mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-26 21:32:10 +00:00
4e815f8a8c
- Although it would be nice to allow this decoupling, the assembler needs to be able to reason about MCSymbolRefExprs in too many places to make this viable. We can use a target specific encoding of the variant if this becomes an issue. - This patch also extends llvm-mc to support parsing of the modifiers, as opposed to lumping them in with the symbol. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98592 91177308-0d34-0410-b5e6-96231b3b80d8
359 lines
11 KiB
C++
359 lines
11 KiB
C++
//===- MCExpr.cpp - Assembly Level Expression Implementation --------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/MC/MCExpr.h"
|
|
#include "llvm/ADT/StringSwitch.h"
|
|
#include "llvm/MC/MCAsmLayout.h"
|
|
#include "llvm/MC/MCAssembler.h"
|
|
#include "llvm/MC/MCContext.h"
|
|
#include "llvm/MC/MCSymbol.h"
|
|
#include "llvm/MC/MCValue.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
#include "llvm/Target/TargetAsmBackend.h"
|
|
using namespace llvm;
|
|
|
|
void MCExpr::print(raw_ostream &OS) const {
|
|
switch (getKind()) {
|
|
case MCExpr::Target:
|
|
return cast<MCTargetExpr>(this)->PrintImpl(OS);
|
|
case MCExpr::Constant:
|
|
OS << cast<MCConstantExpr>(*this).getValue();
|
|
return;
|
|
|
|
case MCExpr::SymbolRef: {
|
|
const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*this);
|
|
const MCSymbol &Sym = SRE.getSymbol();
|
|
|
|
// Parenthesize names that start with $ so that they don't look like
|
|
// absolute names.
|
|
if (Sym.getName()[0] == '$')
|
|
OS << '(' << Sym << ')';
|
|
else
|
|
OS << Sym;
|
|
|
|
if (SRE.getKind() != MCSymbolRefExpr::VK_None)
|
|
OS << '@' << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
|
|
|
|
return;
|
|
}
|
|
|
|
case MCExpr::Unary: {
|
|
const MCUnaryExpr &UE = cast<MCUnaryExpr>(*this);
|
|
switch (UE.getOpcode()) {
|
|
default: assert(0 && "Invalid opcode!");
|
|
case MCUnaryExpr::LNot: OS << '!'; break;
|
|
case MCUnaryExpr::Minus: OS << '-'; break;
|
|
case MCUnaryExpr::Not: OS << '~'; break;
|
|
case MCUnaryExpr::Plus: OS << '+'; break;
|
|
}
|
|
OS << *UE.getSubExpr();
|
|
return;
|
|
}
|
|
|
|
case MCExpr::Binary: {
|
|
const MCBinaryExpr &BE = cast<MCBinaryExpr>(*this);
|
|
|
|
// Only print parens around the LHS if it is non-trivial.
|
|
if (isa<MCConstantExpr>(BE.getLHS()) || isa<MCSymbolRefExpr>(BE.getLHS())) {
|
|
OS << *BE.getLHS();
|
|
} else {
|
|
OS << '(' << *BE.getLHS() << ')';
|
|
}
|
|
|
|
switch (BE.getOpcode()) {
|
|
default: assert(0 && "Invalid opcode!");
|
|
case MCBinaryExpr::Add:
|
|
// Print "X-42" instead of "X+-42".
|
|
if (const MCConstantExpr *RHSC = dyn_cast<MCConstantExpr>(BE.getRHS())) {
|
|
if (RHSC->getValue() < 0) {
|
|
OS << RHSC->getValue();
|
|
return;
|
|
}
|
|
}
|
|
|
|
OS << '+';
|
|
break;
|
|
case MCBinaryExpr::And: OS << '&'; break;
|
|
case MCBinaryExpr::Div: OS << '/'; break;
|
|
case MCBinaryExpr::EQ: OS << "=="; break;
|
|
case MCBinaryExpr::GT: OS << '>'; break;
|
|
case MCBinaryExpr::GTE: OS << ">="; break;
|
|
case MCBinaryExpr::LAnd: OS << "&&"; break;
|
|
case MCBinaryExpr::LOr: OS << "||"; break;
|
|
case MCBinaryExpr::LT: OS << '<'; break;
|
|
case MCBinaryExpr::LTE: OS << "<="; break;
|
|
case MCBinaryExpr::Mod: OS << '%'; break;
|
|
case MCBinaryExpr::Mul: OS << '*'; break;
|
|
case MCBinaryExpr::NE: OS << "!="; break;
|
|
case MCBinaryExpr::Or: OS << '|'; break;
|
|
case MCBinaryExpr::Shl: OS << "<<"; break;
|
|
case MCBinaryExpr::Shr: OS << ">>"; break;
|
|
case MCBinaryExpr::Sub: OS << '-'; break;
|
|
case MCBinaryExpr::Xor: OS << '^'; break;
|
|
}
|
|
|
|
// Only print parens around the LHS if it is non-trivial.
|
|
if (isa<MCConstantExpr>(BE.getRHS()) || isa<MCSymbolRefExpr>(BE.getRHS())) {
|
|
OS << *BE.getRHS();
|
|
} else {
|
|
OS << '(' << *BE.getRHS() << ')';
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
|
|
assert(0 && "Invalid expression kind!");
|
|
}
|
|
|
|
void MCExpr::dump() const {
|
|
print(dbgs());
|
|
dbgs() << '\n';
|
|
}
|
|
|
|
/* *** */
|
|
|
|
const MCBinaryExpr *MCBinaryExpr::Create(Opcode Opc, const MCExpr *LHS,
|
|
const MCExpr *RHS, MCContext &Ctx) {
|
|
return new (Ctx) MCBinaryExpr(Opc, LHS, RHS);
|
|
}
|
|
|
|
const MCUnaryExpr *MCUnaryExpr::Create(Opcode Opc, const MCExpr *Expr,
|
|
MCContext &Ctx) {
|
|
return new (Ctx) MCUnaryExpr(Opc, Expr);
|
|
}
|
|
|
|
const MCConstantExpr *MCConstantExpr::Create(int64_t Value, MCContext &Ctx) {
|
|
return new (Ctx) MCConstantExpr(Value);
|
|
}
|
|
|
|
/* *** */
|
|
|
|
const MCSymbolRefExpr *MCSymbolRefExpr::Create(const MCSymbol *Sym,
|
|
VariantKind Kind,
|
|
MCContext &Ctx) {
|
|
return new (Ctx) MCSymbolRefExpr(Sym, Kind);
|
|
}
|
|
|
|
const MCSymbolRefExpr *MCSymbolRefExpr::Create(StringRef Name, VariantKind Kind,
|
|
MCContext &Ctx) {
|
|
return Create(Ctx.GetOrCreateSymbol(Name), Kind, Ctx);
|
|
}
|
|
|
|
const MCSymbolRefExpr *MCSymbolRefExpr::CreateTemp(StringRef Name,
|
|
VariantKind Kind,
|
|
MCContext &Ctx) {
|
|
return Create(Ctx.GetOrCreateTemporarySymbol(Name), Kind, Ctx);
|
|
}
|
|
|
|
StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) {
|
|
switch (Kind) {
|
|
default:
|
|
case VK_Invalid: return "<<invalid>>";
|
|
case VK_None: return "<<none>>";
|
|
|
|
case VK_GOT: return "GOT";
|
|
case VK_GOTOFF: return "GOTOFF";
|
|
case VK_GOTPCREL: return "GOTPCREL";
|
|
case VK_GOTTPOFF: return "GOTTPOFF";
|
|
case VK_INDNTPOFF: return "INDNTPOFF";
|
|
case VK_NTPOFF: return "NTPOFF";
|
|
case VK_PLT: return "PLT";
|
|
case VK_TLSGD: return "TLSGD";
|
|
case VK_TPOFF: return "TPOFF";
|
|
}
|
|
}
|
|
|
|
MCSymbolRefExpr::VariantKind
|
|
MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
|
|
return StringSwitch<VariantKind>(Name)
|
|
.Case("GOT", VK_GOT)
|
|
.Case("GOTOFF", VK_GOTOFF)
|
|
.Case("GOTPCREL", VK_GOTPCREL)
|
|
.Case("GOTTPOFF", VK_GOTTPOFF)
|
|
.Case("INDNTPOFF", VK_INDNTPOFF)
|
|
.Case("NTPOFF", VK_NTPOFF)
|
|
.Case("PLT", VK_PLT)
|
|
.Case("TLSGD", VK_TLSGD)
|
|
.Case("TPOFF", VK_TPOFF)
|
|
.Default(VK_Invalid);
|
|
}
|
|
|
|
/* *** */
|
|
|
|
void MCTargetExpr::Anchor() {}
|
|
|
|
/* *** */
|
|
|
|
bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout *Layout) const {
|
|
MCValue Value;
|
|
|
|
if (!EvaluateAsRelocatable(Value, Layout) || !Value.isAbsolute())
|
|
return false;
|
|
|
|
Res = Value.getConstant();
|
|
return true;
|
|
}
|
|
|
|
static bool EvaluateSymbolicAdd(const MCValue &LHS, const MCSymbol *RHS_A,
|
|
const MCSymbol *RHS_B, int64_t RHS_Cst,
|
|
MCValue &Res) {
|
|
// We can't add or subtract two symbols.
|
|
if ((LHS.getSymA() && RHS_A) ||
|
|
(LHS.getSymB() && RHS_B))
|
|
return false;
|
|
|
|
const MCSymbol *A = LHS.getSymA() ? LHS.getSymA() : RHS_A;
|
|
const MCSymbol *B = LHS.getSymB() ? LHS.getSymB() : RHS_B;
|
|
if (B) {
|
|
// If we have a negated symbol, then we must have also have a non-negated
|
|
// symbol in order to encode the expression. We can do this check later to
|
|
// permit expressions which eventually fold to a representable form -- such
|
|
// as (a + (0 - b)) -- if necessary.
|
|
if (!A)
|
|
return false;
|
|
}
|
|
Res = MCValue::get(A, B, LHS.getConstant() + RHS_Cst);
|
|
return true;
|
|
}
|
|
|
|
bool MCExpr::EvaluateAsRelocatable(MCValue &Res,
|
|
const MCAsmLayout *Layout) const {
|
|
switch (getKind()) {
|
|
case Target:
|
|
return cast<MCTargetExpr>(this)->EvaluateAsRelocatableImpl(Res, Layout);
|
|
|
|
case Constant:
|
|
Res = MCValue::get(cast<MCConstantExpr>(this)->getValue());
|
|
return true;
|
|
|
|
case SymbolRef: {
|
|
const MCSymbol &Sym = cast<MCSymbolRefExpr>(this)->getSymbol();
|
|
|
|
// Evaluate recursively if this is a variable.
|
|
if (Sym.isVariable()) {
|
|
if (!Sym.getValue()->EvaluateAsRelocatable(Res, Layout))
|
|
return false;
|
|
|
|
// Absolutize symbol differences between defined symbols when we have a
|
|
// layout object and the target requests it.
|
|
if (Layout && Res.getSymB() &&
|
|
Layout->getAssembler().getBackend().hasAbsolutizedSet() &&
|
|
Res.getSymA()->isDefined() && Res.getSymB()->isDefined()) {
|
|
MCSymbolData &A = Layout->getAssembler().getSymbolData(*Res.getSymA());
|
|
MCSymbolData &B = Layout->getAssembler().getSymbolData(*Res.getSymB());
|
|
Res = MCValue::get(+ A.getFragment()->getAddress() + A.getOffset()
|
|
- B.getFragment()->getAddress() - B.getOffset()
|
|
+ Res.getConstant());
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
Res = MCValue::get(&Sym, 0, 0);
|
|
return true;
|
|
}
|
|
|
|
case Unary: {
|
|
const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this);
|
|
MCValue Value;
|
|
|
|
if (!AUE->getSubExpr()->EvaluateAsRelocatable(Value, Layout))
|
|
return false;
|
|
|
|
switch (AUE->getOpcode()) {
|
|
case MCUnaryExpr::LNot:
|
|
if (!Value.isAbsolute())
|
|
return false;
|
|
Res = MCValue::get(!Value.getConstant());
|
|
break;
|
|
case MCUnaryExpr::Minus:
|
|
/// -(a - b + const) ==> (b - a - const)
|
|
if (Value.getSymA() && !Value.getSymB())
|
|
return false;
|
|
Res = MCValue::get(Value.getSymB(), Value.getSymA(),
|
|
-Value.getConstant());
|
|
break;
|
|
case MCUnaryExpr::Not:
|
|
if (!Value.isAbsolute())
|
|
return false;
|
|
Res = MCValue::get(~Value.getConstant());
|
|
break;
|
|
case MCUnaryExpr::Plus:
|
|
Res = Value;
|
|
break;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
case Binary: {
|
|
const MCBinaryExpr *ABE = cast<MCBinaryExpr>(this);
|
|
MCValue LHSValue, RHSValue;
|
|
|
|
if (!ABE->getLHS()->EvaluateAsRelocatable(LHSValue, Layout) ||
|
|
!ABE->getRHS()->EvaluateAsRelocatable(RHSValue, Layout))
|
|
return false;
|
|
|
|
// We only support a few operations on non-constant expressions, handle
|
|
// those first.
|
|
if (!LHSValue.isAbsolute() || !RHSValue.isAbsolute()) {
|
|
switch (ABE->getOpcode()) {
|
|
default:
|
|
return false;
|
|
case MCBinaryExpr::Sub:
|
|
// Negate RHS and add.
|
|
return EvaluateSymbolicAdd(LHSValue,
|
|
RHSValue.getSymB(), RHSValue.getSymA(),
|
|
-RHSValue.getConstant(),
|
|
Res);
|
|
|
|
case MCBinaryExpr::Add:
|
|
return EvaluateSymbolicAdd(LHSValue,
|
|
RHSValue.getSymA(), RHSValue.getSymB(),
|
|
RHSValue.getConstant(),
|
|
Res);
|
|
}
|
|
}
|
|
|
|
// FIXME: We need target hooks for the evaluation. It may be limited in
|
|
// width, and gas defines the result of comparisons and right shifts
|
|
// differently from Apple as.
|
|
int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant();
|
|
int64_t Result = 0;
|
|
switch (ABE->getOpcode()) {
|
|
case MCBinaryExpr::Add: Result = LHS + RHS; break;
|
|
case MCBinaryExpr::And: Result = LHS & RHS; break;
|
|
case MCBinaryExpr::Div: Result = LHS / RHS; break;
|
|
case MCBinaryExpr::EQ: Result = LHS == RHS; break;
|
|
case MCBinaryExpr::GT: Result = LHS > RHS; break;
|
|
case MCBinaryExpr::GTE: Result = LHS >= RHS; break;
|
|
case MCBinaryExpr::LAnd: Result = LHS && RHS; break;
|
|
case MCBinaryExpr::LOr: Result = LHS || RHS; break;
|
|
case MCBinaryExpr::LT: Result = LHS < RHS; break;
|
|
case MCBinaryExpr::LTE: Result = LHS <= RHS; break;
|
|
case MCBinaryExpr::Mod: Result = LHS % RHS; break;
|
|
case MCBinaryExpr::Mul: Result = LHS * RHS; break;
|
|
case MCBinaryExpr::NE: Result = LHS != RHS; break;
|
|
case MCBinaryExpr::Or: Result = LHS | RHS; break;
|
|
case MCBinaryExpr::Shl: Result = LHS << RHS; break;
|
|
case MCBinaryExpr::Shr: Result = LHS >> RHS; break;
|
|
case MCBinaryExpr::Sub: Result = LHS - RHS; break;
|
|
case MCBinaryExpr::Xor: Result = LHS ^ RHS; break;
|
|
}
|
|
|
|
Res = MCValue::get(Result);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
assert(0 && "Invalid assembly expression kind!");
|
|
return false;
|
|
}
|