{{.*}}, #1
+; CHECK-O0-DAG: mov r{{.*}}, #16
+; CHECK-O0: malloc
+; CHECK-O0-DAG: mov [[ID:r[0-9]+]], r0
+; CHECK-O0-DAG: ldr [[ID2:r[0-9]+]], [sp{{.*}}]
+; CHECK-O0: strb [[ID2]], [{{.*}}[[ID]], #8]
+; spill r0
+; CHECK-O0: str r0, [sp{{.*}}]
+; CHECK-O0: vcmpe
+; CHECK-O0: ble
+; reload from stack
+; CHECK-O0: ldr r6
+entry:
+  br label %bb_loop
+
+bb_loop:
+  %cond = icmp ne i32 %cc, 0
+  br i1 %cond, label %gen_error, label %bb_cont
+
+gen_error:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  br label %bb_cont
+
+bb_cont:
+  %cmp = fcmp ogt float %cc2, 1.000000e+00
+  br i1 %cmp, label %bb_end, label %bb_loop
+bb_end:
+  ret float 0.0
+}
+
+; "foo_sret" is a function that takes a swifterror parameter, it also has a sret
+; parameter.
+define void @foo_sret(%struct.S* sret %agg.result, i32 %val1, %swift_error** swifterror %error_ptr_ref) {
+; CHECK-APPLE-LABEL: foo_sret:
+; CHECK-APPLE: mov [[SRET:r[0-9]+]], r0
+; CHECK-APPLE: mov r0, #16
+; CHECK-APPLE: malloc
+; CHECK-APPLE: mov [[REG:r[0-9]+]], #1
+; CHECK-APPLE-DAG: mov r6, r0
+; CHECK-APPLE-DAG: strb [[REG]], [r0, #8]
+; CHECK-APPLE-DAG: str r{{.*}}, [{{.*}}[[SRET]], #4]
+
+; CHECK-O0-LABEL: foo_sret:
+; CHECK-O0: mov r{{.*}}, #16
+; spill to stack: sret and val1
+; CHECK-O0-DAG: str r0
+; CHECK-O0-DAG: str r1
+; CHECK-O0: malloc
+; CHECK-O0: mov [[ID:r[0-9]+]], #1
+; CHECK-O0: strb [[ID]], [r0, #8]
+; reload from stack: sret and val1
+; CHECK-O0: ldr
+; CHECK-O0: ldr
+; CHECK-O0: str r{{.*}}, [{{.*}}, #4]
+; CHECK-O0: mov r6
+entry:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  %v2 = getelementptr inbounds %struct.S, %struct.S* %agg.result, i32 0, i32 1
+  store i32 %val1, i32* %v2
+  ret void
+}
+
+; "caller3" calls "foo_sret" that takes a swifterror parameter.
+define float @caller3(i8* %error_ref) {
+; CHECK-APPLE-LABEL: caller3:
+; CHECK-APPLE: mov [[ID:r[0-9]+]], r0
+; CHECK-APPLE: mov r6, #0
+; CHECK-APPLE: bl {{.*}}foo_sret
+; CHECK-APPLE: cmp r6, #0
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: ldrbeq [[CODE:r[0-9]+]], [r6, #8]
+; CHECK-APPLE: strbeq [[CODE]], [{{.*}}[[ID]]]
+; CHECK-APPLE: mov r0, r6
+; CHECK_APPLE: bl {{.*}}free
+
+; CHECK-O0-LABEL: caller3:
+; CHECK-O0-DAG: mov r6, #0
+; CHECK-O0-DAG: mov r0
+; CHECK-O0-DAG: mov r1
+; CHECK-O0: bl {{.*}}foo_sret
+; CHECK-O0: mov [[ID2:r[0-9]+]], r6
+; CHECK-O0: cmp [[ID2]]
+; CHECK-O0: bne
+; Access part of the error object and save it to error_ref
+; CHECK-O0: ldrb [[CODE:r[0-9]+]]
+; CHECK-O0: ldr [[ID:r[0-9]+]]
+; CHECK-O0: strb [[CODE]], [{{.*}}[[ID]]]
+; CHECK-O0: mov r0,
+; CHECK_O0: bl {{.*}}free
+entry:
+  %s = alloca %struct.S, align 8
+  %error_ptr_ref = alloca swifterror %swift_error*
+  store %swift_error* null, %swift_error** %error_ptr_ref
+  call void @foo_sret(%struct.S* sret %s, i32 1, %swift_error** swifterror %error_ptr_ref)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+cont:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+  ret float 1.0
+}
+
+; "foo_vararg" is a function that takes a swifterror parameter, it also has
+; variable number of arguments.
+declare void @llvm.va_start(i8*) nounwind
+define float @foo_vararg(%swift_error** swifterror %error_ptr_ref, ...) {
+; CHECK-APPLE-LABEL: foo_vararg:
+; CHECK-APPLE: mov r0, #16
+; CHECK-APPLE: malloc
+; CHECK-APPLE: mov [[REG:r[0-9]+]], r0
+; CHECK-APPLE: mov [[ID:r[0-9]+]], #1
+; CHECK-APPLE-DAG: strb [[ID]], [{{.*}}[[REG]], #8]
+; CHECK-APPLE-DAG: mov r6, [[REG]]
+
+entry:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+
+  %args = alloca i8*, align 8
+  %a10 = alloca i32, align 4
+  %a11 = alloca i32, align 4
+  %a12 = alloca i32, align 4
+  %v10 = bitcast i8** %args to i8*
+  call void @llvm.va_start(i8* %v10)
+  %v11 = va_arg i8** %args, i32
+  store i32 %v11, i32* %a10, align 4
+  %v12 = va_arg i8** %args, i32
+  store i32 %v12, i32* %a11, align 4
+  %v13 = va_arg i8** %args, i32
+  store i32 %v13, i32* %a12, align 4
+
+  ret float 1.0
+}
+
+; "caller4" calls "foo_vararg" that takes a swifterror parameter.
+define float @caller4(i8* %error_ref) {
+; CHECK-APPLE-LABEL: caller4:
+; CHECK-APPLE: mov [[ID:r[0-9]+]], r0
+; CHECK-APPLE: mov r6, #0
+; CHECK-APPLE: bl {{.*}}foo_vararg
+; CHECK-APPLE: cmp r6, #0
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: ldrbeq [[CODE:r[0-9]+]], [r6, #8]
+; CHECK-APPLE: strbeq [[CODE]], [{{.*}}[[ID]]]
+; CHECK-APPLE: mov r0, r6
+; CHECK_APPLE: bl {{.*}}free
+entry:
+  %error_ptr_ref = alloca swifterror %swift_error*
+  store %swift_error* null, %swift_error** %error_ptr_ref
+
+  %a10 = alloca i32, align 4
+  %a11 = alloca i32, align 4
+  %a12 = alloca i32, align 4
+  store i32 10, i32* %a10, align 4
+  store i32 11, i32* %a11, align 4
+  store i32 12, i32* %a12, align 4
+  %v10 = load i32, i32* %a10, align 4
+  %v11 = load i32, i32* %a11, align 4
+  %v12 = load i32, i32* %a12, align 4
+
+  %call = call float (%swift_error**, ...) @foo_vararg(%swift_error** swifterror %error_ptr_ref, i32 %v10, i32 %v11, i32 %v12)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+
+cont:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+  ret float 1.0
+}
diff --git a/llvm/test/CodeGen/X86/swifterror.ll b/llvm/test/CodeGen/X86/swifterror.ll
@@ -0,0 +1,359 @@
+; RUN: llc -verify-machineinstrs < %s -mtriple=x86_64-apple-darwin | FileCheck --check-prefix=CHECK-APPLE %s
+; RUN: llc -verify-machineinstrs -O0 < %s -mtriple=x86_64-apple-darwin | FileCheck --check-prefix=CHECK-O0 %s
+
+declare i8* @malloc(i64)
+declare void @free(i8*)
+%swift_error = type {i64, i8}
+
+; This tests the basic usage of a swifterror parameter. "foo" is the function
+; that takes a swifterror parameter and "caller" is the caller of "foo".
+define float @foo(%swift_error** swifterror %error_ptr_ref) {
+; CHECK-APPLE-LABEL: foo:
+; CHECK-APPLE: movl $16, %edi
+; CHECK-APPLE: malloc
+; CHECK-APPLE: movb $1, 8(%rax)
+; CHECK-APPLE: movq %rax, %r12
+
+; CHECK-O0-LABEL: foo:
+; CHECK-O0: movl $16
+; CHECK-O0: malloc
+; CHECK-O0: movb $1, 8(%rax)
+; CHECK-O0: movq %{{.*}}, %r12
+entry:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  ret float 1.0
+}
+
+; "caller" calls "foo" that takes a swifterror parameter.
+define float @caller(i8* %error_ref) {
+; CHECK-APPLE-LABEL: caller:
+; CHECK-APPLE: xorl %r12d, %r12d
+; CHECK-APPLE: callq {{.*}}foo
+; CHECK-APPLE: testq %r12, %r12
+; CHECK-APPLE: jne
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: movb 8(%r12)
+; CHECK-APPLE: movq %r12, %rdi
+; CHECK_APPLE: callq {{.*}}free
+
+; CHECK-O0-LABEL: caller:
+; CHECK-O0: xorl
+; CHECK-O0: movl %{{.*}}, %r12d
+; CHECK-O0: callq {{.*}}foo
+; CHECK-O0: jne
+entry:
+  %error_ptr_ref = alloca swifterror %swift_error*
+  store %swift_error* null, %swift_error** %error_ptr_ref
+  %call = call float @foo(%swift_error** swifterror %error_ptr_ref)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+cont:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+  ret float 1.0
+}
+
+; "caller2" is the caller of "foo", it calls "foo" inside a loop.
+define float @caller2(i8* %error_ref) {
+; CHECK-APPLE-LABEL: caller2:
+; CHECK-APPLE: xorl %r12d, %r12d
+; CHECK-APPLE: callq {{.*}}foo
+; CHECK-APPLE: testq %r12, %r12
+; CHECK-APPLE: jne
+; CHECK-APPLE: ucomiss
+; CHECK-APPLE: jbe
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: movb 8(%r12)
+; CHECK-APPLE: movq %r12, %rdi
+; CHECK_APPLE: callq {{.*}}free
+
+; CHECK-O0-LABEL: caller2:
+; CHECK-O0: xorl
+; CHECK-O0: movl %{{.*}}, %r12d
+; CHECK-O0: callq {{.*}}foo
+; CHECK-O0: movq %r12, [[ID:%[a-z]+]]
+; CHECK-O0: cmpq $0, [[ID]]
+; CHECK-O0: jne
+entry:
+  %error_ptr_ref = alloca swifterror %swift_error*
+  br label %bb_loop
+bb_loop:
+  store %swift_error* null, %swift_error** %error_ptr_ref
+  %call = call float @foo(%swift_error** swifterror %error_ptr_ref)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+cont:
+  %cmp = fcmp ogt float %call, 1.000000e+00
+  br i1 %cmp, label %bb_end, label %bb_loop
+bb_end:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+  ret float 1.0
+}
+
+; "foo_if" is a function that takes a swifterror parameter, it sets swifterror
+; under a certain condition.
+define float @foo_if(%swift_error** swifterror %error_ptr_ref, i32 %cc) {
+; CHECK-APPLE-LABEL: foo_if:
+; CHECK-APPLE: testl %edi, %edi
+; CHECK-APPLE: je
+; CHECK-APPLE: movl $16, %edi
+; CHECK-APPLE: malloc
+; CHECK-APPLE: movb $1, 8(%rax)
+; CHECK-APPLE: movq %rax, %r12
+; CHECK-APPLE-NOT: %r12
+; CHECK-APPLE: ret
+
+; CHECK-O0-LABEL: foo_if:
+; CHECK-O0: cmpl $0
+; spill to stack
+; CHECK-O0: movq %r12, {{.*}}(%rsp)
+; CHECK-O0: je
+; CHECK-O0: movl $16,
+; CHECK-O0: malloc
+; CHECK-O0: movq %rax, [[ID:%[a-z]+]]
+; CHECK-O0-DAG: movb $1, 8(%rax)
+; CHECK-O0-DAG: movq [[ID]], %r12
+; CHECK-O0: ret
+; reload from stack
+; CHECK-O0: movq {{.*}}(%rsp), %r12
+; CHECK-O0: ret
+entry:
+  %cond = icmp ne i32 %cc, 0
+  br i1 %cond, label %gen_error, label %normal
+
+gen_error:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  ret float 1.0
+
+normal:
+  ret float 0.0
+}
+
+; "foo_loop" is a function that takes a swifterror parameter, it sets swifterror
+; under a certain condition inside a loop.
+define float @foo_loop(%swift_error** swifterror %error_ptr_ref, i32 %cc, float %cc2) {
+; CHECK-APPLE-LABEL: foo_loop:
+; CHECK-APPLE: movq %r12, %rax
+; CHECK-APPLE: testl
+; CHECK-APPLE: je
+; CHECK-APPLE: movl $16, %edi
+; CHECK-APPLE: malloc
+; CHECK-APPLE: movb $1, 8(%rax)
+; CHECK-APPLE: ucomiss
+; CHECK-APPLE: jbe
+; CHECK-APPLE: movq %rax, %r12
+; CHECK-APPLE: ret
+
+; CHECK-O0-LABEL: foo_loop:
+; spill to stack
+; CHECK-O0: movq %r12, {{.*}}(%rsp)
+; CHECK-O0: cmpl $0
+; CHECK-O0: je
+; CHECK-O0: movl $16,
+; CHECK-O0: malloc
+; CHECK-O0: movq %rax, [[ID:%[a-z]+]]
+; CHECK-O0: movb $1, 8([[ID]])
+; CHECK-O0: jbe
+; reload from stack
+; CHECK-O0: movq {{.*}}(%rsp), %r12
+; CHECK-O0: ret
+entry:
+  br label %bb_loop
+
+bb_loop:
+  %cond = icmp ne i32 %cc, 0
+  br i1 %cond, label %gen_error, label %bb_cont
+
+gen_error:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  br label %bb_cont
+
+bb_cont:
+  %cmp = fcmp ogt float %cc2, 1.000000e+00
+  br i1 %cmp, label %bb_end, label %bb_loop
+bb_end:
+  ret float 0.0
+}
+
+%struct.S = type { i32, i32, i32, i32, i32, i32 }
+
+; "foo_sret" is a function that takes a swifterror parameter, it also has a sret
+; parameter.
+define void @foo_sret(%struct.S* sret %agg.result, i32 %val1, %swift_error** swifterror %error_ptr_ref) {
+; CHECK-APPLE-LABEL: foo_sret:
+; CHECK-APPLE: movq %rdi, %{{.*}}
+; CHECK-APPLE: movl $16, %edi
+; CHECK-APPLE: malloc
+; CHECK-APPLE: movb $1, 8(%rax)
+; CHECK-APPLE: movl %{{.*}}, 4(%{{.*}})
+; CHECK-APPLE: movq %rax, %r12
+; CHECK-APPLE: movq %{{.*}}, %rax
+; CHECK-APPLE-NOT: x19
+
+; CHECK-O0-LABEL: foo_sret:
+; CHECK-O0: movl $16,
+; spill sret to stack
+; CHECK-O0: movq %rdi,
+; CHECK-O0: movq {{.*}}, %rdi
+; CHECK-O0: malloc
+; CHECK-O0: movb $1, 8(%rax)
+; CHECK-O0: movl %{{.*}}, 4(%{{.*}})
+; CHECK-O0: movq %{{.*}}, %r12
+; reload sret from stack
+; CHECK-O0: movq {{.*}}(%rsp), %rax
+; CHECK-O0: ret
+entry:
+  %call = call i8* @malloc(i64 16)
+  %call.0 = bitcast i8* %call to %swift_error*
+  store %swift_error* %call.0, %swift_error** %error_ptr_ref
+  %tmp = getelementptr inbounds i8, i8* %call, i64 8
+  store i8 1, i8* %tmp
+  %v2 = getelementptr inbounds %struct.S, %struct.S* %agg.result, i32 0, i32 1
+  store i32 %val1, i32* %v2
+  ret void
+}
+
+; "caller3" calls "foo_sret" that takes a swifterror parameter.
+define float @caller3(i8* %error_ref) {
+; CHECK-APPLE-LABEL: caller3:
+; CHECK-APPLE: movl $1, %esi
+; CHECK-APPLE: xorl %r12d, %r12d
+; CHECK-APPLE: callq {{.*}}foo_sret
+; CHECK-APPLE: testq %r12, %r12
+; CHECK-APPLE: jne
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: movb 8(%r12),
+; CHECK-APPLE: movb %{{.*}},
+; CHECK-APPLE: movq %r12, %rdi
+; CHECK_APPLE: callq {{.*}}free
+
+; CHECK-O0-LABEL: caller3:
+; CHECK-O0: xorl
+; CHECK-O0: movl {{.*}}, %r12d
+; CHECK-O0: movl $1, %esi
+; CHECK-O0: movq {{.*}}, %rdi
+; CHECK-O0: callq {{.*}}foo_sret
+; CHECK-O0: movq %r12,
+; CHECK-O0: cmpq $0
+; CHECK-O0: jne
+; Access part of the error object and save it to error_ref
+; CHECK-O0: movb 8(%{{.*}}),
+; CHECK-O0: movb %{{.*}},
+; reload from stack
+; CHECK-O0: movq {{.*}}(%rsp), %rdi
+; CHECK-O0: callq {{.*}}free
+entry:
+  %s = alloca %struct.S, align 8
+  %error_ptr_ref = alloca swifterror %swift_error*
+  store %swift_error* null, %swift_error** %error_ptr_ref
+  call void @foo_sret(%struct.S* sret %s, i32 1, %swift_error** swifterror %error_ptr_ref)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+cont:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+  ret float 1.0
+}
+
+; This is a caller with multiple swifterror values, it calls "foo" twice, each
+; time with a different swifterror value, from "alloca swifterror".
+define float @caller_with_multiple_swifterror_values(i8* %error_ref, i8* %error_ref2) {
+; CHECK-APPLE-LABEL: caller_with_multiple_swifterror_values:
+
+; The first swifterror value:
+; CHECK-APPLE: xorl %r12d, %r12d
+; CHECK-APPLE: callq {{.*}}foo
+; CHECK-APPLE: testq %r12, %r12
+; CHECK-APPLE: jne
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: movb 8(%r12)
+; CHECK-APPLE: movq %r12, %rdi
+; CHECK_APPLE: callq {{.*}}free
+
+; The second swifterror value:
+; CHECK-APPLE: xorl %r12d, %r12d
+; CHECK-APPLE: callq {{.*}}foo
+; CHECK-APPLE: testq %r12, %r12
+; CHECK-APPLE: jne
+; Access part of the error object and save it to error_ref
+; CHECK-APPLE: movb 8(%r12)
+; CHECK-APPLE: movq %r12, %rdi
+; CHECK_APPLE: callq {{.*}}free
+
+; CHECK-O0-LABEL: caller_with_multiple_swifterror_values:
+
+; The first swifterror value:
+; CHECK-O0: xorl
+; CHECK-O0: movl %{{.*}}, %r12d
+; CHECK-O0: callq {{.*}}foo
+; CHECK-O0: jne
+
+; The second swifterror value:
+; CHECK-O0: xorl
+; CHECK-O0: movl %{{.*}}, %r12d
+; CHECK-O0: callq {{.*}}foo
+; CHECK-O0: jne
+entry:
+  %error_ptr_ref = alloca swifterror %swift_error*
+  store %swift_error* null, %swift_error** %error_ptr_ref
+  %call = call float @foo(%swift_error** swifterror %error_ptr_ref)
+  %error_from_foo = load %swift_error*, %swift_error** %error_ptr_ref
+  %had_error_from_foo = icmp ne %swift_error* %error_from_foo, null
+  %tmp = bitcast %swift_error* %error_from_foo to i8*
+  br i1 %had_error_from_foo, label %handler, label %cont
+cont:
+  %v1 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo, i64 0, i32 1
+  %t = load i8, i8* %v1
+  store i8 %t, i8* %error_ref
+  br label %handler
+handler:
+  call void @free(i8* %tmp)
+
+  %error_ptr_ref2 = alloca swifterror %swift_error*
+  store %swift_error* null, %swift_error** %error_ptr_ref2
+  %call2 = call float @foo(%swift_error** swifterror %error_ptr_ref2)
+  %error_from_foo2 = load %swift_error*, %swift_error** %error_ptr_ref2
+  %had_error_from_foo2 = icmp ne %swift_error* %error_from_foo2, null
+  %bitcast2 = bitcast %swift_error* %error_from_foo2 to i8*
+  br i1 %had_error_from_foo2, label %handler2, label %cont2
+cont2:
+  %v2 = getelementptr inbounds %swift_error, %swift_error* %error_from_foo2, i64 0, i32 1
+  %t2 = load i8, i8* %v2
+  store i8 %t2, i8* %error_ref2
+  br label %handler2
+handler2:
+  call void @free(i8* %bitcast2)
+
+  ret float 1.0
+}