aboutsummaryrefslogtreecommitdiff
path: root/lib/CodeGen/GlobalISel/CallLowering.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'lib/CodeGen/GlobalISel/CallLowering.cpp')
-rw-r--r--lib/CodeGen/GlobalISel/CallLowering.cpp288
1 files changed, 243 insertions, 45 deletions
diff --git a/lib/CodeGen/GlobalISel/CallLowering.cpp b/lib/CodeGen/GlobalISel/CallLowering.cpp
index a5d8205a34a8..cdad92f7db4f 100644
--- a/lib/CodeGen/GlobalISel/CallLowering.cpp
+++ b/lib/CodeGen/GlobalISel/CallLowering.cpp
@@ -11,14 +11,16 @@
///
//===----------------------------------------------------------------------===//
-#include "llvm/CodeGen/GlobalISel/CallLowering.h"
#include "llvm/CodeGen/Analysis.h"
+#include "llvm/CodeGen/GlobalISel/CallLowering.h"
+#include "llvm/CodeGen/GlobalISel/Utils.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Instructions.h"
+#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#define DEBUG_TYPE "call-lowering"
@@ -32,66 +34,70 @@ bool CallLowering::lowerCall(MachineIRBuilder &MIRBuilder, ImmutableCallSite CS,
ArrayRef<ArrayRef<Register>> ArgRegs,
Register SwiftErrorVReg,
std::function<unsigned()> GetCalleeReg) const {
+ CallLoweringInfo Info;
auto &DL = CS.getParent()->getParent()->getParent()->getDataLayout();
// First step is to marshall all the function's parameters into the correct
// physregs and memory locations. Gather the sequence of argument types that
// we'll pass to the assigner function.
- SmallVector<ArgInfo, 8> OrigArgs;
unsigned i = 0;
unsigned NumFixedArgs = CS.getFunctionType()->getNumParams();
for (auto &Arg : CS.args()) {
ArgInfo OrigArg{ArgRegs[i], Arg->getType(), ISD::ArgFlagsTy{},
i < NumFixedArgs};
setArgFlags(OrigArg, i + AttributeList::FirstArgIndex, DL, CS);
- // We don't currently support swiftself args.
- if (OrigArg.Flags.isSwiftSelf())
- return false;
- OrigArgs.push_back(OrigArg);
+ Info.OrigArgs.push_back(OrigArg);
++i;
}
- MachineOperand Callee = MachineOperand::CreateImm(0);
if (const Function *F = CS.getCalledFunction())
- Callee = MachineOperand::CreateGA(F, 0);
+ Info.Callee = MachineOperand::CreateGA(F, 0);
else
- Callee = MachineOperand::CreateReg(GetCalleeReg(), false);
-
- ArgInfo OrigRet{ResRegs, CS.getType(), ISD::ArgFlagsTy{}};
- if (!OrigRet.Ty->isVoidTy())
- setArgFlags(OrigRet, AttributeList::ReturnIndex, DL, CS);
-
- return lowerCall(MIRBuilder, CS.getCallingConv(), Callee, OrigRet, OrigArgs,
- SwiftErrorVReg);
+ Info.Callee = MachineOperand::CreateReg(GetCalleeReg(), false);
+
+ Info.OrigRet = ArgInfo{ResRegs, CS.getType(), ISD::ArgFlagsTy{}};
+ if (!Info.OrigRet.Ty->isVoidTy())
+ setArgFlags(Info.OrigRet, AttributeList::ReturnIndex, DL, CS);
+
+ Info.KnownCallees =
+ CS.getInstruction()->getMetadata(LLVMContext::MD_callees);
+ Info.CallConv = CS.getCallingConv();
+ Info.SwiftErrorVReg = SwiftErrorVReg;
+ Info.IsMustTailCall = CS.isMustTailCall();
+ Info.IsTailCall = CS.isTailCall() &&
+ isInTailCallPosition(CS, MIRBuilder.getMF().getTarget());
+ Info.IsVarArg = CS.getFunctionType()->isVarArg();
+ return lowerCall(MIRBuilder, Info);
}
template <typename FuncInfoTy>
void CallLowering::setArgFlags(CallLowering::ArgInfo &Arg, unsigned OpIdx,
const DataLayout &DL,
const FuncInfoTy &FuncInfo) const {
+ auto &Flags = Arg.Flags[0];
const AttributeList &Attrs = FuncInfo.getAttributes();
if (Attrs.hasAttribute(OpIdx, Attribute::ZExt))
- Arg.Flags.setZExt();
+ Flags.setZExt();
if (Attrs.hasAttribute(OpIdx, Attribute::SExt))
- Arg.Flags.setSExt();
+ Flags.setSExt();
if (Attrs.hasAttribute(OpIdx, Attribute::InReg))
- Arg.Flags.setInReg();
+ Flags.setInReg();
if (Attrs.hasAttribute(OpIdx, Attribute::StructRet))
- Arg.Flags.setSRet();
+ Flags.setSRet();
if (Attrs.hasAttribute(OpIdx, Attribute::SwiftSelf))
- Arg.Flags.setSwiftSelf();
+ Flags.setSwiftSelf();
if (Attrs.hasAttribute(OpIdx, Attribute::SwiftError))
- Arg.Flags.setSwiftError();
+ Flags.setSwiftError();
if (Attrs.hasAttribute(OpIdx, Attribute::ByVal))
- Arg.Flags.setByVal();
+ Flags.setByVal();
if (Attrs.hasAttribute(OpIdx, Attribute::InAlloca))
- Arg.Flags.setInAlloca();
+ Flags.setInAlloca();
- if (Arg.Flags.isByVal() || Arg.Flags.isInAlloca()) {
+ if (Flags.isByVal() || Flags.isInAlloca()) {
Type *ElementTy = cast<PointerType>(Arg.Ty)->getElementType();
auto Ty = Attrs.getAttribute(OpIdx, Attribute::ByVal).getValueAsType();
- Arg.Flags.setByValSize(DL.getTypeAllocSize(Ty ? Ty : ElementTy));
+ Flags.setByValSize(DL.getTypeAllocSize(Ty ? Ty : ElementTy));
// For ByVal, alignment should be passed from FE. BE will guess if
// this info is not there but there are cases it cannot get right.
@@ -100,11 +106,11 @@ void CallLowering::setArgFlags(CallLowering::ArgInfo &Arg, unsigned OpIdx,
FrameAlign = FuncInfo.getParamAlignment(OpIdx - 2);
else
FrameAlign = getTLI()->getByValTypeAlignment(ElementTy, DL);
- Arg.Flags.setByValAlign(FrameAlign);
+ Flags.setByValAlign(Align(FrameAlign));
}
if (Attrs.hasAttribute(OpIdx, Attribute::Nest))
- Arg.Flags.setNest();
- Arg.Flags.setOrigAlign(DL.getABITypeAlignment(Arg.Ty));
+ Flags.setNest();
+ Flags.setOrigAlign(Align(DL.getABITypeAlignment(Arg.Ty)));
}
template void
@@ -159,7 +165,7 @@ void CallLowering::unpackRegs(ArrayRef<Register> DstRegs, Register SrcReg,
}
bool CallLowering::handleAssignments(MachineIRBuilder &MIRBuilder,
- ArrayRef<ArgInfo> Args,
+ SmallVectorImpl<ArgInfo> &Args,
ValueHandler &Handler) const {
MachineFunction &MF = MIRBuilder.getMF();
const Function &F = MF.getFunction();
@@ -171,7 +177,7 @@ bool CallLowering::handleAssignments(MachineIRBuilder &MIRBuilder,
bool CallLowering::handleAssignments(CCState &CCInfo,
SmallVectorImpl<CCValAssign> &ArgLocs,
MachineIRBuilder &MIRBuilder,
- ArrayRef<ArgInfo> Args,
+ SmallVectorImpl<ArgInfo> &Args,
ValueHandler &Handler) const {
MachineFunction &MF = MIRBuilder.getMF();
const Function &F = MF.getFunction();
@@ -180,14 +186,99 @@ bool CallLowering::handleAssignments(CCState &CCInfo,
unsigned NumArgs = Args.size();
for (unsigned i = 0; i != NumArgs; ++i) {
MVT CurVT = MVT::getVT(Args[i].Ty);
- if (Handler.assignArg(i, CurVT, CurVT, CCValAssign::Full, Args[i], CCInfo)) {
- // Try to use the register type if we couldn't assign the VT.
- if (!Handler.isArgumentHandler() || !CurVT.isValid())
+ if (Handler.assignArg(i, CurVT, CurVT, CCValAssign::Full, Args[i],
+ Args[i].Flags[0], CCInfo)) {
+ if (!CurVT.isValid())
return false;
- CurVT = TLI->getRegisterTypeForCallingConv(
+ MVT NewVT = TLI->getRegisterTypeForCallingConv(
F.getContext(), F.getCallingConv(), EVT(CurVT));
- if (Handler.assignArg(i, CurVT, CurVT, CCValAssign::Full, Args[i], CCInfo))
- return false;
+
+ // If we need to split the type over multiple regs, check it's a scenario
+ // we currently support.
+ unsigned NumParts = TLI->getNumRegistersForCallingConv(
+ F.getContext(), F.getCallingConv(), CurVT);
+ if (NumParts > 1) {
+ // For now only handle exact splits.
+ if (NewVT.getSizeInBits() * NumParts != CurVT.getSizeInBits())
+ return false;
+ }
+
+ // For incoming arguments (physregs to vregs), we could have values in
+ // physregs (or memlocs) which we want to extract and copy to vregs.
+ // During this, we might have to deal with the LLT being split across
+ // multiple regs, so we have to record this information for later.
+ //
+ // If we have outgoing args, then we have the opposite case. We have a
+ // vreg with an LLT which we want to assign to a physical location, and
+ // we might have to record that the value has to be split later.
+ if (Handler.isIncomingArgumentHandler()) {
+ if (NumParts == 1) {
+ // Try to use the register type if we couldn't assign the VT.
+ if (Handler.assignArg(i, NewVT, NewVT, CCValAssign::Full, Args[i],
+ Args[i].Flags[0], CCInfo))
+ return false;
+ } else {
+ // We're handling an incoming arg which is split over multiple regs.
+ // E.g. passing an s128 on AArch64.
+ ISD::ArgFlagsTy OrigFlags = Args[i].Flags[0];
+ Args[i].OrigRegs.push_back(Args[i].Regs[0]);
+ Args[i].Regs.clear();
+ Args[i].Flags.clear();
+ LLT NewLLT = getLLTForMVT(NewVT);
+ // For each split register, create and assign a vreg that will store
+ // the incoming component of the larger value. These will later be
+ // merged to form the final vreg.
+ for (unsigned Part = 0; Part < NumParts; ++Part) {
+ Register Reg =
+ MIRBuilder.getMRI()->createGenericVirtualRegister(NewLLT);
+ ISD::ArgFlagsTy Flags = OrigFlags;
+ if (Part == 0) {
+ Flags.setSplit();
+ } else {
+ Flags.setOrigAlign(Align::None());
+ if (Part == NumParts - 1)
+ Flags.setSplitEnd();
+ }
+ Args[i].Regs.push_back(Reg);
+ Args[i].Flags.push_back(Flags);
+ if (Handler.assignArg(i + Part, NewVT, NewVT, CCValAssign::Full,
+ Args[i], Args[i].Flags[Part], CCInfo)) {
+ // Still couldn't assign this smaller part type for some reason.
+ return false;
+ }
+ }
+ }
+ } else {
+ // Handling an outgoing arg that might need to be split.
+ if (NumParts < 2)
+ return false; // Don't know how to deal with this type combination.
+
+ // This type is passed via multiple registers in the calling convention.
+ // We need to extract the individual parts.
+ Register LargeReg = Args[i].Regs[0];
+ LLT SmallTy = LLT::scalar(NewVT.getSizeInBits());
+ auto Unmerge = MIRBuilder.buildUnmerge(SmallTy, LargeReg);
+ assert(Unmerge->getNumOperands() == NumParts + 1);
+ ISD::ArgFlagsTy OrigFlags = Args[i].Flags[0];
+ // We're going to replace the regs and flags with the split ones.
+ Args[i].Regs.clear();
+ Args[i].Flags.clear();
+ for (unsigned PartIdx = 0; PartIdx < NumParts; ++PartIdx) {
+ ISD::ArgFlagsTy Flags = OrigFlags;
+ if (PartIdx == 0) {
+ Flags.setSplit();
+ } else {
+ Flags.setOrigAlign(Align::None());
+ if (PartIdx == NumParts - 1)
+ Flags.setSplitEnd();
+ }
+ Args[i].Regs.push_back(Unmerge.getReg(PartIdx));
+ Args[i].Flags.push_back(Flags);
+ if (Handler.assignArg(i + PartIdx, NewVT, NewVT, CCValAssign::Full,
+ Args[i], Args[i].Flags[PartIdx], CCInfo))
+ return false;
+ }
+ }
}
}
@@ -202,18 +293,32 @@ bool CallLowering::handleAssignments(CCState &CCInfo,
continue;
}
- assert(Args[i].Regs.size() == 1 &&
- "Can't handle multiple virtual regs yet");
-
// FIXME: Pack registers if we have more than one.
Register ArgReg = Args[i].Regs[0];
+ MVT OrigVT = MVT::getVT(Args[i].Ty);
+ MVT VAVT = VA.getValVT();
if (VA.isRegLoc()) {
- MVT OrigVT = MVT::getVT(Args[i].Ty);
- MVT VAVT = VA.getValVT();
- if (Handler.isArgumentHandler() && VAVT != OrigVT) {
- if (VAVT.getSizeInBits() < OrigVT.getSizeInBits())
- return false; // Can't handle this type of arg yet.
+ if (Handler.isIncomingArgumentHandler() && VAVT != OrigVT) {
+ if (VAVT.getSizeInBits() < OrigVT.getSizeInBits()) {
+ // Expected to be multiple regs for a single incoming arg.
+ unsigned NumArgRegs = Args[i].Regs.size();
+ if (NumArgRegs < 2)
+ return false;
+
+ assert((j + (NumArgRegs - 1)) < ArgLocs.size() &&
+ "Too many regs for number of args");
+ for (unsigned Part = 0; Part < NumArgRegs; ++Part) {
+ // There should be Regs.size() ArgLocs per argument.
+ VA = ArgLocs[j + Part];
+ Handler.assignValueToReg(Args[i].Regs[Part], VA.getLocReg(), VA);
+ }
+ j += NumArgRegs - 1;
+ // Merge the split registers into the expected larger result vreg
+ // of the original call.
+ MIRBuilder.buildMerge(Args[i].OrigRegs[0], Args[i].Regs);
+ continue;
+ }
const LLT VATy(VAVT);
Register NewReg =
MIRBuilder.getMRI()->createGenericVirtualRegister(VATy);
@@ -234,10 +339,28 @@ bool CallLowering::handleAssignments(CCState &CCInfo,
} else {
MIRBuilder.buildTrunc(ArgReg, {NewReg}).getReg(0);
}
+ } else if (!Handler.isIncomingArgumentHandler()) {
+ assert((j + (Args[i].Regs.size() - 1)) < ArgLocs.size() &&
+ "Too many regs for number of args");
+ // This is an outgoing argument that might have been split.
+ for (unsigned Part = 0; Part < Args[i].Regs.size(); ++Part) {
+ // There should be Regs.size() ArgLocs per argument.
+ VA = ArgLocs[j + Part];
+ Handler.assignValueToReg(Args[i].Regs[Part], VA.getLocReg(), VA);
+ }
+ j += Args[i].Regs.size() - 1;
} else {
Handler.assignValueToReg(ArgReg, VA.getLocReg(), VA);
}
} else if (VA.isMemLoc()) {
+ // Don't currently support loading/storing a type that needs to be split
+ // to the stack. Should be easy, just not implemented yet.
+ if (Args[i].Regs.size() > 1) {
+ LLVM_DEBUG(
+ dbgs()
+ << "Load/store a split arg to/from the stack not implemented yet");
+ return false;
+ }
MVT VT = MVT::getVT(Args[i].Ty);
unsigned Size = VT == MVT::iPTR ? DL.getPointerSize()
: alignTo(VT.getSizeInBits(), 8) / 8;
@@ -253,6 +376,81 @@ bool CallLowering::handleAssignments(CCState &CCInfo,
return true;
}
+bool CallLowering::analyzeArgInfo(CCState &CCState,
+ SmallVectorImpl<ArgInfo> &Args,
+ CCAssignFn &AssignFnFixed,
+ CCAssignFn &AssignFnVarArg) const {
+ for (unsigned i = 0, e = Args.size(); i < e; ++i) {
+ MVT VT = MVT::getVT(Args[i].Ty);
+ CCAssignFn &Fn = Args[i].IsFixed ? AssignFnFixed : AssignFnVarArg;
+ if (Fn(i, VT, VT, CCValAssign::Full, Args[i].Flags[0], CCState)) {
+ // Bail out on anything we can't handle.
+ LLVM_DEBUG(dbgs() << "Cannot analyze " << EVT(VT).getEVTString()
+ << " (arg number = " << i << "\n");
+ return false;
+ }
+ }
+ return true;
+}
+
+bool CallLowering::resultsCompatible(CallLoweringInfo &Info,
+ MachineFunction &MF,
+ SmallVectorImpl<ArgInfo> &InArgs,
+ CCAssignFn &CalleeAssignFnFixed,
+ CCAssignFn &CalleeAssignFnVarArg,
+ CCAssignFn &CallerAssignFnFixed,
+ CCAssignFn &CallerAssignFnVarArg) const {
+ const Function &F = MF.getFunction();
+ CallingConv::ID CalleeCC = Info.CallConv;
+ CallingConv::ID CallerCC = F.getCallingConv();
+
+ if (CallerCC == CalleeCC)
+ return true;
+
+ SmallVector<CCValAssign, 16> ArgLocs1;
+ CCState CCInfo1(CalleeCC, false, MF, ArgLocs1, F.getContext());
+ if (!analyzeArgInfo(CCInfo1, InArgs, CalleeAssignFnFixed,
+ CalleeAssignFnVarArg))
+ return false;
+
+ SmallVector<CCValAssign, 16> ArgLocs2;
+ CCState CCInfo2(CallerCC, false, MF, ArgLocs2, F.getContext());
+ if (!analyzeArgInfo(CCInfo2, InArgs, CallerAssignFnFixed,
+ CalleeAssignFnVarArg))
+ return false;
+
+ // We need the argument locations to match up exactly. If there's more in
+ // one than the other, then we are done.
+ if (ArgLocs1.size() != ArgLocs2.size())
+ return false;
+
+ // Make sure that each location is passed in exactly the same way.
+ for (unsigned i = 0, e = ArgLocs1.size(); i < e; ++i) {
+ const CCValAssign &Loc1 = ArgLocs1[i];
+ const CCValAssign &Loc2 = ArgLocs2[i];
+
+ // We need both of them to be the same. So if one is a register and one
+ // isn't, we're done.
+ if (Loc1.isRegLoc() != Loc2.isRegLoc())
+ return false;
+
+ if (Loc1.isRegLoc()) {
+ // If they don't have the same register location, we're done.
+ if (Loc1.getLocReg() != Loc2.getLocReg())
+ return false;
+
+ // They matched, so we can move to the next ArgLoc.
+ continue;
+ }
+
+ // Loc1 wasn't a RegLoc, so they both must be MemLocs. Check if they match.
+ if (Loc1.getLocMemOffset() != Loc2.getLocMemOffset())
+ return false;
+ }
+
+ return true;
+}
+
Register CallLowering::ValueHandler::extendRegister(Register ValReg,
CCValAssign &VA) {
LLT LocTy{VA.getLocVT()};
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-31 05:14:57 +0000