diff options
| -rw-r--r-- | lib/CodeGen/StackSlotColoring.cpp | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/lib/CodeGen/StackSlotColoring.cpp b/lib/CodeGen/StackSlotColoring.cpp index 13d608692a..fc941df8d9 100644 --- a/lib/CodeGen/StackSlotColoring.cpp +++ b/lib/CodeGen/StackSlotColoring.cpp @@ -13,6 +13,8 @@ #define DEBUG_TYPE "stackcoloring" #include "VirtRegMap.h" +#include "llvm/Function.h" +#include "llvm/Module.h" #include "llvm/CodeGen/Passes.h" #include "llvm/CodeGen/LiveIntervalAnalysis.h" #include "llvm/CodeGen/LiveStackAnalysis.h" @@ -116,6 +118,7 @@ namespace { private: void InitializeSlots(); + bool CheckForSetJmpCall(const MachineFunction &MF); void ScanForSpillSlotRefs(MachineFunction &MF); bool OverlapWithAssignments(LiveInterval *li, int Color) const; int ColorSlot(LiveInterval *li); @@ -159,6 +162,34 @@ namespace { }; } +/// CheckForSetJmpCall - Return true if there's a call to setjmp/sigsetjmp in +/// this function. +bool StackSlotColoring::CheckForSetJmpCall(const MachineFunction &MF) { + const Function *F = MF.getFunction(); + const Module *M = F->getParent(); + const Function *SetJmp = M->getFunction("setjmp"); + const Function *SigSetJmp = M->getFunction("sigsetjmp"); + + if (!SetJmp && !SigSetJmp) + return false; + + if (SetJmp && !SetJmp->use_empty()) + for (Value::const_use_iterator + I = SetJmp->use_begin(), E = SetJmp->use_end(); I != E; ++I) + if (const CallInst *CI = dyn_cast<CallInst>(I)) + if (CI->getParent()->getParent() == F) + return true; + + if (SigSetJmp && !SigSetJmp->use_empty()) + for (Value::const_use_iterator + I = SigSetJmp->use_begin(), E = SigSetJmp->use_end(); I != E; ++I) + if (const CallInst *CI = dyn_cast<CallInst>(I)) + if (CI->getParent()->getParent() == F) + return true; + + return false; +} + /// ScanForSpillSlotRefs - Scan all the machine instructions for spill slot /// references and update spill slot weights. void StackSlotColoring::ScanForSpillSlotRefs(MachineFunction &MF) { @@ -722,6 +753,16 @@ bool StackSlotColoring::runOnMachineFunction(MachineFunction &MF) { return false; } + // If there are calls to setjmp or sigsetjmp, don't perform stack slot + // coloring. The stack could be modified before the longjmp is executed, + // resulting in the wrong value being used afterwards. (See + // <rdar://problem/8007500>.) + // + // FIXME: This goes beyond the setjmp/sigsetjmp functions. Ideally, we should + // check for the GCC "returns twice" attribute. + if (CheckForSetJmpCall(MF)) + return false; + // Gather spill slot references ScanForSpillSlotRefs(MF); InitializeSlots(); |