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-rw-r--r--llvm/lib/CodeGen/SelectionDAG/FastISel.cpp210
1 files changed, 208 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
index f68843e54a6..f77343b3f7c 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -39,6 +39,7 @@
//
//===----------------------------------------------------------------------===//
+#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/Statistic.h"
@@ -74,6 +75,21 @@ STATISTIC(NumFastIselSuccessTarget, "Number of insts selected by "
"target-specific selector");
STATISTIC(NumFastIselDead, "Number of dead insts removed on failure");
+/// \brief Set CallLoweringInfo attribute flags based on a call instruction
+/// and called function attributes.
+void FastISel::ArgListEntry::setAttributes(ImmutableCallSite *CS,
+ unsigned AttrIdx) {
+ isSExt = CS->paramHasAttr(AttrIdx, Attribute::SExt);
+ isZExt = CS->paramHasAttr(AttrIdx, Attribute::ZExt);
+ isInReg = CS->paramHasAttr(AttrIdx, Attribute::InReg);
+ 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);
+}
+
/// startNewBlock - Set the current block to which generated machine
/// instructions will be appended, and clear the local CSE map.
///
@@ -662,6 +678,193 @@ bool FastISel::SelectStackmap(const CallInst *I) {
return true;
}
+/// Returns an AttributeSet representing the attributes applied to the return
+/// value of the given call.
+static AttributeSet getReturnAttrs(FastISel::CallLoweringInfo &CLI) {
+ SmallVector<Attribute::AttrKind, 2> Attrs;
+ if (CLI.RetSExt)
+ Attrs.push_back(Attribute::SExt);
+ if (CLI.RetZExt)
+ Attrs.push_back(Attribute::ZExt);
+ if (CLI.IsInReg)
+ Attrs.push_back(Attribute::InReg);
+
+ return AttributeSet::get(CLI.RetTy->getContext(), AttributeSet::ReturnIndex,
+ Attrs);
+}
+
+bool FastISel::LowerCallTo(const CallInst *CI, const char *SymName,
+ unsigned NumArgs) {
+ ImmutableCallSite CS(CI);
+
+ PointerType *PT = cast<PointerType>(CS.getCalledValue()->getType());
+ FunctionType *FTy = cast<FunctionType>(PT->getElementType());
+ Type *RetTy = FTy->getReturnType();
+
+ ArgListTy Args;
+ Args.reserve(NumArgs);
+
+ // Populate the argument list.
+ // Attributes for args start at offset 1, after the return attribute.
+ for (unsigned ArgI = 0; ArgI != NumArgs; ++ArgI) {
+ Value *V = CI->getOperand(ArgI);
+
+ assert(!V->getType()->isEmptyTy() && "Empty type passed to intrinsic.");
+
+ ArgListEntry Entry;
+ Entry.Val = V;
+ Entry.Ty = V->getType();
+ Entry.setAttributes(&CS, ArgI + 1);
+ Args.push_back(Entry);
+ }
+
+ CallLoweringInfo CLI;
+ CLI.setCallee(RetTy, FTy, SymName, std::move(Args), CS, NumArgs);
+
+ return LowerCallTo(CLI);
+}
+
+bool FastISel::LowerCallTo(CallLoweringInfo &CLI) {
+ // Handle the incoming return values from the call.
+ CLI.clearIns();
+ SmallVector<EVT, 4> RetTys;
+ ComputeValueVTs(TLI, CLI.RetTy, RetTys);
+
+ SmallVector<ISD::OutputArg, 4> Outs;
+ GetReturnInfo(CLI.RetTy, getReturnAttrs(CLI), Outs, TLI);
+
+ bool CanLowerReturn = TLI.CanLowerReturn(CLI.CallConv, *FuncInfo.MF,
+ CLI.IsVarArg, Outs,
+ CLI.RetTy->getContext());
+
+ // FIXME: sret demotion isn't supported yet - bail out.
+ if (!CanLowerReturn)
+ return false;
+
+ for (unsigned I = 0, E = RetTys.size(); I != E; ++I) {
+ EVT VT = RetTys[I];
+ MVT RegisterVT = TLI.getRegisterType(CLI.RetTy->getContext(), VT);
+ unsigned NumRegs = TLI.getNumRegisters(CLI.RetTy->getContext(), VT);
+ for (unsigned i = 0; i != NumRegs; ++i) {
+ ISD::InputArg MyFlags;
+ MyFlags.VT = RegisterVT;
+ MyFlags.ArgVT = VT;
+ MyFlags.Used = CLI.IsReturnValueUsed;
+ if (CLI.RetSExt)
+ MyFlags.Flags.setSExt();
+ if (CLI.RetZExt)
+ MyFlags.Flags.setZExt();
+ if (CLI.IsInReg)
+ MyFlags.Flags.setInReg();
+ CLI.Ins.push_back(MyFlags);
+ }
+ }
+
+ // Handle all of the outgoing arguments.
+ CLI.clearOuts();
+ for (auto &Arg : CLI.getArgs()) {
+ Type *FinalType = Arg.Ty;
+ if (Arg.isByVal)
+ FinalType = cast<PointerType>(Arg.Ty)->getElementType();
+ bool NeedsRegBlock = TLI.functionArgumentNeedsConsecutiveRegisters(
+ FinalType, CLI.CallConv, CLI.IsVarArg);
+
+ ISD::ArgFlagsTy Flags;
+ if (Arg.isZExt)
+ Flags.setZExt();
+ if (Arg.isSExt)
+ Flags.setSExt();
+ if (Arg.isInReg)
+ Flags.setInReg();
+ if (Arg.isSRet)
+ Flags.setSRet();
+ if (Arg.isByVal)
+ Flags.setByVal();
+ if (Arg.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 (Arg.isByVal || Arg.isInAlloca) {
+ PointerType *Ty = cast<PointerType>(Arg.Ty);
+ Type *ElementTy = Ty->getElementType();
+ unsigned FrameSize = DL.getTypeAllocSize(ElementTy);
+ // For ByVal, alignment should come from FE. BE will guess if this info is
+ // not there, but there are cases it cannot get right.
+ unsigned FrameAlign = Arg.Alignment;
+ if (!FrameAlign)
+ FrameAlign = TLI.getByValTypeAlignment(ElementTy);
+ Flags.setByValSize(FrameSize);
+ Flags.setByValAlign(FrameAlign);
+ }
+ if (Arg.isNest)
+ Flags.setNest();
+ if (NeedsRegBlock)
+ Flags.setInConsecutiveRegs();
+ unsigned OriginalAlignment = DL.getABITypeAlignment(Arg.Ty);
+ Flags.setOrigAlign(OriginalAlignment);
+
+ CLI.OutVals.push_back(Arg.Val);
+ CLI.OutFlags.push_back(Flags);
+ }
+
+ if (!FastLowerCall(CLI))
+ return false;
+
+ // Set all unused physreg defs as dead.
+ assert(CLI.Call && "No call instruction specified.");
+ CLI.Call->setPhysRegsDeadExcept(CLI.InRegs, TRI);
+
+ if (CLI.NumResultRegs && CLI.CS)
+ UpdateValueMap(CLI.CS->getInstruction(), CLI.ResultReg, CLI.NumResultRegs);
+
+ return true;
+}
+
+bool FastISel::LowerCall(const CallInst *CI) {
+ ImmutableCallSite CS(CI);
+
+ PointerType *PT = cast<PointerType>(CS.getCalledValue()->getType());
+ FunctionType *FuncTy = cast<FunctionType>(PT->getElementType());
+ Type *RetTy = FuncTy->getReturnType();
+
+ ArgListTy Args;
+ ArgListEntry Entry;
+ Args.reserve(CS.arg_size());
+
+ for (ImmutableCallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end();
+ i != e; ++i) {
+ Value *V = *i;
+
+ // Skip empty types
+ if (V->getType()->isEmptyTy())
+ continue;
+
+ Entry.Val = V;
+ Entry.Ty = V->getType();
+
+ // Skip the first return-type Attribute to get to params.
+ Entry.setAttributes(&CS, i - CS.arg_begin() + 1);
+ Args.push_back(Entry);
+ }
+
+ // Check if target-independent constraints permit a tail call here.
+ // Target-dependent constraints are checked within FastLowerCall.
+ bool IsTailCall = CI->isTailCall();
+ if (IsTailCall && !isInTailCallPosition(CS, TM, TLI))
+ IsTailCall = false;
+
+ CallLoweringInfo CLI;
+ CLI.setCallee(RetTy, FuncTy, CI->getCalledValue(), std::move(Args), CS)
+ .setTailCall(IsTailCall);
+
+ return LowerCallTo(CLI);
+}
+
bool FastISel::SelectCall(const User *I) {
const CallInst *Call = cast<CallInst>(I);
@@ -700,8 +903,7 @@ bool FastISel::SelectCall(const User *I) {
// since they tend to be inlined.
flushLocalValueMap();
- // An arbitrary call. Bail.
- return false;
+ return LowerCall(Call);
}
bool FastISel::SelectIntrinsicCall(const IntrinsicInst *II) {
@@ -1229,6 +1431,10 @@ bool FastISel::FastLowerArguments() {
return false;
}
+bool FastISel::FastLowerCall(CallLoweringInfo &/*CLI*/) {
+ return false;
+}
+
bool FastISel::FastLowerIntrinsicCall(const IntrinsicInst */*II*/) {
return false;
}
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