| //===-- RISCVMCExpr.cpp - RISCV specific MC expression classes ------------===// |
| // |
| // 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 implementation of the assembly expression modifiers |
| // accepted by the RISCV architecture (e.g. ":lo12:", ":gottprel_g1:", ...). |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "RISCV.h" |
| #include "RISCVMCExpr.h" |
| #include "llvm/MC/MCAssembler.h" |
| #include "llvm/MC/MCContext.h" |
| #include "llvm/MC/MCStreamer.h" |
| #include "llvm/MC/MCSymbolELF.h" |
| #include "llvm/MC/MCValue.h" |
| #include "llvm/Object/ELF.h" |
| #include "llvm/Support/ErrorHandling.h" |
| |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "riscvmcexpr" |
| |
| const RISCVMCExpr *RISCVMCExpr::create(const MCExpr *Expr, VariantKind Kind, |
| MCContext &Ctx) { |
| return new (Ctx) RISCVMCExpr(Expr, Kind); |
| } |
| |
| void RISCVMCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const { |
| bool HasVariant = |
| ((getKind() != VK_RISCV_None) && (getKind() != VK_RISCV_CALL)); |
| if (HasVariant) |
| OS << '%' << getVariantKindName(getKind()) << '('; |
| Expr->print(OS, MAI); |
| if (HasVariant) |
| OS << ')'; |
| } |
| |
| bool RISCVMCExpr::evaluateAsRelocatableImpl(MCValue &Res, |
| const MCAsmLayout *Layout, |
| const MCFixup *Fixup) const { |
| if (!getSubExpr()->evaluateAsRelocatable(Res, Layout, Fixup)) |
| return false; |
| |
| // Some custom fixup types are not valid with symbol difference expressions |
| if (Res.getSymA() && Res.getSymB()) { |
| switch (getKind()) { |
| default: |
| return true; |
| case VK_RISCV_LO: |
| case VK_RISCV_HI: |
| case VK_RISCV_PCREL_LO: |
| case VK_RISCV_PCREL_HI: |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| void RISCVMCExpr::visitUsedExpr(MCStreamer &Streamer) const { |
| Streamer.visitUsedExpr(*getSubExpr()); |
| } |
| |
| RISCVMCExpr::VariantKind RISCVMCExpr::getVariantKindForName(StringRef name) { |
| return StringSwitch<RISCVMCExpr::VariantKind>(name) |
| .Case("lo", VK_RISCV_LO) |
| .Case("hi", VK_RISCV_HI) |
| .Case("pcrel_lo", VK_RISCV_PCREL_LO) |
| .Case("pcrel_hi", VK_RISCV_PCREL_HI) |
| .Default(VK_RISCV_Invalid); |
| } |
| |
| StringRef RISCVMCExpr::getVariantKindName(VariantKind Kind) { |
| switch (Kind) { |
| default: |
| llvm_unreachable("Invalid ELF symbol kind"); |
| case VK_RISCV_LO: |
| return "lo"; |
| case VK_RISCV_HI: |
| return "hi"; |
| case VK_RISCV_PCREL_LO: |
| return "pcrel_lo"; |
| case VK_RISCV_PCREL_HI: |
| return "pcrel_hi"; |
| } |
| } |
| |
| bool RISCVMCExpr::evaluateAsConstant(int64_t &Res) const { |
| MCValue Value; |
| |
| if (Kind == VK_RISCV_PCREL_HI || Kind == VK_RISCV_PCREL_LO || |
| Kind == VK_RISCV_CALL) |
| return false; |
| |
| if (!getSubExpr()->evaluateAsRelocatable(Value, nullptr, nullptr)) |
| return false; |
| |
| if (!Value.isAbsolute()) |
| return false; |
| |
| Res = evaluateAsInt64(Value.getConstant()); |
| return true; |
| } |
| |
| int64_t RISCVMCExpr::evaluateAsInt64(int64_t Value) const { |
| switch (Kind) { |
| default: |
| llvm_unreachable("Invalid kind"); |
| case VK_RISCV_LO: |
| return SignExtend64<12>(Value); |
| case VK_RISCV_HI: |
| // Add 1 if bit 11 is 1, to compensate for low 12 bits being negative. |
| return ((Value + 0x800) >> 12) & 0xfffff; |
| } |
| } |