//
// This file implements a simple interprocedural pass which walks the
// call-graph, looking for functions which do not access or only read
-// non-local memory, and marking them readnone/readonly. In addition,
-// it marks function arguments (of pointer type) 'nocapture' if a call
-// to the function does not create any copies of the pointer value that
-// outlive the call. This more or less means that the pointer is only
-// dereferenced, and not returned from the function or stored in a global.
-// Finally, well-known library call declarations are marked with all
-// attributes that are consistent with the function's standard definition.
-// This pass is implemented as a bottom-up traversal of the call-graph.
+// non-local memory, and marking them readnone/readonly. It does the
+// same with function arguments independently, marking them readonly/
+// readnone/nocapture. Finally, well-known library call declarations
+// are marked with all attributes that are consistent with the
+// function's standard definition. This pass is implemented as a
+// bottom-up traversal of the call-graph.
//
//===----------------------------------------------------------------------===//
STATISTIC(NumReadNone, "Number of functions marked readnone");
STATISTIC(NumReadOnly, "Number of functions marked readonly");
STATISTIC(NumNoCapture, "Number of arguments marked nocapture");
+STATISTIC(NumReadNoneArg, "Number of arguments marked readnone");
+STATISTIC(NumReadOnlyArg, "Number of arguments marked readonly");
STATISTIC(NumNoAlias, "Number of function returns marked noalias");
STATISTIC(NumAnnotated, "Number of attributes added to library functions");
// AddReadAttrs - Deduce readonly/readnone attributes for the SCC.
bool AddReadAttrs(const CallGraphSCC &SCC);
- // AddNoCaptureAttrs - Deduce nocapture attributes for the SCC.
- bool AddNoCaptureAttrs(const CallGraphSCC &SCC);
+ // AddArgumentAttrs - Deduce nocapture attributes for the SCC.
+ bool AddArgumentAttrs(const CallGraphSCC &SCC);
// IsFunctionMallocLike - Does this function allocate new memory?
bool IsFunctionMallocLike(Function *F,
void setDoesNotAccessMemory(Function &F) {
if (!F.doesNotAccessMemory()) {
- F.setDoesNotAccessMemory();
- ++NumAnnotated;
+ F.setDoesNotAccessMemory();
+ ++NumAnnotated;
}
}
void setOnlyReadsMemory(Function &F) {
if (!F.onlyReadsMemory()) {
- F.setOnlyReadsMemory();
- ++NumAnnotated;
+ F.setOnlyReadsMemory();
+ ++NumAnnotated;
}
}
void setDoesNotThrow(Function &F) {
if (!F.doesNotThrow()) {
- F.setDoesNotThrow();
- ++NumAnnotated;
+ F.setDoesNotThrow();
+ ++NumAnnotated;
}
}
void setDoesNotCapture(Function &F, unsigned n) {
if (!F.doesNotCapture(n)) {
- F.setDoesNotCapture(n);
- ++NumAnnotated;
+ F.setDoesNotCapture(n);
+ ++NumAnnotated;
+ }
+ }
+
+ void setOnlyReadsMemory(Function &F, unsigned n) {
+ if (!F.onlyReadsMemory(n)) {
+ F.setOnlyReadsMemory(n);
+ ++NumAnnotated;
}
}
void setDoesNotAlias(Function &F, unsigned n) {
if (!F.doesNotAlias(n)) {
- F.setDoesNotAlias(n);
- ++NumAnnotated;
+ F.setDoesNotAlias(n);
+ ++NumAnnotated;
}
}
char FunctionAttrs::ID = 0;
INITIALIZE_PASS_BEGIN(FunctionAttrs, "functionattrs",
"Deduce function attributes", false, false)
-INITIALIZE_AG_DEPENDENCY(CallGraph)
+INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
+INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo)
INITIALIZE_PASS_END(FunctionAttrs, "functionattrs",
"Deduce function attributes", false, false)
Function *F = CS.getCalledFunction();
if (!F || !SCCNodes.count(F)) { Captured = true; return true; }
+ bool Found = false;
Function::arg_iterator AI = F->arg_begin(), AE = F->arg_end();
for (CallSite::arg_iterator PI = CS.arg_begin(), PE = CS.arg_end();
PI != PE; ++PI, ++AI) {
}
if (PI == U) {
Uses.push_back(AI);
+ Found = true;
break;
}
}
- assert(!Uses.empty() && "Capturing call-site captured nothing?");
+ assert(Found && "Capturing call-site captured nothing?");
+ (void)Found;
return false;
}
};
}
-/// AddNoCaptureAttrs - Deduce nocapture attributes for the SCC.
-bool FunctionAttrs::AddNoCaptureAttrs(const CallGraphSCC &SCC) {
+// Returns Attribute::None, Attribute::ReadOnly or Attribute::ReadNone.
+static Attribute::AttrKind
+determinePointerReadAttrs(Argument *A,
+ const SmallPtrSet<Argument*, 8> &SCCNodes) {
+
+ SmallVector<Use*, 32> Worklist;
+ SmallSet<Use*, 32> Visited;
+ int Count = 0;
+
+ bool IsRead = false;
+ // We don't need to track IsWritten. If A is written to, return immediately.
+
+ for (Value::use_iterator UI = A->use_begin(), UE = A->use_end();
+ UI != UE; ++UI) {
+ if (Count++ >= 20)
+ return Attribute::None;
+
+ Use *U = &UI.getUse();
+ Visited.insert(U);
+ Worklist.push_back(U);
+ }
+
+ while (!Worklist.empty()) {
+ Use *U = Worklist.pop_back_val();
+ Instruction *I = cast<Instruction>(U->getUser());
+ Value *V = U->get();
+
+ switch (I->getOpcode()) {
+ case Instruction::BitCast:
+ case Instruction::GetElementPtr:
+ case Instruction::PHI:
+ case Instruction::Select:
+ case Instruction::AddrSpaceCast:
+ // The original value is not read/written via this if the new value isn't.
+ for (Instruction::use_iterator UI = I->use_begin(), UE = I->use_end();
+ UI != UE; ++UI) {
+ Use *U = &UI.getUse();
+ if (Visited.insert(U))
+ Worklist.push_back(U);
+ }
+ break;
+
+ case Instruction::Call:
+ case Instruction::Invoke: {
+ CallSite CS(I);
+ if (CS.doesNotAccessMemory())
+ continue;
+
+ Function *F = CS.getCalledFunction();
+ if (!F) {
+ if (CS.onlyReadsMemory()) {
+ IsRead = true;
+ continue;
+ }
+ return Attribute::None;
+ }
+
+ Function::arg_iterator AI = F->arg_begin(), AE = F->arg_end();
+ CallSite::arg_iterator B = CS.arg_begin(), E = CS.arg_end();
+ for (CallSite::arg_iterator A = B; A != E; ++A, ++AI) {
+ if (A->get() == V) {
+ if (AI == AE) {
+ assert(F->isVarArg() &&
+ "More params than args in non-varargs call.");
+ return Attribute::None;
+ }
+ if (SCCNodes.count(AI))
+ continue;
+ if (!CS.onlyReadsMemory() && !CS.onlyReadsMemory(A - B))
+ return Attribute::None;
+ if (!CS.doesNotAccessMemory(A - B))
+ IsRead = true;
+ }
+ }
+ break;
+ }
+
+ case Instruction::Load:
+ IsRead = true;
+ break;
+
+ case Instruction::ICmp:
+ case Instruction::Ret:
+ break;
+
+ default:
+ return Attribute::None;
+ }
+ }
+
+ return IsRead ? Attribute::ReadOnly : Attribute::ReadNone;
+}
+
+/// AddArgumentAttrs - Deduce nocapture attributes for the SCC.
+bool FunctionAttrs::AddArgumentAttrs(const CallGraphSCC &SCC) {
bool Changed = false;
SmallPtrSet<Function*, 8> SCCNodes;
continue;
}
- for (Function::arg_iterator A = F->arg_begin(), E = F->arg_end(); A!=E; ++A)
- if (A->getType()->isPointerTy() && !A->hasNoCaptureAttr()) {
+ for (Function::arg_iterator A = F->arg_begin(), E = F->arg_end();
+ A != E; ++A) {
+ if (!A->getType()->isPointerTy()) continue;
+ bool HasNonLocalUses = false;
+ if (!A->hasNoCaptureAttr()) {
ArgumentUsesTracker Tracker(SCCNodes);
PointerMayBeCaptured(A, &Tracker);
if (!Tracker.Captured) {
// its particulars for Argument-SCC analysis later.
ArgumentGraphNode *Node = AG[A];
for (SmallVectorImpl<Argument*>::iterator UI = Tracker.Uses.begin(),
- UE = Tracker.Uses.end(); UI != UE; ++UI)
+ UE = Tracker.Uses.end(); UI != UE; ++UI) {
Node->Uses.push_back(AG[*UI]);
+ if (*UI != A)
+ HasNonLocalUses = true;
+ }
}
}
// Otherwise, it's captured. Don't bother doing SCC analysis on it.
}
+ if (!HasNonLocalUses && !A->onlyReadsMemory()) {
+ // Can we determine that it's readonly/readnone without doing an SCC?
+ // Note that we don't allow any calls at all here, or else our result
+ // will be dependent on the iteration order through the functions in the
+ // SCC.
+ SmallPtrSet<Argument*, 8> Self;
+ Self.insert(A);
+ Attribute::AttrKind R = determinePointerReadAttrs(A, Self);
+ if (R != Attribute::None) {
+ AttrBuilder B;
+ B.addAttribute(R);
+ A->addAttr(AttributeSet::get(A->getContext(), A->getArgNo() + 1, B));
+ Changed = true;
+ R == Attribute::ReadOnly ? ++NumReadOnlyArg : ++NumReadNoneArg;
+ }
+ }
+ }
}
// The graph we've collected is partial because we stopped scanning for
// eg. "void f(int* x) { if (...) f(x); }"
if (ArgumentSCC[0]->Uses.size() == 1 &&
ArgumentSCC[0]->Uses[0] == ArgumentSCC[0]) {
- ArgumentSCC[0]->
- Definition->
- addAttr(AttributeSet::get(ArgumentSCC[0]->Definition->getContext(),
- ArgumentSCC[0]->Definition->getArgNo() + 1,
- B));
+ Argument *A = ArgumentSCC[0]->Definition;
+ A->addAttr(AttributeSet::get(A->getContext(), A->getArgNo() + 1, B));
++NumNoCapture;
Changed = true;
}
++NumNoCapture;
Changed = true;
}
+
+ // We also want to compute readonly/readnone. With a small number of false
+ // negatives, we can assume that any pointer which is captured isn't going
+ // to be provably readonly or readnone, since by definition we can't
+ // analyze all uses of a captured pointer.
+ //
+ // The false negatives happen when the pointer is captured by a function
+ // that promises readonly/readnone behaviour on the pointer, then the
+ // pointer's lifetime ends before anything that writes to arbitrary memory.
+ // Also, a readonly/readnone pointer may be returned, but returning a
+ // pointer is capturing it.
+
+ Attribute::AttrKind ReadAttr = Attribute::ReadNone;
+ for (unsigned i = 0, e = ArgumentSCC.size(); i != e; ++i) {
+ Argument *A = ArgumentSCC[i]->Definition;
+ Attribute::AttrKind K = determinePointerReadAttrs(A, ArgumentSCCNodes);
+ if (K == Attribute::ReadNone)
+ continue;
+ if (K == Attribute::ReadOnly) {
+ ReadAttr = Attribute::ReadOnly;
+ continue;
+ }
+ ReadAttr = K;
+ break;
+ }
+
+ if (ReadAttr != Attribute::None) {
+ AttrBuilder B;
+ B.addAttribute(ReadAttr);
+ for (unsigned i = 0, e = ArgumentSCC.size(); i != e; ++i) {
+ Argument *A = ArgumentSCC[i]->Definition;
+ A->addAttr(AttributeSet::get(A->getContext(), A->getArgNo() + 1, B));
+ ReadAttr == Attribute::ReadOnly ? ++NumReadOnlyArg : ++NumReadNoneArg;
+ Changed = true;
+ }
+ }
}
return Changed;
// Extend the analysis by looking upwards.
case Instruction::BitCast:
case Instruction::GetElementPtr:
+ case Instruction::AddrSpaceCast:
FlowsToReturn.insert(RVI->getOperand(0));
continue;
case Instruction::Select: {
setOnlyReadsMemory(F);
setDoesNotThrow(F);
break;
- case LibFunc::strcpy:
- case LibFunc::stpcpy:
- case LibFunc::strcat:
case LibFunc::strtol:
case LibFunc::strtod:
case LibFunc::strtof:
case LibFunc::strtoul:
case LibFunc::strtoll:
case LibFunc::strtold:
+ case LibFunc::strtoull:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ break;
+ case LibFunc::strcpy:
+ case LibFunc::stpcpy:
+ case LibFunc::strcat:
case LibFunc::strncat:
case LibFunc::strncpy:
case LibFunc::stpncpy:
- case LibFunc::strtoull:
if (FTy->getNumParams() < 2 ||
!FTy->getParamType(1)->isPointerTy())
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::strxfrm:
if (FTy->getNumParams() != 3 ||
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
- break;
- case LibFunc::strcmp:
- case LibFunc::strspn:
- case LibFunc::strncmp:
- case LibFunc::strcspn:
- case LibFunc::strcoll:
- case LibFunc::strcasecmp:
- case LibFunc::strncasecmp:
+ setOnlyReadsMemory(F, 2);
+ break;
+ case LibFunc::strcmp: //0,1
+ case LibFunc::strspn: // 0,1
+ case LibFunc::strncmp: // 0,1
+ case LibFunc::strcspn: //0,1
+ case LibFunc::strcoll: //0,1
+ case LibFunc::strcasecmp: // 0,1
+ case LibFunc::strncasecmp: //
if (FTy->getNumParams() < 2 ||
!FTy->getParamType(0)->isPointerTy() ||
!FTy->getParamType(1)->isPointerTy())
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::scanf:
+ if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
case LibFunc::setbuf:
case LibFunc::setvbuf:
if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
setDoesNotThrow(F);
setDoesNotAlias(F, 0);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::stat:
+ case LibFunc::statvfs:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ break;
case LibFunc::sscanf:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
+ break;
case LibFunc::sprintf:
- case LibFunc::statvfs:
if (FTy->getNumParams() < 2 ||
!FTy->getParamType(0)->isPointerTy() ||
!FTy->getParamType(1)->isPointerTy())
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::snprintf:
if (FTy->getNumParams() != 3 ||
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 3);
+ setOnlyReadsMemory(F, 3);
break;
case LibFunc::setitimer:
if (FTy->getNumParams() != 3 ||
setDoesNotThrow(F);
setDoesNotCapture(F, 2);
setDoesNotCapture(F, 3);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::system:
if (FTy->getNumParams() != 1 ||
return false;
// May throw; "system" is a valid pthread cancellation point.
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::malloc:
if (FTy->getNumParams() != 1 ||
case LibFunc::modf:
case LibFunc::modff:
case LibFunc::modfl:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ break;
case LibFunc::memcpy:
case LibFunc::memccpy:
case LibFunc::memmove:
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::memalign:
if (!FTy->getReturnType()->isPointerTy())
setDoesNotAlias(F, 0);
break;
case LibFunc::mkdir:
+ if (FTy->getNumParams() == 0 ||
+ !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
case LibFunc::mktime:
if (FTy->getNumParams() == 0 ||
!FTy->getParamType(0)->isPointerTy())
// May throw; "read" is a valid pthread cancellation point.
setDoesNotCapture(F, 2);
break;
- case LibFunc::rmdir:
case LibFunc::rewind:
+ if (FTy->getNumParams() < 1 ||
+ !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
+ case LibFunc::rmdir:
case LibFunc::remove:
case LibFunc::realpath:
if (FTy->getNumParams() < 1 ||
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::rename:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
+ break;
case LibFunc::readlink:
if (FTy->getNumParams() < 2 ||
!FTy->getParamType(0)->isPointerTy() ||
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::write:
if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy())
return false;
// May throw; "write" is a valid pthread cancellation point.
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::bcopy:
if (FTy->getNumParams() != 3 ||
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::bcmp:
if (FTy->getNumParams() != 3 ||
break;
case LibFunc::chmod:
case LibFunc::chown:
+ if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
case LibFunc::ctermid:
case LibFunc::clearerr:
case LibFunc::closedir:
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::fopen:
if (FTy->getNumParams() != 2 ||
setDoesNotAlias(F, 0);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::fdopen:
if (FTy->getNumParams() != 2 ||
setDoesNotThrow(F);
setDoesNotAlias(F, 0);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::feof:
case LibFunc::free:
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 3);
+ break;
case LibFunc::fread:
+ if (FTy->getNumParams() != 4 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(3)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 4);
+ break;
case LibFunc::fwrite:
if (FTy->getNumParams() != 4 ||
!FTy->getParamType(0)->isPointerTy() ||
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 4);
+ break;
case LibFunc::fputs:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ break;
case LibFunc::fscanf:
case LibFunc::fprintf:
+ if (FTy->getNumParams() < 2 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
+ break;
case LibFunc::fgetpos:
if (FTy->getNumParams() < 2 ||
!FTy->getParamType(0)->isPointerTy() ||
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::ungetc:
if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
setDoesNotCapture(F, 2);
break;
case LibFunc::uname:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ break;
case LibFunc::unlink:
+ if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
+ break;
case LibFunc::unsetenv:
if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::utime:
case LibFunc::utimes:
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::putc:
if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::pread:
+ if (FTy->getNumParams() != 4 || !FTy->getParamType(1)->isPointerTy())
+ return false;
+ // May throw; "pread" is a valid pthread cancellation point.
+ setDoesNotCapture(F, 2);
+ break;
case LibFunc::pwrite:
if (FTy->getNumParams() != 4 || !FTy->getParamType(1)->isPointerTy())
return false;
- // May throw; these are valid pthread cancellation points.
+ // May throw; "pwrite" is a valid pthread cancellation point.
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::putchar:
setDoesNotThrow(F);
setDoesNotAlias(F, 0);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::pclose:
if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::vsscanf:
+ if (FTy->getNumParams() != 3 ||
+ !FTy->getParamType(1)->isPointerTy() ||
+ !FTy->getParamType(2)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
+ break;
case LibFunc::vfscanf:
if (FTy->getNumParams() != 3 ||
!FTy->getParamType(1)->isPointerTy() ||
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::valloc:
if (!FTy->getReturnType()->isPointerTy())
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::vfprintf:
case LibFunc::vsprintf:
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::vsnprintf:
if (FTy->getNumParams() != 4 ||
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 3);
+ setOnlyReadsMemory(F, 3);
break;
case LibFunc::open:
if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy())
return false;
// May throw; "open" is a valid pthread cancellation point.
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::opendir:
if (FTy->getNumParams() != 1 ||
setDoesNotThrow(F);
setDoesNotAlias(F, 0);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::tmpfile:
if (!FTy->getReturnType()->isPointerTy())
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::lchown:
if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy())
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::qsort:
if (FTy->getNumParams() != 4 || !FTy->getParamType(3)->isPointerTy())
setDoesNotThrow(F);
setDoesNotAlias(F, 0);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::dunder_strtok_r:
if (FTy->getNumParams() != 3 ||
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::under_IO_getc:
if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
return false;
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
case LibFunc::stat64:
case LibFunc::lstat64:
case LibFunc::statvfs64:
+ if (FTy->getNumParams() < 1 ||
+ !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ break;
case LibFunc::dunder_isoc99_sscanf:
if (FTy->getNumParams() < 1 ||
!FTy->getParamType(0)->isPointerTy() ||
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::fopen64:
if (FTy->getNumParams() != 2 ||
setDoesNotAlias(F, 0);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ setOnlyReadsMemory(F, 1);
+ setOnlyReadsMemory(F, 2);
break;
case LibFunc::fseeko64:
case LibFunc::ftello64:
return false;
// May throw; "open" is a valid pthread cancellation point.
setDoesNotCapture(F, 1);
+ setOnlyReadsMemory(F, 1);
break;
+ case LibFunc::gettimeofday:
+ if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
+ !FTy->getParamType(1)->isPointerTy())
+ return false;
+ // Currently some platforms have the restrict keyword on the arguments to
+ // gettimeofday. To be conservative, do not add noalias to gettimeofday's
+ // arguments.
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
default:
// Didn't mark any attributes.
return false;
bool Changed = annotateLibraryCalls(SCC);
Changed |= AddReadAttrs(SCC);
- Changed |= AddNoCaptureAttrs(SCC);
+ Changed |= AddArgumentAttrs(SCC);
Changed |= AddNoAliasAttrs(SCC);
return Changed;
}
projects / oota-llvm.git / blobdiff