[llvm] r193769 - Lower stackmap intrinsics directly to their target opcode in the DAG builder.
Aaron Ballman
aaron at aaronballman.com
Fri Nov 1 08:17:34 PDT 2013
I commented out the assert in r193862; atrick can determine whether
the assert is faulty, or there is a logic error with this commit.
~Aaron
On Fri, Nov 1, 2013 at 11:12 AM, Rafael Espíndola
<rafael.espindola at gmail.com> wrote:
> Can you revert for now?
>
> On 1 November 2013 11:09, Aaron Ballman <aaron at aaronballman.com> wrote:
>> On Thu, Oct 31, 2013 at 1:18 PM, Andrew Trick <atrick at apple.com> wrote:
>>> Author: atrick
>>> Date: Thu Oct 31 12:18:24 2013
>>> New Revision: 193769
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=193769&view=rev
>>> Log:
>>> Lower stackmap intrinsics directly to their target opcode in the DAG builder.
>>>
>>> Modified:
>>> llvm/trunk/include/llvm/Target/Target.td
>>> llvm/trunk/include/llvm/Target/TargetLowering.h
>>> llvm/trunk/include/llvm/Target/TargetOpcodes.h
>>> llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
>>> llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
>>> llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
>>> llvm/trunk/utils/TableGen/CodeGenTarget.cpp
>>>
>>> Modified: llvm/trunk/include/llvm/Target/Target.td
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/Target.td?rev=193769&r1=193768&r2=193769&view=diff
>>> ==============================================================================
>>> --- llvm/trunk/include/llvm/Target/Target.td (original)
>>> +++ llvm/trunk/include/llvm/Target/Target.td Thu Oct 31 12:18:24 2013
>>> @@ -800,6 +800,19 @@ def LIFETIME_END : Instruction {
>>> let AsmString = "LIFETIME_END";
>>> let neverHasSideEffects = 1;
>>> }
>>> +def STACKMAP : Instruction {
>>> + let OutOperandList = (outs);
>>> + let InOperandList = (ins i32imm:$id, i32imm:$nbytes, variable_ops);
>>> + let isCall = 1;
>>> + let mayLoad = 1;
>>> +}
>>> +def PATCHPOINT : Instruction {
>>> + let OutOperandList = (outs);
>>> + let InOperandList = (ins i32imm:$id, i32imm:$nbytes, unknown:$callee,
>>> + i32imm:$nargs, variable_ops);
>>> + let isCall = 1;
>>> + let mayLoad = 1;
>>> +}
>>> }
>>>
>>> //===----------------------------------------------------------------------===//
>>>
>>> Modified: llvm/trunk/include/llvm/Target/TargetLowering.h
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetLowering.h?rev=193769&r1=193768&r2=193769&view=diff
>>> ==============================================================================
>>> --- llvm/trunk/include/llvm/Target/TargetLowering.h (original)
>>> +++ llvm/trunk/include/llvm/Target/TargetLowering.h Thu Oct 31 12:18:24 2013
>>> @@ -1920,6 +1920,8 @@ public:
>>> ArgListEntry() : isSExt(false), isZExt(false), isInReg(false),
>>> isSRet(false), isNest(false), isByVal(false), isReturned(false),
>>> Alignment(0) { }
>>> +
>>> + void setAttributes(ImmutableCallSite *CS, unsigned AttrIdx);
>>> };
>>> typedef std::vector<ArgListEntry> ArgListTy;
>>>
>>>
>>> Modified: llvm/trunk/include/llvm/Target/TargetOpcodes.h
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetOpcodes.h?rev=193769&r1=193768&r2=193769&view=diff
>>> ==============================================================================
>>> --- llvm/trunk/include/llvm/Target/TargetOpcodes.h (original)
>>> +++ llvm/trunk/include/llvm/Target/TargetOpcodes.h Thu Oct 31 12:18:24 2013
>>> @@ -92,7 +92,19 @@ namespace TargetOpcode {
>>>
>>> /// Lifetime markers.
>>> LIFETIME_START = 15,
>>> - LIFETIME_END = 16
>>> + LIFETIME_END = 16,
>>> +
>>> + /// A Stackmap instruction captures the location of live variables at its
>>> + /// position in the instruction stream. It is followed by a shadow of bytes
>>> + /// that must lie within the function and not contain another stackmap.
>>> + STACKMAP = 17,
>>> +
>>> + /// Patchable call instruction - this instruction represents a call to a
>>> + /// constant address, followed by a series of NOPs. It is intended to
>>> + /// support optimizations for dynamic languages (such as javascript) that
>>> + /// rewrite calls to runtimes with more efficient code sequences.
>>> + /// This also implies a stack map.
>>> + PATCHPOINT = 18
>>> };
>>> } // end namespace TargetOpcode
>>> } // end namespace llvm
>>>
>>> Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=193769&r1=193768&r2=193769&view=diff
>>> ==============================================================================
>>> --- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
>>> +++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Thu Oct 31 12:18:24 2013
>>> @@ -5309,6 +5309,15 @@ SelectionDAGBuilder::visitIntrinsicCall(
>>> case Intrinsic::donothing:
>>> // ignore
>>> return 0;
>>> + case Intrinsic::experimental_stackmap: {
>>> + visitStackmap(I);
>>> + return 0;
>>> + }
>>> + case Intrinsic::experimental_patchpoint_void:
>>> + case Intrinsic::experimental_patchpoint_i64: {
>>> + visitPatchpoint(I);
>>> + return 0;
>>> + }
>>> }
>>> }
>>>
>>> @@ -5373,15 +5382,8 @@ void SelectionDAGBuilder::LowerCallTo(Im
>>> SDValue ArgNode = getValue(V);
>>> Entry.Node = ArgNode; Entry.Ty = V->getType();
>>>
>>> - unsigned attrInd = i - CS.arg_begin() + 1;
>>> - Entry.isSExt = CS.paramHasAttr(attrInd, Attribute::SExt);
>>> - Entry.isZExt = CS.paramHasAttr(attrInd, Attribute::ZExt);
>>> - Entry.isInReg = CS.paramHasAttr(attrInd, Attribute::InReg);
>>> - Entry.isSRet = CS.paramHasAttr(attrInd, Attribute::StructRet);
>>> - Entry.isNest = CS.paramHasAttr(attrInd, Attribute::Nest);
>>> - Entry.isByVal = CS.paramHasAttr(attrInd, Attribute::ByVal);
>>> - Entry.isReturned = CS.paramHasAttr(attrInd, Attribute::Returned);
>>> - Entry.Alignment = CS.getParamAlignment(attrInd);
>>> + // Skip the first return-type Attribute to get to params.
>>> + Entry.setAttributes(&CS, i - CS.arg_begin() + 1);
>>> Args.push_back(Entry);
>>> }
>>>
>>> @@ -5463,8 +5465,8 @@ void SelectionDAGBuilder::LowerCallTo(Im
>>> }
>>>
>>> if (!Result.second.getNode()) {
>>> - // As a special case, a null chain means that a tail call has been emitted and
>>> - // the DAG root is already updated.
>>> + // As a special case, a null chain means that a tail call has been emitted
>>> + // and the DAG root is already updated.
>>> HasTailCall = true;
>>>
>>> // Since there's no actual continuation from this block, nothing can be
>>> @@ -6721,6 +6723,189 @@ void SelectionDAGBuilder::visitVACopy(co
>>> DAG.getSrcValue(I.getArgOperand(1))));
>>> }
>>>
>>> +/// \brief Lower an argument list according to the target calling convention.
>>> +///
>>> +/// \return A tuple of <return-value, token-chain>
>>> +///
>>> +/// This is a helper for lowering intrinsics that follow a target calling
>>> +/// convention or require stack pointer adjustment. Only a subset of the
>>> +/// intrinsic's operands need to participate in the calling convention.
>>> +std::pair<SDValue, SDValue>
>>> +SelectionDAGBuilder::LowerCallOperands(const CallInst &CI, unsigned ArgIdx,
>>> + unsigned NumArgs, SDValue Callee) {
>>> + TargetLowering::ArgListTy Args;
>>> + Args.reserve(NumArgs);
>>> +
>>> + // Populate the argument list.
>>> + // Attributes for args start at offset 1, after the return attribute.
>>> + ImmutableCallSite CS(&CI);
>>> + for (unsigned ArgI = ArgIdx, ArgE = ArgIdx + NumArgs, AttrI = ArgIdx + 1;
>>> + ArgI != ArgE; ++ArgI) {
>>> + const Value *V = CI.getOperand(ArgI);
>>> +
>>> + assert(!V->getType()->isEmptyTy() && "Empty type passed to intrinsic.");
>>> +
>>> + TargetLowering::ArgListEntry Entry;
>>> + Entry.Node = getValue(V);
>>> + Entry.Ty = V->getType();
>>> + Entry.setAttributes(&CS, AttrI);
>>> + Args.push_back(Entry);
>>> + }
>>> +
>>> + TargetLowering::CallLoweringInfo CLI(getRoot(), CI.getType(),
>>> + /*retSExt*/ false, /*retZExt*/ false, /*isVarArg*/ false, /*isInReg*/ false,
>>> + NumArgs, CI.getCallingConv(), /*isTailCall*/ false, /*doesNotReturn*/ false,
>>> + /*isReturnValueUsed*/ CI.use_empty(), Callee, Args, DAG, getCurSDLoc());
>>> +
>>> + const TargetLowering *TLI = TM.getTargetLowering();
>>> + return TLI->LowerCallTo(CLI);
>>> +}
>>> +
>>> +/// \brief Lower llvm.experimental.stackmap directly to its target opcode.
>>> +void SelectionDAGBuilder::visitStackmap(const CallInst &CI) {
>>> + // void @llvm.experimental.stackmap(i32 <id>, i32 <numShadowBytes>,
>>> + // [live variables...])
>>> +
>>> + assert(CI.getType()->isVoidTy() && "Stackmap cannot return a value.");
>>> +
>>> + SDValue Callee = getValue(CI.getCalledValue());
>>> +
>>> + // Lower into a call sequence with no args and no return value.
>>> + std::pair<SDValue, SDValue> Result = LowerCallOperands(CI, 0, 0, Callee);
>>> + // Set the root to the target-lowered call chain.
>>> + SDValue Chain = Result.second;
>>> + DAG.setRoot(Chain);
>>> +
>>> + /// Get a call instruction from the call sequence chain.
>>> + /// Tail calls are not allowed.
>>> + SDNode *CallEnd = Chain.getNode();
>>> + assert(CallEnd->getOpcode() == ISD::CALLSEQ_END &&
>>> + "Expected a callseq node.");
>>> + SDNode *Call = CallEnd->getOperand(0).getNode();
>>> + bool hasGlue = Call->getGluedNode();
>>> +
>>> + assert(Call->getNumOperands() == hasGlue ? 2 : 1 &&
>>> + "Unexpected extra stackmap call arguments.");
>>
>> This assert has an order of evaluation logic error in it, and so it
>> could never fire. I fixed this in r193861, but the assert is now
>> firing on the build bots. Can you look into the failure?
>>
>> Thanks!
>>
>> ~Aaron
>> _______________________________________________
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>> llvm-commits at cs.uiuc.edu
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