namespace branch_island {
+static std::map<const Atom*, uint64_t> sAtomToAddress;
struct TargetAndOffset { const ld::Atom* atom; uint32_t offset; };
ld::Atom::scopeLinkageUnit, ld::Atom::typeBranchIsland,
ld::Atom::symbolTableIn, false, false, false, ld::Atom::Alignment(2)),
_name(nm),
- _target(target),
- _finalTarget(finalTarget) { }
+ _fixup1(0, ld::Fixup::k1of1, ld::Fixup::kindStoreTargetAddressARMBranch24, target),
+ _fixup2(0, ld::Fixup::k1of1, ld::Fixup::kindIslandTarget, finalTarget.atom) {
+ if (_s_log) fprintf(stderr, "%p: ARM-to-ARM branch island to final target %s\n",
+ this, finalTarget.atom->name());
+ }
virtual const ld::File* file() const { return NULL; }
- virtual bool translationUnitSource(const char** dir, const char**) const
- { return false; }
virtual const char* name() const { return _name; }
virtual uint64_t size() const { return 4; }
virtual uint64_t objectAddress() const { return 0; }
virtual void copyRawContent(uint8_t buffer[]) const {
- int64_t displacement = _target->finalAddress() - this->finalAddress() - 8;
- if ( _target->contentType() == ld::Atom::typeBranchIsland ) {
- // an ARM branch can branch farther than a thumb branch. The branch
- // island generation was conservative and put islands every thumb
- // branch distance apart. Check to see if this is a an island
- // hopping branch that could be optimized to go directly to target.
- int64_t skipToFinalDisplacement = _finalTarget.atom->finalAddress() + _finalTarget.offset - this->finalAddress() - 8;
- if ( (skipToFinalDisplacement < 33554428LL) && (skipToFinalDisplacement > (-33554432LL)) ) {
- // can skip branch island and jump straight to target
- if (_s_log) fprintf(stderr, "%s: optimized jump to final target at 0x%08llX, thisAddr=0x%08llX\n",
- _target->name(), _finalTarget.atom->finalAddress(), this->finalAddress());
- displacement = skipToFinalDisplacement;
- }
- else {
- // ultimate target is too far, jump to island
- if (_s_log) fprintf(stderr, "%s: jump to branch island at 0x%08llX\n",
- _target->name(), _finalTarget.atom->finalAddress());
- }
- }
- uint32_t imm24 = (displacement >> 2) & 0x00FFFFFF;
- int32_t branchInstruction = 0xEA000000 | imm24;
- OSWriteLittleInt32(buffer, 0, branchInstruction);
+ OSWriteLittleInt32(buffer, 0, 0xEA000000);
}
virtual void setScope(Scope) { }
+ virtual ld::Fixup::iterator fixupsBegin() const { return (ld::Fixup*)&_fixup1; }
+ virtual ld::Fixup::iterator fixupsEnd() const { return &((ld::Fixup*)&_fixup2)[1]; }
private:
const char* _name;
- const ld::Atom* _target;
- TargetAndOffset _finalTarget;
+ ld::Fixup _fixup1;
+ ld::Fixup _fixup2;
};
ld::Atom::scopeLinkageUnit, ld::Atom::typeBranchIsland,
ld::Atom::symbolTableIn, false, false, false, ld::Atom::Alignment(2)),
_name(nm),
- _target(target),
- _finalTarget(finalTarget) { }
+ _finalTarget(finalTarget) {
+ if (_s_log) fprintf(stderr, "%p: ARM-to-thumb1 branch island to final target %s\n",
+ this, finalTarget.atom->name());
+ }
virtual const ld::File* file() const { return NULL; }
- virtual bool translationUnitSource(const char** dir, const char**) const
- { return false; }
virtual const char* name() const { return _name; }
virtual uint64_t size() const { return 16; }
virtual uint64_t objectAddress() const { return 0; }
int64_t displacement = _finalTarget.atom->finalAddress() + _finalTarget.offset - (this->finalAddress() + 12);
if ( _finalTarget.atom->isThumb() )
displacement |= 1;
- if (_s_log) fprintf(stderr, "%s: 4 ARM instruction jump to final target at 0x%08llX\n",
- _target->name(), _finalTarget.atom->finalAddress());
OSWriteLittleInt32(&buffer[ 0], 0, 0xe59fc004); // ldr ip, pc + 4
OSWriteLittleInt32(&buffer[ 4], 0, 0xe08fc00c); // add ip, pc, ip
OSWriteLittleInt32(&buffer[ 8], 0, 0xe12fff1c); // bx ip
private:
const char* _name;
- const ld::Atom* _target;
TargetAndOffset _finalTarget;
};
ld::Atom::scopeLinkageUnit, ld::Atom::typeBranchIsland,
ld::Atom::symbolTableIn, false, true, false, ld::Atom::Alignment(1)),
_name(nm),
- _target(target),
- _finalTarget(finalTarget) { }
+ _fixup1(0, ld::Fixup::k1of1, ld::Fixup::kindStoreTargetAddressThumbBranch22, target),
+ _fixup2(0, ld::Fixup::k1of1, ld::Fixup::kindIslandTarget, finalTarget.atom) {
+ if (_s_log) fprintf(stderr, "%p: Thumb-to-thumb branch island to final target %s\n",
+ this, finalTarget.atom->name());
+ }
virtual const ld::File* file() const { return NULL; }
- virtual bool translationUnitSource(const char** dir, const char**) const
- { return false; }
virtual const char* name() const { return _name; }
virtual uint64_t size() const { return 4; }
virtual uint64_t objectAddress() const { return 0; }
virtual void copyRawContent(uint8_t buffer[]) const {
- int64_t displacement = _target->finalAddress() - this->finalAddress() - 4;
- if ( _target->contentType() == ld::Atom::typeBranchIsland ) {
- // an ARM branch can branch farther than a thumb branch. The branch
- // island generation was conservative and put islands every thumb
- // branch distance apart. Check to see if this is a an island
- // hopping branch that could be optimized to go directly to target.
- int64_t skipToFinalDisplacement = _finalTarget.atom->finalAddress() + _finalTarget.offset - this->finalAddress() - 4;
- if ( (skipToFinalDisplacement < 16777214) && (skipToFinalDisplacement > (-16777216LL)) ) {
- // can skip branch island and jump straight to target
- if (_s_log) fprintf(stderr, "%s: optimized jump to final target at 0x%08llX, thisAddr=0x%08llX\n",
- _target->name(), _finalTarget.atom->finalAddress(), this->finalAddress());
- displacement = skipToFinalDisplacement;
- }
- else {
- // ultimate target is too far for thumb2 branch, jump to island
- if (_s_log) fprintf(stderr, "%s: jump to branch island at 0x%08llX\n",
- _target->name(), _finalTarget.atom->finalAddress());
- }
- }
- // The instruction is really two instructions:
- // The lower 16 bits are the first instruction, which contains the high
- // 11 bits of the displacement.
- // The upper 16 bits are the second instruction, which contains the low
- // 11 bits of the displacement, as well as differentiating bl and blx.
- uint32_t s = (uint32_t)(displacement >> 24) & 0x1;
- uint32_t i1 = (uint32_t)(displacement >> 23) & 0x1;
- uint32_t i2 = (uint32_t)(displacement >> 22) & 0x1;
- uint32_t imm10 = (uint32_t)(displacement >> 12) & 0x3FF;
- uint32_t imm11 = (uint32_t)(displacement >> 1) & 0x7FF;
- uint32_t j1 = (i1 == s);
- uint32_t j2 = (i2 == s);
- uint32_t opcode = 0x9000F000;
- uint32_t nextDisp = (j1 << 13) | (j2 << 11) | imm11;
- uint32_t firstDisp = (s << 10) | imm10;
- uint32_t newInstruction = opcode | (nextDisp << 16) | firstDisp;
- //warning("s=%d, j1=%d, j2=%d, imm10=0x%0X, imm11=0x%0X, opcode=0x%08X, first=0x%04X, next=0x%04X, new=0x%08X, disp=0x%llX for %s to %s\n",
- // s, j1, j2, imm10, imm11, opcode, firstDisp, nextDisp, newInstruction, displacement, inAtom->getDisplayName(), ref->getTarget().getDisplayName());
- OSWriteLittleInt32(buffer, 0, newInstruction);
+ OSWriteLittleInt32(buffer, 0, 0xf0008000);
}
virtual void setScope(Scope) { }
+ virtual ld::Fixup::iterator fixupsBegin() const { return (ld::Fixup*)&_fixup1; }
+ virtual ld::Fixup::iterator fixupsEnd() const { return &((ld::Fixup*)&_fixup2)[1]; }
private:
const char* _name;
- const ld::Atom* _target;
- TargetAndOffset _finalTarget;
+ ld::Fixup _fixup1;
+ ld::Fixup _fixup2;
};
+
+class Thumb2toThumbBranchAbsoluteIslandAtom : public ld::Atom {
+public:
+ Thumb2toThumbBranchAbsoluteIslandAtom(const char* nm, const ld::Section& inSect, TargetAndOffset finalTarget)
+ : ld::Atom(inSect, ld::Atom::definitionRegular, ld::Atom::combineNever,
+ ld::Atom::scopeLinkageUnit, ld::Atom::typeBranchIsland,
+ ld::Atom::symbolTableIn, false, true, false, ld::Atom::Alignment(1)),
+ _name(nm),
+ _fixup1(0, ld::Fixup::k1of2, ld::Fixup::kindSetTargetAddress, finalTarget.atom),
+ _fixup2(0, ld::Fixup::k2of2, ld::Fixup::kindStoreThumbLow16),
+ _fixup3(4, ld::Fixup::k1of2, ld::Fixup::kindSetTargetAddress, finalTarget.atom),
+ _fixup4(4, ld::Fixup::k2of2, ld::Fixup::kindStoreThumbHigh16),
+ _fixup5(0, ld::Fixup::k1of1, ld::Fixup::kindIslandTarget, finalTarget.atom) {
+ if (_s_log) fprintf(stderr, "%p: Thumb-to-thumb absolute branch island to final target %s\n",
+ this, finalTarget.atom->name());
+ }
+
+ virtual const ld::File* file() const { return NULL; }
+ virtual const char* name() const { return _name; }
+ virtual uint64_t size() const { return 10; }
+ virtual uint64_t objectAddress() const { return 0; }
+ virtual void copyRawContent(uint8_t buffer[]) const {
+ OSWriteLittleInt32(&buffer[0], 0, 0x0c00f240); // movw r12, #0x5678
+ OSWriteLittleInt32(&buffer[4], 0, 0x0c00f2c0); // movt r12, #0x1234
+ OSWriteLittleInt16(&buffer[8], 0, 0x4760); // bx r12
+ }
+ virtual void setScope(Scope) { }
+ virtual ld::Fixup::iterator fixupsBegin() const { return (ld::Fixup*)&_fixup1; }
+ virtual ld::Fixup::iterator fixupsEnd() const { return &((ld::Fixup*)&_fixup5)[1]; }
+
+private:
+ const char* _name;
+ ld::Fixup _fixup1;
+ ld::Fixup _fixup2;
+ ld::Fixup _fixup3;
+ ld::Fixup _fixup4;
+ ld::Fixup _fixup5;
+};
+
+
+
class NoPicARMtoThumbMBranchIslandAtom : public ld::Atom {
public:
NoPicARMtoThumbMBranchIslandAtom(const char* nm, const ld::Atom* target, TargetAndOffset finalTarget)
ld::Atom::scopeLinkageUnit, ld::Atom::typeBranchIsland,
ld::Atom::symbolTableIn, false, false, false, ld::Atom::Alignment(2)),
_name(nm),
- _target(target),
- _finalTarget(finalTarget) { }
+ _finalTarget(finalTarget) {
+ if (_s_log) fprintf(stderr, "%p: NoPIC ARM-to-Thumb branch island to final target %s\n",
+ this, finalTarget.atom->name());
+ }
virtual const ld::File* file() const { return NULL; }
- virtual bool translationUnitSource(const char** dir, const char**) const
- { return false; }
virtual const char* name() const { return _name; }
virtual uint64_t size() const { return 8; }
virtual uint64_t objectAddress() const { return 0; }
uint32_t targetAddr = _finalTarget.atom->finalAddress();
if ( _finalTarget.atom->isThumb() )
targetAddr |= 1;
- if (_s_log) fprintf(stderr, "%s: 2 ARM instruction jump to final target at 0x%08llX\n",
- _target->name(), _finalTarget.atom->finalAddress());
OSWriteLittleInt32(&buffer[0], 0, 0xe51ff004); // ldr pc, [pc, #-4]
OSWriteLittleInt32(&buffer[4], 0, targetAddr); // .long target-this
}
private:
const char* _name;
- const ld::Atom* _target;
TargetAndOffset _finalTarget;
};
-static ld::Atom* makeBranchIsland(const Options& opts, ld::Fixup::Kind kind, int islandRegion, const ld::Atom* nextTarget, TargetAndOffset finalTarget)
+static ld::Atom* makeBranchIsland(const Options& opts, ld::Fixup::Kind kind, int islandRegion, const ld::Atom* nextTarget,
+ TargetAndOffset finalTarget, const ld::Section& inSect, bool crossSectionBranch)
{
char* name;
if ( finalTarget.offset == 0 ) {
case ld::Fixup::kindStoreThumbBranch22:
case ld::Fixup::kindStoreTargetAddressARMBranch24:
case ld::Fixup::kindStoreTargetAddressThumbBranch22:
- if ( finalTarget.atom->isThumb() ) {
+ if ( crossSectionBranch && opts.preferSubArchitecture() && opts.archSupportsThumb2() ) {
+ return new Thumb2toThumbBranchAbsoluteIslandAtom(name, inSect, finalTarget);
+ }
+ else if ( finalTarget.atom->isThumb() ) {
if ( opts.preferSubArchitecture() && opts.archSupportsThumb2() ) {
return new Thumb2toThumbBranchIslandAtom(name, nextTarget, finalTarget);
}
// before any branches could be pushed out of range.
//
-void doPass(const Options& opts, ld::Internal& state)
-{
- // only make branch islands in final linked images
- if ( opts.outputKind() == Options::kObjectFile )
- return;
- // only ARM needs branch islands
- switch ( opts.architecture() ) {
- case CPU_TYPE_ARM:
- break;
- default:
- return;
- }
-
- // scan to find __text section
- ld::Internal::FinalSection* textSection = NULL;
- for (std::vector<ld::Internal::FinalSection*>::iterator sit=state.sections.begin(); sit != state.sections.end(); ++sit) {
- ld::Internal::FinalSection* sect = *sit;
- if ( strcmp(sect->sectionName(), "__text") == 0 )
- textSection = sect;
- }
- if ( textSection == NULL )
- return;
-
+static void makeIslandsForSection(const Options& opts, ld::Internal& state, ld::Internal::FinalSection* textSection)
+{
// assign section offsets to each atom in __text section, watch for thumb branches, and find total size
- const bool isARM = (opts.architecture() == CPU_TYPE_ARM);
bool hasThumbBranches = false;
+ bool haveCrossSectionBranches = false;
+ const bool preload = (opts.outputKind() == Options::kPreload);
uint64_t offset = 0;
for (std::vector<const ld::Atom*>::iterator ait=textSection->atoms.begin(); ait != textSection->atoms.end(); ++ait) {
const ld::Atom* atom = *ait;
- // check for thumb branches
- if ( isARM && ~hasThumbBranches ) {
- for (ld::Fixup::iterator fit = atom->fixupsBegin(), end=atom->fixupsEnd(); fit != end; ++fit) {
- switch ( fit->kind ) {
- case ld::Fixup::kindStoreThumbBranch22:
- case ld::Fixup::kindStoreTargetAddressThumbBranch22:
- hasThumbBranches = true;
- break;
- default:
- break;
- }
+ // check for thumb branches and cross section branches
+ const ld::Atom* target = NULL;
+ for (ld::Fixup::iterator fit = atom->fixupsBegin(), end=atom->fixupsEnd(); fit != end; ++fit) {
+ if ( fit->firstInCluster() ) {
+ target = NULL;
+ }
+ switch ( fit->binding ) {
+ case ld::Fixup::bindingNone:
+ case ld::Fixup::bindingByNameUnbound:
+ break;
+ case ld::Fixup::bindingByContentBound:
+ case ld::Fixup::bindingDirectlyBound:
+ target = fit->u.target;
+ break;
+ case ld::Fixup::bindingsIndirectlyBound:
+ target = state.indirectBindingTable[fit->u.bindingIndex];
+ break;
+ }
+ bool haveBranch = false;
+ switch (fit->kind) {
+ case ld::Fixup::kindStoreThumbBranch22:
+ case ld::Fixup::kindStoreTargetAddressThumbBranch22:
+ hasThumbBranches = true;
+ // fall into arm branch case
+ case ld::Fixup::kindStoreARMBranch24:
+ case ld::Fixup::kindStoreTargetAddressARMBranch24:
+ haveBranch = true;
+ break;
+ default:
+ break;
+ }
+ if ( haveBranch && (target->contentType() != ld::Atom::typeStub) ) {
+ // <rdar://problem/14792124> haveCrossSectionBranches only applies to -preload builds
+ if ( preload && (atom->section() != target->section()) )
+ haveCrossSectionBranches = true;
}
}
// align atom
offset += atom->size();
}
uint64_t totalTextSize = offset;
- if ( totalTextSize < textSizeWhenMightNeedBranchIslands(opts, hasThumbBranches) )
+ if ( (totalTextSize < textSizeWhenMightNeedBranchIslands(opts, hasThumbBranches)) && !haveCrossSectionBranches )
return;
- if (_s_log) fprintf(stderr, "ld: __text section size=%llu, might need branch islands\n", totalTextSize);
+ if (_s_log) fprintf(stderr, "ld: section %s size=%llu, might need branch islands\n", textSection->sectionName(), totalTextSize);
- // figure out how many regions of branch islands will be needed
- const uint32_t kBetweenRegions = maxDistanceBetweenIslands(opts, hasThumbBranches); // place regions of islands every 14MB in __text section
- const int kIslandRegionsCount = totalTextSize / kBetweenRegions;
+ // Figure out how many regions of branch islands will be needed, and their locations.
+ // Construct a vector containing the atoms after which branch islands will be inserted,
+ // taking into account follow on fixups. No atom run without an island can exceed kBetweenRegions.
+ const uint64_t kBetweenRegions = maxDistanceBetweenIslands(opts, hasThumbBranches); // place regions of islands every 14MB in __text section
+ std::vector<const ld::Atom*> branchIslandInsertionPoints; // atoms in the atom list after which branch islands will be inserted
+ uint64_t previousIslandEndAddr = 0;
+ const ld::Atom *insertionPoint = NULL;
+ branchIslandInsertionPoints.reserve(totalTextSize/kBetweenRegions*2);
+ for (std::vector<const ld::Atom*>::iterator it=textSection->atoms.begin(); it != textSection->atoms.end(); it++) {
+ const ld::Atom* atom = *it;
+ // if we move past the next atom, will the run length exceed kBetweenRegions?
+ if ( atom->sectionOffset() + atom->size() > previousIslandEndAddr + kBetweenRegions ) {
+ // yes. Add the last known good location (atom) for inserting a branch island.
+ if ( insertionPoint == NULL )
+ throwf("Unable to insert branch island. No insertion point available.");
+ branchIslandInsertionPoints.push_back(insertionPoint);
+ previousIslandEndAddr = insertionPoint->sectionOffset()+insertionPoint->size();
+ insertionPoint = NULL;
+ }
+ // Can we insert an island after this atom? If so then keep track of it.
+ if ( !atom->hasFixupsOfKind(ld::Fixup::kindNoneFollowOn) )
+ insertionPoint = atom;
+ }
+ // add one more island after the last atom if close to limit
+ if ( (insertionPoint != NULL) && (insertionPoint->sectionOffset() + insertionPoint->size() > previousIslandEndAddr + (kBetweenRegions-0x100000)) )
+ branchIslandInsertionPoints.push_back(insertionPoint);
+ if ( haveCrossSectionBranches && branchIslandInsertionPoints.empty() ) {
+ branchIslandInsertionPoints.push_back(textSection->atoms.back());
+ }
+ const int kIslandRegionsCount = branchIslandInsertionPoints.size();
+
+ if (_s_log) fprintf(stderr, "ld: will use %u branch island regions\n", kIslandRegionsCount);
typedef std::map<TargetAndOffset,const ld::Atom*, TargetAndOffsetComparor> AtomToIsland;
AtomToIsland* regionsMap[kIslandRegionsCount];
+ uint64_t regionAddresses[kIslandRegionsCount];
std::vector<const ld::Atom*>* regionsIslands[kIslandRegionsCount];
for(int i=0; i < kIslandRegionsCount; ++i) {
regionsMap[i] = new AtomToIsland();
regionsIslands[i] = new std::vector<const ld::Atom*>();
+ regionAddresses[i] = branchIslandInsertionPoints[i]->sectionOffset() + branchIslandInsertionPoints[i]->size();
+ if (_s_log) fprintf(stderr, "ld: branch islands will be inserted at 0x%08llX after %s\n", regionAddresses[i], branchIslandInsertionPoints[i]->name());
}
unsigned int islandCount = 0;
- if (_s_log) fprintf(stderr, "ld: will use %u branch island regions\n", kIslandRegionsCount);
// create islands for branches in __text that are out of range
for (std::vector<const ld::Atom*>::iterator ait=textSection->atoms.begin(); ait != textSection->atoms.end(); ++ait) {
break;
}
if ( haveBranch ) {
+ bool crossSectionBranch = ( preload && (atom->section() != target->section()) );
int64_t srcAddr = atom->sectionOffset() + fit->offsetInAtom;
int64_t dstAddr = target->sectionOffset() + addend;
+ if ( preload ) {
+ srcAddr = sAtomToAddress[atom] + fit->offsetInAtom;
+ dstAddr = sAtomToAddress[target] + addend;
+ }
if ( target->section().type() == ld::Section::typeStub )
dstAddr = totalTextSize;
int64_t displacement = dstAddr - srcAddr;
TargetAndOffset finalTargetAndOffset = { target, addend };
const int64_t kBranchLimit = kBetweenRegions;
- if ( displacement > kBranchLimit ) {
+ if ( crossSectionBranch && ((displacement > kBranchLimit) || (displacement < (-kBranchLimit))) ) {
+ const ld::Atom* island;
+ AtomToIsland* region = regionsMap[0];
+ AtomToIsland::iterator pos = region->find(finalTargetAndOffset);
+ if ( pos == region->end() ) {
+ island = makeBranchIsland(opts, fit->kind, 0, target, finalTargetAndOffset, atom->section(), true);
+ (*region)[finalTargetAndOffset] = island;
+ if (_s_log) fprintf(stderr, "added absolute branching island %p %s, displacement=%lld\n",
+ island, island->name(), displacement);
+ ++islandCount;
+ regionsIslands[0]->push_back(island);
+ }
+ else {
+ island = pos->second;
+ }
+ if (_s_log) fprintf(stderr, "using island %p %s for branch to %s from %s\n", island, island->name(), target->name(), atom->name());
+ fixupWithTarget->u.target = island;
+ fixupWithTarget->binding = ld::Fixup::bindingDirectlyBound;
+ }
+ else if ( displacement > kBranchLimit ) {
// create forward branch chain
const ld::Atom* nextTarget = target;
+ if (_s_log) fprintf(stderr, "need forward branching island srcAdr=0x%08llX, dstAdr=0x%08llX, target=%s\n",
+ srcAddr, dstAddr, target->name());
for (int i=kIslandRegionsCount-1; i >=0 ; --i) {
AtomToIsland* region = regionsMap[i];
- int64_t islandRegionAddr = kBetweenRegions * (i+1);
- if ( (srcAddr < islandRegionAddr) && (islandRegionAddr <= dstAddr) ) {
+ int64_t islandRegionAddr = regionAddresses[i];
+ if ( (srcAddr < islandRegionAddr) && ((islandRegionAddr <= dstAddr)) ) {
AtomToIsland::iterator pos = region->find(finalTargetAndOffset);
if ( pos == region->end() ) {
- ld::Atom* island = makeBranchIsland(opts, fit->kind, i, nextTarget, finalTargetAndOffset);
+ ld::Atom* island = makeBranchIsland(opts, fit->kind, i, nextTarget, finalTargetAndOffset, atom->section(), false);
(*region)[finalTargetAndOffset] = island;
- if (_s_log) fprintf(stderr, "added island %s to region %d for %s\n", island->name(), i, atom->name());
+ if (_s_log) fprintf(stderr, "added forward branching island %p %s to region %d for %s\n", island, island->name(), i, atom->name());
regionsIslands[i]->push_back(island);
++islandCount;
nextTarget = island;
}
}
}
- if (_s_log) fprintf(stderr, "using island %s for branch to %s from %s\n", nextTarget->name(), target->name(), atom->name());
+ if (_s_log) fprintf(stderr, "using island %p %s for branch to %s from %s\n", nextTarget, nextTarget->name(), target->name(), atom->name());
fixupWithTarget->u.target = nextTarget;
fixupWithTarget->binding = ld::Fixup::bindingDirectlyBound;
}
const ld::Atom* prevTarget = target;
for (int i=0; i < kIslandRegionsCount ; ++i) {
AtomToIsland* region = regionsMap[i];
- int64_t islandRegionAddr = kBetweenRegions * (i+1);
- if ( (dstAddr <= islandRegionAddr) && (islandRegionAddr < srcAddr) ) {
+ int64_t islandRegionAddr = regionAddresses[i];
+ if ( (dstAddr < islandRegionAddr) && (islandRegionAddr <= srcAddr) ) {
+ if (_s_log) fprintf(stderr, "need backward branching island srcAdr=0x%08llX, dstAdr=0x%08llX, target=%s\n", srcAddr, dstAddr, target->name());
AtomToIsland::iterator pos = region->find(finalTargetAndOffset);
if ( pos == region->end() ) {
- ld::Atom* island = makeBranchIsland(opts, fit->kind, i, prevTarget, finalTargetAndOffset);
+ ld::Atom* island = makeBranchIsland(opts, fit->kind, i, prevTarget, finalTargetAndOffset, atom->section(), false);
(*region)[finalTargetAndOffset] = island;
- if (_s_log) fprintf(stderr, "added back island %s to region %d for %s\n", island->name(), i, atom->name());
+ if (_s_log) fprintf(stderr, "added back branching island %p %s to region %d for %s\n", island, island->name(), i, atom->name());
regionsIslands[i]->push_back(island);
++islandCount;
prevTarget = island;
}
}
}
- if (_s_log) fprintf(stderr, "using back island %s for %s\n", prevTarget->name(), atom->name());
+ if (_s_log) fprintf(stderr, "using back island %p %s for %s\n", prevTarget, prevTarget->name(), atom->name());
fixupWithTarget->u.target = prevTarget;
fixupWithTarget->binding = ld::Fixup::bindingDirectlyBound;
}
if ( _s_log ) fprintf(stderr, "ld: %u branch islands required in %u regions\n", islandCount, kIslandRegionsCount);
std::vector<const ld::Atom*> newAtomList;
newAtomList.reserve(textSection->atoms.size()+islandCount);
- uint64_t islandRegionAddr = kBetweenRegions;;
+
int regionIndex = 0;
- for (std::vector<const ld::Atom*>::iterator it=textSection->atoms.begin(); it != textSection->atoms.end(); it++) {
- const ld::Atom* atom = *it;
- if ( (atom->sectionOffset()+atom->size()) > islandRegionAddr ) {
- std::vector<const ld::Atom*>* regionIslands = regionsIslands[regionIndex];
- for (std::vector<const ld::Atom*>::iterator rit=regionIslands->begin(); rit != regionIslands->end(); rit++) {
- const ld::Atom* islandAtom = *rit;
- newAtomList.push_back(islandAtom);
- if ( _s_log ) fprintf(stderr, "inserting island %s into __text section\n", islandAtom->name());
- }
- ++regionIndex;
- islandRegionAddr += kBetweenRegions;
- }
+ for (std::vector<const ld::Atom*>::iterator ait=textSection->atoms.begin(); ait != textSection->atoms.end(); ait++) {
+ const ld::Atom* atom = *ait;
newAtomList.push_back(atom);
- }
- // put any remaining islands at end of __text section
- if ( regionIndex < kIslandRegionsCount ) {
- std::vector<const ld::Atom*>* regionIslands = regionsIslands[regionIndex];
- for (std::vector<const ld::Atom*>::iterator rit=regionIslands->begin(); rit != regionIslands->end(); rit++) {
- const ld::Atom* islandAtom = *rit;
- newAtomList.push_back(islandAtom);
- if ( _s_log ) fprintf(stderr, "inserting island %s into __text section\n", islandAtom->name());
+ if ( (regionIndex < kIslandRegionsCount) && (atom == branchIslandInsertionPoints[regionIndex]) ) {
+ std::vector<const ld::Atom*>* islands = regionsIslands[regionIndex];
+ newAtomList.insert(newAtomList.end(), islands->begin(), islands->end());
+ ++regionIndex;
}
}
// swap in new list of atoms for __text section
}
+static void buildAddressMap(const Options& opts, ld::Internal& state) {
+ // Assign addresses to sections
+ state.setSectionSizesAndAlignments();
+ state.assignFileOffsets();
+
+ // Assign addresses to atoms in a side table
+ const bool log = false;
+ if ( log ) fprintf(stderr, "buildAddressMap()\n");
+ for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
+ ld::Internal::FinalSection* sect = *sit;
+ uint16_t maxAlignment = 0;
+ uint64_t offset = 0;
+ if ( log ) fprintf(stderr, " section=%s/%s, address=0x%08llX\n", sect->segmentName(), sect->sectionName(), sect->address);
+ for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
+ const ld::Atom* atom = *ait;
+ uint32_t atomAlignmentPowerOf2 = atom->alignment().powerOf2;
+ uint32_t atomModulus = atom->alignment().modulus;
+ if ( atomAlignmentPowerOf2 > maxAlignment )
+ maxAlignment = atomAlignmentPowerOf2;
+ // calculate section offset for this atom
+ uint64_t alignment = 1 << atomAlignmentPowerOf2;
+ uint64_t currentModulus = (offset % alignment);
+ uint64_t requiredModulus = atomModulus;
+ if ( currentModulus != requiredModulus ) {
+ if ( requiredModulus > currentModulus )
+ offset += requiredModulus-currentModulus;
+ else
+ offset += requiredModulus+alignment-currentModulus;
+ }
+
+ if ( log ) fprintf(stderr, " 0x%08llX atom=%p, name=%s\n", sect->address+offset, atom, atom->name());
+ sAtomToAddress[atom] = sect->address + offset;
+
+ offset += atom->size();
+ }
+ }
+
+
+}
+
+void doPass(const Options& opts, ld::Internal& state)
+{
+ // only make branch islands in final linked images
+ if ( opts.outputKind() == Options::kObjectFile )
+ return;
+
+ // Allow user to disable branch island generation
+ if ( !opts.allowBranchIslands() )
+ return;
+
+ // only ARM needs branch islands
+ switch ( opts.architecture() ) {
+ case CPU_TYPE_ARM:
+ break;
+ default:
+ return;
+ }
+
+ if ( opts.outputKind() == Options::kPreload ) {
+ buildAddressMap(opts, state);
+ }
+
+ // scan sections and add island to each code section
+ for (std::vector<ld::Internal::FinalSection*>::iterator sit=state.sections.begin(); sit != state.sections.end(); ++sit) {
+ ld::Internal::FinalSection* sect = *sit;
+ if ( sect->type() == ld::Section::typeCode )
+ makeIslandsForSection(opts, state, sect);
+ }
+}
+
+
} // namespace branch_island
} // namespace passes
} // namespace ld
projects / apple / ld64.git / blobdiff