llvm-6502/lib/MC/MCExpr.cpp
Bill Schmidt 349c2787cf This patch implements local-dynamic TLS model support for the 64-bit
PowerPC target.  This is the last of the four models, so we now have 
full TLS support.

This is mostly a straightforward extension of the general dynamic model.
I had to use an additional Chain operand to tie ADDIS_DTPREL_HA to the
register copy following ADDI_TLSLD_L; otherwise everything above the
ADDIS_DTPREL_HA appeared dead and was removed.

As before, there are new test cases to test the assembly generation, and
the relocations output during integrated assembly.  The expected code
gen sequence can be read in test/CodeGen/PowerPC/tls-ld.ll.

There are a couple of things I think can be done more efficiently in the
overall TLS code, so there will likely be a clean-up patch forthcoming;
but for now I want to be sure the functionality is in place.

Bill


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170003 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-12 19:29:35 +00:00

658 lines
22 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.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mcexpr"
#include "llvm/MC/MCExpr.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
namespace stats {
STATISTIC(MCExprEvaluate, "Number of MCExpr evaluations");
}
}
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.
bool UseParens = Sym.getName()[0] == '$';
if (SRE.getKind() == MCSymbolRefExpr::VK_PPC_DARWIN_HA16 ||
SRE.getKind() == MCSymbolRefExpr::VK_PPC_DARWIN_LO16) {
OS << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
UseParens = true;
}
if (UseParens)
OS << '(' << Sym << ')';
else
OS << Sym;
if (SRE.getKind() == MCSymbolRefExpr::VK_ARM_NONE ||
SRE.getKind() == MCSymbolRefExpr::VK_ARM_PLT ||
SRE.getKind() == MCSymbolRefExpr::VK_ARM_TLSGD ||
SRE.getKind() == MCSymbolRefExpr::VK_ARM_GOT ||
SRE.getKind() == MCSymbolRefExpr::VK_ARM_GOTOFF ||
SRE.getKind() == MCSymbolRefExpr::VK_ARM_TPOFF ||
SRE.getKind() == MCSymbolRefExpr::VK_ARM_GOTTPOFF ||
SRE.getKind() == MCSymbolRefExpr::VK_ARM_TARGET1 ||
SRE.getKind() == MCSymbolRefExpr::VK_ARM_TARGET2 ||
SRE.getKind() == MCSymbolRefExpr::VK_ARM_PREL31)
OS << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
else if (SRE.getKind() != MCSymbolRefExpr::VK_None &&
SRE.getKind() != MCSymbolRefExpr::VK_PPC_DARWIN_HA16 &&
SRE.getKind() != MCSymbolRefExpr::VK_PPC_DARWIN_LO16)
OS << '@' << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
return;
}
case MCExpr::Unary: {
const MCUnaryExpr &UE = cast<MCUnaryExpr>(*this);
switch (UE.getOpcode()) {
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()) {
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;
}
}
llvm_unreachable("Invalid expression kind!");
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MCExpr::dump() const {
print(dbgs());
dbgs() << '\n';
}
#endif
/* *** */
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);
}
StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) {
switch (Kind) {
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_GOTNTPOFF: return "GOTNTPOFF";
case VK_PLT: return "PLT";
case VK_TLSGD: return "TLSGD";
case VK_TLSLD: return "TLSLD";
case VK_TLSLDM: return "TLSLDM";
case VK_TPOFF: return "TPOFF";
case VK_DTPOFF: return "DTPOFF";
case VK_TLVP: return "TLVP";
case VK_SECREL: return "SECREL";
case VK_ARM_NONE: return "(NONE)";
case VK_ARM_PLT: return "(PLT)";
case VK_ARM_GOT: return "(GOT)";
case VK_ARM_GOTOFF: return "(GOTOFF)";
case VK_ARM_TPOFF: return "(tpoff)";
case VK_ARM_GOTTPOFF: return "(gottpoff)";
case VK_ARM_TLSGD: return "(tlsgd)";
case VK_ARM_TARGET1: return "(target1)";
case VK_ARM_TARGET2: return "(target2)";
case VK_ARM_PREL31: return "(prel31)";
case VK_PPC_TOC: return "tocbase";
case VK_PPC_TOC_ENTRY: return "toc";
case VK_PPC_DARWIN_HA16: return "ha16";
case VK_PPC_DARWIN_LO16: return "lo16";
case VK_PPC_GAS_HA16: return "ha";
case VK_PPC_GAS_LO16: return "l";
case VK_PPC_TPREL16_HA: return "tprel@ha";
case VK_PPC_TPREL16_LO: return "tprel@l";
case VK_PPC_DTPREL16_HA: return "dtprel@ha";
case VK_PPC_DTPREL16_LO: return "dtprel@l";
case VK_PPC_TOC16_HA: return "toc@ha";
case VK_PPC_TOC16_LO: return "toc@l";
case VK_PPC_GOT_TPREL16_DS: return "got@tprel";
case VK_PPC_TLS: return "tls";
case VK_PPC_GOT_TLSGD16_HA: return "got@tlsgd@ha";
case VK_PPC_GOT_TLSGD16_LO: return "got@tlsgd@l";
case VK_PPC_GOT_TLSLD16_HA: return "got@tlsld@ha";
case VK_PPC_GOT_TLSLD16_LO: return "got@tlsld@l";
case VK_PPC_TLSGD: return "tlsgd";
case VK_PPC_TLSLD: return "tlsld";
case VK_Mips_GPREL: return "GPREL";
case VK_Mips_GOT_CALL: return "GOT_CALL";
case VK_Mips_GOT16: return "GOT16";
case VK_Mips_GOT: return "GOT";
case VK_Mips_ABS_HI: return "ABS_HI";
case VK_Mips_ABS_LO: return "ABS_LO";
case VK_Mips_TLSGD: return "TLSGD";
case VK_Mips_TLSLDM: return "TLSLDM";
case VK_Mips_DTPREL_HI: return "DTPREL_HI";
case VK_Mips_DTPREL_LO: return "DTPREL_LO";
case VK_Mips_GOTTPREL: return "GOTTPREL";
case VK_Mips_TPREL_HI: return "TPREL_HI";
case VK_Mips_TPREL_LO: return "TPREL_LO";
case VK_Mips_GPOFF_HI: return "GPOFF_HI";
case VK_Mips_GPOFF_LO: return "GPOFF_LO";
case VK_Mips_GOT_DISP: return "GOT_DISP";
case VK_Mips_GOT_PAGE: return "GOT_PAGE";
case VK_Mips_GOT_OFST: return "GOT_OFST";
case VK_Mips_HIGHER: return "HIGHER";
case VK_Mips_HIGHEST: return "HIGHEST";
case VK_Mips_GOT_HI16: return "GOT_HI16";
case VK_Mips_GOT_LO16: return "GOT_LO16";
case VK_Mips_CALL_HI16: return "CALL_HI16";
case VK_Mips_CALL_LO16: return "CALL_LO16";
}
llvm_unreachable("Invalid variant kind");
}
MCSymbolRefExpr::VariantKind
MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
return StringSwitch<VariantKind>(Name)
.Case("GOT", VK_GOT)
.Case("got", VK_GOT)
.Case("GOTOFF", VK_GOTOFF)
.Case("gotoff", VK_GOTOFF)
.Case("GOTPCREL", VK_GOTPCREL)
.Case("gotpcrel", VK_GOTPCREL)
.Case("GOTTPOFF", VK_GOTTPOFF)
.Case("gottpoff", VK_GOTTPOFF)
.Case("INDNTPOFF", VK_INDNTPOFF)
.Case("indntpoff", VK_INDNTPOFF)
.Case("NTPOFF", VK_NTPOFF)
.Case("ntpoff", VK_NTPOFF)
.Case("GOTNTPOFF", VK_GOTNTPOFF)
.Case("gotntpoff", VK_GOTNTPOFF)
.Case("PLT", VK_PLT)
.Case("plt", VK_PLT)
.Case("TLSGD", VK_TLSGD)
.Case("tlsgd", VK_TLSGD)
.Case("TLSLD", VK_TLSLD)
.Case("tlsld", VK_TLSLD)
.Case("TLSLDM", VK_TLSLDM)
.Case("tlsldm", VK_TLSLDM)
.Case("TPOFF", VK_TPOFF)
.Case("tpoff", VK_TPOFF)
.Case("DTPOFF", VK_DTPOFF)
.Case("dtpoff", VK_DTPOFF)
.Case("TLVP", VK_TLVP)
.Case("tlvp", VK_TLVP)
.Default(VK_Invalid);
}
/* *** */
void MCTargetExpr::anchor() {}
/* *** */
bool MCExpr::EvaluateAsAbsolute(int64_t &Res) const {
return EvaluateAsAbsolute(Res, 0, 0, 0);
}
bool MCExpr::EvaluateAsAbsolute(int64_t &Res,
const MCAsmLayout &Layout) const {
return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, 0);
}
bool MCExpr::EvaluateAsAbsolute(int64_t &Res,
const MCAsmLayout &Layout,
const SectionAddrMap &Addrs) const {
return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, &Addrs);
}
bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const {
return EvaluateAsAbsolute(Res, &Asm, 0, 0);
}
bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
const MCAsmLayout *Layout,
const SectionAddrMap *Addrs) const {
MCValue Value;
// Fast path constants.
if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(this)) {
Res = CE->getValue();
return true;
}
// FIXME: The use if InSet = Addrs is a hack. Setting InSet causes us
// absolutize differences across sections and that is what the MachO writer
// uses Addrs for.
bool IsRelocatable =
EvaluateAsRelocatableImpl(Value, Asm, Layout, Addrs, /*InSet*/ Addrs);
// Record the current value.
Res = Value.getConstant();
return IsRelocatable && Value.isAbsolute();
}
/// \brief Helper method for \see EvaluateSymbolAdd().
static void AttemptToFoldSymbolOffsetDifference(const MCAssembler *Asm,
const MCAsmLayout *Layout,
const SectionAddrMap *Addrs,
bool InSet,
const MCSymbolRefExpr *&A,
const MCSymbolRefExpr *&B,
int64_t &Addend) {
if (!A || !B)
return;
const MCSymbol &SA = A->getSymbol();
const MCSymbol &SB = B->getSymbol();
if (SA.isUndefined() || SB.isUndefined())
return;
if (!Asm->getWriter().IsSymbolRefDifferenceFullyResolved(*Asm, A, B, InSet))
return;
MCSymbolData &AD = Asm->getSymbolData(SA);
MCSymbolData &BD = Asm->getSymbolData(SB);
if (AD.getFragment() == BD.getFragment()) {
Addend += (AD.getOffset() - BD.getOffset());
// Pointers to Thumb symbols need to have their low-bit set to allow
// for interworking.
if (Asm->isThumbFunc(&SA))
Addend |= 1;
// Clear the symbol expr pointers to indicate we have folded these
// operands.
A = B = 0;
return;
}
if (!Layout)
return;
const MCSectionData &SecA = *AD.getFragment()->getParent();
const MCSectionData &SecB = *BD.getFragment()->getParent();
if ((&SecA != &SecB) && !Addrs)
return;
// Eagerly evaluate.
Addend += (Layout->getSymbolOffset(&Asm->getSymbolData(A->getSymbol())) -
Layout->getSymbolOffset(&Asm->getSymbolData(B->getSymbol())));
if (Addrs && (&SecA != &SecB))
Addend += (Addrs->lookup(&SecA) - Addrs->lookup(&SecB));
// Pointers to Thumb symbols need to have their low-bit set to allow
// for interworking.
if (Asm->isThumbFunc(&SA))
Addend |= 1;
// Clear the symbol expr pointers to indicate we have folded these
// operands.
A = B = 0;
}
/// \brief Evaluate the result of an add between (conceptually) two MCValues.
///
/// This routine conceptually attempts to construct an MCValue:
/// Result = (Result_A - Result_B + Result_Cst)
/// from two MCValue's LHS and RHS where
/// Result = LHS + RHS
/// and
/// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
///
/// This routine attempts to aggresively fold the operands such that the result
/// is representable in an MCValue, but may not always succeed.
///
/// \returns True on success, false if the result is not representable in an
/// MCValue.
/// NOTE: It is really important to have both the Asm and Layout arguments.
/// They might look redundant, but this function can be used before layout
/// is done (see the object streamer for example) and having the Asm argument
/// lets us avoid relaxations early.
static bool EvaluateSymbolicAdd(const MCAssembler *Asm,
const MCAsmLayout *Layout,
const SectionAddrMap *Addrs,
bool InSet,
const MCValue &LHS,const MCSymbolRefExpr *RHS_A,
const MCSymbolRefExpr *RHS_B, int64_t RHS_Cst,
MCValue &Res) {
// FIXME: This routine (and other evaluation parts) are *incredibly* sloppy
// about dealing with modifiers. This will ultimately bite us, one day.
const MCSymbolRefExpr *LHS_A = LHS.getSymA();
const MCSymbolRefExpr *LHS_B = LHS.getSymB();
int64_t LHS_Cst = LHS.getConstant();
// Fold the result constant immediately.
int64_t Result_Cst = LHS_Cst + RHS_Cst;
assert((!Layout || Asm) &&
"Must have an assembler object if layout is given!");
// If we have a layout, we can fold resolved differences.
if (Asm) {
// First, fold out any differences which are fully resolved. By
// reassociating terms in
// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
// we have the four possible differences:
// (LHS_A - LHS_B),
// (LHS_A - RHS_B),
// (RHS_A - LHS_B),
// (RHS_A - RHS_B).
// Since we are attempting to be as aggressive as possible about folding, we
// attempt to evaluate each possible alternative.
AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, LHS_B,
Result_Cst);
AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, RHS_B,
Result_Cst);
AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, LHS_B,
Result_Cst);
AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, RHS_B,
Result_Cst);
}
// We can't represent the addition or subtraction of two symbols.
if ((LHS_A && RHS_A) || (LHS_B && RHS_B))
return false;
// At this point, we have at most one additive symbol and one subtractive
// symbol -- find them.
const MCSymbolRefExpr *A = LHS_A ? LHS_A : RHS_A;
const MCSymbolRefExpr *B = LHS_B ? LHS_B : RHS_B;
// If we have a negated symbol, then we must have also have a non-negated
// symbol in order to encode the expression.
if (B && !A)
return false;
Res = MCValue::get(A, B, Result_Cst);
return true;
}
bool MCExpr::EvaluateAsRelocatable(MCValue &Res,
const MCAsmLayout &Layout) const {
return EvaluateAsRelocatableImpl(Res, &Layout.getAssembler(), &Layout,
0, false);
}
bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
const MCAssembler *Asm,
const MCAsmLayout *Layout,
const SectionAddrMap *Addrs,
bool InSet) const {
++stats::MCExprEvaluate;
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 MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
const MCSymbol &Sym = SRE->getSymbol();
// Evaluate recursively if this is a variable.
if (Sym.isVariable() && SRE->getKind() == MCSymbolRefExpr::VK_None) {
bool Ret = Sym.getVariableValue()->EvaluateAsRelocatableImpl(Res, Asm,
Layout,
Addrs,
true);
// If we failed to simplify this to a constant, let the target
// handle it.
if (Ret && !Res.getSymA() && !Res.getSymB())
return true;
}
Res = MCValue::get(SRE, 0, 0);
return true;
}
case Unary: {
const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this);
MCValue Value;
if (!AUE->getSubExpr()->EvaluateAsRelocatableImpl(Value, Asm, Layout,
Addrs, InSet))
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()->EvaluateAsRelocatableImpl(LHSValue, Asm, Layout,
Addrs, InSet) ||
!ABE->getRHS()->EvaluateAsRelocatableImpl(RHSValue, Asm, Layout,
Addrs, InSet))
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(Asm, Layout, Addrs, InSet, LHSValue,
RHSValue.getSymB(), RHSValue.getSymA(),
-RHSValue.getConstant(),
Res);
case MCBinaryExpr::Add:
return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, 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;
}
}
llvm_unreachable("Invalid assembly expression kind!");
}
const MCSection *MCExpr::FindAssociatedSection() const {
switch (getKind()) {
case Target:
// We never look through target specific expressions.
return cast<MCTargetExpr>(this)->FindAssociatedSection();
case Constant:
return MCSymbol::AbsolutePseudoSection;
case SymbolRef: {
const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
const MCSymbol &Sym = SRE->getSymbol();
if (Sym.isDefined())
return &Sym.getSection();
return 0;
}
case Unary:
return cast<MCUnaryExpr>(this)->getSubExpr()->FindAssociatedSection();
case Binary: {
const MCBinaryExpr *BE = cast<MCBinaryExpr>(this);
const MCSection *LHS_S = BE->getLHS()->FindAssociatedSection();
const MCSection *RHS_S = BE->getRHS()->FindAssociatedSection();
// If either section is absolute, return the other.
if (LHS_S == MCSymbol::AbsolutePseudoSection)
return RHS_S;
if (RHS_S == MCSymbol::AbsolutePseudoSection)
return LHS_S;
// Otherwise, return the first non-null section.
return LHS_S ? LHS_S : RHS_S;
}
}
llvm_unreachable("Invalid assembly expression kind!");
}