maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[SSP, 2/2] Create llvm.stackguard() intrinsic and lower it to LOAD_STACK_GUARD 

With this change, ideally IR pass can always generate llvm.stackguard
call to get the stack guard; but for now there are still IR form stack
guard customizations around (see getIRStackGuard()). Future SSP
customization should go through LOAD_STACK_GUARD.

There is a behavior change: stack guard values are not CSEed anymore,
since we should never reuse the value in case that it has been spilled (and
corrupted). See ssp-guard-spill.ll. This also cause the change of stack
size and codegen in X86 and AArch64 test cases.

Ideally we'd like to know if the guard created in llvm.stackprotector() gets
spilled or not. If the value is spilled, discard the value and reload
stack guard; otherwise reuse the value. This can be done by teaching
register allocator to know how to rematerialize LOAD_STACK_GUARD and
force a rematerialization (which seems hard), or check for spilling in
expandPostRAPseudo. It only makes sense when the stack guard is a global
variable, which requires more instructions to load. Anyway, this seems to go out
of the scope of the current patch.

llvm-svn: 266806
This commit is contained in:
Tim Shen 2016-04-19 19:40:37 +00:00
parent 6e39e0ba87
commit e885d5e4d3
18 changed files with 208 additions and 98 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
llvm/docs/LangRef.rst
View File

@ -11996,6 +11996,41 @@ checked against the original guard by ``llvm.stackprotectorcheck``. If they are
different, then ``llvm.stackprotectorcheck`` causes the program to abort by
calling the ``__stack_chk_fail()`` function.
'``llvm.stackguard``' Intrinsic
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Syntax:
"""""""
::
declare i8* @llvm.stackguard()
Overview:
"""""""""
The ``llvm.stackguard`` intrinsic returns the system stack guard value.
It should not be generated by frontends, since it is only for internal usage.
The reason why we create this intrinsic is that we still support IR form Stack
Protector in FastISel.
Arguments:
""""""""""
None.
Semantics:
""""""""""
On some platforms, the value returned by this intrinsic remains unchanged
between loads in the same thread. On other platforms, it returns the same
global variable value, if any, e.g. ``@__stack_chk_guard``.
Currently some platforms have IR-level customized stack guard loading (e.g.
X86 Linux) that is not handled by ``llvm.stackguard()``, while they should be
in the future.
'``llvm.objectsize``' Intrinsic
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

1
llvm/include/llvm/IR/Intrinsics.td
View File

@ -324,6 +324,7 @@ def int_assume : Intrinsic<[], [llvm_i1_ty], []>;
// Stack Protector Intrinsic - The stackprotector intrinsic writes the stack
// guard to the correct place on the stack frame.
def int_stackprotector : Intrinsic<[], [llvm_ptr_ty, llvm_ptrptr_ty], []>;
def int_stackguard : Intrinsic<[llvm_ptr_ty], [], []>;
// A counter increment for instrumentation based profiling.
def int_instrprof_increment : Intrinsic<[],

2
llvm/include/llvm/Target/TargetLowering.h
View File

@ -1013,6 +1013,8 @@ public:
/// If the target has a standard location for the stack protector guard,
/// returns the address of that location. Otherwise, returns nullptr.
/// DEPRECATED: please override useLoadStackGuardNode and customize
/// LOAD_STACK_GUARD, or customize @llvm.stackguard().
virtual Value *getIRStackGuard(IRBuilder<> &IRB) const;
/// Inserts necessary declarations for SSP purpose. Should be used only when

6
llvm/lib/CodeGen/MachineCSE.cpp
View File

@ -352,6 +352,12 @@ bool MachineCSE::isCSECandidate(MachineInstr *MI) {
// This is a trivial form of alias analysis.
return false;
}
// Ignore stack guard loads, otherwise the register that holds CSEed value may
// be spilled and get loaded back with corrupted data.
if (MI->getOpcode() == TargetOpcode::LOAD_STACK_GUARD)
return false;
return true;
}

93
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
View File

@ -1998,6 +1998,26 @@ void SelectionDAGBuilder::visitJumpTableHeader(JumpTable &JT,
DAG.setRoot(BrCond);
}
/// Create a LOAD_STACK_GUARD node, and let it carry the target specific global
/// variable if there exists one.
static SDValue getLoadStackGuard(SelectionDAG &DAG, SDLoc DL, SDValue &Chain) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout());
MachineFunction &MF = DAG.getMachineFunction();
Value *Global = TLI.getSDStackGuard(*MF.getFunction()->getParent());
MachineSDNode *Node =
DAG.getMachineNode(TargetOpcode::LOAD_STACK_GUARD, DL, PtrTy, Chain);
if (Global) {
MachinePointerInfo MPInfo(Global);
MachineInstr::mmo_iterator MemRefs = MF.allocateMemRefsArray(1);
unsigned Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOInvariant;
*MemRefs = MF.getMachineMemOperand(MPInfo, Flags, PtrTy.getSizeInBits() / 8,
DAG.getEVTAlignment(PtrTy));
Node->setMemRefs(MemRefs, MemRefs + 1);
}
return SDValue(Node, 0);
}
/// Codegen a new tail for a stack protector check ParentMBB which has had its
/// tail spliced into a stack protector check success bb.
///
@ -2026,18 +2046,15 @@ void SelectionDAGBuilder::visitSPDescriptorParent(StackProtectorDescriptor &SPD,
SDValue Guard;
SDLoc dl = getCurSDLoc();
// If GuardReg is set and useLoadStackGuardNode returns true, retrieve the
// guard value from the virtual register holding the value. Otherwise, emit a
// volatile load to retrieve the stack guard value.
unsigned GuardReg = SPD.getGuardReg();
if (GuardReg && TLI.useLoadStackGuardNode())
Guard = DAG.getCopyFromReg(DAG.getEntryNode(), dl, GuardReg,
PtrTy);
// If useLoadStackGuardNode returns true, generate LOAD_STACK_GUARD.
// Otherwise, emit a volatile load to retrieve the stack guard value.
SDValue Chain = DAG.getEntryNode();
if (TLI.useLoadStackGuardNode())
Guard = getLoadStackGuard(DAG, dl, Chain);
else
Guard = DAG.getLoad(PtrTy, dl, DAG.getEntryNode(),
GuardPtr, MachinePointerInfo(IRGuard, 0),
true, false, false, Align);
Guard =
DAG.getLoad(PtrTy, dl, Chain, GuardPtr, MachinePointerInfo(IRGuard, 0),
true, false, false, Align);
SDValue StackSlot = DAG.getLoad(
PtrTy, dl, DAG.getEntryNode(), StackSlotPtr,
@ -5288,47 +5305,35 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) {
setValue(&I, Res);
return nullptr;
}
case Intrinsic::stackguard: {
EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout());
MachineFunction &MF = DAG.getMachineFunction();
const Module &M = *MF.getFunction()->getParent();
SDValue Chain = getRoot();
if (TLI.useLoadStackGuardNode()) {
Res = getLoadStackGuard(DAG, sdl, Chain);
} else {
const Value *Global = TLI.getSDStackGuard(M);
unsigned Align = DL->getPrefTypeAlignment(Global->getType());
Res =
DAG.getLoad(PtrTy, sdl, Chain, getValue(Global),
MachinePointerInfo(Global, 0), true, false, false, Align);
}
DAG.setRoot(Chain);
setValue(&I, Res);
return nullptr;
}
case Intrinsic::stackprotector: {
// Emit code into the DAG to store the stack guard onto the stack.
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout());
SDValue Src, Chain = getRoot();
const Value *Ptr = cast<LoadInst>(I.getArgOperand(0))->getPointerOperand();
const GlobalVariable *GV = dyn_cast<GlobalVariable>(Ptr);
// See if Ptr is a bitcast. If it is, look through it and see if we can get
// global variable __stack_chk_guard.
if (!GV)
if (const Operator *BC = dyn_cast<Operator>(Ptr))
if (BC->getOpcode() == Instruction::BitCast)
GV = dyn_cast<GlobalVariable>(BC->getOperand(0));
if (GV && TLI.useLoadStackGuardNode()) {
// Emit a LOAD_STACK_GUARD node.
MachineSDNode *Node = DAG.getMachineNode(TargetOpcode::LOAD_STACK_GUARD,
sdl, PtrTy, Chain);
MachinePointerInfo MPInfo(GV);
MachineInstr::mmo_iterator MemRefs = MF.allocateMemRefsArray(1);
unsigned Flags = MachineMemOperand::MOLoad |
MachineMemOperand::MOInvariant;
*MemRefs = MF.getMachineMemOperand(MPInfo, Flags,
PtrTy.getSizeInBits() / 8,
DAG.getEVTAlignment(PtrTy));
Node->setMemRefs(MemRefs, MemRefs + 1);
// Copy the guard value to a virtual register so that it can be
// retrieved in the epilogue.
Src = SDValue(Node, 0);
const TargetRegisterClass *RC =
TLI.getRegClassFor(Src.getSimpleValueType());
unsigned Reg = MF.getRegInfo().createVirtualRegister(RC);
SPDescriptor.setGuardReg(Reg);
Chain = DAG.getCopyToReg(Chain, sdl, Reg, Src);
} else {
if (TLI.useLoadStackGuardNode())
Src = getLoadStackGuard(DAG, sdl, Chain);
else
Src = getValue(I.getArgOperand(0)); // The guard's value.
}
AllocaInst *Slot = cast<AllocaInst>(I.getArgOperand(1));

10
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
View File

@ -465,8 +465,7 @@ private:
class StackProtectorDescriptor {
public:
StackProtectorDescriptor()
: ParentMBB(nullptr), SuccessMBB(nullptr), FailureMBB(nullptr),
GuardReg(0) {}
: ParentMBB(nullptr), SuccessMBB(nullptr), FailureMBB(nullptr) {}
/// Returns true if all fields of the stack protector descriptor are
/// initialized implying that we should/are ready to emit a stack protector.
@ -511,16 +510,12 @@ private:
/// always the same.
void resetPerFunctionState() {
FailureMBB = nullptr;
GuardReg = 0;
}
MachineBasicBlock *getParentMBB() { return ParentMBB; }
MachineBasicBlock *getSuccessMBB() { return SuccessMBB; }
MachineBasicBlock *getFailureMBB() { return FailureMBB; }
unsigned getGuardReg() const { return GuardReg; }
void setGuardReg(unsigned R) { GuardReg = R; }
private:
/// The basic block for which we are generating the stack protector.
///
@ -539,9 +534,6 @@ private:
/// contain a call to __stack_chk_fail().
MachineBasicBlock *FailureMBB;
/// The virtual register holding the stack guard value.
unsigned GuardReg;
/// Add a successor machine basic block to ParentMBB. If the successor mbb
/// has not been created yet (i.e. if SuccMBB = 0), then the machine basic
/// block will be created. Assign a large weight if IsLikely is true.

61
llvm/lib/CodeGen/StackProtector.cpp
View File

@ -271,36 +271,51 @@ bool StackProtector::RequiresStackProtector() {
return NeedsProtector;
}
/// Insert code into the entry block that stores the __stack_chk_guard
/// Create a stack guard loading and populate whether SelectionDAG SSP is
/// supported.
static Value *getStackGuard(const TargetLoweringBase *TLI, Module *M,
IRBuilder<> &B,
bool *SupportsSelectionDAGSP = nullptr) {
if (Value *Guard = TLI->getIRStackGuard(B))
return B.CreateLoad(Guard, true, "StackGuard");
// Use SelectionDAG SSP handling, since there isn't an IR guard.
//
// This is more or less weird, since we optionally output whether we
// should perform a SelectionDAG SP here. The reason is that it's strictly
// defined as !TLI->getIRStackGuard(B), where getIRStackGuard is also
// mutating. There is no way to get this bit without mutating the IR, so
// getting this bit has to happen in this right time.
//
// We could have define a new function TLI::supportsSelectionDAGSP(), but that
// will put more burden on the backends' overriding work, especially when it
// actually conveys the same information getIRStackGuard() already gives.
if (SupportsSelectionDAGSP)
*SupportsSelectionDAGSP = true;
TLI->insertSSPDeclarations(*M);
return B.CreateCall(Intrinsic::getDeclaration(M, Intrinsic::stackguard));
}
/// Insert code into the entry block that stores the stack guard
/// variable onto the stack:
///
/// entry:
/// StackGuardSlot = alloca i8*
/// StackGuard = load __stack_chk_guard
/// call void @llvm.stackprotect.create(StackGuard, StackGuardSlot)
/// StackGuard = <stack guard>
/// call void @llvm.stackprotector(StackGuard, StackGuardSlot)
///
/// Returns true if the platform/triple supports the stackprotectorcreate pseudo
/// node.
static bool CreatePrologue(Function *F, Module *M, ReturnInst *RI,
const TargetLoweringBase *TLI, AllocaInst *&AI,
Value *&StackGuardVar) {
const TargetLoweringBase *TLI, AllocaInst *&AI) {
bool SupportsSelectionDAGSP = false;
IRBuilder<> B(&F->getEntryBlock().front());
StackGuardVar = TLI->getIRStackGuard(B);
if (!StackGuardVar) {
/// Use SelectionDAG SSP handling, since there isn't an IR guard.
SupportsSelectionDAGSP = true;
TLI->insertSSPDeclarations(*M);
StackGuardVar = TLI->getSDStackGuard(*M);
}
assert(StackGuardVar && "Must have stack guard available");
PointerType *PtrTy = Type::getInt8PtrTy(RI->getContext());
AI = B.CreateAlloca(PtrTy, nullptr, "StackGuardSlot");
LoadInst *LI = B.CreateLoad(StackGuardVar, "StackGuard");
Value *Guard = getStackGuard(TLI, M, B, &SupportsSelectionDAGSP);
B.CreateCall(Intrinsic::getDeclaration(M, Intrinsic::stackprotector),
{LI, AI});
{Guard, AI});
return SupportsSelectionDAGSP;
}
@ -314,7 +329,6 @@ bool StackProtector::InsertStackProtectors() {
bool SupportsSelectionDAGSP =
EnableSelectionDAGSP && !TM->Options.EnableFastISel;
AllocaInst *AI = nullptr; // Place on stack that stores the stack guard.
Value *StackGuardVar = nullptr; // The stack guard variable.
for (Function::iterator I = F->begin(), E = F->end(); I != E;) {
BasicBlock *BB = &*I++;
@ -324,8 +338,7 @@ bool StackProtector::InsertStackProtectors() {
if (!HasPrologue) {
HasPrologue = true;
SupportsSelectionDAGSP &=
CreatePrologue(F, M, RI, TLI, AI, StackGuardVar);
SupportsSelectionDAGSP &= CreatePrologue(F, M, RI, TLI, AI);
}
if (!SupportsSelectionDAGSP) {
@ -342,7 +355,7 @@ bool StackProtector::InsertStackProtectors() {
//
// return:
// ...
// %1 = load __stack_chk_guard
// %1 = <stack guard>
// %2 = load StackGuardSlot
// %3 = cmp i1 %1, %2
// br i1 %3, label %SP_return, label %CallStackCheckFailBlk
@ -381,9 +394,9 @@ bool StackProtector::InsertStackProtectors() {
// Generate the stack protector instructions in the old basic block.
IRBuilder<> B(BB);
LoadInst *LI1 = B.CreateLoad(StackGuardVar);
LoadInst *LI2 = B.CreateLoad(AI);
Value *Cmp = B.CreateICmpEQ(LI1, LI2);
Value *Guard = getStackGuard(TLI, M, B);
LoadInst *LI2 = B.CreateLoad(AI, true);
Value *Cmp = B.CreateICmpEQ(Guard, LI2);
auto SuccessProb =
BranchProbabilityInfo::getBranchProbStackProtector(true);
auto FailureProb =

4
llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
View File

@ -10114,7 +10114,9 @@ void AArch64TargetLowering::ReplaceNodeResults(
}
bool AArch64TargetLowering::useLoadStackGuardNode() const {
return true;
if (!Subtarget->isTargetAndroid())
return true;
return TargetLowering::useLoadStackGuardNode();
}
unsigned AArch64TargetLowering::combineRepeatedFPDivisors() const {

4
llvm/lib/Target/X86/X86ISelLowering.cpp
View File

@ -2016,14 +2016,12 @@ Value *X86TargetLowering::getIRStackGuard(IRBuilder<> &IRB) const {
void X86TargetLowering::insertSSPDeclarations(Module &M) const {
if (!Subtarget.isTargetLinux())
TargetLowering::insertSSPDeclarations(M);
else
llvm_unreachable("X86 Linux supports customized IR stack guard load");
}
Value *X86TargetLowering::getSDStackGuard(const Module &M) const {
if (!Subtarget.isTargetLinux())
return TargetLowering::getSDStackGuard(M);
llvm_unreachable("X86 Linux supports customized IR stack guard load");
return nullptr;
}
Value *X86TargetLowering::getSafeStackPointerLocation(IRBuilder<> &IRB) const {

6
llvm/test/CodeGen/AArch64/stack-guard-remat-bitcast.ll
View File

@ -6,10 +6,14 @@
; CHECK: adrp [[R0:x[0-9]+]], ___stack_chk_guard@GOTPAGE
; CHECK: ldr [[R1:x[0-9]+]], {{\[}}[[R0]], ___stack_chk_guard@GOTPAGEOFF{{\]}}
; Load the stack guard for the second time, just in case the previous value gets spilled.
; CHECK: adrp [[GUARD_PAGE:x[0-9]+]], ___stack_chk_guard@GOTPAGE
; CHECK: ldr [[R2:x[0-9]+]], {{\[}}[[R1]]{{\]}}
; CHECK: stur [[R2]], {{\[}}x29, [[SLOT0:[0-9#\-]+]]{{\]}}
; CHECK: ldur [[R3:x[0-9]+]], {{\[}}x29, [[SLOT0]]{{\]}}
; CHECK: sub [[R4:x[0-9]+]], [[R2]], [[R3]]
; CHECK: ldr [[GUARD_ADDR:x[0-9]+]], {{\[}}[[GUARD_PAGE]], ___stack_chk_guard@GOTPAGEOFF{{\]}}
; CHECK: ldr [[GUARD:x[0-9]+]], {{\[}}[[GUARD_ADDR]]{{\]}}
; CHECK: sub [[R4:x[0-9]+]], [[GUARD]], [[R3]]
; CHECK: cbnz [[R4]], LBB
define i32 @test_stack_guard_remat2() {

2
llvm/test/CodeGen/ARM/warn-stack.ll
View File

@ -12,7 +12,7 @@ entry:
ret void
}
; CHECK: warning: stack size limit exceeded (96) in warn
; CHECK: warning: stack size limit exceeded (92) in warn
define void @warn() nounwind ssp {
entry:
%buffer = alloca [80 x i8], align 1

2
llvm/test/CodeGen/X86/2009-02-12-DebugInfoVLA.ll
View File

@ -12,7 +12,7 @@ define signext i8 @foo(i8* %s1) nounwind ssp {
; movq %rax, %rsp
; CHECK-LABEL: @foo
; CHECK: movq -40(%rbp), %rsp
; CHECK: movq -{{[0-9]+}}(%rbp), %rsp
entry:
%s1_addr = alloca i8* ; <i8**> [#uses=2]

4
llvm/test/CodeGen/X86/StackColoring.ll
View File

@ -243,8 +243,8 @@ bb3:
; Adopt the test from Transforms/Inline/array_merge.ll'
;CHECK-LABEL: array_merge:
;YESCOLOR: subq $816, %rsp
;NOCOLOR: subq $1616, %rsp
;YESCOLOR: subq $808, %rsp
;NOCOLOR: subq $1608, %rsp
define void @array_merge() nounwind ssp {
entry:
%A.i1 = alloca [100 x i32], align 4

8
llvm/test/CodeGen/X86/dynamic-allocas-VLAs.ll
View File

@ -60,12 +60,10 @@ entry:
; CHECK: _t3
; CHECK: pushq %rbp
; CHECK: movq %rsp, %rbp
; CHECK: pushq %rbx
; CHECK-NOT: andq $-{{[0-9]+}}, %rsp
; CHECK: subq ${{[0-9]+}}, %rsp
;
; CHECK: leaq -{{[0-9]+}}(%rbp), %rsp
; CHECK: popq %rbx
; CHECK: movq %rbp, %rsp
; CHECK: popq %rbp
}
@ -85,7 +83,6 @@ entry:
; CHECK: _t4
; CHECK: pushq %rbp
; CHECK: movq %rsp, %rbp
; CHECK: pushq %r14
; CHECK: pushq %rbx
; CHECK: andq $-32, %rsp
; CHECK: subq ${{[0-9]+}}, %rsp
@ -95,9 +92,8 @@ entry:
; CHECK: leaq {{[0-9]*}}(%rbx), %rdx
; CHECK: callq _t4_helper
;
; CHECK: leaq -16(%rbp), %rsp
; CHECK: leaq -{{[0-9]+}}(%rbp), %rsp
; CHECK: popq %rbx
; CHECK: popq %r14
; CHECK: popq %rbp
}

8
llvm/test/CodeGen/X86/fast-isel-stackcheck.ll
View File

@ -8,7 +8,7 @@ target triple = "x86_64-apple-macosx"
; CHECK-LABEL: foo:
; CHECK: movq ___stack_chk_guard@GOTPCREL(%rip), %rax
; CHECK-NOT: movq ___stack_chk_guard@GOTPCREL(%rip), %rax
; CHECK: movq ___stack_chk_guard@GOTPCREL(%rip), %rax
define void @foo() #0 {
entry:
%_tags = alloca [3 x i32], align 4
@ -16,8 +16,10 @@ entry:
}
; CHECK-LABEL: bar:
; CHECK: movq ___stack_chk_guard@GOTPCREL(%rip), %rax
; CHECK: movq ___stack_chk_guard@GOTPCREL(%rip), %rax
; CHECK: movq ___stack_chk_guard@GOTPCREL(%rip), %{{r.x}}
; CHECK-DAG: movq ___stack_chk_guard@GOTPCREL(%rip), %[[GUARD:r.x]]
; CHECK-DAG: movq {{[0-9]+}}(%rsp), %[[CANARY:r.x]]
; CHECK: subq %[[CANARY]], %[[GUARD]]
define void @bar() #1 {
entry:
%vt = alloca [2 x double], align 16

54
llvm/test/CodeGen/X86/ssp-guard-spill.ll Normal file
View File

@ -0,0 +1,54 @@
; RUN: llc < %s | FileCheck %s
target triple = "x86_64-apple-macosx10.4.0"
; __stack_chk_guard must be loaded for twice, once for setting up the canary,
; another time for performing the check. It is because if we reuse the same
; stack guard value, it may get spilled to the stack, then the for loop may
; corrupt it.
;
; bool Bar(int*);
; bool Foo(int n) {
; int a[10];
; for (int i = 0; i < n; i++) {
; a[i] = 0;
; }
; return Bar(a);
; }
;
; CHECK: movq ___stack_chk_guard
; CHECK: movq ___stack_chk_guard
define zeroext i1 @_Z3Fooi(i32 %n) sspstrong {
entry:
%n.addr = alloca i32, align 4
%a = alloca [10 x i32], align 16
%i = alloca i32, align 4
store i32 %n, i32* %n.addr, align 4
store i32 0, i32* %i, align 4
br label %for.cond
for.cond: ; preds = %for.inc, %entry
%tmp = load i32, i32* %i, align 4
%tmp1 = load i32, i32* %n.addr, align 4
%cmp = icmp slt i32 %tmp, %tmp1
br i1 %cmp, label %for.body, label %for.end
for.body: ; preds = %for.cond
%tmp2 = load i32, i32* %i, align 4
%idxprom = sext i32 %tmp2 to i64
%arrayidx = getelementptr inbounds [10 x i32], [10 x i32]* %a, i64 0, i64 %idxprom
store i32 0, i32* %arrayidx, align 4
br label %for.inc
for.inc: ; preds = %for.body
%tmp3 = load i32, i32* %i, align 4
%inc = add nsw i32 %tmp3, 1
store i32 %inc, i32* %i, align 4
br label %for.cond
for.end: ; preds = %for.cond
%arraydecay = getelementptr inbounds [10 x i32], [10 x i32]* %a, i32 0, i32 0
%call = call zeroext i1 @_Z3BarPi(i32* %arraydecay)
ret i1 %call
}
declare zeroext i1 @_Z3BarPi(i32*)

2
llvm/test/CodeGen/X86/warn-stack.ll
View File

@ -12,7 +12,7 @@ entry:
ret void
}
; CHECK: warning: stack size limit exceeded (104) in warn
; CHECK: warning: stack size limit exceeded (88) in warn
define void @warn() nounwind ssp {
entry:
%buffer = alloca [80 x i8], align 1

4
llvm/test/DebugInfo/X86/vla.ll
View File

@ -1,7 +1,7 @@
; RUN: llc -O0 -mtriple=x86_64-apple-darwin -filetype=asm %s -o - | FileCheck %s
; Ensure that we generate an indirect location for the variable length array a.
; CHECK: ##DEBUG_VALUE: vla:a <- [%RDX+0]
; CHECK: DW_OP_breg1
; CHECK: ##DEBUG_VALUE: vla:a <- [%RCX+0]
; CHECK: DW_OP_breg2
; rdar://problem/13658587
;
; generated from: