//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "mccodeemitter"
#include "MCTargetDesc/ARMMCTargetDesc.h"
#include "MCTargetDesc/ARMAddressingModes.h"
#include "MCTargetDesc/ARMBaseInfo.h"
using namespace llvm;
+#define DEBUG_TYPE "mccodeemitter"
+
STATISTIC(MCNumEmitted, "Number of MC instructions emitted.");
STATISTIC(MCNumCPRelocations, "Number of constant pool relocations created.");
namespace {
class ARMMCCodeEmitter : public MCCodeEmitter {
- ARMMCCodeEmitter(const ARMMCCodeEmitter &) LLVM_DELETED_FUNCTION;
- void operator=(const ARMMCCodeEmitter &) LLVM_DELETED_FUNCTION;
+ ARMMCCodeEmitter(const ARMMCCodeEmitter &) = delete;
+ void operator=(const ARMMCCodeEmitter &) = delete;
const MCInstrInfo &MCII;
const MCContext &CTX;
+ bool IsLittleEndian;
public:
- ARMMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx)
- : MCII(mcii), CTX(ctx) {
+ ARMMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx, bool IsLittle)
+ : MCII(mcii), CTX(ctx), IsLittleEndian(IsLittle) {
}
- ~ARMMCCodeEmitter() {}
+ ~ARMMCCodeEmitter() override {}
bool isThumb(const MCSubtargetInfo &STI) const {
return (STI.getFeatureBits() & ARM::ModeThumb) != 0;
unsigned getSOImmOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
- int SoImmVal = -1;
const MCOperand &MO = MI.getOperand(Op);
- if (MO.isImm()) {
- SoImmVal = ARM_AM::getSOImmVal(MO.getImm());
- } else if (MO.isExpr()) {
- int64_t Value;
- bool Invalid = MO.getExpr()->EvaluateAsAbsolute(Value);
- (void) Invalid;
- assert(!Invalid && "non-constant expression is not a valid SOImm operand");
- assert((Value >= INT32_MIN && Value <= INT32_MAX) &&
- "expression must be representable in 32 bits");
- SoImmVal = Value;
+
+ // We expect MO to be an immediate or an expression,
+ // if it is an immediate - that's fine, just encode the value.
+ // Otherwise - create a Fixup.
+ if (MO.isExpr()) {
+ const MCExpr *Expr = MO.getExpr();
+ // In instruction code this value always encoded as lowest 12 bits,
+ // so we don't have to perform any specific adjustments.
+ // Due to requirements of relocatable records we have to use FK_Data_4.
+ // See ARMELFObjectWriter::ExplicitRelSym and
+ // ARMELFObjectWriter::GetRelocTypeInner for more details.
+ MCFixupKind Kind = MCFixupKind(FK_Data_4);
+ Fixups.push_back(MCFixup::Create(0, Expr, Kind, MI.getLoc()));
+ return 0;
}
+
+ unsigned SoImm = MO.getImm();
+ int SoImmVal = ARM_AM::getSOImmVal(SoImm);
assert(SoImmVal != -1 && "Not a valid so_imm value!");
// Encode rotate_imm.
return Binary;
}
+ unsigned getModImmOpValue(const MCInst &MI, unsigned Op,
+ SmallVectorImpl<MCFixup> &Fixups,
+ const MCSubtargetInfo &ST) const {
+ const MCOperand &MO = MI.getOperand(Op);
+
+ // Support for fixups (MCFixup)
+ if (MO.isExpr()) {
+ const MCExpr *Expr = MO.getExpr();
+ // In instruction code this value always encoded as lowest 12 bits,
+ // so we don't have to perform any specific adjustments.
+ // Due to requirements of relocatable records we have to use FK_Data_4.
+ // See ARMELFObjectWriter::ExplicitRelSym and
+ // ARMELFObjectWriter::GetRelocTypeInner for more details.
+ MCFixupKind Kind = MCFixupKind(FK_Data_4);
+ Fixups.push_back(MCFixup::Create(0, Expr, Kind, MI.getLoc()));
+ return 0;
+ }
+
+ // Immediate is already in its encoded format
+ return MO.getImm();
+ }
+
/// getT2SOImmOpValue - Return an encoded 12-bit shifted-immediate value.
unsigned getT2SOImmOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups,
void EmitConstant(uint64_t Val, unsigned Size, raw_ostream &OS) const {
// Output the constant in little endian byte order.
for (unsigned i = 0; i != Size; ++i) {
- EmitByte(Val & 255, OS);
- Val >>= 8;
+ unsigned Shift = IsLittleEndian ? i * 8 : (Size - 1 - i) * 8;
+ EmitByte((Val >> Shift) & 0xff, OS);
}
}
} // end anonymous namespace
-MCCodeEmitter *llvm::createARMMCCodeEmitter(const MCInstrInfo &MCII,
- const MCRegisterInfo &MRI,
- const MCSubtargetInfo &STI,
- MCContext &Ctx) {
- return new ARMMCCodeEmitter(MCII, Ctx);
+MCCodeEmitter *llvm::createARMLEMCCodeEmitter(const MCInstrInfo &MCII,
+ const MCRegisterInfo &MRI,
+ MCContext &Ctx) {
+ return new ARMMCCodeEmitter(MCII, Ctx, true);
+}
+
+MCCodeEmitter *llvm::createARMBEMCCodeEmitter(const MCInstrInfo &MCII,
+ const MCRegisterInfo &MRI,
+ MCContext &Ctx) {
+ return new ARMMCCodeEmitter(MCII, Ctx, false);
}
/// NEONThumb2DataIPostEncoder - Post-process encoded NEON data-processing
return (Reg << 8) | Imm8;
}
-// FIXME: This routine assumes that a binary
-// expression will always result in a PCRel expression
-// In reality, its only true if one or more subexpressions
-// is itself a PCRel (i.e. "." in asm or some other pcrel construct)
-// but this is good enough for now.
-static bool EvaluateAsPCRel(const MCExpr *Expr) {
- switch (Expr->getKind()) {
- default: llvm_unreachable("Unexpected expression type");
- case MCExpr::SymbolRef: return false;
- case MCExpr::Binary: return true;
- }
-}
-
uint32_t
ARMMCCodeEmitter::getHiLo16ImmOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
switch (ARM16Expr->getKind()) {
default: llvm_unreachable("Unsupported ARMFixup");
case ARMMCExpr::VK_ARM_HI16:
- if (!isTargetMachO(STI) && EvaluateAsPCRel(E))
- Kind = MCFixupKind(isThumb2(STI)
- ? ARM::fixup_t2_movt_hi16_pcrel
- : ARM::fixup_arm_movt_hi16_pcrel);
- else
- Kind = MCFixupKind(isThumb2(STI)
- ? ARM::fixup_t2_movt_hi16
- : ARM::fixup_arm_movt_hi16);
+ Kind = MCFixupKind(isThumb2(STI) ? ARM::fixup_t2_movt_hi16
+ : ARM::fixup_arm_movt_hi16);
break;
case ARMMCExpr::VK_ARM_LO16:
- if (!isTargetMachO(STI) && EvaluateAsPCRel(E))
- Kind = MCFixupKind(isThumb2(STI)
- ? ARM::fixup_t2_movw_lo16_pcrel
- : ARM::fixup_arm_movw_lo16_pcrel);
- else
- Kind = MCFixupKind(isThumb2(STI)
- ? ARM::fixup_t2_movw_lo16
- : ARM::fixup_arm_movw_lo16);
+ Kind = MCFixupKind(isThumb2(STI) ? ARM::fixup_t2_movw_lo16
+ : ARM::fixup_arm_movw_lo16);
break;
}
+
Fixups.push_back(MCFixup::Create(0, E, Kind, MI.getLoc()));
return 0;
}
// If the expression doesn't have :upper16: or :lower16: on it,
- // it's just a plain immediate expression, and those evaluate to
+ // it's just a plain immediate expression, previously those evaluated to
// the lower 16 bits of the expression regardless of whether
- // we have a movt or a movw.
- if (!isTargetMachO(STI) && EvaluateAsPCRel(E))
- Kind = MCFixupKind(isThumb2(STI)
- ? ARM::fixup_t2_movw_lo16_pcrel
- : ARM::fixup_arm_movw_lo16_pcrel);
- else
- Kind = MCFixupKind(isThumb2(STI)
- ? ARM::fixup_t2_movw_lo16
- : ARM::fixup_arm_movw_lo16);
- Fixups.push_back(MCFixup::Create(0, E, Kind, MI.getLoc()));
- return 0;
+ // we have a movt or a movw, but that led to misleadingly results.
+ // This is now disallowed in the the AsmParser in validateInstruction()
+ // so this should never happen.
+ llvm_unreachable("expression without :upper16: or :lower16:");
}
uint32_t ARMMCCodeEmitter::