auto merge of #6437 : Thiez/rust/atomic, r=Aatch

This pull request adds 4 atomic intrinsics to the compiler, in preparation for #5042.

* `atomic_load(src: &int) -> int` performs an atomic sequentially consistent load.
* `atomic_load_acq(src: &int) -> int` performs an atomic acquiring load.
* `atomic_store(dst: &mut int, val: int)` performs an atomic sequentially consistent store.
* `atomic_store_rel(dst: &mut int, val: int)` performs an atomic releasing store.

For more information about the whole acquire/release thing: http://llvm.org/docs/Atomics.html

r?

1 files changed, 22 insertions, 0 deletions

diff --git a/src/rustllvm/RustWrapper.cpp b/src/rustllvm/RustWrapper.cpp
index 04e616de223..8c081858d60 100644
--- a/src/rustllvm/RustWrapper.cpp
+++ b/src/rustllvm/RustWrapper.cpp
@@ -545,6 +545,28 @@ extern "C" LLVMTypeRef LLVMMetadataType(void) {
   return LLVMMetadataTypeInContext(LLVMGetGlobalContext());
 }
 
+extern "C" LLVMValueRef LLVMBuildAtomicLoad(LLVMBuilderRef B,
+                                            LLVMValueRef source,
+                                            const char* Name,
+                                            AtomicOrdering order) {
+    LoadInst* li = new LoadInst(unwrap(source),0);
+    li->setVolatile(true);
+    li->setAtomic(order);
+    li->setAlignment(sizeof(intptr_t));
+    return wrap(unwrap(B)->Insert(li));
+}
+
+extern "C" LLVMValueRef LLVMBuildAtomicStore(LLVMBuilderRef B,
+                                            LLVMValueRef val,
+                                            LLVMValueRef target,
+                                            AtomicOrdering order) {
+    StoreInst* si = new StoreInst(unwrap(val),unwrap(target));
+    si->setVolatile(true);
+    si->setAtomic(order);
+    si->setAlignment(sizeof(intptr_t));
+    return wrap(unwrap(B)->Insert(si));
+}
+
 extern "C" LLVMValueRef LLVMBuildAtomicCmpXchg(LLVMBuilderRef B,
                                                LLVMValueRef target,
                                                LLVMValueRef old,