[AVR] Add AVRMCExpr

Summary: This adds the AVRMCExpr headers and implementation.

Reviewers: arsenm, ruiu, grosbach, kparzysz

Subscribers: wdng, beanz, mgorny, kparzysz, jtbandes, llvm-commits

Differential Revision: https://reviews.llvm.org/D20503

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282397 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dylan McKay 2016-09-26 11:35:32 +00:00
parent ecba0242f4
commit 679be7ea7e
4 changed files with 427 additions and 0 deletions

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//===-- AVRFixupKinds.h - AVR Specific Fixup Entries ------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_AVR_FIXUP_KINDS_H
#define LLVM_AVR_FIXUP_KINDS_H
#include "llvm/MC/MCFixup.h"
namespace llvm {
namespace AVR {
/// The set of supported fixups.
///
/// Although most of the current fixup types reflect a unique relocation
/// one can have multiple fixup types for a given relocation and thus need
/// to be uniquely named.
///
/// \note This table *must* be in the same order of
/// MCFixupKindInfo Infos[AVR::NumTargetFixupKinds]
/// in `AVRAsmBackend.cpp`.
enum Fixups {
/// A 32-bit AVR fixup.
fixup_32 = FirstTargetFixupKind,
/// A 7-bit PC-relative fixup for the family of conditional
/// branches which take 7-bit targets (BRNE,BRGT,etc).
fixup_7_pcrel,
/// A 12-bit PC-relative fixup for the family of branches
/// which take 12-bit targets (RJMP,RCALL,etc).
/// \note Although the fixup is labelled as 13 bits, it
/// is actually only encoded in 12. The reason for
/// The nonmenclature is that AVR branch targets are
/// rightshifted by 1, because instructions are always
/// aligned to 2 bytes, so the 0'th bit is always 0.
/// This way there is 13-bits of precision.
fixup_13_pcrel,
/// A 16-bit address.
fixup_16,
/// A 16-bit program memory address.
fixup_16_pm,
/// Replaces the 8-bit immediate with another value.
fixup_ldi,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the lower 8 bits of a 16-bit value (bits 0-7).
fixup_lo8_ldi,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the upper 8 bits of a 16-bit value (bits 8-15).
fixup_hi8_ldi,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the upper 8 bits of a 24-bit value (bits 16-23).
fixup_hh8_ldi,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the upper 8 bits of a 32-bit value (bits 24-31).
fixup_ms8_ldi,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the lower 8 bits of a negated 16-bit value (bits 0-7).
fixup_lo8_ldi_neg,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the upper 8 bits of a negated 16-bit value (bits 8-15).
fixup_hi8_ldi_neg,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the upper 8 bits of a negated negated 24-bit value (bits 16-23).
fixup_hh8_ldi_neg,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the upper 8 bits of a negated negated 32-bit value (bits 24-31).
fixup_ms8_ldi_neg,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the lower 8 bits of a 16-bit program memory address value (bits 0-7).
fixup_lo8_ldi_pm,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the upper 8 bits of a 16-bit program memory address value (bits
/// 8-15).
fixup_hi8_ldi_pm,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the upper 8 bits of a 24-bit program memory address value (bits
/// 16-23).
fixup_hh8_ldi_pm,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the lower 8 bits of a negated 16-bit program memory address value
/// (bits 0-7).
fixup_lo8_ldi_pm_neg,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the upper 8 bits of a negated 16-bit program memory address value
/// (bits 8-15).
fixup_hi8_ldi_pm_neg,
/// Replaces the immediate operand of a 16-bit `Rd, K` instruction
/// with the upper 8 bits of a negated 24-bit program memory address value
/// (bits 16-23).
fixup_hh8_ldi_pm_neg,
/// A 22-bit fixup for the target of a `CALL k` or `JMP k` instruction.
fixup_call,
fixup_6,
/// A symbol+addr fixup for the `LDD <x>+<n>, <r>" family of instructions.
fixup_6_adiw,
fixup_lo8_ldi_gs,
fixup_hi8_ldi_gs,
fixup_8,
fixup_8_lo8,
fixup_8_hi8,
fixup_8_hlo8,
/// Fixup to calculate the difference between two symbols.
/// Is the only stateful fixup. We do not support it yet.
fixup_sym_diff,
fixup_16_ldst,
fixup_lds_sts_16,
/// A 6-bit port address.
fixup_port6,
/// A 5-bit port address.
fixup_port5,
// Marker
LastTargetFixupKind,
NumTargetFixupKinds = LastTargetFixupKind - FirstTargetFixupKind
};
namespace fixups {
/// Adjusts the value of a branch target.
/// All branch targets in AVR are rightshifted by 1 to take advantage
/// of the fact that all instructions are aligned to addresses of size
/// 2, so bit 0 of an address is always 0. This gives us another bit
/// of precision.
/// \param[in,out] The target to adjust.
template <typename T> inline void adjustBranchTarget(T &val) { val >>= 1; }
} // end of namespace fixups
}
} // end of namespace llvm::AVR
#endif // LLVM_AVR_FIXUP_KINDS_H

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//===-- AVRMCExpr.cpp - AVR 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.
//
//===----------------------------------------------------------------------===//
#include "AVRMCExpr.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCValue.h"
#include "llvm/MC/MCAsmLayout.h"
namespace llvm {
namespace {
const struct ModifierEntry {
const char * const Spelling;
AVRMCExpr::VariantKind VariantKind;
} ModifierNames[] = {
{"lo8", AVRMCExpr::VK_AVR_LO8}, {"hi8", AVRMCExpr::VK_AVR_HI8},
{"hh8", AVRMCExpr::VK_AVR_HH8}, // synonym with hlo8
{"hlo8", AVRMCExpr::VK_AVR_HH8}, {"hhi8", AVRMCExpr::VK_AVR_HHI8},
{"pm_lo8", AVRMCExpr::VK_AVR_PM_LO8}, {"pm_hi8", AVRMCExpr::VK_AVR_PM_HI8},
{"pm_hh8", AVRMCExpr::VK_AVR_PM_HH8},
};
} // end of anonymous namespace
const AVRMCExpr *AVRMCExpr::create(VariantKind Kind, const MCExpr *Expr,
bool Negated, MCContext &Ctx) {
return new (Ctx) AVRMCExpr(Kind, Expr, Negated);
}
void AVRMCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
assert(Kind != VK_AVR_None);
if (isNegated())
OS << '-';
OS << getName() << '(';
getSubExpr()->print(OS, MAI);
OS << ')';
}
bool AVRMCExpr::evaluateAsConstant(int64_t &Result) const {
MCValue Value;
bool isRelocatable =
getSubExpr()->evaluateAsRelocatable(Value, nullptr, nullptr);
if (!isRelocatable)
return false;
if (Value.isAbsolute()) {
Result = evaluateAsInt64(Value.getConstant());
return true;
}
return false;
}
bool AVRMCExpr::evaluateAsRelocatableImpl(MCValue &Result,
const MCAsmLayout *Layout,
const MCFixup *Fixup) const {
MCValue Value;
bool isRelocatable = SubExpr->evaluateAsRelocatable(Value, Layout, Fixup);
if (!isRelocatable)
return false;
if (Value.isAbsolute()) {
Result = MCValue::get(evaluateAsInt64(Value.getConstant()));
} else {
if (!Layout) return false;
MCContext &Context = Layout->getAssembler().getContext();
const MCSymbolRefExpr *Sym = Value.getSymA();
MCSymbolRefExpr::VariantKind Modifier = Sym->getKind();
if (Modifier != MCSymbolRefExpr::VK_None)
return false;
Sym = MCSymbolRefExpr::create(&Sym->getSymbol(), Modifier, Context);
Result = MCValue::get(Sym, Value.getSymB(), Value.getConstant());
}
return true;
}
int64_t AVRMCExpr::evaluateAsInt64(int64_t Value) const {
if (Negated)
Value *= -1;
switch (Kind) {
case AVRMCExpr::VK_AVR_LO8:
break;
case AVRMCExpr::VK_AVR_HI8:
Value >>= 8;
break;
case AVRMCExpr::VK_AVR_HH8:
Value >>= 16;
break;
case AVRMCExpr::VK_AVR_HHI8:
Value >>= 24;
break;
case AVRMCExpr::VK_AVR_PM_LO8:
Value >>= 1;
break;
case AVRMCExpr::VK_AVR_PM_HI8:
Value >>= 9;
break;
case AVRMCExpr::VK_AVR_PM_HH8:
Value >>= 17;
break;
case AVRMCExpr::VK_AVR_None:
llvm_unreachable("Uninitialized expression.");
}
return static_cast<uint64_t>(Value) & 0xff;
}
AVR::Fixups AVRMCExpr::getFixupKind() const {
AVR::Fixups Kind = AVR::Fixups::LastTargetFixupKind;
switch (getKind()) {
case VK_AVR_LO8:
Kind = isNegated() ? AVR::fixup_lo8_ldi_neg : AVR::fixup_lo8_ldi;
break;
case VK_AVR_HI8:
Kind = isNegated() ? AVR::fixup_hi8_ldi_neg : AVR::fixup_hi8_ldi;
break;
case VK_AVR_HH8:
Kind = isNegated() ? AVR::fixup_hh8_ldi_neg : AVR::fixup_hh8_ldi;
break;
case VK_AVR_HHI8:
Kind = isNegated() ? AVR::fixup_ms8_ldi_neg : AVR::fixup_ms8_ldi;
break;
case VK_AVR_PM_LO8:
Kind = isNegated() ? AVR::fixup_lo8_ldi_pm_neg : AVR::fixup_lo8_ldi_pm;
break;
case VK_AVR_PM_HI8:
Kind = isNegated() ? AVR::fixup_hi8_ldi_pm_neg : AVR::fixup_hi8_ldi_pm;
break;
case VK_AVR_PM_HH8:
Kind = isNegated() ? AVR::fixup_hh8_ldi_pm_neg : AVR::fixup_hh8_ldi_pm;
break;
case VK_AVR_None:
llvm_unreachable("Uninitialized expression");
}
return Kind;
}
void AVRMCExpr::visitUsedExpr(MCStreamer &Streamer) const {
Streamer.visitUsedExpr(*getSubExpr());
}
const char *AVRMCExpr::getName() const {
const auto &Modifier = std::find_if(
std::begin(ModifierNames), std::end(ModifierNames),
[this](ModifierEntry const &Mod) { return Mod.VariantKind == Kind; });
if (Modifier != std::end(ModifierNames)) {
return Modifier->Spelling;
}
return nullptr;
}
AVRMCExpr::VariantKind AVRMCExpr::getKindByName(StringRef Name) {
const auto &Modifier = std::find_if(
std::begin(ModifierNames), std::end(ModifierNames),
[&Name](ModifierEntry const &Mod) { return Mod.Spelling == Name; });
if (Modifier != std::end(ModifierNames)) {
return Modifier->VariantKind;
}
return VK_AVR_None;
}
} // end of namespace llvm

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//===-- AVRMCExpr.h - AVR specific MC expression classes --------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_AVR_MCEXPR_H
#define LLVM_AVR_MCEXPR_H
#include "llvm/MC/MCExpr.h"
#include "MCTargetDesc/AVRFixupKinds.h"
namespace llvm {
/// A expression in AVR machine code.
class AVRMCExpr : public MCTargetExpr {
public:
/// Specifies the type of an expression.
enum VariantKind {
VK_AVR_None,
VK_AVR_HI8, ///< Corresponds to `hi8()`.
VK_AVR_LO8, ///< Corresponds to `lo8()`.
VK_AVR_HH8, ///< Corresponds to `hlo8() and hh8()`.
VK_AVR_HHI8, ///< Corresponds to `hhi8()`.
VK_AVR_PM_LO8, ///< Corresponds to `pm_lo8()`.
VK_AVR_PM_HI8, ///< Corresponds to `pm_hi8()`.
VK_AVR_PM_HH8 ///< Corresponds to `pm_hh8()`.
};
public:
/// Creates an AVR machine code expression.
static const AVRMCExpr *create(VariantKind Kind, const MCExpr *Expr,
bool isNegated, MCContext &Ctx);
/// Gets the type of the expression.
VariantKind getKind() const { return Kind; }
/// Gets the name of the expression.
const char *getName() const;
const MCExpr *getSubExpr() const { return SubExpr; }
/// Gets the fixup which corresponds to the expression.
AVR::Fixups getFixupKind() const;
/// Evaluates the fixup as a constant value.
bool evaluateAsConstant(int64_t &Result) const;
bool isNegated() const { return Negated; }
void setNegated(bool negated = true) { Negated = negated; }
void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override;
bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
const MCFixup *Fixup) const override;
void visitUsedExpr(MCStreamer &streamer) const override;
MCFragment *findAssociatedFragment() const override {
return getSubExpr()->findAssociatedFragment();
}
void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override {}
static bool classof(const MCExpr *E) {
return E->getKind() == MCExpr::Target;
}
public:
static VariantKind getKindByName(StringRef Name);
private:
int64_t evaluateAsInt64(int64_t Value) const;
const VariantKind Kind;
const MCExpr *SubExpr;
bool Negated;
private:
explicit AVRMCExpr(VariantKind Kind, const MCExpr *Expr, bool Negated)
: Kind(Kind), SubExpr(Expr), Negated(Negated) {}
~AVRMCExpr() {}
};
} // end namespace llvm
#endif // LLVM_AVR_MCEXPR_H

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add_llvm_library(LLVMAVRDesc
AVRELFStreamer.cpp
AVRMCAsmInfo.cpp
AVRMCExpr.cpp
AVRTargetStreamer.cpp
)