llvm-project/llvm/lib/Target/X86/X86CallingConv.h

108 lines
3.8 KiB
C++

//=== X86CallingConv.h - X86 Custom Calling Convention Routines -*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the custom routines for the X86 Calling Convention that
// aren't done by tablegen.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_X86_X86CALLINGCONV_H
#define LLVM_LIB_TARGET_X86_X86CALLINGCONV_H
#include "MCTargetDesc/X86MCTargetDesc.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/IR/CallingConv.h"
namespace llvm {
inline bool CC_X86_32_VectorCallIndirect(unsigned &ValNo, MVT &ValVT,
MVT &LocVT,
CCValAssign::LocInfo &LocInfo,
ISD::ArgFlagsTy &ArgFlags,
CCState &State) {
// Similar to CCPassIndirect, with the addition of inreg.
LocVT = MVT::i32;
LocInfo = CCValAssign::Indirect;
ArgFlags.setInReg();
return false; // Continue the search, but now for i32.
}
inline bool CC_X86_AnyReg_Error(unsigned &, MVT &, MVT &,
CCValAssign::LocInfo &, ISD::ArgFlagsTy &,
CCState &) {
llvm_unreachable("The AnyReg calling convention is only supported by the " \
"stackmap and patchpoint intrinsics.");
// gracefully fallback to X86 C calling convention on Release builds.
return false;
}
inline bool CC_X86_32_MCUInReg(unsigned &ValNo, MVT &ValVT,
MVT &LocVT,
CCValAssign::LocInfo &LocInfo,
ISD::ArgFlagsTy &ArgFlags,
CCState &State) {
// This is similar to CCAssignToReg<[EAX, EDX, ECX]>, but makes sure
// not to split i64 and double between a register and stack
static const MCPhysReg RegList[] = {X86::EAX, X86::EDX, X86::ECX};
static const unsigned NumRegs = sizeof(RegList)/sizeof(RegList[0]);
SmallVectorImpl<CCValAssign> &PendingMembers = State.getPendingLocs();
// If this is the first part of an double/i64/i128, or if we're already
// in the middle of a split, add to the pending list. If this is not
// the end of the split, return, otherwise go on to process the pending
// list
if (ArgFlags.isSplit() || !PendingMembers.empty()) {
PendingMembers.push_back(
CCValAssign::getPending(ValNo, ValVT, LocVT, LocInfo));
if (!ArgFlags.isSplitEnd())
return true;
}
// If there are no pending members, we are not in the middle of a split,
// so do the usual inreg stuff.
if (PendingMembers.empty()) {
if (unsigned Reg = State.AllocateReg(RegList)) {
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return true;
}
return false;
}
assert(ArgFlags.isSplitEnd());
// We now have the entire original argument in PendingMembers, so decide
// whether to use registers or the stack.
// Per the MCU ABI:
// a) To use registers, we need to have enough of them free to contain
// the entire argument.
// b) We never want to use more than 2 registers for a single argument.
unsigned FirstFree = State.getFirstUnallocated(RegList);
bool UseRegs = PendingMembers.size() <= std::min(2U, NumRegs - FirstFree);
for (auto &It : PendingMembers) {
if (UseRegs)
It.convertToReg(State.AllocateReg(RegList[FirstFree++]));
else
It.convertToMem(State.AllocateStack(4, 4));
State.addLoc(It);
}
PendingMembers.clear();
return true;
}
} // End llvm namespace
#endif