search for: atomiccmpxchg

Hi, is there currently a way to create a cmpxchg instruction using the C bindings? I only found LLVMBuildAtomicRMW and LLVMBuildFence in the documentation. Regards, Christoph Grenz

Oh, no. I should have been more clear. The patch was not rejected, just lost in the daily shuffle. I already have my employer's approval to send this upstream, so I will prepare a patch against trunk this morning. > I proposed a similar patch to LLVM (left circular shift) around 10/2011. > > Parts of my patch did make it into trunk about a year after, but others > > did not.

On Monday, July 30, 2012 12:16 AM, Cameron McInally wrote: > Hey Andy, > > I proposed a similar patch to LLVM (left circular shift) around 10/2011. > Parts of my patch did make it into trunk about a year after, but others > did not. > > At that time, my solution was to add a binary operator to the IRBuilder, > since LCS fits in nicely with the other shift operators. But,

...MORY_INST(26, Alloca, AllocaInst) // Stack management -HANDLE_MEMORY_INST(27, Load , LoadInst ) // Memory manipulation instrs -HANDLE_MEMORY_INST(28, Store , StoreInst ) -HANDLE_MEMORY_INST(29, GetElementPtr, GetElementPtrInst) -HANDLE_MEMORY_INST(30, Fence , FenceInst ) -HANDLE_MEMORY_INST(31, AtomicCmpXchg , AtomicCmpXchgInst ) -HANDLE_MEMORY_INST(32, AtomicRMW , AtomicRMWInst ) - LAST_MEMORY_INST(32) + FIRST_MEMORY_INST(27) +HANDLE_MEMORY_INST(27, Alloca, AllocaInst) // Stack management +HANDLE_MEMORY_INST(28, Load , LoadInst ) // Memory manipulation instrs +HANDLE_MEMORY_INST(29, Store , Store...

> I am planning in doing in IR, but with target specific-passes (such as X86ExpandAtomicPass) > that just share some of the code This would more normally be done via target hooks in LLVM, though the principle is sound. > But it must be target-dependent as for example on Power a > seq_cst store has a fence before it, while on ARM it has a fence > both before and after it (per

...p(CodeGenFunction &CGF, AtomicExpr *E, llvm::Value *Dest, LoadVal1->setAlignment(Align); llvm::LoadInst *LoadVal2 = CGF.Builder.CreateLoad(Val2); LoadVal2->setAlignment(Align); + // FIXME: The failure order needs demoting if it's AcquireRelease or Release. llvm::AtomicCmpXchgInst *CXI = - CGF.Builder.CreateAtomicCmpXchg(Ptr, LoadVal1, LoadVal2, Order); + CGF.Builder.CreateAtomicCmpXchg(Ptr, LoadVal1, LoadVal2, Order, Order); CXI->setVolatile(E->isVolatile()); llvm::StoreInst *StoreVal1 = CGF.Builder.CreateStore(CXI, Val1); StoreVal1->...