llvm-6502/lib/Target/ARM64/MCTargetDesc/ARM64MCAsmInfo.cpp
Tim Northover 7b837d8c75 ARM64: initial backend import
This adds a second implementation of the AArch64 architecture to LLVM,
accessible in parallel via the "arm64" triple. The plan over the
coming weeks & months is to merge the two into a single backend,
during which time thorough code review should naturally occur.

Everything will be easier with the target in-tree though, hence this
commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205090 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-29 10:18:08 +00:00

93 lines
2.9 KiB
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//===-- ARM64MCAsmInfo.cpp - ARM64 asm properties -----------------------===//
//
// 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 declarations of the ARM64MCAsmInfo properties.
//
//===----------------------------------------------------------------------===//
#include "ARM64MCAsmInfo.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Support/CommandLine.h"
using namespace llvm;
enum AsmWriterVariantTy {
Default = -1,
Generic = 0,
Apple = 1
};
static cl::opt<AsmWriterVariantTy> AsmWriterVariant(
"arm64-neon-syntax", cl::init(Default),
cl::desc("Choose style of NEON code to emit from ARM64 backend:"),
cl::values(clEnumValN(Generic, "generic", "Emit generic NEON assembly"),
clEnumValN(Apple, "apple", "Emit Apple-style NEON assembly"),
clEnumValEnd));
ARM64MCAsmInfoDarwin::ARM64MCAsmInfoDarwin() {
// We prefer NEON instructions to be printed in the short form.
AssemblerDialect = AsmWriterVariant == Default ? 1 : AsmWriterVariant;
PrivateGlobalPrefix = "L";
SeparatorString = "%%";
CommentString = ";";
PointerSize = CalleeSaveStackSlotSize = 8;
AlignmentIsInBytes = false;
UsesELFSectionDirectiveForBSS = true;
SupportsDebugInformation = true;
UseDataRegionDirectives = true;
ExceptionsType = ExceptionHandling::DwarfCFI;
}
const MCExpr *ARM64MCAsmInfoDarwin::getExprForPersonalitySymbol(
const MCSymbol *Sym, unsigned Encoding, MCStreamer &Streamer) const {
// On Darwin, we can reference dwarf symbols with foo@GOT-., which
// is an indirect pc-relative reference. The default implementation
// won't reference using the GOT, so we need this target-specific
// version.
MCContext &Context = Streamer.getContext();
const MCExpr *Res =
MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_GOT, Context);
MCSymbol *PCSym = Context.CreateTempSymbol();
Streamer.EmitLabel(PCSym);
const MCExpr *PC = MCSymbolRefExpr::Create(PCSym, Context);
return MCBinaryExpr::CreateSub(Res, PC, Context);
}
ARM64MCAsmInfoELF::ARM64MCAsmInfoELF() {
// We prefer NEON instructions to be printed in the short form.
AssemblerDialect = AsmWriterVariant == Default ? 0 : AsmWriterVariant;
PointerSize = 8;
// ".comm align is in bytes but .align is pow-2."
AlignmentIsInBytes = false;
CommentString = "//";
PrivateGlobalPrefix = ".L";
Code32Directive = ".code\t32";
Data16bitsDirective = "\t.hword\t";
Data32bitsDirective = "\t.word\t";
Data64bitsDirective = "\t.xword\t";
UseDataRegionDirectives = false;
WeakRefDirective = "\t.weak\t";
HasLEB128 = true;
SupportsDebugInformation = true;
// Exceptions handling
ExceptionsType = ExceptionHandling::DwarfCFI;
}