llvm-project/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp

126 lines
3.6 KiB
C++

//===-- WebAssemblyInstrInfo.cpp - WebAssembly Instruction Information ----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file contains the WebAssembly implementation of the
/// TargetInstrInfo class.
///
//===----------------------------------------------------------------------===//
#include "WebAssemblyInstrInfo.h"
#include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
#include "WebAssemblySubtarget.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
using namespace llvm;
#define DEBUG_TYPE "wasm-instr-info"
#define GET_INSTRINFO_CTOR_DTOR
#include "WebAssemblyGenInstrInfo.inc"
WebAssemblyInstrInfo::WebAssemblyInstrInfo(const WebAssemblySubtarget &STI)
: RI(STI.getTargetTriple()) {}
void WebAssemblyInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
DebugLoc DL, unsigned DestReg,
unsigned SrcReg, bool KillSrc) const {
BuildMI(MBB, I, DL, get(WebAssembly::COPY), DestReg)
.addReg(SrcReg, KillSrc ? RegState::Kill : 0);
}
// Branch analysis.
bool WebAssemblyInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
bool HaveCond = false;
for (MachineInstr &MI : iterator_range<MachineBasicBlock::instr_iterator>(
MBB.getFirstInstrTerminator(), MBB.instr_end())) {
switch (MI.getOpcode()) {
default:
// Unhandled instruction; bail out.
return true;
case WebAssembly::BR_IF:
if (HaveCond)
return true;
Cond.push_back(MI.getOperand(1));
TBB = MI.getOperand(0).getMBB();
HaveCond = true;
break;
case WebAssembly::BR:
if (!HaveCond)
TBB = MI.getOperand(0).getMBB();
else
FBB = MI.getOperand(0).getMBB();
break;
}
if (MI.isBarrier())
break;
}
return false;
}
unsigned WebAssemblyInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
MachineBasicBlock::instr_iterator I = MBB.instr_end();
unsigned Count = 0;
while (I != MBB.instr_begin()) {
--I;
if (I->isDebugValue())
continue;
if (!I->isTerminator())
break;
// Remove the branch.
I->eraseFromParent();
I = MBB.instr_end();
++Count;
}
return Count;
}
unsigned WebAssemblyInstrInfo::InsertBranch(
MachineBasicBlock &MBB, MachineBasicBlock *TBB, MachineBasicBlock *FBB,
ArrayRef<MachineOperand> Cond, DebugLoc DL) const {
assert(Cond.size() <= 1);
if (Cond.empty()) {
if (!TBB)
return 0;
BuildMI(&MBB, DL, get(WebAssembly::BR)).addMBB(TBB);
return 1;
}
BuildMI(&MBB, DL, get(WebAssembly::BR_IF))
.addMBB(TBB)
.addOperand(Cond[0]);
if (!FBB)
return 1;
BuildMI(&MBB, DL, get(WebAssembly::BR)).addMBB(FBB);
return 2;
}
bool WebAssemblyInstrInfo::ReverseBranchCondition(
SmallVectorImpl<MachineOperand> &Cond) const {
assert(Cond.size() == 1);
// TODO: Add branch reversal here... And re-enable MachineBlockPlacementID
// when we do.
return true;
}