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

4 files changed, 62 insertions, 1 deletions

diff --git a/lib/AsmParser/LLLexer.cpp b/lib/AsmParser/LLLexer.cpp
index 29eb944..cdee98b 100644
--- a/lib/AsmParser/LLLexer.cpp
+++ b/lib/AsmParser/LLLexer.cpp
@@ -506,6 +506,15 @@ lltok::Kind LLLexer::LexIdentifier() {
   KEYWORD(deplibs);
   KEYWORD(datalayout);
   KEYWORD(volatile);
+  KEYWORD(atomic);
+  KEYWORD(unordered);
+  KEYWORD(monotonic);
+  KEYWORD(acquire);
+  KEYWORD(release);
+  KEYWORD(acq_rel);
+  KEYWORD(seq_cst);
+  KEYWORD(singlethread);
+
   KEYWORD(nuw);
   KEYWORD(nsw);
   KEYWORD(exact);
@@ -630,6 +639,7 @@ lltok::Kind LLLexer::LexIdentifier() {
   INSTKEYWORD(alloca,      Alloca);
   INSTKEYWORD(load,        Load);
   INSTKEYWORD(store,       Store);
+  INSTKEYWORD(fence,       Fence);
   INSTKEYWORD(getelementptr, GetElementPtr);
 
   INSTKEYWORD(extractelement, ExtractElement);
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 @@ bool LLParser::ParseOptionalCommaAlign(unsigned &Alignment,
   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 @@ int LLParser::ParseInstruction(Instruction *&Inst, BasicBlock *BB,
   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 @@ int LLParser::ParseStore(Instruction *&Inst, PerFunctionState &PFS,
   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) {
diff --git a/lib/AsmParser/LLParser.h b/lib/AsmParser/LLParser.h
index 41e42ca..1eaf325 100644
--- a/lib/AsmParser/LLParser.h
+++ b/lib/AsmParser/LLParser.h
@@ -15,6 +15,7 @@
 #define LLVM_ASMPARSER_LLPARSER_H
 
 #include "LLLexer.h"
+#include "llvm/Instructions.h"
 #include "llvm/Module.h"
 #include "llvm/Type.h"
 #include "llvm/ADT/DenseMap.h"
@@ -178,6 +179,8 @@ namespace llvm {
     bool ParseOptionalVisibility(unsigned &Visibility);
     bool ParseOptionalCallingConv(CallingConv::ID &CC);
     bool ParseOptionalAlignment(unsigned &Alignment);
+    bool ParseScopeAndOrdering(bool isAtomic, SynchronizationScope &Scope,
+                               AtomicOrdering &Ordering);
     bool ParseOptionalStackAlignment(unsigned &Alignment);
     bool ParseOptionalCommaAlign(unsigned &Alignment, bool &AteExtraComma);
     bool ParseIndexList(SmallVectorImpl<unsigned> &Indices,bool &AteExtraComma);
@@ -360,6 +363,7 @@ namespace llvm {
     int ParseAlloc(Instruction *&I, PerFunctionState &PFS);
     int ParseLoad(Instruction *&I, PerFunctionState &PFS, bool isVolatile);
     int ParseStore(Instruction *&I, PerFunctionState &PFS, bool isVolatile);
+    int ParseFence(Instruction *&I, PerFunctionState &PFS);
     int ParseGetElementPtr(Instruction *&I, PerFunctionState &PFS);
     int ParseExtractValue(Instruction *&I, PerFunctionState &PFS);
     int ParseInsertValue(Instruction *&I, PerFunctionState &PFS);
diff --git a/lib/AsmParser/LLToken.h b/lib/AsmParser/LLToken.h
index a5f89fc..bf41c68 100644
--- a/lib/AsmParser/LLToken.h
+++ b/lib/AsmParser/LLToken.h
@@ -53,6 +53,9 @@ namespace lltok {
     kw_deplibs,
     kw_datalayout,
     kw_volatile,
+    kw_atomic,
+    kw_unordered, kw_monotonic, kw_acquire, kw_release, kw_acq_rel, kw_seq_cst,
+    kw_singlethread,
     kw_nuw,
     kw_nsw,
     kw_exact,
@@ -121,7 +124,7 @@ namespace lltok {
     kw_ret, kw_br, kw_switch, kw_indirectbr, kw_invoke, kw_unwind,
     kw_unreachable,
 
-    kw_alloca, kw_load, kw_store, kw_getelementptr,
+    kw_alloca, kw_load, kw_store, kw_fence, kw_getelementptr,
 
     kw_extractelement, kw_insertelement, kw_shufflevector,
     kw_extractvalue, kw_insertvalue, kw_blockaddress,