Initial implementation of 'fence' instruction, the new C++0x-style replacement for llvm.memory.barrier.
This is just a LangRef entry and reading/writing/memory representation; optimizer+codegen support coming soon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136009 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 7164ae1..76771c2 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -1145,6 +1145,32 @@
return false;
}
+/// ParseScopeAndOrdering
+/// if isAtomic: ::= 'singlethread'? AtomicOrdering
+/// else: ::=
+///
+/// This sets Scope and Ordering to the parsed values.
+bool LLParser::ParseScopeAndOrdering(bool isAtomic, SynchronizationScope &Scope,
+ AtomicOrdering &Ordering) {
+ if (!isAtomic)
+ return false;
+
+ Scope = CrossThread;
+ if (EatIfPresent(lltok::kw_singlethread))
+ Scope = SingleThread;
+ switch (Lex.getKind()) {
+ default: return TokError("Expected ordering on atomic instruction");
+ case lltok::kw_unordered: Ordering = Unordered; break;
+ case lltok::kw_monotonic: Ordering = Monotonic; break;
+ case lltok::kw_acquire: Ordering = Acquire; break;
+ case lltok::kw_release: Ordering = Release; break;
+ case lltok::kw_acq_rel: Ordering = AcquireRelease; break;
+ case lltok::kw_seq_cst: Ordering = SequentiallyConsistent; break;
+ }
+ Lex.Lex();
+ return false;
+}
+
/// ParseOptionalStackAlignment
/// ::= /* empty */
/// ::= 'alignstack' '(' 4 ')'
@@ -2924,6 +2950,7 @@
case lltok::kw_alloca: return ParseAlloc(Inst, PFS);
case lltok::kw_load: return ParseLoad(Inst, PFS, false);
case lltok::kw_store: return ParseStore(Inst, PFS, false);
+ case lltok::kw_fence: return ParseFence(Inst, PFS);
case lltok::kw_volatile:
if (EatIfPresent(lltok::kw_load))
return ParseLoad(Inst, PFS, true);
@@ -3633,6 +3660,23 @@
return AteExtraComma ? InstExtraComma : InstNormal;
}
+/// ParseFence
+/// ::= 'fence' 'singlethread'? AtomicOrdering
+int LLParser::ParseFence(Instruction *&Inst, PerFunctionState &PFS) {
+ AtomicOrdering Ordering = NotAtomic;
+ SynchronizationScope Scope = CrossThread;
+ if (ParseScopeAndOrdering(true /*Always atomic*/, Scope, Ordering))
+ return true;
+
+ if (Ordering == Unordered)
+ return TokError("fence cannot be unordered");
+ if (Ordering == Monotonic)
+ return TokError("fence cannot be monotonic");
+
+ Inst = new FenceInst(Context, Ordering, Scope);
+ return InstNormal;
+}
+
/// ParseGetElementPtr
/// ::= 'getelementptr' 'inbounds'? TypeAndValue (',' TypeAndValue)*
int LLParser::ParseGetElementPtr(Instruction *&Inst, PerFunctionState &PFS) {