From d0169a8474d1885c36ef78878396cb361c44f3a1 Mon Sep 17 00:00:00 2001
From: Filip Pizlo <fpizlo@apple.com>
Date: Wed, 20 Nov 2013 00:07:49 +0000
Subject: [PATCH] Expose the fence instruction via the C API.

llvm-svn: 195173
---
 include/llvm-c/Core.h       |  4 +++-
 include/llvm/IR/IRBuilder.h |  5 +++--
 lib/IR/Core.cpp             | 39 +++++++++++++++++++++++--------------
 3 files changed, 30 insertions(+), 18 deletions(-)

diff --git a/include/llvm-c/Core.h b/include/llvm-c/Core.h
index 9953d52edd6..c5707224e64 100644
--- a/include/llvm-c/Core.h
+++ b/include/llvm-c/Core.h
@@ -2663,7 +2663,9 @@ LLVMValueRef LLVMBuildIsNotNull(LLVMBuilderRef, LLVMValueRef Val,
                                 const char *Name);
 LLVMValueRef LLVMBuildPtrDiff(LLVMBuilderRef, LLVMValueRef LHS,
                               LLVMValueRef RHS, const char *Name);
-LLVMValueRef LLVMBuildAtomicRMW(LLVMBuilderRef B,LLVMAtomicRMWBinOp op,
+LLVMValueRef LLVMBuildFence(LLVMBuilderRef B, LLVMAtomicOrdering ordering,
+                            LLVMBool singleThread, const char *Name);
+LLVMValueRef LLVMBuildAtomicRMW(LLVMBuilderRef B, LLVMAtomicRMWBinOp op,
                                 LLVMValueRef PTR, LLVMValueRef Val,
                                 LLVMAtomicOrdering ordering,
                                 LLVMBool singleThread);
diff --git a/include/llvm/IR/IRBuilder.h b/include/llvm/IR/IRBuilder.h
index 8d1432d6c92..56e818417aa 100644
--- a/include/llvm/IR/IRBuilder.h
+++ b/include/llvm/IR/IRBuilder.h
@@ -915,8 +915,9 @@ public:
     return SI;
   }
   FenceInst *CreateFence(AtomicOrdering Ordering,
-                         SynchronizationScope SynchScope = CrossThread) {
-    return Insert(new FenceInst(Context, Ordering, SynchScope));
+                         SynchronizationScope SynchScope = CrossThread,
+                         const Twine &Name = "") {
+    return Insert(new FenceInst(Context, Ordering, SynchScope), Name);
   }
   AtomicCmpXchgInst *CreateAtomicCmpXchg(Value *Ptr, Value *Cmp, Value *New,
                                          AtomicOrdering Ordering,
diff --git a/lib/IR/Core.cpp b/lib/IR/Core.cpp
index c70f4591186..62e2dd58660 100644
--- a/lib/IR/Core.cpp
+++ b/lib/IR/Core.cpp
@@ -2219,6 +2219,29 @@ LLVMValueRef LLVMBuildStore(LLVMBuilderRef B, LLVMValueRef Val,
   return wrap(unwrap(B)->CreateStore(unwrap(Val), unwrap(PointerVal)));
 }
 
+static AtomicOrdering mapFromLLVMOrdering(LLVMAtomicOrdering Ordering) {
+  switch (Ordering) {
+    case LLVMAtomicOrderingNotAtomic: return NotAtomic;
+    case LLVMAtomicOrderingUnordered: return Unordered;
+    case LLVMAtomicOrderingMonotonic: return Monotonic;
+    case LLVMAtomicOrderingAcquire: return Acquire;
+    case LLVMAtomicOrderingRelease: return Release;
+    case LLVMAtomicOrderingAcquireRelease: return AcquireRelease;
+    case LLVMAtomicOrderingSequentiallyConsistent:
+      return SequentiallyConsistent;
+  }
+  
+  llvm_unreachable("Invalid LLVMAtomicOrdering value!");
+}
+
+LLVMValueRef LLVMBuildFence(LLVMBuilderRef B, LLVMAtomicOrdering Ordering,
+                            LLVMBool isSingleThread, const char *Name) {
+  return wrap(
+    unwrap(B)->CreateFence(mapFromLLVMOrdering(Ordering),
+                           isSingleThread ? SingleThread : CrossThread,
+                           Name));
+}
+
 LLVMValueRef LLVMBuildGEP(LLVMBuilderRef B, LLVMValueRef Pointer,
                           LLVMValueRef *Indices, unsigned NumIndices,
                           const char *Name) {
@@ -2476,22 +2499,8 @@ LLVMValueRef LLVMBuildAtomicRMW(LLVMBuilderRef B,LLVMAtomicRMWBinOp op,
     case LLVMAtomicRMWBinOpUMax: intop = AtomicRMWInst::UMax; break;
     case LLVMAtomicRMWBinOpUMin: intop = AtomicRMWInst::UMin; break;
   }
-  AtomicOrdering intordering;
-  switch (ordering) {
-    case LLVMAtomicOrderingNotAtomic: intordering = NotAtomic; break;
-    case LLVMAtomicOrderingUnordered: intordering = Unordered; break;
-    case LLVMAtomicOrderingMonotonic: intordering = Monotonic; break;
-    case LLVMAtomicOrderingAcquire: intordering = Acquire; break;
-    case LLVMAtomicOrderingRelease: intordering = Release; break;
-    case LLVMAtomicOrderingAcquireRelease:
-      intordering = AcquireRelease;
-      break;
-    case LLVMAtomicOrderingSequentiallyConsistent:
-      intordering = SequentiallyConsistent;
-      break;
-  }
   return wrap(unwrap(B)->CreateAtomicRMW(intop, unwrap(PTR), unwrap(Val),
-    intordering, singleThread ? SingleThread : CrossThread));
+    mapFromLLVMOrdering(ordering), singleThread ? SingleThread : CrossThread));
 }