mirror of
https://github.com/RPCSX/llvm.git
synced 2024-12-13 23:18:51 +00:00
875b7560fb
This patch adds support for the MachO .alt_entry assembly directive, and uses it for global aliases with non-zero GEP offsets. The alt_entry flag indicates that a symbol should be layed out immediately after the preceding symbol. Conceptually it introduces an alternate entry point for a function or data structure. E.g.: safe_foo: // check preconditions for foo .alt_entry fast_foo fast_foo: // body of foo, can assume preconditions. The .alt_entry flag is also implicitly set on assembly aliases of the form: a = b + C where C is a non-zero constant, since these have the same effect as an alt_entry symbol: they introduce a label that cannot be moved relative to the preceding one. Setting the alt_entry flag on aliases of this form fixes http://llvm.org/PR25381. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263521 91177308-0d34-0410-b5e6-96231b3b80d8
98 lines
3.0 KiB
C++
98 lines
3.0 KiB
C++
//===-- 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;
|
|
HasAltEntry = true;
|
|
|
|
DwarfUsesRelocationsAcrossSections = false;
|
|
|
|
UseIntegratedAssembler = true;
|
|
SetDirectiveSuppressesReloc = true;
|
|
}
|