//===-- CSKYAsmBackend.cpp - CSKY Assembler Backend -----------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "CSKYAsmBackend.h"
#include "MCTargetDesc/CSKYMCTargetDesc.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCFixupKindInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/Support/Debug.h"
#define DEBUG_TYPE "csky-asmbackend"
using namespace llvm;
std::unique_ptr<MCObjectTargetWriter>
CSKYAsmBackend::createObjectTargetWriter() const {
return createCSKYELFObjectWriter();
}
const MCFixupKindInfo &
CSKYAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
static llvm::DenseMap<unsigned, MCFixupKindInfo> Infos = {
{CSKY::Fixups::fixup_csky_addr32, {"fixup_csky_addr32", 0, 32, 0}},
{CSKY::Fixups::fixup_csky_addr_hi16, {"fixup_csky_addr_hi16", 0, 32, 0}},
{CSKY::Fixups::fixup_csky_addr_lo16, {"fixup_csky_addr_lo16", 0, 32, 0}},
{CSKY::Fixups::fixup_csky_pcrel_imm16_scale2,
{"fixup_csky_pcrel_imm16_scale2", 0, 32, MCFixupKindInfo::FKF_IsPCRel}},
{CSKY::Fixups::fixup_csky_pcrel_uimm16_scale4,
{"fixup_csky_pcrel_uimm16_scale4", 0, 32,
MCFixupKindInfo::FKF_IsPCRel |
MCFixupKindInfo::FKF_IsAlignedDownTo32Bits}},
{CSKY::Fixups::fixup_csky_pcrel_uimm8_scale4,
{"fixup_csky_pcrel_uimm8_scale4", 0, 32,
MCFixupKindInfo::FKF_IsPCRel |
MCFixupKindInfo::FKF_IsAlignedDownTo32Bits}},
{CSKY::Fixups::fixup_csky_pcrel_imm26_scale2,
{"fixup_csky_pcrel_imm26_scale2", 0, 32, MCFixupKindInfo::FKF_IsPCRel}},
{CSKY::Fixups::fixup_csky_pcrel_imm18_scale2,
{"fixup_csky_pcrel_imm18_scale2", 0, 32, MCFixupKindInfo::FKF_IsPCRel}},
{CSKY::Fixups::fixup_csky_got32, {"fixup_csky_got32", 0, 32, 0}},
{CSKY::Fixups::fixup_csky_got_imm18_scale4,
{"fixup_csky_got_imm18_scale4", 0, 32, 0}},
{CSKY::Fixups::fixup_csky_gotoff, {"fixup_csky_gotoff", 0, 32, 0}},
{CSKY::Fixups::fixup_csky_gotpc,
{"fixup_csky_gotpc", 0, 32, MCFixupKindInfo::FKF_IsPCRel}},
{CSKY::Fixups::fixup_csky_plt32, {"fixup_csky_plt32", 0, 32, 0}},
{CSKY::Fixups::fixup_csky_plt_imm18_scale4,
{"fixup_csky_plt_imm18_scale4", 0, 32, 0}},
{CSKY::Fixups::fixup_csky_pcrel_imm10_scale2,
{"fixup_csky_pcrel_imm10_scale2", 0, 16, MCFixupKindInfo::FKF_IsPCRel}},
{CSKY::Fixups::fixup_csky_pcrel_uimm7_scale4,
{"fixup_csky_pcrel_uimm7_scale4", 0, 16,
MCFixupKindInfo::FKF_IsPCRel |
MCFixupKindInfo::FKF_IsAlignedDownTo32Bits}},
{CSKY::Fixups::fixup_csky_doffset_imm18,
{"fixup_csky_doffset_imm18", 0, 18, 0}},
{CSKY::Fixups::fixup_csky_doffset_imm18_scale2,
{"fixup_csky_doffset_imm18_scale2", 0, 18, 0}},
{CSKY::Fixups::fixup_csky_doffset_imm18_scale4,
{"fixup_csky_doffset_imm18_scale4", 0, 18, 0}}};
assert(Infos.size() == CSKY::NumTargetFixupKinds &&
"Not all fixup kinds added to Infos array");
if (FirstTargetFixupKind <= Kind && Kind < FirstLiteralRelocationKind) {
assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
"Invalid kind!");
return Infos[Kind];
} else if (Kind < FirstTargetFixupKind) {
return MCAsmBackend::getFixupKindInfo(Kind);
} else {
return MCAsmBackend::getFixupKindInfo(FK_NONE);
}
}
static uint64_t adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
MCContext &Ctx) {
switch (Fixup.getTargetKind()) {
default:
llvm_unreachable("Unknown fixup kind!");
case CSKY::fixup_csky_got32:
case CSKY::fixup_csky_got_imm18_scale4:
case CSKY::fixup_csky_gotoff:
case CSKY::fixup_csky_gotpc:
case CSKY::fixup_csky_plt32:
case CSKY::fixup_csky_plt_imm18_scale4:
llvm_unreachable("Relocation should be unconditionally forced\n");
case FK_Data_1:
case FK_Data_2:
case FK_Data_4:
case FK_Data_8:
return Value;
case CSKY::fixup_csky_addr32:
return Value & 0xffffffff;
case CSKY::fixup_csky_pcrel_imm16_scale2:
if (!isIntN(17, Value))
Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value.");
if (Value & 0x1)
Ctx.reportError(Fixup.getLoc(), "fixup value must be 2-byte aligned.");
return (Value >> 1) & 0xffff;
case CSKY::fixup_csky_pcrel_uimm16_scale4:
if (!isUIntN(18, Value))
Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value.");
if (Value & 0x3)
Ctx.reportError(Fixup.getLoc(), "fixup value must be 4-byte aligned.");
return (Value >> 2) & 0xffff;
case CSKY::fixup_csky_pcrel_imm26_scale2:
if (!isIntN(27, Value))
Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value.");
if (Value & 0x1)
Ctx.reportError(Fixup.getLoc(), "fixup value must be 2-byte aligned.");
return (Value >> 1) & 0x3ffffff;
case CSKY::fixup_csky_pcrel_imm18_scale2:
if (!isIntN(19, Value))
Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value.");
if (Value & 0x1)
Ctx.reportError(Fixup.getLoc(), "fixup value must be 2-byte aligned.");
return (Value >> 1) & 0x3ffff;
case CSKY::fixup_csky_pcrel_uimm8_scale4: {
if (!isUIntN(10, Value))
Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value.");
if (Value & 0x3)
Ctx.reportError(Fixup.getLoc(), "fixup value must be 4-byte aligned.");
unsigned IMM4L = (Value >> 2) & 0xf;
unsigned IMM4H = (Value >> 6) & 0xf;
Value = (IMM4H << 21) | (IMM4L << 4);
return Value;
}
case CSKY::fixup_csky_pcrel_imm10_scale2:
if (!isIntN(11, Value))
Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value.");
if (Value & 0x1)
Ctx.reportError(Fixup.getLoc(), "fixup value must be 2-byte aligned.");
return (Value >> 1) & 0x3ff;
case CSKY::fixup_csky_pcrel_uimm7_scale4:
if ((Value >> 2) > 0xfe)
Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value.");
if (Value & 0x3)
Ctx.reportError(Fixup.getLoc(), "fixup value must be 4-byte aligned.");
if ((Value >> 2) <= 0x7f) {
unsigned IMM5L = (Value >> 2) & 0x1f;
unsigned IMM2H = (Value >> 7) & 0x3;
Value = (1 << 12) | (IMM2H << 8) | IMM5L;
} else {
unsigned IMM5L = (~Value >> 2) & 0x1f;
unsigned IMM2H = (~Value >> 7) & 0x3;
Value = (IMM2H << 8) | IMM5L;
}
return Value;
}
}
bool CSKYAsmBackend::fixupNeedsRelaxationAdvanced(const MCAssembler &Asm,
const MCFixup &Fixup,
bool Resolved, uint64_t Value,
const MCRelaxableFragment *DF,
const bool WasForced) const {
// Return true if the symbol is actually unresolved.
// Resolved could be always false when shouldForceRelocation return true.
// We use !WasForced to indicate that the symbol is unresolved and not forced
// by shouldForceRelocation.
if (!Resolved && !WasForced)
return true;
int64_t Offset = int64_t(Value);
switch (Fixup.getTargetKind()) {
default:
return false;
case CSKY::fixup_csky_pcrel_imm10_scale2:
return !isShiftedInt<10, 1>(Offset);
case CSKY::fixup_csky_pcrel_imm16_scale2:
return !isShiftedInt<16, 1>(Offset);
case CSKY::fixup_csky_pcrel_imm26_scale2:
return !isShiftedInt<26, 1>(Offset);
case CSKY::fixup_csky_pcrel_uimm7_scale4:
return ((Value >> 2) > 0xfe) || (Value & 0x3);
}
}
void CSKYAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
const MCValue &Target,
MutableArrayRef<char> Data, uint64_t Value,
bool IsResolved,
const MCSubtargetInfo *STI) const {
MCFixupKind Kind = Fixup.getKind();
if (Kind >= FirstLiteralRelocationKind)
return;
MCContext &Ctx = Asm.getContext();
MCFixupKindInfo Info = getFixupKindInfo(Kind);
if (!Value)
return; // Doesn't change encoding.
// Apply any target-specific value adjustments.
Value = adjustFixupValue(Fixup, Value, Ctx);
// Shift the value into position.
Value <<= Info.TargetOffset;
unsigned Offset = Fixup.getOffset();
unsigned NumBytes = alignTo(Info.TargetSize + Info.TargetOffset, 8) / 8;
assert(Offset + NumBytes <= Data.size() && "Invalid fixup offset!");
// For each byte of the fragment that the fixup touches, mask in the
// bits from the fixup value.
bool IsLittleEndian = (Endian == llvm::endianness::little);
bool IsInstFixup = (Kind >= FirstTargetFixupKind);
if (IsLittleEndian && IsInstFixup && (NumBytes == 4)) {
Data[Offset + 0] |= uint8_t((Value >> 16) & 0xff);
Data[Offset + 1] |= uint8_t((Value >> 24) & 0xff);
Data[Offset + 2] |= uint8_t(Value & 0xff);
Data[Offset + 3] |= uint8_t((Value >> 8) & 0xff);
} else {
for (unsigned I = 0; I != NumBytes; I++) {
unsigned Idx = IsLittleEndian ? I : (NumBytes - 1 - I);
Data[Offset + Idx] |= uint8_t((Value >> (I * 8)) & 0xff);
}
}
}
bool CSKYAsmBackend::mayNeedRelaxation(const MCInst &Inst,
const MCSubtargetInfo &STI) const {
switch (Inst.getOpcode()) {
default:
return false;
case CSKY::JBR32:
case CSKY::JBT32:
case CSKY::JBF32:
case CSKY::JBSR32:
if (!STI.hasFeature(CSKY::Has2E3))
return false;
return true;
case CSKY::JBR16:
case CSKY::JBT16:
case CSKY::JBF16:
case CSKY::LRW16:
case CSKY::BR16:
return true;
}
}
bool CSKYAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
const MCFixup &Fixup,
const MCValue &Target,
const MCSubtargetInfo * /*STI*/) {
if (Fixup.getKind() >= FirstLiteralRelocationKind)
return true;
switch (Fixup.getTargetKind()) {
default:
break;
case CSKY::fixup_csky_got32:
case CSKY::fixup_csky_got_imm18_scale4:
case CSKY::fixup_csky_gotoff:
case CSKY::fixup_csky_gotpc:
case CSKY::fixup_csky_plt32:
case CSKY::fixup_csky_plt_imm18_scale4:
case CSKY::fixup_csky_doffset_imm18:
case CSKY::fixup_csky_doffset_imm18_scale2:
case CSKY::fixup_csky_doffset_imm18_scale4:
return true;
}
return false;
}
bool CSKYAsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup,
uint64_t Value) const {
return false;
}
void CSKYAsmBackend::relaxInstruction(MCInst &Inst,
const MCSubtargetInfo &STI) const {
MCInst Res;
switch (Inst.getOpcode()) {
default:
LLVM_DEBUG(Inst.dump());
llvm_unreachable("Opcode not expected!");
case CSKY::LRW16:
Res.setOpcode(CSKY::LRW32);
Res.addOperand(Inst.getOperand(0));
Res.addOperand(Inst.getOperand(1));
break;
case CSKY::BR16:
Res.setOpcode(CSKY::BR32);
Res.addOperand(Inst.getOperand(0));
break;
case CSKY::JBSR32:
Res.setOpcode(CSKY::JSRI32);
Res.addOperand(Inst.getOperand(1));
break;
case CSKY::JBR32:
Res.setOpcode(CSKY::JMPI32);
Res.addOperand(Inst.getOperand(1));
break;
case CSKY::JBT32:
case CSKY::JBF32:
Res.setOpcode(Inst.getOpcode() == CSKY::JBT32 ? CSKY::JBT_E : CSKY::JBF_E);
Res.addOperand(Inst.getOperand(0));
Res.addOperand(Inst.getOperand(1));
Res.addOperand(Inst.getOperand(2));
break;
case CSKY::JBR16:
Res.setOpcode(CSKY::JBR32);
Res.addOperand(Inst.getOperand(0));
Res.addOperand(Inst.getOperand(1));
break;
case CSKY::JBT16:
case CSKY::JBF16:
// ck801
unsigned opcode;
if (STI.hasFeature(CSKY::HasE2))
opcode = Inst.getOpcode() == CSKY::JBT16 ? CSKY::JBT32 : CSKY::JBF32;
else
opcode = Inst.getOpcode() == CSKY::JBT16 ? CSKY::JBT_E : CSKY::JBF_E;
Res.setOpcode(opcode);
Res.addOperand(Inst.getOperand(0));
Res.addOperand(Inst.getOperand(1));
Res.addOperand(Inst.getOperand(2));
break;
}
Inst = std::move(Res);
}
bool CSKYAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
const MCSubtargetInfo *STI) const {
OS.write_zeros(Count);
return true;
}
MCAsmBackend *llvm::createCSKYAsmBackend(const Target &T,
const MCSubtargetInfo &STI,
const MCRegisterInfo &MRI,
const MCTargetOptions &Options) {
return new CSKYAsmBackend(STI, Options);
}
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