llvm-6502/lib/MC/MCAsmInfoDarwin.cpp
Ahmed Bougacha e1f835ab59 [MC] Use LShr for constant evaluation of ">>" on ELF/arm64--darwin.
This matches other assemblers and is less unexpected (e.g. PR23227).
On ELF, I tried binutils gas v2.24 and nasm 2.10.09, and they both
agree on LShr.  On COFF, I couldn't get my hands on an assembler yet,
so don't change the behavior.  For now, don't change it on non-AArch64
Darwin either, as the other assembler is gas v1.38, which does an AShr.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235963 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-28 01:37:11 +00:00

102 lines
3.2 KiB
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//===-- MCAsmInfoDarwin.cpp - Darwin asm properties -------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines target asm properties related what form asm statements
// should take in general on Darwin-based targets
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCAsmInfoDarwin.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCSectionMachO.h"
using namespace llvm;
bool MCAsmInfoDarwin::isSectionAtomizableBySymbols(
const MCSection &Section) const {
const MCSectionMachO &SMO = static_cast<const MCSectionMachO &>(Section);
// Sections holding 1 byte strings are atomized based on the data they
// contain.
// Sections holding 2 byte strings require symbols in order to be atomized.
// There is no dedicated section for 4 byte strings.
if (SMO.getType() == MachO::S_CSTRING_LITERALS)
return false;
if (SMO.getSegmentName() == "__DATA" && SMO.getSectionName() == "__cfstring")
return false;
if (SMO.getSegmentName() == "__DATA" &&
SMO.getSectionName() == "__objc_classrefs")
return false;
switch (SMO.getType()) {
default:
return true;
// These sections are atomized at the element boundaries without using
// symbols.
case MachO::S_4BYTE_LITERALS:
case MachO::S_8BYTE_LITERALS:
case MachO::S_16BYTE_LITERALS:
case MachO::S_LITERAL_POINTERS:
case MachO::S_NON_LAZY_SYMBOL_POINTERS:
case MachO::S_LAZY_SYMBOL_POINTERS:
case MachO::S_MOD_INIT_FUNC_POINTERS:
case MachO::S_MOD_TERM_FUNC_POINTERS:
case MachO::S_INTERPOSING:
return false;
}
}
MCAsmInfoDarwin::MCAsmInfoDarwin() {
// Common settings for all Darwin targets.
// Syntax:
LinkerPrivateGlobalPrefix = "l";
HasSingleParameterDotFile = false;
HasSubsectionsViaSymbols = true;
AlignmentIsInBytes = false;
COMMDirectiveAlignmentIsInBytes = false;
LCOMMDirectiveAlignmentType = LCOMM::Log2Alignment;
InlineAsmStart = " InlineAsm Start";
InlineAsmEnd = " InlineAsm End";
// Directives:
HasWeakDefDirective = true;
HasWeakDefCanBeHiddenDirective = true;
WeakRefDirective = "\t.weak_reference ";
ZeroDirective = "\t.space\t"; // ".space N" emits N zeros.
HasMachoZeroFillDirective = true; // Uses .zerofill
HasMachoTBSSDirective = true; // Uses .tbss
HasStaticCtorDtorReferenceInStaticMode = true;
// FIXME: Change this once MC is the system assembler.
HasAggressiveSymbolFolding = false;
HiddenVisibilityAttr = MCSA_PrivateExtern;
HiddenDeclarationVisibilityAttr = MCSA_Invalid;
// Doesn't support protected visibility.
ProtectedVisibilityAttr = MCSA_Invalid;
HasDotTypeDotSizeDirective = false;
HasNoDeadStrip = true;
DwarfUsesRelocationsAcrossSections = false;
UseIntegratedAssembler = true;
SetDirectiveSuppressesReloc = true;
// FIXME: For now keep the previous behavior, AShr, matching the previous
// behavior of as(1) (both -q and -Q: resp. LLVM and gas v1.38).
// If/when this changes, the AArch64 Darwin special case can go away.
UseLogicalShr = false;
}