From 8a24e835504105efdf6d882053d5da7b0e1dccd3 Mon Sep 17 00:00:00 2001 From: Reid Kleckner Date: Fri, 31 Jan 2014 23:50:57 +0000 Subject: Implement inalloca codegen for x86 with the new inalloca design Calls with inalloca are lowered by skipping all stores for arguments passed in memory and the initial stack adjustment to allocate argument memory. Now the frontend is responsible for the memory layout, and the backend doesn't have to do any work. As a result these changes are pretty minimal. Reviewers: echristo Differential Revision: http://llvm-reviews.chandlerc.com/D2637 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200596 91177308-0d34-0410-b5e6-96231b3b80d8 --- docs/LangRef.rst | 5 +- include/llvm/Support/CallSite.h | 5 +- include/llvm/Target/TargetCallingConv.h | 5 ++ include/llvm/Target/TargetLowering.h | 10 ++-- lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 26 +++++++++- lib/CodeGen/SelectionDAG/TargetLowering.cpp | 1 + lib/IR/Mangler.cpp | 4 +- lib/Target/X86/X86FastISel.cpp | 4 ++ lib/Target/X86/X86ISelLowering.cpp | 29 ++++++++--- test/CodeGen/X86/inalloca-ctor.ll | 34 +++++++++++++ test/CodeGen/X86/inalloca-invoke.ll | 54 ++++++++++++++++++++ test/CodeGen/X86/inalloca-stdcall.ll | 26 ++++++++++ test/CodeGen/X86/inalloca.ll | 65 ++++++++++++++++++++++++ 13 files changed, 251 insertions(+), 17 deletions(-) create mode 100644 test/CodeGen/X86/inalloca-ctor.ll create mode 100644 test/CodeGen/X86/inalloca-invoke.ll create mode 100644 test/CodeGen/X86/inalloca-stdcall.ll create mode 100644 test/CodeGen/X86/inalloca.ll diff --git a/docs/LangRef.rst b/docs/LangRef.rst index 62ce112d57..07e94a9f84 100644 --- a/docs/LangRef.rst +++ b/docs/LangRef.rst @@ -792,7 +792,10 @@ Currently, only the following parameter attributes are defined: An argument allocation may be used by a call at most once because the call may deallocate it. The ``inalloca`` attribute cannot be used in conjunction with other attributes that affect argument - storage, like ``inreg``, ``nest``, ``sret``, or ``byval``. + storage, like ``inreg``, ``nest``, ``sret``, or ``byval``. The + ``inalloca`` attribute also disables LLVM's implicit lowering of + large aggregate return values, which means that frontend authors + must lower them with ``sret`` pointers. When the call site is reached, the argument allocation must have been the most recent stack allocation that is still live, or the diff --git a/include/llvm/Support/CallSite.h b/include/llvm/Support/CallSite.h index d2c47b53ed..f4324cb7ba 100644 --- a/include/llvm/Support/CallSite.h +++ b/include/llvm/Support/CallSite.h @@ -268,9 +268,10 @@ public: paramHasAttr(ArgNo + 1, Attribute::InAlloca); } - /// @brief Determine if there are any inalloca arguments. + /// @brief Determine if there are is an inalloca argument. Only the last + /// argument can have the inalloca attribute. bool hasInAllocaArgument() const { - return getAttributes().hasAttrSomewhere(Attribute::InAlloca); + return paramHasAttr(arg_size(), Attribute::InAlloca); } bool doesNotAccessMemory(unsigned ArgNo) const { diff --git a/include/llvm/Target/TargetCallingConv.h b/include/llvm/Target/TargetCallingConv.h index 9cc52a591b..758a9c9ca8 100644 --- a/include/llvm/Target/TargetCallingConv.h +++ b/include/llvm/Target/TargetCallingConv.h @@ -42,6 +42,8 @@ namespace ISD { static const uint64_t ByValAlignOffs = 7; static const uint64_t Split = 1ULL<<11; static const uint64_t SplitOffs = 11; + static const uint64_t InAlloca = 1ULL<<12; ///< Passed with inalloca + static const uint64_t InAllocaOffs = 12; static const uint64_t OrigAlign = 0x1FULL<<27; static const uint64_t OrigAlignOffs = 27; static const uint64_t ByValSize = 0xffffffffULL<<32; ///< Struct size @@ -68,6 +70,9 @@ namespace ISD { bool isByVal() const { return Flags & ByVal; } void setByVal() { Flags |= One << ByValOffs; } + bool isInAlloca() const { return Flags & InAlloca; } + void setInAlloca() { Flags |= One << InAllocaOffs; } + bool isNest() const { return Flags & Nest; } void setNest() { Flags |= One << NestOffs; } diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h index e9d87291aa..b5c7e43858 100644 --- a/include/llvm/Target/TargetLowering.h +++ b/include/llvm/Target/TargetLowering.h @@ -609,8 +609,9 @@ public: return getValueType(Ty, AllowUnknown).getSimpleVT(); } - /// Return the desired alignment for ByVal aggregate function arguments in the - /// caller parameter area. This is the actual alignment, not its logarithm. + /// Return the desired alignment for ByVal or InAlloca aggregate function + /// arguments in the caller parameter area. This is the actual alignment, not + /// its logarithm. virtual unsigned getByValTypeAlignment(Type *Ty) const; /// Return the type of registers that this ValueType will eventually require. @@ -1965,12 +1966,13 @@ public: bool isSRet : 1; bool isNest : 1; bool isByVal : 1; + bool isInAlloca : 1; bool isReturned : 1; uint16_t Alignment; ArgListEntry() : isSExt(false), isZExt(false), isInReg(false), - isSRet(false), isNest(false), isByVal(false), isReturned(false), - Alignment(0) { } + isSRet(false), isNest(false), isByVal(false), isInAlloca(false), + isReturned(false), Alignment(0) { } void setAttributes(ImmutableCallSite *CS, unsigned AttrIdx); }; diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index c177038102..55e96a4dea 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -5434,6 +5434,8 @@ void SelectionDAGBuilder::LowerCallTo(ImmutableCallSite CS, SDValue Callee, int DemoteStackIdx = -100; if (!CanLowerReturn) { + assert(!CS.hasInAllocaArgument() && + "sret demotion is incompatible with inalloca"); uint64_t TySize = TLI->getDataLayout()->getTypeAllocSize( FTy->getReturnType()); unsigned Align = TLI->getDataLayout()->getPrefTypeAlignment( @@ -7142,8 +7144,18 @@ TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const { Flags.setInReg(); if (Args[i].isSRet) Flags.setSRet(); - if (Args[i].isByVal) { + if (Args[i].isByVal) Flags.setByVal(); + if (Args[i].isInAlloca) { + Flags.setInAlloca(); + // Set the byval flag for CCAssignFn callbacks that don't know about + // inalloca. This way we can know how many bytes we should've allocated + // and how many bytes a callee cleanup function will pop. If we port + // inalloca to more targets, we'll have to add custom inalloca handling + // in the various CC lowering callbacks. + Flags.setByVal(); + } + if (Args[i].isByVal || Args[i].isInAlloca) { PointerType *Ty = cast(Args[i].Ty); Type *ElementTy = Ty->getElementType(); Flags.setByValSize(getDataLayout()->getTypeAllocSize(ElementTy)); @@ -7362,8 +7374,18 @@ void SelectionDAGISel::LowerArguments(const Function &F) { Flags.setInReg(); if (F.getAttributes().hasAttribute(Idx, Attribute::StructRet)) Flags.setSRet(); - if (F.getAttributes().hasAttribute(Idx, Attribute::ByVal)) { + if (F.getAttributes().hasAttribute(Idx, Attribute::ByVal)) Flags.setByVal(); + if (F.getAttributes().hasAttribute(Idx, Attribute::InAlloca)) { + Flags.setInAlloca(); + // Set the byval flag for CCAssignFn callbacks that don't know about + // inalloca. This way we can know how many bytes we should've allocated + // and how many bytes a callee cleanup function will pop. If we port + // inalloca to more targets, we'll have to add custom inalloca handling + // in the various CC lowering callbacks. + Flags.setByVal(); + } + if (Flags.isByVal() || Flags.isInAlloca()) { PointerType *Ty = cast(I->getType()); Type *ElementTy = Ty->getElementType(); Flags.setByValSize(TD->getTypeAllocSize(ElementTy)); diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp index 6052a48640..82e5ae8534 100644 --- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -75,6 +75,7 @@ void TargetLowering::ArgListEntry::setAttributes(ImmutableCallSite *CS, isSRet = CS->paramHasAttr(AttrIdx, Attribute::StructRet); isNest = CS->paramHasAttr(AttrIdx, Attribute::Nest); isByVal = CS->paramHasAttr(AttrIdx, Attribute::ByVal); + isInAlloca = CS->paramHasAttr(AttrIdx, Attribute::InAlloca); isReturned = CS->paramHasAttr(AttrIdx, Attribute::Returned); Alignment = CS->getParamAlignment(AttrIdx); } diff --git a/lib/IR/Mangler.cpp b/lib/IR/Mangler.cpp index 5a099738d5..bc1362dc80 100644 --- a/lib/IR/Mangler.cpp +++ b/lib/IR/Mangler.cpp @@ -65,8 +65,8 @@ static void AddFastCallStdCallSuffix(raw_ostream &OS, const Function *F, for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end(); AI != AE; ++AI) { Type *Ty = AI->getType(); - // 'Dereference' type in case of byval parameter attribute - if (AI->hasByValAttr()) + // 'Dereference' type in case of byval or inalloca parameter attribute. + if (AI->hasByValOrInAllocaAttr()) Ty = cast(Ty)->getElementType(); // Size should be aligned to DWORD boundary ArgWords += ((TD.getTypeAllocSize(Ty) + 3)/4)*4; diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp index be6f13899c..9b842b74e4 100644 --- a/lib/Target/X86/X86FastISel.cpp +++ b/lib/Target/X86/X86FastISel.cpp @@ -1910,6 +1910,10 @@ bool X86FastISel::DoSelectCall(const Instruction *I, const char *MemIntName) { if (isVarArg && isWin64) return false; + // Don't know about inalloca yet. + if (CS.hasInAllocaArgument()) + return false; + // Fast-isel doesn't know about callee-pop yet. if (X86::isCalleePop(CC, Subtarget->is64Bit(), isVarArg, TM.Options.GuaranteedTailCallOpt)) diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 1b04cf46fc..bfe93877e4 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -2584,9 +2584,21 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI, X86Info->setTCReturnAddrDelta(FPDiff); } + unsigned NumBytesToPush = NumBytes; + unsigned NumBytesToPop = NumBytes; + + // If we have an inalloca argument, all stack space has already been allocated + // for us and be right at the top of the stack. We don't support multiple + // arguments passed in memory when using inalloca. + if (!Outs.empty() && Outs.back().Flags.isInAlloca()) { + NumBytesToPush = 0; + assert(ArgLocs.back().getLocMemOffset() == 0 && + "an inalloca argument must be the only memory argument"); + } + if (!IsSibcall) - Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true), - dl); + Chain = DAG.getCALLSEQ_START( + Chain, DAG.getIntPtrConstant(NumBytesToPush, true), dl); SDValue RetAddrFrIdx; // Load return address for tail calls. @@ -2603,10 +2615,14 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI, const X86RegisterInfo *RegInfo = static_cast(getTargetMachine().getRegisterInfo()); for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { + // Skip inalloca arguments, they have already been written. + ISD::ArgFlagsTy Flags = Outs[i].Flags; + if (Flags.isInAlloca()) + continue; + CCValAssign &VA = ArgLocs[i]; EVT RegVT = VA.getLocVT(); SDValue Arg = OutVals[i]; - ISD::ArgFlagsTy Flags = Outs[i].Flags; bool isByVal = Flags.isByVal(); // Promote the value if needed. @@ -2873,8 +2889,9 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI, SmallVector Ops; if (!IsSibcall && isTailCall) { - Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true), - DAG.getIntPtrConstant(0, true), InFlag, dl); + Chain = DAG.getCALLSEQ_END(Chain, + DAG.getIntPtrConstant(NumBytesToPop, true), + DAG.getIntPtrConstant(0, true), InFlag, dl); InFlag = Chain.getValue(1); } @@ -2931,7 +2948,7 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI, // Returns a flag for retval copy to use. if (!IsSibcall) { Chain = DAG.getCALLSEQ_END(Chain, - DAG.getIntPtrConstant(NumBytes, true), + DAG.getIntPtrConstant(NumBytesToPop, true), DAG.getIntPtrConstant(NumBytesForCalleeToPop, true), InFlag, dl); diff --git a/test/CodeGen/X86/inalloca-ctor.ll b/test/CodeGen/X86/inalloca-ctor.ll new file mode 100644 index 0000000000..f81e9675b7 --- /dev/null +++ b/test/CodeGen/X86/inalloca-ctor.ll @@ -0,0 +1,34 @@ +; RUN: llc < %s -mtriple=i686-pc-win32 | FileCheck %s + +%Foo = type { i32, i32 } + +%frame = type { %Foo, i32, %Foo } + +declare void @f(%frame* inalloca %a) + +declare void @Foo_ctor(%Foo* %this) + +define void @g() { +entry: + %args = alloca %frame, inalloca + %c = getelementptr %frame* %args, i32 0, i32 2 +; CHECK: movl $20, %eax +; CHECK: calll __chkstk +; CHECK: movl %esp, + call void @Foo_ctor(%Foo* %c) +; CHECK: leal 12(%{{.*}}), +; CHECK: subl $4, %esp +; CHECK: calll _Foo_ctor +; CHECK: addl $4, %esp + %b = getelementptr %frame* %args, i32 0, i32 1 + store i32 42, i32* %b +; CHECK: movl $42, + %a = getelementptr %frame* %args, i32 0, i32 0 + call void @Foo_ctor(%Foo* %a) +; CHECK: subl $4, %esp +; CHECK: calll _Foo_ctor +; CHECK: addl $4, %esp + call void @f(%frame* inalloca %args) +; CHECK: calll _f + ret void +} diff --git a/test/CodeGen/X86/inalloca-invoke.ll b/test/CodeGen/X86/inalloca-invoke.ll new file mode 100644 index 0000000000..ac530ca525 --- /dev/null +++ b/test/CodeGen/X86/inalloca-invoke.ll @@ -0,0 +1,54 @@ +; RUN: llc < %s -mtriple=i686-pc-win32 | FileCheck %s + +%Iter = type { i32, i32, i32 } + +%frame.reverse = type { %Iter, %Iter } + +declare void @llvm.stackrestore(i8*) +declare i8* @llvm.stacksave() +declare void @begin(%Iter* sret) +declare void @plus(%Iter* sret, %Iter*, i32) +declare void @reverse(%frame.reverse* inalloca align 4) + +define i32 @main() { + %temp.lvalue = alloca %Iter + br label %blah + +blah: + %inalloca.save = call i8* @llvm.stacksave() + %rev_args = alloca %frame.reverse, inalloca, align 4 + %beg = getelementptr %frame.reverse* %rev_args, i32 0, i32 0 + %end = getelementptr %frame.reverse* %rev_args, i32 0, i32 1 + +; CHECK: calll __chkstk +; CHECK: movl %[[beg:[^,]*]], %esp +; CHECK: leal 12(%[[beg]]), %[[end:[^ ]*]] + + call void @begin(%Iter* sret %temp.lvalue) +; CHECK: calll _begin + + invoke void @plus(%Iter* sret %end, %Iter* %temp.lvalue, i32 4) + to label %invoke.cont unwind label %lpad + +; Uses end as sret param. +; CHECK: movl %[[end]], (%esp) +; CHECK: calll _plus + +invoke.cont: + call void @begin(%Iter* sret %beg) + +; CHECK: movl %[[beg]], +; CHECK: calll _begin + + invoke void @reverse(%frame.reverse* inalloca align 4 %rev_args) + to label %invoke.cont5 unwind label %lpad + +invoke.cont5: ; preds = %invoke.cont + call void @llvm.stackrestore(i8* %inalloca.save) + ret i32 0 + +lpad: ; preds = %invoke.cont, %entry + %lp = landingpad { i8*, i32 } personality i8* null + cleanup + unreachable +} diff --git a/test/CodeGen/X86/inalloca-stdcall.ll b/test/CodeGen/X86/inalloca-stdcall.ll new file mode 100644 index 0000000000..93ac451a50 --- /dev/null +++ b/test/CodeGen/X86/inalloca-stdcall.ll @@ -0,0 +1,26 @@ +; RUN: llc < %s -mtriple=i686-pc-win32 | FileCheck %s + +%Foo = type { i32, i32 } + +declare x86_stdcallcc void @f(%Foo* inalloca %a) +declare x86_stdcallcc void @i(i32 %a) + +define void @g() { + %b = alloca %Foo, inalloca +; CHECK: movl $8, %eax +; CHECK: calll __chkstk +; CHECK: movl %[[REG:[^,]*]], %esp + %f1 = getelementptr %Foo* %b, i32 0, i32 0 + %f2 = getelementptr %Foo* %b, i32 0, i32 1 + store i32 13, i32* %f1 + store i32 42, i32* %f2 +; CHECK: movl $13, (%[[REG]]) +; CHECK: movl $42, 4(%[[REG]]) + call x86_stdcallcc void @f(%Foo* inalloca %b) +; CHECK: calll _f@8 +; CHECK-NOT: %esp +; CHECK: subl $4, %esp +; CHECK: calll _i@4 + call x86_stdcallcc void @i(i32 0) + ret void +} diff --git a/test/CodeGen/X86/inalloca.ll b/test/CodeGen/X86/inalloca.ll new file mode 100644 index 0000000000..84d694a1fb --- /dev/null +++ b/test/CodeGen/X86/inalloca.ll @@ -0,0 +1,65 @@ +; RUN: llc < %s -mtriple=i686-pc-win32 | FileCheck %s + +%Foo = type { i32, i32 } + +declare void @f(%Foo* inalloca %b) + +define void @a() { +; CHECK-LABEL: _a: +entry: + %b = alloca %Foo, inalloca +; CHECK: movl $8, %eax +; CHECK: calll __chkstk +; CHECK: movl %[[REG:[^,]*]], %esp + %f1 = getelementptr %Foo* %b, i32 0, i32 0 + %f2 = getelementptr %Foo* %b, i32 0, i32 1 + store i32 13, i32* %f1 + store i32 42, i32* %f2 +; CHECK: movl $13, (%[[REG]]) +; CHECK: movl $42, 4(%[[REG]]) + call void @f(%Foo* inalloca %b) +; CHECK: calll _f + ret void +} + +declare void @inreg_with_inalloca(i32 inreg %a, %Foo* inalloca %b) + +define void @b() { +; CHECK-LABEL: _b: +entry: + %b = alloca %Foo, inalloca +; CHECK: movl $8, %eax +; CHECK: calll __chkstk +; CHECK: movl %[[REG:[^,]*]], %esp + %f1 = getelementptr %Foo* %b, i32 0, i32 0 + %f2 = getelementptr %Foo* %b, i32 0, i32 1 + store i32 13, i32* %f1 + store i32 42, i32* %f2 +; CHECK: movl $13, (%[[REG]]) +; CHECK: movl $42, 4(%[[REG]]) + call void @inreg_with_inalloca(i32 inreg 1, %Foo* inalloca %b) +; CHECK: movl $1, %eax +; CHECK: calll _inreg_with_inalloca + ret void +} + +declare x86_thiscallcc void @thiscall_with_inalloca(i8* %a, %Foo* inalloca %b) + +define void @c() { +; CHECK-LABEL: _c: +entry: + %b = alloca %Foo, inalloca +; CHECK: movl $8, %eax +; CHECK: calll __chkstk +; CHECK: movl %[[REG:[^,]*]], %esp + %f1 = getelementptr %Foo* %b, i32 0, i32 0 + %f2 = getelementptr %Foo* %b, i32 0, i32 1 + store i32 13, i32* %f1 + store i32 42, i32* %f2 +; CHECK: movl $13, (%[[REG]]) +; CHECK: movl $42, 4(%[[REG]]) + call x86_thiscallcc void @thiscall_with_inalloca(i8* null, %Foo* inalloca %b) +; CHECK: xorl %ecx, %ecx +; CHECK: calll _thiscall_with_inalloca + ret void +} -- cgit v1.2.3