diff options
Diffstat (limited to 'llvm/lib/Target/X86/X86ISelLowering.cpp')
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index c68fe28f4d2..162b684e927 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -16985,21 +16985,21 @@ X86TargetLowering::lowerIdempotentRMWIntoFencedLoad(AtomicRMWInst *AI) const { // otherwise, we might be able to be more agressive on relaxed idempotent // rmw. In practice, they do not look useful, so we don't try to be // especially clever. - if (SynchScope == SingleThread) { + if (SynchScope == SingleThread) // FIXME: we could just insert an X86ISD::MEMBARRIER here, except we are at // the IR level, so we must wrap it in an intrinsic. return nullptr; - } else if (hasMFENCE(*Subtarget)) { - Function *MFence = llvm::Intrinsic::getDeclaration(M, - Intrinsic::x86_sse2_mfence); - Builder.CreateCall(MFence); - } else { + + if (!hasMFENCE(*Subtarget)) // FIXME: it might make sense to use a locked operation here but on a // different cache-line to prevent cache-line bouncing. In practice it // is probably a small win, and x86 processors without mfence are rare // enough that we do not bother. return nullptr; - } + + Function *MFence = + llvm::Intrinsic::getDeclaration(M, Intrinsic::x86_sse2_mfence); + Builder.CreateCall(MFence, {}); // Finally we can emit the atomic load. LoadInst *Loaded = Builder.CreateAlignedLoad(Ptr, |

