[llvm] r254799 - [WebAssembly] Initial varargs support.
Dan Gohman via llvm-commits
llvm-commits at lists.llvm.org
Fri Dec 4 15:22:35 PST 2015
Author: djg
Date: Fri Dec 4 17:22:35 2015
New Revision: 254799
URL: http://llvm.org/viewvc/llvm-project?rev=254799&view=rev
Log:
[WebAssembly] Initial varargs support.
Full varargs support will depend on prologue/epilogue support, but this patch
gets us started with most of the basic infrastructure.
Differential Revision: http://reviews.llvm.org/D15231
Added:
llvm/trunk/test/CodeGen/WebAssembly/varargs.ll
Modified:
llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.h
llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrCall.td
llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegisterInfo.cpp
llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegisterInfo.h
Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp?rev=254799&r1=254798&r2=254799&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp Fri Dec 4 17:22:35 2015
@@ -118,6 +118,13 @@ WebAssemblyTargetLowering::WebAssemblyTa
setOperationAction(ISD::ExternalSymbol, MVTPtr, Custom);
setOperationAction(ISD::JumpTable, MVTPtr, Custom);
+ // Take the default expansion for va_arg, va_copy, and va_end. There is no
+ // default action for va_start, so we do that custom.
+ setOperationAction(ISD::VASTART, MVT::Other, Custom);
+ setOperationAction(ISD::VAARG, MVT::Other, Expand);
+ setOperationAction(ISD::VACOPY, MVT::Other, Expand);
+ setOperationAction(ISD::VAEND, MVT::Other, Expand);
+
for (auto T : {MVT::f32, MVT::f64}) {
// Don't expand the floating-point types to constant pools.
setOperationAction(ISD::ConstantFP, T, Legal);
@@ -314,23 +321,67 @@ WebAssemblyTargetLowering::LowerCall(Cal
}
bool IsVarArg = CLI.IsVarArg;
- if (IsVarArg)
- fail(DL, DAG, "WebAssembly doesn't support varargs yet");
+ unsigned NumFixedArgs = CLI.NumFixedArgs;
+ auto PtrVT = getPointerTy(MF.getDataLayout());
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CallConv, IsVarArg, MF, ArgLocs, *DAG.getContext());
- unsigned NumBytes = CCInfo.getNextStackOffset();
- auto PtrVT = getPointerTy(MF.getDataLayout());
- auto Zero = DAG.getConstant(0, DL, PtrVT, true);
+ if (IsVarArg) {
+ // Outgoing non-fixed arguments are placed at the top of the stack. First
+ // compute their offsets and the total amount of argument stack space
+ // needed.
+ for (SDValue Arg :
+ make_range(OutVals.begin() + NumFixedArgs, OutVals.end())) {
+ EVT VT = Arg.getValueType();
+ assert(VT != MVT::iPTR && "Legalized args should be concrete");
+ Type *Ty = VT.getTypeForEVT(*DAG.getContext());
+ unsigned Offset =
+ CCInfo.AllocateStack(MF.getDataLayout().getTypeAllocSize(Ty),
+ MF.getDataLayout().getABITypeAlignment(Ty));
+ CCInfo.addLoc(CCValAssign::getMem(ArgLocs.size(), VT.getSimpleVT(),
+ Offset, VT.getSimpleVT(),
+ CCValAssign::Full));
+ }
+ }
+
+ unsigned NumBytes = CCInfo.getAlignedCallFrameSize();
+
auto NB = DAG.getConstant(NumBytes, DL, PtrVT, true);
Chain = DAG.getCALLSEQ_START(Chain, NB, DL);
+ if (IsVarArg) {
+ // For non-fixed arguments, next emit stores to store the argument values
+ // to the stack at the offsets computed above.
+ SDValue SP = DAG.getCopyFromReg(
+ Chain, DL, getStackPointerRegisterToSaveRestore(), PtrVT);
+ unsigned ValNo = 0;
+ SmallVector<SDValue, 8> Chains;
+ for (SDValue Arg :
+ make_range(OutVals.begin() + NumFixedArgs, OutVals.end())) {
+ assert(ArgLocs[ValNo].getValNo() == ValNo &&
+ "ArgLocs should remain in order and only hold varargs args");
+ unsigned Offset = ArgLocs[ValNo++].getLocMemOffset();
+ SDValue Add = DAG.getNode(ISD::ADD, DL, PtrVT, SP,
+ DAG.getConstant(Offset, DL, PtrVT));
+ Chains.push_back(DAG.getStore(Chain, DL, Arg, Add,
+ MachinePointerInfo::getStack(MF, Offset),
+ false, false, 0));
+ }
+ if (!Chains.empty())
+ Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Chains);
+ }
+
+ // Compute the operands for the CALLn node.
SmallVector<SDValue, 16> Ops;
Ops.push_back(Chain);
Ops.push_back(Callee);
- Ops.append(OutVals.begin(), OutVals.end());
+
+ // Add all fixed arguments. Note that for non-varargs calls, NumFixedArgs
+ // isn't reliable.
+ Ops.append(OutVals.begin(),
+ IsVarArg ? OutVals.begin() + NumFixedArgs : OutVals.end());
SmallVector<EVT, 8> Tys;
for (const auto &In : Ins) {
@@ -360,7 +411,8 @@ WebAssemblyTargetLowering::LowerCall(Cal
Chain = Res.getValue(1);
}
- Chain = DAG.getCALLSEQ_END(Chain, NB, Zero, SDValue(), DL);
+ SDValue Unused = DAG.getUNDEF(PtrVT);
+ Chain = DAG.getCALLSEQ_END(Chain, NB, Unused, SDValue(), DL);
return Chain;
}
@@ -374,15 +426,13 @@ bool WebAssemblyTargetLowering::CanLower
}
SDValue WebAssemblyTargetLowering::LowerReturn(
- SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
+ SDValue Chain, CallingConv::ID CallConv, bool /*IsVarArg*/,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals, SDLoc DL,
SelectionDAG &DAG) const {
assert(Outs.size() <= 1 && "WebAssembly can only return up to one value");
if (!CallingConvSupported(CallConv))
fail(DL, DAG, "WebAssembly doesn't support non-C calling conventions");
- if (IsVarArg)
- fail(DL, DAG, "WebAssembly doesn't support varargs yet");
SmallVector<SDValue, 4> RetOps(1, Chain);
RetOps.append(OutVals.begin(), OutVals.end());
@@ -392,29 +442,26 @@ SDValue WebAssemblyTargetLowering::Lower
for (const ISD::OutputArg &Out : Outs) {
assert(!Out.Flags.isByVal() && "byval is not valid for return values");
assert(!Out.Flags.isNest() && "nest is not valid for return values");
+ assert(Out.IsFixed && "non-fixed return value is not valid");
if (Out.Flags.isInAlloca())
fail(DL, DAG, "WebAssembly hasn't implemented inalloca results");
if (Out.Flags.isInConsecutiveRegs())
fail(DL, DAG, "WebAssembly hasn't implemented cons regs results");
if (Out.Flags.isInConsecutiveRegsLast())
fail(DL, DAG, "WebAssembly hasn't implemented cons regs last results");
- if (!Out.IsFixed)
- fail(DL, DAG, "WebAssembly doesn't support non-fixed results yet");
}
return Chain;
}
SDValue WebAssemblyTargetLowering::LowerFormalArguments(
- SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
+ SDValue Chain, CallingConv::ID CallConv, bool /*IsVarArg*/,
const SmallVectorImpl<ISD::InputArg> &Ins, SDLoc DL, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const {
MachineFunction &MF = DAG.getMachineFunction();
if (!CallingConvSupported(CallConv))
fail(DL, DAG, "WebAssembly doesn't support non-C calling conventions");
- if (IsVarArg)
- fail(DL, DAG, "WebAssembly doesn't support varargs yet");
// Set up the incoming ARGUMENTS value, which serves to represent the liveness
// of the incoming values before they're represented by virtual registers.
@@ -443,6 +490,9 @@ SDValue WebAssemblyTargetLowering::Lower
MF.getInfo<WebAssemblyFunctionInfo>()->addParam(In.VT);
}
+ // Incoming varargs arguments are on the stack and will be accessed through
+ // va_arg, so we don't need to do anything for them here.
+
return Chain;
}
@@ -464,6 +514,8 @@ SDValue WebAssemblyTargetLowering::Lower
return LowerJumpTable(Op, DAG);
case ISD::BR_JT:
return LowerBR_JT(Op, DAG);
+ case ISD::VASTART:
+ return LowerVASTART(Op, DAG);
}
}
@@ -529,6 +581,24 @@ SDValue WebAssemblyTargetLowering::Lower
return DAG.getNode(WebAssemblyISD::TABLESWITCH, DL, MVT::Other, Ops);
}
+SDValue WebAssemblyTargetLowering::LowerVASTART(SDValue Op,
+ SelectionDAG &DAG) const {
+ SDLoc DL(Op);
+ EVT PtrVT = getPointerTy(DAG.getMachineFunction().getDataLayout());
+
+ // The incoming non-fixed arguments are placed on the top of the stack, with
+ // natural alignment, at the point of the call, so the base pointer is just
+ // the current frame pointer.
+ DAG.getMachineFunction().getFrameInfo()->setFrameAddressIsTaken(true);
+ unsigned FP =
+ static_cast<const WebAssemblyRegisterInfo *>(Subtarget->getRegisterInfo())
+ ->getFrameRegister(DAG.getMachineFunction());
+ SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), DL, FP, PtrVT);
+ const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
+ return DAG.getStore(Op.getOperand(0), DL, FrameAddr, Op.getOperand(1),
+ MachinePointerInfo(SV), false, false, 0);
+}
+
//===----------------------------------------------------------------------===//
// WebAssembly Optimization Hooks
//===----------------------------------------------------------------------===//
Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.h?rev=254799&r1=254798&r2=254799&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.h (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.h Fri Dec 4 17:22:35 2015
@@ -77,6 +77,7 @@ private:
SDValue LowerExternalSymbol(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
+ SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
};
namespace WebAssembly {
Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrCall.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrCall.td?rev=254799&r1=254798&r2=254799&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrCall.td (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrCall.td Fri Dec 4 17:22:35 2015
@@ -19,8 +19,8 @@ let Defs = [ARGUMENTS] in {
let isCodeGenOnly = 1 in {
def ADJCALLSTACKDOWN : I<(outs), (ins i64imm:$amt),
[(WebAssemblycallseq_start timm:$amt)]>;
-def ADJCALLSTACKUP : I<(outs), (ins i64imm:$amt1, i64imm:$amt2),
- [(WebAssemblycallseq_end timm:$amt1, timm:$amt2)]>;
+def ADJCALLSTACKUP : I<(outs), (ins i64imm:$amt),
+ [(WebAssemblycallseq_end timm:$amt, undef)]>;
} // isCodeGenOnly = 1
multiclass CALL<WebAssemblyRegClass vt> {
Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp?rev=254799&r1=254798&r2=254799&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp Fri Dec 4 17:22:35 2015
@@ -28,7 +28,9 @@ using namespace llvm;
#include "WebAssemblyGenInstrInfo.inc"
WebAssemblyInstrInfo::WebAssemblyInstrInfo(const WebAssemblySubtarget &STI)
- : RI(STI.getTargetTriple()) {}
+ : WebAssemblyGenInstrInfo(WebAssembly::ADJCALLSTACKDOWN,
+ WebAssembly::ADJCALLSTACKUP),
+ RI(STI.getTargetTriple()) {}
void WebAssemblyInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp?rev=254799&r1=254798&r2=254799&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp Fri Dec 4 17:22:35 2015
@@ -204,6 +204,10 @@ bool WebAssemblyRegStackify::runOnMachin
continue;
unsigned VReg = MO.getReg();
+ // Don't stackify physregs like SP or FP.
+ if (!TargetRegisterInfo::isVirtualRegister(VReg))
+ continue;
+
if (MFI.isVRegStackified(VReg)) {
if (MO.isDef())
Stack.push_back(VReg);
Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegisterInfo.cpp?rev=254799&r1=254798&r2=254799&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegisterInfo.cpp (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegisterInfo.cpp Fri Dec 4 17:22:35 2015
@@ -67,3 +67,12 @@ WebAssemblyRegisterInfo::getFrameRegiste
const WebAssemblyFrameLowering *TFI = getFrameLowering(MF);
return Regs[TFI->hasFP(MF)][TT.isArch64Bit()];
}
+
+const TargetRegisterClass *
+WebAssemblyRegisterInfo::getPointerRegClass(const MachineFunction &MF,
+ unsigned Kind) const {
+ assert(Kind == 0 && "Only one kind of pointer on WebAssembly");
+ if (MF.getSubtarget<WebAssemblySubtarget>().hasAddr64())
+ return &WebAssembly::I64RegClass;
+ return &WebAssembly::I32RegClass;
+}
Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegisterInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegisterInfo.h?rev=254799&r1=254798&r2=254799&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegisterInfo.h (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegisterInfo.h Fri Dec 4 17:22:35 2015
@@ -41,6 +41,10 @@ public:
// Debug information queries.
unsigned getFrameRegister(const MachineFunction &MF) const override;
+
+ const TargetRegisterClass *
+ getPointerRegClass(const MachineFunction &MF,
+ unsigned Kind = 0) const override;
};
} // end namespace llvm
Added: llvm/trunk/test/CodeGen/WebAssembly/varargs.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/WebAssembly/varargs.ll?rev=254799&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/WebAssembly/varargs.ll (added)
+++ llvm/trunk/test/CodeGen/WebAssembly/varargs.ll Fri Dec 4 17:22:35 2015
@@ -0,0 +1,122 @@
+; RUN: llc < %s -asm-verbose=false | FileCheck %s
+
+; Test varargs constructs.
+
+target datalayout = "e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown"
+
+; Test va_start.
+
+; TODO: Test va_start.
+
+;define void @start(i8** %ap, ...) {
+;entry:
+; %0 = bitcast i8** %ap to i8*
+; call void @llvm.va_start(i8* %0)
+; ret void
+;}
+
+; Test va_end.
+
+; CHECK-LABEL: end:
+; CHECK-NEXT: .param i32{{$}}
+; CHECK-NEXT: return{{$}}
+define void @end(i8** %ap) {
+entry:
+ %0 = bitcast i8** %ap to i8*
+ call void @llvm.va_end(i8* %0)
+ ret void
+}
+
+; Test va_copy.
+
+; CHECK-LABEL: copy:
+; CHECK-NEXT: .param i32, i32{{$}}
+; CHECK-NEXT: i32.load $push0=, $1{{$}}
+; CHECK-NEXT: i32.store $discard=, $0, $pop0{{$}}
+; CHECK-NEXT: return{{$}}
+define void @copy(i8** %ap, i8** %bp) {
+entry:
+ %0 = bitcast i8** %ap to i8*
+ %1 = bitcast i8** %bp to i8*
+ call void @llvm.va_copy(i8* %0, i8* %1)
+ ret void
+}
+
+; Test va_arg with an i8 argument.
+
+; CHECK-LABEL: arg_i8:
+; CHECK-NEXT: .param i32{{$}}
+; CHECK-NEXT: .result i32{{$}}
+; CHECK-NEXT: .local i32{{$}}
+; CHECK-NEXT: i32.load $1=, $0{{$}}
+; CHECK-NEXT: i32.const $push0=, 4{{$}}
+; CHECK-NEXT: i32.add $push1=, $1, $pop0{{$}}
+; CHECK-NEXT: i32.store $discard=, $0, $pop1{{$}}
+; CHECK-NEXT: i32.load $push2=, $1{{$}}
+; CHECK-NEXT: return $pop2{{$}}
+define i8 @arg_i8(i8** %ap) {
+entry:
+ %t = va_arg i8** %ap, i8
+ ret i8 %t
+}
+
+; Test va_arg with an i32 argument.
+
+; CHECK-LABEL: arg_i32:
+; CHECK-NEXT: .param i32{{$}}
+; CHECK-NEXT: .result i32{{$}}
+; CHECK-NEXT: .local i32{{$}}
+; CHECK-NEXT: i32.load $push0=, $0{{$}}
+; CHECK-NEXT: i32.const $push1=, 3{{$}}
+; CHECK-NEXT: i32.add $push2=, $pop0, $pop1{{$}}
+; CHECK-NEXT: i32.const $push3=, -4{{$}}
+; CHECK-NEXT: i32.and $1=, $pop2, $pop3{{$}}
+; CHECK-NEXT: i32.const $push4=, 4{{$}}
+; CHECK-NEXT: i32.add $push5=, $1, $pop4{{$}}
+; CHECK-NEXT: i32.store $discard=, $0, $pop5{{$}}
+; CHECK-NEXT: i32.load $push6=, $1{{$}}
+; CHECK-NEXT: return $pop6{{$}}
+define i32 @arg_i32(i8** %ap) {
+entry:
+ %t = va_arg i8** %ap, i32
+ ret i32 %t
+}
+
+; Test va_arg with an i128 argument.
+
+; CHECK-LABEL: arg_i128:
+; CHECK-NEXT: .param i32, i32{{$}}
+; CHECK-NEXT: .local
+; CHECK: i32.and
+; CHECK: i64.load
+; CHECK: i64.load
+; CHECK: return{{$}}
+define i128 @arg_i128(i8** %ap) {
+entry:
+ %t = va_arg i8** %ap, i128
+ ret i128 %t
+}
+
+; Test a varargs call with no actual arguments.
+
+declare void @callee(...)
+
+; CHECK-LABEL: caller_none:
+; CHECK-NEXT: call callee{{$}}
+; CHECK-NEXT: return{{$}}
+define void @caller_none() {
+ call void (...) @callee()
+ ret void
+}
+
+; TODO: Test a varargs call with actual arguments.
+
+;define void @caller_some() {
+; call void (...) @callee(i32 0, double 2.0)
+; ret void
+;}
+
+declare void @llvm.va_start(i8*)
+declare void @llvm.va_end(i8*)
+declare void @llvm.va_copy(i8*, i8*)
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