Index: docs/LangRef.rst
===================================================================
--- docs/LangRef.rst
+++ docs/LangRef.rst
@@ -9337,6 +9337,52 @@
See the description for :ref:`llvm.stacksave <int_stacksave>`.
+.. _int_getdynamicareaoffset:
+
+'``llvm.getdynamicareaoffset``' Intrinsic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+ declare i32 @llvm.getdynamicareaoffset.i32()
+ declare i64 @llvm.getdynamicareaoffset.i64()
+
+ Overview:
+ """""""""
+
+ The '``llvm.getdynamicareaoffset.*``' intrinsic family is used to
+ get the offset from native stack pointer to the address of the most
+ recent dynamic alloca on the caller's stack. These intrinsics are
+ intendend for use in combination with
+ :ref:`llvm.stackrestore <int_stackrestore>` to get a
+ pointer to the most recent dynamic alloca. This is useful, for example,
+ for AddressSanitizer's stack unpoisoning routines.
+
+Semantics:
+""""""""""
+
+ These intrinsics return a non-negative integer value that can be used to
+ get the address of the most recent dynamic alloca, allocated by :ref:`alloca <i_alloca>`
+ on the caller's stack. In particular, for targets where stack grows downwards,
+ adding this offset to the native stack pointer would get the address of the most
+ recent dynamic alloca. For targets where stack grows upwards situation is a bit more
+ complicated, because substracting this value from stack pointer would get the address
+ for upper bound of recent dynamic alloca.
+
+ Although for most targets `llvm.getdynamicareaoffset <int_getdynamicareaoffset>`
+ returns just a zero, for others, such as PowerPC and PowerPC64, it returns a
+ compile-time known constant value.
+
+ Return value type of :ref:`llvm.getdynamicareaoffset <int_getdynamicareaoffset>`
+ must match generic address space's (address-space-0) pointer type for given target,
+ otherwise LLVM would issue an error on the lowering stage.
+
+ Warning: So far it known to work on selected architectures (ARM, AArch64, PowerPC,
+ PowerPC64, x86 and x86_64) where stack grows downwards.
+
'``llvm.prefetch``' Intrinsic
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Index: include/llvm/CodeGen/ISDOpcodes.h
===================================================================
--- include/llvm/CodeGen/ISDOpcodes.h
+++ include/llvm/CodeGen/ISDOpcodes.h
@@ -754,6 +754,12 @@
GC_TRANSITION_START,
GC_TRANSITION_END,
+ /// GET_DYNAMIC_AREA_OFFSET - get offset from native SP to the address of
+ /// the most recent dynamic alloca. For most targets that would be 0, but
+ /// for some others (e.g. PowerPC, PowerPC64) that would be compile-time
+ /// known nonzero constant. The only operand here is the chain.
+ GET_DYNAMIC_AREA_OFFSET,
+
/// BUILTIN_OP_END - This must be the last enum value in this list.
/// The target-specific pre-isel opcode values start here.
BUILTIN_OP_END
Index: include/llvm/IR/Intrinsics.td
===================================================================
--- include/llvm/IR/Intrinsics.td
+++ include/llvm/IR/Intrinsics.td
@@ -304,6 +304,8 @@
def int_stackrestore : Intrinsic<[], [llvm_ptr_ty]>,
GCCBuiltin<"__builtin_stack_restore">;
+def int_getdynamicareaoffset : Intrinsic<[llvm_anyint_ty]>;
+
// IntrReadWriteArgMem is more pessimistic than strictly necessary for prefetch,
// however it does conveniently prevent the prefetch from being reordered
// with respect to nearby accesses to the same memory.
Index: lib/CodeGen/IntrinsicLowering.cpp
===================================================================
--- lib/CodeGen/IntrinsicLowering.cpp
+++ lib/CodeGen/IntrinsicLowering.cpp
@@ -424,6 +424,13 @@
break;
}
+ case Intrinsic::getdynamicareaoffset:
+ errs() << "WARNING: this target does not support the custom llvm."
+ "getdynamicareaoffset. It is being lowered to a constant 0\n";
+ // Just lower it to a constant 0 because for most targets
+ // @llvm.getdynamicareaoffset is lowered to zero.
+ CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 0));
+ break;
case Intrinsic::returnaddress:
case Intrinsic::frameaddress:
errs() << "WARNING: this target does not support the llvm."
Index: lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1213,6 +1213,10 @@
case ISD::STACKSAVE:
Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
break;
+ case ISD::GET_DYNAMIC_AREA_OFFSET:
+ Action = TLI.getOperationAction(Node->getOpcode(),
+ Node->getValueType(0));
+ break;
case ISD::VAARG:
Action = TLI.getOperationAction(Node->getOpcode(),
Node->getValueType(0));
@@ -3295,6 +3299,10 @@
Results.push_back(Node->getOperand(0));
}
break;
+ case ISD::GET_DYNAMIC_AREA_OFFSET:
+ Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
+ Results.push_back(Results[0].getValue(0));
+ break;
case ISD::FCOPYSIGN:
Results.push_back(ExpandFCOPYSIGN(Node));
break;
Index: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4933,6 +4933,21 @@
DAG.setRoot(DAG.getNode(ISD::STACKRESTORE, sdl, MVT::Other, getRoot(), Res));
return nullptr;
}
+ case Intrinsic::getdynamicareaoffset: {
+ SDValue Op = getRoot();
+ EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout());
+ EVT ResTy = TLI.getValueType(DAG.getDataLayout(), I.getType());
+ // Result type for @llvm.getdynamicareaoffset should match PtrTy for
+ // target.
+ if (PtrTy != ResTy)
+ report_fatal_error("Wrong result type for @llvm.getdynamicareaoffset"
+ " intrinsic!");
+ Res = DAG.getNode(ISD::GET_DYNAMIC_AREA_OFFSET, sdl, DAG.getVTList(ResTy),
+ Op);
+ DAG.setRoot(Op);
+ 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();
Index: lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp
@@ -310,6 +310,7 @@
case ISD::LIFETIME_END: return "lifetime.end";
case ISD::GC_TRANSITION_START: return "gc_transition.start";
case ISD::GC_TRANSITION_END: return "gc_transition.end";
+ case ISD::GET_DYNAMIC_AREA_OFFSET: return "getdynamicareaoffset";
// Bit manipulation
case ISD::BITREVERSE: return "bitreverse";
Index: lib/CodeGen/TargetLoweringBase.cpp
===================================================================
--- lib/CodeGen/TargetLoweringBase.cpp
+++ lib/CodeGen/TargetLoweringBase.cpp
@@ -840,6 +840,9 @@
setOperationAction(ISD::SIGN_EXTEND_VECTOR_INREG, VT, Expand);
setOperationAction(ISD::ZERO_EXTEND_VECTOR_INREG, VT, Expand);
}
+
+ // For most targets @llvm.getdynamicareaoffest just returns 0.
+ setOperationAction(ISD::GET_DYNAMIC_AREA_OFFSET, VT, Expand);
}
// Most targets ignore the @llvm.prefetch intrinsic.
Index: lib/Target/PowerPC/PPCISelLowering.h
===================================================================
--- lib/Target/PowerPC/PPCISelLowering.h
+++ lib/Target/PowerPC/PPCISelLowering.h
@@ -79,6 +79,11 @@
/// compute an allocation on the stack.
DYNALLOC,
+ /// This instruction is lowered in PPCRegisterInfo::eliminateFrameIndex to
+ /// compute an offset from native SP to the address of the most recent
+ /// dynamic alloca.
+ DYNAREAOFFSET,
+
/// GlobalBaseReg - On Darwin, this node represents the result of the mflr
/// at function entry, used for PIC code.
GlobalBaseReg,
@@ -728,6 +733,8 @@
const PPCSubtarget &Subtarget) const;
SDValue LowerSTACKRESTORE(SDValue Op, SelectionDAG &DAG,
const PPCSubtarget &Subtarget) const;
+ SDValue LowerGET_DYNAMIC_AREA_OFFSET(SDValue Op, SelectionDAG &DAG,
+ const PPCSubtarget &Subtarget) const;
SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG,
const PPCSubtarget &Subtarget) const;
SDValue LowerLOAD(SDValue Op, SelectionDAG &DAG) const;
Index: lib/Target/PowerPC/PPCISelLowering.cpp
===================================================================
--- lib/Target/PowerPC/PPCISelLowering.cpp
+++ lib/Target/PowerPC/PPCISelLowering.cpp
@@ -329,6 +329,8 @@
setOperationAction(ISD::STACKRESTORE , MVT::Other, Custom);
setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32 , Custom);
setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64 , Custom);
+ setOperationAction(ISD::GET_DYNAMIC_AREA_OFFSET, MVT::i32, Custom);
+ setOperationAction(ISD::GET_DYNAMIC_AREA_OFFSET, MVT::i64, Custom);
// We want to custom lower some of our intrinsics.
setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
@@ -998,6 +1000,7 @@
case PPCISD::Lo: return "PPCISD::Lo";
case PPCISD::TOC_ENTRY: return "PPCISD::TOC_ENTRY";
case PPCISD::DYNALLOC: return "PPCISD::DYNALLOC";
+ case PPCISD::DYNAREAOFFSET: return "PPCISD::DYNAREAOFFSET";
case PPCISD::GlobalBaseReg: return "PPCISD::GlobalBaseReg";
case PPCISD::SRL: return "PPCISD::SRL";
case PPCISD::SRA: return "PPCISD::SRA";
@@ -5808,6 +5811,22 @@
return DAG.getNode(PPCISD::RET_FLAG, dl, MVT::Other, RetOps);
}
+SDValue PPCTargetLowering::LowerGET_DYNAMIC_AREA_OFFSET(
+ SDValue Op, SelectionDAG &DAG, const PPCSubtarget &Subtarget) const {
+ SDLoc dl(Op);
+
+ // Get the corect type for integers.
+ EVT IntVT = Op.getValueType();
+
+ // Get the inputs.
+ SDValue Chain = Op.getOperand(0);
+ SDValue FPSIdx = getFramePointerFrameIndex(DAG);
+ // Build a DYNAREAOFFSET node.
+ SDValue Ops[2] = {Chain, FPSIdx};
+ SDVTList VTs = DAG.getVTList(IntVT);
+ return DAG.getNode(PPCISD::DYNAREAOFFSET, dl, VTs, Ops);
+}
+
SDValue PPCTargetLowering::LowerSTACKRESTORE(SDValue Op, SelectionDAG &DAG,
const PPCSubtarget &Subtarget) const {
// When we pop the dynamic allocation we need to restore the SP link.
@@ -7939,6 +7958,7 @@
case ISD::STACKRESTORE: return LowerSTACKRESTORE(Op, DAG, Subtarget);
case ISD::DYNAMIC_STACKALLOC:
return LowerDYNAMIC_STACKALLOC(Op, DAG, Subtarget);
+ case ISD::GET_DYNAMIC_AREA_OFFSET: return LowerGET_DYNAMIC_AREA_OFFSET(Op, DAG, Subtarget);
case ISD::EH_SJLJ_SETJMP: return lowerEH_SJLJ_SETJMP(Op, DAG);
case ISD::EH_SJLJ_LONGJMP: return lowerEH_SJLJ_LONGJMP(Op, DAG);
Index: lib/Target/PowerPC/PPCInstr64Bit.td
===================================================================
--- lib/Target/PowerPC/PPCInstr64Bit.td
+++ lib/Target/PowerPC/PPCInstr64Bit.td
@@ -369,6 +369,8 @@
def DYNALLOC8 : Pseudo<(outs g8rc:$result), (ins g8rc:$negsize, memri:$fpsi),"#DYNALLOC8",
[(set i64:$result,
(PPCdynalloc i64:$negsize, iaddr:$fpsi))]>;
+def DYNAREAOFFSET8 : Pseudo<(outs i64imm:$result), (ins memri:$fpsi), "#DYNAREAOFFSET8",
+ [(set i64:$result, (PPCdynareaoffset iaddr:$fpsi))]>;
let Defs = [LR8] in {
def MTLR8 : XFXForm_7_ext<31, 467, 8, (outs), (ins g8rc:$rS),
Index: lib/Target/PowerPC/PPCInstrInfo.td
===================================================================
--- lib/Target/PowerPC/PPCInstrInfo.td
+++ lib/Target/PowerPC/PPCInstrInfo.td
@@ -226,7 +226,9 @@
// Instructions to support dynamic alloca.
def SDTDynOp : SDTypeProfile<1, 2, []>;
+def SDTDynAreaOp : SDTypeProfile<1, 1, []>;
def PPCdynalloc : SDNode<"PPCISD::DYNALLOC", SDTDynOp, [SDNPHasChain]>;
+def PPCdynareaoffset : SDNode<"PPCISD::DYNAREAOFFSET", SDTDynAreaOp, [SDNPHasChain]>;
//===----------------------------------------------------------------------===//
// PowerPC specific transformation functions and pattern fragments.
@@ -1029,6 +1031,8 @@
def DYNALLOC : Pseudo<(outs gprc:$result), (ins gprc:$negsize, memri:$fpsi), "#DYNALLOC",
[(set i32:$result,
(PPCdynalloc i32:$negsize, iaddr:$fpsi))]>;
+def DYNAREAOFFSET : Pseudo<(outs i32imm:$result), (ins memri:$fpsi), "#DYNAREAOFFSET",
+ [(set i32:$result, (PPCdynareaoffset iaddr:$fpsi))]>;
// SELECT_CC_* - Used to implement the SELECT_CC DAG operation. Expanded after
// instruction selection into a branch sequence.
Index: lib/Target/PowerPC/PPCRegisterInfo.h
===================================================================
--- lib/Target/PowerPC/PPCRegisterInfo.h
+++ lib/Target/PowerPC/PPCRegisterInfo.h
@@ -101,6 +101,7 @@
}
void lowerDynamicAlloc(MachineBasicBlock::iterator II) const;
+ void lowerDynamicAreaOffset(MachineBasicBlock::iterator II) const;
void lowerCRSpilling(MachineBasicBlock::iterator II,
unsigned FrameIndex) const;
void lowerCRRestore(MachineBasicBlock::iterator II,
Index: lib/Target/PowerPC/PPCRegisterInfo.cpp
===================================================================
--- lib/Target/PowerPC/PPCRegisterInfo.cpp
+++ lib/Target/PowerPC/PPCRegisterInfo.cpp
@@ -430,6 +430,27 @@
MBB.erase(II);
}
+void PPCRegisterInfo::lowerDynamicAreaOffset(
+ MachineBasicBlock::iterator II) const {
+ // Get the instruction.
+ MachineInstr &MI = *II;
+ // Get the instruction's basic block.
+ MachineBasicBlock &MBB = *MI.getParent();
+ // Get the basic block's function.
+ MachineFunction &MF = *MBB.getParent();
+ // Get the frame info.
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
+ // Get the instruction info.
+ const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
+
+ unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
+ DebugLoc dl = MI.getDebugLoc();
+ BuildMI(MBB, II, dl, TII.get(PPC::LI), MI.getOperand(0).getReg())
+ .addImm(maxCallFrameSize);
+ MBB.erase(II);
+}
+
/// lowerCRSpilling - Generate the code for spilling a CR register. Instead of
/// reserving a whole register (R0), we scrounge for one here. This generates
/// code like this:
@@ -754,6 +775,11 @@
// Get the instruction opcode.
unsigned OpC = MI.getOpcode();
+ if ((OpC == PPC::DYNAREAOFFSET || OpC == PPC::DYNAREAOFFSET8)) {
+ lowerDynamicAreaOffset(II);
+ return;
+ }
+
// Special case for dynamic alloca.
if (FPSI && FrameIndex == FPSI &&
(OpC == PPC::DYNALLOC || OpC == PPC::DYNALLOC8)) {
Index: test/CodeGen/PowerPC/dyn-alloca-offset.ll
===================================================================
--- /dev/null
+++ test/CodeGen/PowerPC/dyn-alloca-offset.ll
@@ -0,0 +1,21 @@
+; RUN: llc -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 < %s | FileCheck %s
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+declare i64 @llvm.getdynamicareaoffset.i64()
+
+declare i64 @bar(i64)
+
+attributes #0 = { nounwind }
+
+; Function Attrs: nounwind sanitize_address uwtable
+define signext i64 @foo(i32 signext %N, i32 signext %M) #0 {
+ %1 = alloca i64, align 32
+ %getdynamicareaoffset1 = call i64 @llvm.getdynamicareaoffset.i64()
+ %2 = call i64 @bar(i64 %getdynamicareaoffset1)
+ ret i64 %2
+
+; CHECK-DAG: li [[REG1:[0-9]+]], 112
+; CHECK: blr
+
+}