forked from OSchip/llvm-project
451 lines
15 KiB
C++
451 lines
15 KiB
C++
//===-- XCoreInstrInfo.cpp - XCore Instruction Information ----------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file contains the XCore implementation of the TargetInstrInfo class.
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//
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//===----------------------------------------------------------------------===//
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#include "XCoreInstrInfo.h"
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#include "XCore.h"
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#include "XCoreMachineFunctionInfo.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/CodeGen/MachineConstantPool.h"
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#include "llvm/CodeGen/MachineFrameInfo.h"
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#include "llvm/CodeGen/MachineInstrBuilder.h"
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#include "llvm/CodeGen/MachineMemOperand.h"
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/Function.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/TargetRegistry.h"
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using namespace llvm;
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#define GET_INSTRINFO_CTOR_DTOR
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#include "XCoreGenInstrInfo.inc"
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namespace llvm {
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namespace XCore {
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// XCore Condition Codes
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enum CondCode {
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COND_TRUE,
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COND_FALSE,
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COND_INVALID
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};
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}
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}
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// Pin the vtable to this file.
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void XCoreInstrInfo::anchor() {}
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XCoreInstrInfo::XCoreInstrInfo()
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: XCoreGenInstrInfo(XCore::ADJCALLSTACKDOWN, XCore::ADJCALLSTACKUP),
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RI() {
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}
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static bool isZeroImm(const MachineOperand &op) {
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return op.isImm() && op.getImm() == 0;
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}
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/// isLoadFromStackSlot - If the specified machine instruction is a direct
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/// load from a stack slot, return the virtual or physical register number of
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/// the destination along with the FrameIndex of the loaded stack slot. If
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/// not, return 0. This predicate must return 0 if the instruction has
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/// any side effects other than loading from the stack slot.
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unsigned XCoreInstrInfo::isLoadFromStackSlot(const MachineInstr &MI,
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int &FrameIndex) const {
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int Opcode = MI.getOpcode();
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if (Opcode == XCore::LDWFI)
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{
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if ((MI.getOperand(1).isFI()) && // is a stack slot
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(MI.getOperand(2).isImm()) && // the imm is zero
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(isZeroImm(MI.getOperand(2)))) {
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FrameIndex = MI.getOperand(1).getIndex();
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return MI.getOperand(0).getReg();
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}
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}
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return 0;
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}
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/// isStoreToStackSlot - If the specified machine instruction is a direct
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/// store to a stack slot, return the virtual or physical register number of
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/// the source reg along with the FrameIndex of the loaded stack slot. If
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/// not, return 0. This predicate must return 0 if the instruction has
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/// any side effects other than storing to the stack slot.
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unsigned XCoreInstrInfo::isStoreToStackSlot(const MachineInstr &MI,
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int &FrameIndex) const {
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int Opcode = MI.getOpcode();
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if (Opcode == XCore::STWFI)
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{
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if ((MI.getOperand(1).isFI()) && // is a stack slot
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(MI.getOperand(2).isImm()) && // the imm is zero
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(isZeroImm(MI.getOperand(2)))) {
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FrameIndex = MI.getOperand(1).getIndex();
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return MI.getOperand(0).getReg();
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}
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}
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return 0;
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}
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//===----------------------------------------------------------------------===//
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// Branch Analysis
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//===----------------------------------------------------------------------===//
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static inline bool IsBRU(unsigned BrOpc) {
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return BrOpc == XCore::BRFU_u6
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|| BrOpc == XCore::BRFU_lu6
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|| BrOpc == XCore::BRBU_u6
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|| BrOpc == XCore::BRBU_lu6;
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}
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static inline bool IsBRT(unsigned BrOpc) {
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return BrOpc == XCore::BRFT_ru6
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|| BrOpc == XCore::BRFT_lru6
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|| BrOpc == XCore::BRBT_ru6
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|| BrOpc == XCore::BRBT_lru6;
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}
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static inline bool IsBRF(unsigned BrOpc) {
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return BrOpc == XCore::BRFF_ru6
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|| BrOpc == XCore::BRFF_lru6
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|| BrOpc == XCore::BRBF_ru6
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|| BrOpc == XCore::BRBF_lru6;
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}
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static inline bool IsCondBranch(unsigned BrOpc) {
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return IsBRF(BrOpc) || IsBRT(BrOpc);
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}
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static inline bool IsBR_JT(unsigned BrOpc) {
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return BrOpc == XCore::BR_JT
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|| BrOpc == XCore::BR_JT32;
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}
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/// GetCondFromBranchOpc - Return the XCore CC that matches
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/// the correspondent Branch instruction opcode.
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static XCore::CondCode GetCondFromBranchOpc(unsigned BrOpc)
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{
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if (IsBRT(BrOpc)) {
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return XCore::COND_TRUE;
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} else if (IsBRF(BrOpc)) {
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return XCore::COND_FALSE;
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} else {
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return XCore::COND_INVALID;
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}
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}
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/// GetCondBranchFromCond - Return the Branch instruction
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/// opcode that matches the cc.
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static inline unsigned GetCondBranchFromCond(XCore::CondCode CC)
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{
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switch (CC) {
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default: llvm_unreachable("Illegal condition code!");
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case XCore::COND_TRUE : return XCore::BRFT_lru6;
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case XCore::COND_FALSE : return XCore::BRFF_lru6;
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}
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}
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/// GetOppositeBranchCondition - Return the inverse of the specified
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/// condition, e.g. turning COND_E to COND_NE.
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static inline XCore::CondCode GetOppositeBranchCondition(XCore::CondCode CC)
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{
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switch (CC) {
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default: llvm_unreachable("Illegal condition code!");
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case XCore::COND_TRUE : return XCore::COND_FALSE;
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case XCore::COND_FALSE : return XCore::COND_TRUE;
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}
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}
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/// analyzeBranch - Analyze the branching code at the end of MBB, returning
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/// true if it cannot be understood (e.g. it's a switch dispatch or isn't
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/// implemented for a target). Upon success, this returns false and returns
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/// with the following information in various cases:
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///
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/// 1. If this block ends with no branches (it just falls through to its succ)
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/// just return false, leaving TBB/FBB null.
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/// 2. If this block ends with only an unconditional branch, it sets TBB to be
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/// the destination block.
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/// 3. If this block ends with an conditional branch and it falls through to
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/// an successor block, it sets TBB to be the branch destination block and a
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/// list of operands that evaluate the condition. These
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/// operands can be passed to other TargetInstrInfo methods to create new
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/// branches.
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/// 4. If this block ends with an conditional branch and an unconditional
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/// block, it returns the 'true' destination in TBB, the 'false' destination
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/// in FBB, and a list of operands that evaluate the condition. These
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/// operands can be passed to other TargetInstrInfo methods to create new
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/// branches.
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///
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/// Note that removeBranch and insertBranch must be implemented to support
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/// cases where this method returns success.
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///
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bool XCoreInstrInfo::analyzeBranch(MachineBasicBlock &MBB,
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MachineBasicBlock *&TBB,
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MachineBasicBlock *&FBB,
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SmallVectorImpl<MachineOperand> &Cond,
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bool AllowModify) const {
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// If the block has no terminators, it just falls into the block after it.
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MachineBasicBlock::iterator I = MBB.getLastNonDebugInstr();
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if (I == MBB.end())
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return false;
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if (!isUnpredicatedTerminator(*I))
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return false;
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// Get the last instruction in the block.
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MachineInstr *LastInst = &*I;
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// If there is only one terminator instruction, process it.
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if (I == MBB.begin() || !isUnpredicatedTerminator(*--I)) {
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if (IsBRU(LastInst->getOpcode())) {
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TBB = LastInst->getOperand(0).getMBB();
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return false;
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}
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XCore::CondCode BranchCode = GetCondFromBranchOpc(LastInst->getOpcode());
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if (BranchCode == XCore::COND_INVALID)
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return true; // Can't handle indirect branch.
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// Conditional branch
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// Block ends with fall-through condbranch.
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TBB = LastInst->getOperand(1).getMBB();
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Cond.push_back(MachineOperand::CreateImm(BranchCode));
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Cond.push_back(LastInst->getOperand(0));
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return false;
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}
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// Get the instruction before it if it's a terminator.
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MachineInstr *SecondLastInst = &*I;
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// If there are three terminators, we don't know what sort of block this is.
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if (SecondLastInst && I != MBB.begin() && isUnpredicatedTerminator(*--I))
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return true;
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unsigned SecondLastOpc = SecondLastInst->getOpcode();
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XCore::CondCode BranchCode = GetCondFromBranchOpc(SecondLastOpc);
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// If the block ends with conditional branch followed by unconditional,
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// handle it.
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if (BranchCode != XCore::COND_INVALID
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&& IsBRU(LastInst->getOpcode())) {
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TBB = SecondLastInst->getOperand(1).getMBB();
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Cond.push_back(MachineOperand::CreateImm(BranchCode));
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Cond.push_back(SecondLastInst->getOperand(0));
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FBB = LastInst->getOperand(0).getMBB();
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return false;
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}
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// If the block ends with two unconditional branches, handle it. The second
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// one is not executed, so remove it.
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if (IsBRU(SecondLastInst->getOpcode()) &&
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IsBRU(LastInst->getOpcode())) {
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TBB = SecondLastInst->getOperand(0).getMBB();
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I = LastInst;
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if (AllowModify)
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I->eraseFromParent();
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return false;
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}
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// Likewise if it ends with a branch table followed by an unconditional branch.
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if (IsBR_JT(SecondLastInst->getOpcode()) && IsBRU(LastInst->getOpcode())) {
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I = LastInst;
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if (AllowModify)
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I->eraseFromParent();
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return true;
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}
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// Otherwise, can't handle this.
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return true;
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}
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unsigned XCoreInstrInfo::insertBranch(MachineBasicBlock &MBB,
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MachineBasicBlock *TBB,
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MachineBasicBlock *FBB,
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ArrayRef<MachineOperand> Cond,
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const DebugLoc &DL,
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int *BytesAdded) const {
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// Shouldn't be a fall through.
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assert(TBB && "insertBranch must not be told to insert a fallthrough");
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assert((Cond.size() == 2 || Cond.size() == 0) &&
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"Unexpected number of components!");
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assert(!BytesAdded && "code size not handled");
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if (!FBB) { // One way branch.
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if (Cond.empty()) {
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// Unconditional branch
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BuildMI(&MBB, DL, get(XCore::BRFU_lu6)).addMBB(TBB);
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} else {
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// Conditional branch.
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unsigned Opc = GetCondBranchFromCond((XCore::CondCode)Cond[0].getImm());
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BuildMI(&MBB, DL, get(Opc)).addReg(Cond[1].getReg())
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.addMBB(TBB);
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}
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return 1;
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}
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// Two-way Conditional branch.
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assert(Cond.size() == 2 && "Unexpected number of components!");
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unsigned Opc = GetCondBranchFromCond((XCore::CondCode)Cond[0].getImm());
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BuildMI(&MBB, DL, get(Opc)).addReg(Cond[1].getReg())
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.addMBB(TBB);
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BuildMI(&MBB, DL, get(XCore::BRFU_lu6)).addMBB(FBB);
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return 2;
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}
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unsigned
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XCoreInstrInfo::removeBranch(MachineBasicBlock &MBB, int *BytesRemoved) const {
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assert(!BytesRemoved && "code size not handled");
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MachineBasicBlock::iterator I = MBB.getLastNonDebugInstr();
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if (I == MBB.end())
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return 0;
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if (!IsBRU(I->getOpcode()) && !IsCondBranch(I->getOpcode()))
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return 0;
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// Remove the branch.
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I->eraseFromParent();
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I = MBB.end();
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if (I == MBB.begin()) return 1;
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--I;
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if (!IsCondBranch(I->getOpcode()))
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return 1;
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// Remove the branch.
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I->eraseFromParent();
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return 2;
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}
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void XCoreInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator I,
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const DebugLoc &DL, MCRegister DestReg,
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MCRegister SrcReg, bool KillSrc) const {
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bool GRDest = XCore::GRRegsRegClass.contains(DestReg);
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bool GRSrc = XCore::GRRegsRegClass.contains(SrcReg);
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if (GRDest && GRSrc) {
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BuildMI(MBB, I, DL, get(XCore::ADD_2rus), DestReg)
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.addReg(SrcReg, getKillRegState(KillSrc))
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.addImm(0);
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return;
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}
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if (GRDest && SrcReg == XCore::SP) {
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BuildMI(MBB, I, DL, get(XCore::LDAWSP_ru6), DestReg).addImm(0);
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return;
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}
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if (DestReg == XCore::SP && GRSrc) {
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BuildMI(MBB, I, DL, get(XCore::SETSP_1r))
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.addReg(SrcReg, getKillRegState(KillSrc));
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return;
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}
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llvm_unreachable("Impossible reg-to-reg copy");
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}
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void XCoreInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator I,
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Register SrcReg, bool isKill,
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int FrameIndex,
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const TargetRegisterClass *RC,
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const TargetRegisterInfo *TRI) const
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{
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DebugLoc DL;
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if (I != MBB.end() && !I->isDebugInstr())
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DL = I->getDebugLoc();
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MachineFunction *MF = MBB.getParent();
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const MachineFrameInfo &MFI = MF->getFrameInfo();
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MachineMemOperand *MMO = MF->getMachineMemOperand(
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MachinePointerInfo::getFixedStack(*MF, FrameIndex),
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MachineMemOperand::MOStore, MFI.getObjectSize(FrameIndex),
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MFI.getObjectAlign(FrameIndex));
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BuildMI(MBB, I, DL, get(XCore::STWFI))
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.addReg(SrcReg, getKillRegState(isKill))
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.addFrameIndex(FrameIndex)
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.addImm(0)
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.addMemOperand(MMO);
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}
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void XCoreInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator I,
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Register DestReg, int FrameIndex,
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const TargetRegisterClass *RC,
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const TargetRegisterInfo *TRI) const
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{
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DebugLoc DL;
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if (I != MBB.end() && !I->isDebugInstr())
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DL = I->getDebugLoc();
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MachineFunction *MF = MBB.getParent();
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const MachineFrameInfo &MFI = MF->getFrameInfo();
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MachineMemOperand *MMO = MF->getMachineMemOperand(
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MachinePointerInfo::getFixedStack(*MF, FrameIndex),
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MachineMemOperand::MOLoad, MFI.getObjectSize(FrameIndex),
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MFI.getObjectAlign(FrameIndex));
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BuildMI(MBB, I, DL, get(XCore::LDWFI), DestReg)
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.addFrameIndex(FrameIndex)
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.addImm(0)
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.addMemOperand(MMO);
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}
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bool XCoreInstrInfo::
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reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
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assert((Cond.size() == 2) &&
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"Invalid XCore branch condition!");
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Cond[0].setImm(GetOppositeBranchCondition((XCore::CondCode)Cond[0].getImm()));
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return false;
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}
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static inline bool isImmU6(unsigned val) {
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return val < (1 << 6);
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}
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static inline bool isImmU16(unsigned val) {
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return val < (1 << 16);
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}
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static bool isImmMskBitp(unsigned val) {
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if (!isMask_32(val)) {
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return false;
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}
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int N = Log2_32(val) + 1;
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return (N >= 1 && N <= 8) || N == 16 || N == 24 || N == 32;
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}
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MachineBasicBlock::iterator XCoreInstrInfo::loadImmediate(
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MachineBasicBlock &MBB,
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MachineBasicBlock::iterator MI,
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unsigned Reg, uint64_t Value) const {
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DebugLoc dl;
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if (MI != MBB.end() && !MI->isDebugInstr())
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dl = MI->getDebugLoc();
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if (isImmMskBitp(Value)) {
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int N = Log2_32(Value) + 1;
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return BuildMI(MBB, MI, dl, get(XCore::MKMSK_rus), Reg)
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.addImm(N)
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.getInstr();
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}
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if (isImmU16(Value)) {
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int Opcode = isImmU6(Value) ? XCore::LDC_ru6 : XCore::LDC_lru6;
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return BuildMI(MBB, MI, dl, get(Opcode), Reg).addImm(Value).getInstr();
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}
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MachineConstantPool *ConstantPool = MBB.getParent()->getConstantPool();
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const Constant *C = ConstantInt::get(
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Type::getInt32Ty(MBB.getParent()->getFunction().getContext()), Value);
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unsigned Idx = ConstantPool->getConstantPoolIndex(C, Align(4));
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return BuildMI(MBB, MI, dl, get(XCore::LDWCP_lru6), Reg)
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.addConstantPoolIndex(Idx)
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.getInstr();
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}
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