diff --git a/include/llvm/Function.h b/include/llvm/Function.h index 9a0825ab4a9..b34a6b25421 100644 --- a/include/llvm/Function.h +++ b/include/llvm/Function.h @@ -414,6 +414,10 @@ public: /// bool hasAddressTaken(const User** = 0) const; + /// callsFunctionThatReturnsTwice - Return true if the function has a call to + /// setjmp or other function that gcc recognizes as "returning twice". + bool callsFunctionThatReturnsTwice() const; + private: // Shadow Value::setValueSubclassData with a private forwarding method so that // subclasses cannot accidentally use it. diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp index f510fb5f890..d1d28cec66d 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp @@ -208,38 +208,6 @@ void SelectionDAGISel::getAnalysisUsage(AnalysisUsage &AU) const { MachineFunctionPass::getAnalysisUsage(AU); } -/// FunctionCallsSetJmp - Return true if the function has a call to setjmp or -/// other function that gcc recognizes as "returning twice". This is used to -/// limit code-gen optimizations on the machine function. -/// -/// FIXME: Remove after is fixed. -static bool FunctionCallsSetJmp(const Function *F) { - const Module *M = F->getParent(); - static const char *ReturnsTwiceFns[] = { - "_setjmp", - "setjmp", - "sigsetjmp", - "setjmp_syscall", - "savectx", - "qsetjmp", - "vfork", - "getcontext" - }; - - for (unsigned I = 0; I < array_lengthof(ReturnsTwiceFns); ++I) - if (const Function *Callee = M->getFunction(ReturnsTwiceFns[I])) { - if (!Callee->use_empty()) - for (Value::const_use_iterator - I = Callee->use_begin(), E = Callee->use_end(); - I != E; ++I) - if (const CallInst *CI = dyn_cast(*I)) - if (CI->getParent()->getParent() == F) - return true; - } - - return false; -} - /// SplitCriticalSideEffectEdges - Look for critical edges with a PHI value that /// may trap on it. In this case we have to split the edge so that the path /// through the predecessor block that doesn't go to the phi block doesn't @@ -390,7 +358,7 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) { } // Determine if there is a call to setjmp in the machine function. - MF->setCallsSetJmp(FunctionCallsSetJmp(&Fn)); + MF->setCallsSetJmp(Fn.callsFunctionThatReturnsTwice()); // Replace forward-declared registers with the registers containing // the desired value. diff --git a/lib/Transforms/Scalar/TailRecursionElimination.cpp b/lib/Transforms/Scalar/TailRecursionElimination.cpp index 539cc6f0baf..e21eb9dca27 100644 --- a/lib/Transforms/Scalar/TailRecursionElimination.cpp +++ b/lib/Transforms/Scalar/TailRecursionElimination.cpp @@ -59,6 +59,7 @@ #include "llvm/Function.h" #include "llvm/Instructions.h" #include "llvm/IntrinsicInst.h" +#include "llvm/Module.h" #include "llvm/Pass.h" #include "llvm/Analysis/CaptureTracking.h" #include "llvm/Analysis/InlineCost.h" @@ -209,10 +210,10 @@ bool TailCallElim::runOnFunction(Function &F) { } } - // Finally, if this function contains no non-escaping allocas, mark all calls - // in the function as eligible for tail calls (there is no stack memory for - // them to access). - if (!FunctionContainsEscapingAllocas) + // Finally, if this function contains no non-escaping allocas, or calls + // setjmp, mark all calls in the function as eligible for tail calls + //(there is no stack memory for them to access). + if (!FunctionContainsEscapingAllocas && !F.callsFunctionThatReturnsTwice()) for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) if (CallInst *CI = dyn_cast(I)) { diff --git a/lib/VMCore/Function.cpp b/lib/VMCore/Function.cpp index 013c4587c9f..ce2186f5cd0 100644 --- a/lib/VMCore/Function.cpp +++ b/lib/VMCore/Function.cpp @@ -24,6 +24,7 @@ #include "llvm/Support/Threading.h" #include "SymbolTableListTraitsImpl.h" #include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/STLExtras.h" #include "llvm/ADT/StringExtras.h" using namespace llvm; @@ -406,4 +407,36 @@ bool Function::hasAddressTaken(const User* *PutOffender) const { return false; } +/// callsFunctionThatReturnsTwice - Return true if the function has a call to +/// setjmp or other function that gcc recognizes as "returning twice". +/// +/// FIXME: Remove after is fixed. +/// FIXME: Is the obove FIXME valid? +bool Function::callsFunctionThatReturnsTwice() const { + const Module *M = this->getParent(); + static const char *ReturnsTwiceFns[] = { + "_setjmp", + "setjmp", + "sigsetjmp", + "setjmp_syscall", + "savectx", + "qsetjmp", + "vfork", + "getcontext" + }; + + for (unsigned I = 0; I < array_lengthof(ReturnsTwiceFns); ++I) + if (const Function *Callee = M->getFunction(ReturnsTwiceFns[I])) { + if (!Callee->use_empty()) + for (Value::const_use_iterator + I = Callee->use_begin(), E = Callee->use_end(); + I != E; ++I) + if (const CallInst *CI = dyn_cast(*I)) + if (CI->getParent()->getParent() == this) + return true; + } + + return false; +} + // vim: sw=2 ai diff --git a/test/Transforms/TailCallElim/setjmp.ll b/test/Transforms/TailCallElim/setjmp.ll new file mode 100644 index 00000000000..7b7fe568259 --- /dev/null +++ b/test/Transforms/TailCallElim/setjmp.ll @@ -0,0 +1,16 @@ +; RUN: opt < %s -tailcallelim -S | FileCheck %s + +; Test that we don't tail call in a functions that calls setjmp. + +; CHECK-NOT: tail call void @bar() + +define void @foo(i32* %x) { +bb: + %tmp75 = tail call i32 @setjmp(i32* %x) + call void @bar() + ret void +} + +declare i32 @setjmp(i32*) + +declare void @bar()