ARM: locate user-defined text sections next to default text.

Make sure functions located in user specified text sections (via the
section attribute) are located together with the default text sections.
Otherwise, for large object files, the relocations for call instructions
are more likely to be out of range. This becomes even more likely in the
presence of LTO.

rdar://12402636

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165254 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach 2012-10-04 21:33:24 +00:00
parent a36091abcf
commit 837c28a840
2 changed files with 41 additions and 4 deletions

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@ -23,6 +23,8 @@
#include "InstPrinter/ARMInstPrinter.h"
#include "MCTargetDesc/ARMAddressingModes.h"
#include "MCTargetDesc/ARMMCExpr.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Constants.h"
#include "llvm/DebugInfo.h"
#include "llvm/Module.h"
@ -42,7 +44,6 @@
#include "llvm/Target/Mangler.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
@ -592,9 +593,24 @@ void ARMAsmPrinter::EmitStartOfAsmFile(Module &M) {
const TargetLoweringObjectFileMachO &TLOFMacho =
static_cast<const TargetLoweringObjectFileMachO &>(
getObjFileLowering());
OutStreamer.SwitchSection(TLOFMacho.getTextSection());
OutStreamer.SwitchSection(TLOFMacho.getTextCoalSection());
OutStreamer.SwitchSection(TLOFMacho.getConstTextCoalSection());
// Collect the set of sections our functions will go into.
SetVector<const MCSection *, SmallVector<const MCSection *, 8>,
SmallPtrSet<const MCSection *, 8> > TextSections;
// Default text section comes first.
TextSections.insert(TLOFMacho.getTextSection());
// Now any user defined text sections from function attributes.
for (Module::iterator F = M.begin(), e = M.end(); F != e; ++F)
if (!F->isDeclaration() && !F->hasAvailableExternallyLinkage())
TextSections.insert(TLOFMacho.SectionForGlobal(F, Mang, TM));
// Now the coalescable sections.
TextSections.insert(TLOFMacho.getTextCoalSection());
TextSections.insert(TLOFMacho.getConstTextCoalSection());
// Emit the sections in the .s file header to fix the order.
for (unsigned i = 0, e = TextSections.size(); i != e; ++i)
OutStreamer.SwitchSection(TextSections[i]);
if (RelocM == Reloc::DynamicNoPIC) {
const MCSection *sect =
OutContext.getMachOSection("__TEXT", "__symbol_stub4",

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@ -0,0 +1,21 @@
; RUN: llc < %s -mtriple=armv7-apple-darwin | FileCheck %s
; CHECK: .section __TEXT,__text,regular,pure_instructions
; CHECK: .section __TEXT,myprecious
; CHECK: .section __TEXT,__textcoal_nt,coalesced,pure_instructions
; CHECK: .section __TEXT,__const_coal,coalesced
; CHECK: .section __TEXT,__picsymbolstub4,symbol_stubs,none,16
; CHECK: .section __TEXT,__StaticInit,regular,pure_instructions
define void @normal() nounwind readnone {
; CHECK: .section __TEXT,__text,regular,pure_instructions
; CHECK: _normal:
ret void
}
define void @special() nounwind readnone section "__TEXT,myprecious" {
; CHECK: .section __TEXT,myprecious
; CHECK: _special:
ret void
}