[llvm-commits] [PATCH] New (C++0x) atomics: start implementation of 'fence' instruction
Eli Friedman
eli.friedman at gmail.com
Fri Jul 22 17:40:32 PDT 2011
Per subject; patch attached. This is the replacement for the very
confusing llvm.memory.barrier intrinsic. Based off of Jeffrey
Yasskin's branch where he started work on this. This patch is a
little on the large side, but I couldn't usefully commit anything much
smaller.
There's one thing about the definition of fence in this patch I'm not
sure about: it doesn't provide any obvious way to order a load/store
marked !nontemporal. We don't really want to require that by default
because it's a performance hit and not generally useful, but someone
might need it.
I plan on following this with patches to implement proper IR and
CodeGen support for this instruction.
-Eli
-------------- next part --------------
Index: include/llvm/Instruction.def
===================================================================
--- include/llvm/Instruction.def (revision 135822)
+++ include/llvm/Instruction.def (working copy)
@@ -133,41 +133,42 @@
HANDLE_MEMORY_INST(27, Load , LoadInst ) // Memory manipulation instrs
HANDLE_MEMORY_INST(28, Store , StoreInst )
HANDLE_MEMORY_INST(29, GetElementPtr, GetElementPtrInst)
- LAST_MEMORY_INST(29)
+HANDLE_MEMORY_INST(30, Fence , FenceInst )
+ LAST_MEMORY_INST(32)
// Cast operators ...
// NOTE: The order matters here because CastInst::isEliminableCastPair
// NOTE: (see Instructions.cpp) encodes a table based on this ordering.
- FIRST_CAST_INST(30)
-HANDLE_CAST_INST(30, Trunc , TruncInst ) // Truncate integers
-HANDLE_CAST_INST(31, ZExt , ZExtInst ) // Zero extend integers
-HANDLE_CAST_INST(32, SExt , SExtInst ) // Sign extend integers
-HANDLE_CAST_INST(33, FPToUI , FPToUIInst ) // floating point -> UInt
-HANDLE_CAST_INST(34, FPToSI , FPToSIInst ) // floating point -> SInt
-HANDLE_CAST_INST(35, UIToFP , UIToFPInst ) // UInt -> floating point
-HANDLE_CAST_INST(36, SIToFP , SIToFPInst ) // SInt -> floating point
-HANDLE_CAST_INST(37, FPTrunc , FPTruncInst ) // Truncate floating point
-HANDLE_CAST_INST(38, FPExt , FPExtInst ) // Extend floating point
-HANDLE_CAST_INST(39, PtrToInt, PtrToIntInst) // Pointer -> Integer
-HANDLE_CAST_INST(40, IntToPtr, IntToPtrInst) // Integer -> Pointer
-HANDLE_CAST_INST(41, BitCast , BitCastInst ) // Type cast
- LAST_CAST_INST(41)
+ FIRST_CAST_INST(33)
+HANDLE_CAST_INST(34, Trunc , TruncInst ) // Truncate integers
+HANDLE_CAST_INST(35, ZExt , ZExtInst ) // Zero extend integers
+HANDLE_CAST_INST(36, SExt , SExtInst ) // Sign extend integers
+HANDLE_CAST_INST(37, FPToUI , FPToUIInst ) // floating point -> UInt
+HANDLE_CAST_INST(38, FPToSI , FPToSIInst ) // floating point -> SInt
+HANDLE_CAST_INST(39, UIToFP , UIToFPInst ) // UInt -> floating point
+HANDLE_CAST_INST(40, SIToFP , SIToFPInst ) // SInt -> floating point
+HANDLE_CAST_INST(41, FPTrunc , FPTruncInst ) // Truncate floating point
+HANDLE_CAST_INST(42, FPExt , FPExtInst ) // Extend floating point
+HANDLE_CAST_INST(43, PtrToInt, PtrToIntInst) // Pointer -> Integer
+HANDLE_CAST_INST(44, IntToPtr, IntToPtrInst) // Integer -> Pointer
+HANDLE_CAST_INST(45, BitCast , BitCastInst ) // Type cast
+ LAST_CAST_INST(45)
// Other operators...
- FIRST_OTHER_INST(42)
-HANDLE_OTHER_INST(42, ICmp , ICmpInst ) // Integer comparison instruction
-HANDLE_OTHER_INST(43, FCmp , FCmpInst ) // Floating point comparison instr.
-HANDLE_OTHER_INST(44, PHI , PHINode ) // PHI node instruction
-HANDLE_OTHER_INST(45, Call , CallInst ) // Call a function
-HANDLE_OTHER_INST(46, Select , SelectInst ) // select instruction
-HANDLE_OTHER_INST(47, UserOp1, Instruction) // May be used internally in a pass
-HANDLE_OTHER_INST(48, UserOp2, Instruction) // Internal to passes only
-HANDLE_OTHER_INST(49, VAArg , VAArgInst ) // vaarg instruction
-HANDLE_OTHER_INST(50, ExtractElement, ExtractElementInst)// extract from vector
-HANDLE_OTHER_INST(51, InsertElement, InsertElementInst) // insert into vector
-HANDLE_OTHER_INST(52, ShuffleVector, ShuffleVectorInst) // shuffle two vectors.
-HANDLE_OTHER_INST(53, ExtractValue, ExtractValueInst)// extract from aggregate
-HANDLE_OTHER_INST(54, InsertValue, InsertValueInst) // insert into aggregate
+ FIRST_OTHER_INST(46)
+HANDLE_OTHER_INST(46, ICmp , ICmpInst ) // Integer comparison instruction
+HANDLE_OTHER_INST(47, FCmp , FCmpInst ) // Floating point comparison instr.
+HANDLE_OTHER_INST(48, PHI , PHINode ) // PHI node instruction
+HANDLE_OTHER_INST(49, Call , CallInst ) // Call a function
+HANDLE_OTHER_INST(50, Select , SelectInst ) // select instruction
+HANDLE_OTHER_INST(51, UserOp1, Instruction) // May be used internally in a pass
+HANDLE_OTHER_INST(52, UserOp2, Instruction) // Internal to passes only
+HANDLE_OTHER_INST(53, VAArg , VAArgInst ) // vaarg instruction
+HANDLE_OTHER_INST(54, ExtractElement, ExtractElementInst)// extract from vector
+HANDLE_OTHER_INST(55, InsertElement, InsertElementInst) // insert into vector
+HANDLE_OTHER_INST(56, ShuffleVector, ShuffleVectorInst) // shuffle two vectors.
+HANDLE_OTHER_INST(57, ExtractValue, ExtractValueInst)// extract from aggregate
+HANDLE_OTHER_INST(58, InsertValue, InsertValueInst) // insert into aggregate
LAST_OTHER_INST(54)
Index: include/llvm/Instructions.h
===================================================================
--- include/llvm/Instructions.h (revision 135822)
+++ include/llvm/Instructions.h (working copy)
@@ -22,6 +22,7 @@
#include "llvm/CallingConv.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/ErrorHandling.h"
#include <iterator>
namespace llvm {
@@ -31,6 +32,22 @@
class APInt;
class LLVMContext;
+enum AtomicOrdering {
+ NotAtomic = 0,
+ Unordered = 1,
+ Monotonic = 2,
+ // Consume = 3, // Not specified yet.
+ Acquire = 4,
+ Release = 5,
+ AcquireRelease = 6,
+ SequentiallyConsistent = 7
+};
+
+enum SynchronizationScope {
+ SingleThread = 0,
+ CrossThread = 1
+};
+
//===----------------------------------------------------------------------===//
// AllocaInst Class
//===----------------------------------------------------------------------===//
@@ -269,6 +286,82 @@
DEFINE_TRANSPARENT_OPERAND_ACCESSORS(StoreInst, Value)
//===----------------------------------------------------------------------===//
+// FenceInst Class
+//===----------------------------------------------------------------------===//
+
+/// FenceInst - an instruction for ordering other memory operations
+///
+class FenceInst : public Instruction {
+ void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
+ void Init(AtomicOrdering Ordering, SynchronizationScope SynchScope);
+protected:
+ virtual FenceInst *clone_impl() const;
+public:
+ // allocate space for exactly zero operands
+ void *operator new(size_t s) {
+ return User::operator new(s, 0);
+ }
+
+ // Ordering may only be Acquire, Release, AcquireRelease, or
+ // SequentiallyConsistent.
+ FenceInst(LLVMContext &C, AtomicOrdering Ordering,
+ SynchronizationScope SynchScope = CrossThread,
+ Instruction *InsertBefore = 0);
+ FenceInst(LLVMContext &C, AtomicOrdering Ordering,
+ SynchronizationScope SynchScope,
+ BasicBlock *InsertAtEnd);
+
+ /// Returns the ordering effect of this fence.
+ AtomicOrdering getOrdering() const {
+ return AtomicOrdering(getSubclassDataFromInstruction() >> 1);
+ }
+
+ /// Set the ordering constraint on this fence. May only be Acquire, Release,
+ /// AcquireRelease, or SequentiallyConsistent.
+ void setOrdering(AtomicOrdering Ordering) {
+ switch (Ordering) {
+ case Acquire:
+ case Release:
+ case AcquireRelease:
+ case SequentiallyConsistent:
+ setInstructionSubclassData((getSubclassDataFromInstruction() & 1) |
+ (Ordering << 1));
+ return;
+ default:
+ llvm_unreachable("FenceInst ordering must be Acquire, Release,"
+ " AcquireRelease, or SequentiallyConsistent");
+ }
+ }
+
+ SynchronizationScope getSynchScope() const {
+ return SynchronizationScope(getSubclassDataFromInstruction() & 1);
+ }
+
+ /// Specify whether this fence orders other operations with respect to all
+ /// concurrently executing threads, or only with respect to signal handlers
+ /// executing in the same thread.
+ void setSynchScope(SynchronizationScope xthread) {
+ setInstructionSubclassData((getSubclassDataFromInstruction() & ~1) |
+ xthread);
+ }
+
+ // Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const FenceInst *) { return true; }
+ static inline bool classof(const Instruction *I) {
+ return I->getOpcode() == Instruction::Fence;
+ }
+ static inline bool classof(const Value *V) {
+ return isa<Instruction>(V) && classof(cast<Instruction>(V));
+ }
+private:
+ // Shadow Instruction::setInstructionSubclassData with a private forwarding
+ // method so that subclasses cannot accidentally use it.
+ void setInstructionSubclassData(unsigned short D) {
+ Instruction::setInstructionSubclassData(D);
+ }
+};
+
+//===----------------------------------------------------------------------===//
// GetElementPtrInst Class
//===----------------------------------------------------------------------===//
Index: include/llvm/Bitcode/LLVMBitCodes.h
===================================================================
--- include/llvm/Bitcode/LLVMBitCodes.h (revision 135822)
+++ include/llvm/Bitcode/LLVMBitCodes.h (working copy)
@@ -218,6 +218,23 @@
PEO_EXACT = 0
};
+ /// Encoded AtomicOrdering values.
+ enum AtomicOrderingCodes {
+ ORDERING_NOTATOMIC = 0,
+ ORDERING_UNORDERED = 1,
+ ORDERING_MONOTONIC = 2,
+ ORDERING_ACQUIRE = 3,
+ ORDERING_RELEASE = 4,
+ ORDERING_ACQREL = 5,
+ ORDERING_SEQCST = 6
+ };
+
+ /// Encoded SynchronizationScope values.
+ enum AtomicSynchScopeCodes {
+ SYNCHSCOPE_SINGLETHREAD = 0,
+ SYNCHSCOPE_CROSSTHREAD = 1
+ };
+
// The function body block (FUNCTION_BLOCK_ID) describes function bodies. It
// can contain a constant block (CONSTANTS_BLOCK_ID).
enum FunctionCodes {
@@ -266,7 +283,8 @@
FUNC_CODE_INST_CALL = 34, // CALL: [attr, fnty, fnid, args...]
- FUNC_CODE_DEBUG_LOC = 35 // DEBUG_LOC: [Line,Col,ScopeVal, IAVal]
+ FUNC_CODE_DEBUG_LOC = 35, // DEBUG_LOC: [Line,Col,ScopeVal, IAVal]
+ FUNC_CODE_INST_FENCE = 36 // FENCE: [ordering, synchscope]
};
} // End bitc namespace
} // End llvm namespace
Index: include/llvm/Support/IRBuilder.h
===================================================================
--- include/llvm/Support/IRBuilder.h (revision 135822)
+++ include/llvm/Support/IRBuilder.h (working copy)
@@ -762,6 +762,10 @@
StoreInst *CreateStore(Value *Val, Value *Ptr, bool isVolatile = false) {
return Insert(new StoreInst(Val, Ptr, isVolatile));
}
+ FenceInst *CreateFence(AtomicOrdering Ordering,
+ SynchronizationScope SynchScope = CrossThread) {
+ return Insert(new FenceInst(Context, Ordering, SynchScope));
+ }
Value *CreateGEP(Value *Ptr, ArrayRef<Value *> IdxList,
const Twine &Name = "") {
if (Constant *PC = dyn_cast<Constant>(Ptr)) {
Index: include/llvm/Support/InstVisitor.h
===================================================================
--- include/llvm/Support/InstVisitor.h (revision 135822)
+++ include/llvm/Support/InstVisitor.h (working copy)
@@ -169,6 +169,7 @@
RetTy visitAllocaInst(AllocaInst &I) { DELEGATE(Instruction); }
RetTy visitLoadInst(LoadInst &I) { DELEGATE(Instruction); }
RetTy visitStoreInst(StoreInst &I) { DELEGATE(Instruction); }
+ RetTy visitFenceInst(FenceInst &I) { DELEGATE(Instruction); }
RetTy visitGetElementPtrInst(GetElementPtrInst &I){ DELEGATE(Instruction); }
RetTy visitPHINode(PHINode &I) { DELEGATE(Instruction); }
RetTy visitTruncInst(TruncInst &I) { DELEGATE(CastInst); }
Index: docs/LangRef.html
===================================================================
--- docs/LangRef.html (revision 135822)
+++ docs/LangRef.html (working copy)
@@ -170,6 +170,7 @@
<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
+ <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
</ol>
</li>
@@ -4544,6 +4545,63 @@
</div>
<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_fence">'<tt>fence</tt>'
+Instruction</a> </div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ fence [singlethread] <ordering> <i>; yields {void}</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
+between operations.</p>
+
+<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
+href="#ordering">ordering</a> argument which defines what
+<i>synchronizes-with</i> edges they add. They can only be given
+<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
+<code>seq_cst</code> orderings.</p>
+
+<h5>Semantics:</h5>
+<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
+semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
+<code>acquire</code> ordering semantics if and only if there exist atomic
+operations <var>X</var> and <var>Y</var>, both operating on some atomic object
+<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
+<var>X</var> modifies <var>M</var> (either directly or through some side effect
+of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
+<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
+<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
+than an explicit <code>fence</code>, one (but not both) of the atomic operations
+<var>X</var> or <var>Y</var> might provide a <code>release</code> or
+<code>acquire</code> (resp.) ordering constraint and still
+<i>synchronize-with</i> the explicit <code>fence</code> and establish the
+<i>happens-before</i> edge.</p>
+
+<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
+having both <code>acquire</code> and <code>release</code> semantics specified
+above, participates in the global program order of other <code>seq_cst</code>
+operations and/or fences.</p>
+
+<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
+specifies that the fence only synchronizes with other fences in the same
+thread.</p>
+
+<p>FIXME: This instruction is a work in progress; until it is finished, use
+ llvm.memory.barrier.
+
+<h5>Example:</h5>
+<pre>
+ fence acquire <i>; yields {void}</i>
+ fence singlethread seq_cst <i>; yields {void}</i>
+</pre>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
<h4>
<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
</h4>
Index: lib/VMCore/Instructions.cpp
===================================================================
--- lib/VMCore/Instructions.cpp (revision 135822)
+++ lib/VMCore/Instructions.cpp (working copy)
@@ -996,6 +996,26 @@
}
//===----------------------------------------------------------------------===//
+// FenceInst Implementation
+//===----------------------------------------------------------------------===//
+
+FenceInst::FenceInst(LLVMContext &C, AtomicOrdering Ordering,
+ SynchronizationScope SynchScope,
+ Instruction *InsertBefore)
+ : Instruction(Type::getVoidTy(C), Fence, 0, 0, InsertBefore) {
+ setOrdering(Ordering);
+ setSynchScope(SynchScope);
+}
+
+FenceInst::FenceInst(LLVMContext &C, AtomicOrdering Ordering,
+ SynchronizationScope SynchScope,
+ BasicBlock *InsertAtEnd)
+ : Instruction(Type::getVoidTy(C), Fence, 0, 0, InsertAtEnd) {
+ setOrdering(Ordering);
+ setSynchScope(SynchScope);
+}
+
+//===----------------------------------------------------------------------===//
// GetElementPtrInst Implementation
//===----------------------------------------------------------------------===//
@@ -3075,6 +3095,10 @@
isVolatile(), getAlignment());
}
+FenceInst *FenceInst::clone_impl() const {
+ return new FenceInst(getContext(), getOrdering(), getSynchScope());
+}
+
TruncInst *TruncInst::clone_impl() const {
return new TruncInst(getOperand(0), getType());
}
Index: lib/VMCore/Verifier.cpp
===================================================================
--- lib/VMCore/Verifier.cpp (revision 135822)
+++ lib/VMCore/Verifier.cpp (working copy)
@@ -278,6 +278,7 @@
void visitUserOp1(Instruction &I);
void visitUserOp2(Instruction &I) { visitUserOp1(I); }
void visitIntrinsicFunctionCall(Intrinsic::ID ID, CallInst &CI);
+ void visitFenceInst(FenceInst &FI);
void visitAllocaInst(AllocaInst &AI);
void visitExtractValueInst(ExtractValueInst &EVI);
void visitInsertValueInst(InsertValueInst &IVI);
@@ -1316,6 +1317,15 @@
visitInstruction(AI);
}
+void Verifier::visitFenceInst(FenceInst &FI) {
+ const AtomicOrdering Ordering = FI.getOrdering();
+ Assert1(Ordering == Acquire || Ordering == Release ||
+ Ordering == AcquireRelease || Ordering == SequentiallyConsistent,
+ "fence instructions may only have "
+ " acquire, release, acq_rel, or seq_cst ordering.", &FI);
+ visitInstruction(FI);
+}
+
void Verifier::visitExtractValueInst(ExtractValueInst &EVI) {
Assert1(ExtractValueInst::getIndexedType(EVI.getAggregateOperand()->getType(),
EVI.getIndices()) ==
Index: lib/VMCore/AsmWriter.cpp
===================================================================
--- lib/VMCore/AsmWriter.cpp (revision 135822)
+++ lib/VMCore/AsmWriter.cpp (working copy)
@@ -1098,6 +1098,7 @@
void writeOperand(const Value *Op, bool PrintType);
void writeParamOperand(const Value *Operand, Attributes Attrs);
+ void writeAtomic(AtomicOrdering Ordering, SynchronizationScope SynchScope);
void writeAllMDNodes();
@@ -1128,6 +1129,28 @@
WriteAsOperandInternal(Out, Operand, &TypePrinter, &Machine, TheModule);
}
+void AssemblyWriter::writeAtomic(AtomicOrdering Ordering,
+ SynchronizationScope SynchScope) {
+ if (Ordering == NotAtomic)
+ return;
+
+ switch (SynchScope) {
+ default: Out << " <bad scope " << int(SynchScope) << ">"; break;
+ case SingleThread: Out << " singlethread"; break;
+ case CrossThread: break;
+ }
+
+ switch (Ordering) {
+ default: Out << " <bad ordering " << int(Ordering) << ">"; break;
+ case Unordered: Out << " unordered"; break;
+ case Monotonic: Out << " monotonic"; break;
+ case Acquire: Out << " acquire"; break;
+ case Release: Out << " release"; break;
+ case AcquireRelease: Out << " acq_rel"; break;
+ case SequentiallyConsistent: Out << " seq_cst"; break;
+ }
+}
+
void AssemblyWriter::writeParamOperand(const Value *Operand,
Attributes Attrs) {
if (Operand == 0) {
@@ -1883,6 +1906,8 @@
Out << ", align " << cast<LoadInst>(I).getAlignment();
} else if (isa<StoreInst>(I) && cast<StoreInst>(I).getAlignment()) {
Out << ", align " << cast<StoreInst>(I).getAlignment();
+ } else if (const FenceInst *FI = dyn_cast<FenceInst>(&I)) {
+ writeAtomic(FI->getOrdering(), FI->getSynchScope());
}
// Print Metadata info.
Index: lib/VMCore/Instruction.cpp
===================================================================
--- lib/VMCore/Instruction.cpp (revision 135822)
+++ lib/VMCore/Instruction.cpp (working copy)
@@ -127,6 +127,7 @@
case Alloca: return "alloca";
case Load: return "load";
case Store: return "store";
+ case Fence: return "fence";
case GetElementPtr: return "getelementptr";
// Convert instructions...
Index: lib/AsmParser/LLParser.cpp
===================================================================
--- lib/AsmParser/LLParser.cpp (revision 135822)
+++ lib/AsmParser/LLParser.cpp (working copy)
@@ -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 ')'
@@ -2926,6 +2952,7 @@
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);
@@ -3635,6 +3662,23 @@
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) {
Index: lib/AsmParser/LLLexer.cpp
===================================================================
--- lib/AsmParser/LLLexer.cpp (revision 135822)
+++ lib/AsmParser/LLLexer.cpp (working copy)
@@ -506,6 +506,15 @@
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 @@
INSTKEYWORD(alloca, Alloca);
INSTKEYWORD(load, Load);
INSTKEYWORD(store, Store);
+ INSTKEYWORD(fence, Fence);
INSTKEYWORD(getelementptr, GetElementPtr);
INSTKEYWORD(extractelement, ExtractElement);
Index: lib/AsmParser/LLParser.h
===================================================================
--- lib/AsmParser/LLParser.h (revision 135822)
+++ lib/AsmParser/LLParser.h (working copy)
@@ -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 @@
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 @@
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);
Index: lib/AsmParser/LLToken.h
===================================================================
--- lib/AsmParser/LLToken.h (revision 135822)
+++ lib/AsmParser/LLToken.h (working copy)
@@ -53,6 +53,9 @@
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 @@
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,
Index: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (revision 135822)
+++ lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (working copy)
@@ -3211,6 +3211,10 @@
DAG.setRoot(StoreNode);
}
+void SelectionDAGBuilder::visitFence(const FenceInst &I) {
+ llvm_unreachable("Not implemented yet");
+}
+
/// visitTargetIntrinsic - Lower a call of a target intrinsic to an INTRINSIC
/// node.
void SelectionDAGBuilder::visitTargetIntrinsic(const CallInst &I,
Index: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h (revision 135822)
+++ lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h (working copy)
@@ -504,6 +504,7 @@
void visitAlloca(const AllocaInst &I);
void visitLoad(const LoadInst &I);
void visitStore(const StoreInst &I);
+ void visitFence(const FenceInst &I);
void visitPHI(const PHINode &I);
void visitCall(const CallInst &I);
bool visitMemCmpCall(const CallInst &I);
Index: lib/Bitcode/Reader/BitcodeReader.cpp
===================================================================
--- lib/Bitcode/Reader/BitcodeReader.cpp (revision 135822)
+++ lib/Bitcode/Reader/BitcodeReader.cpp (working copy)
@@ -131,6 +131,27 @@
}
}
+static AtomicOrdering GetDecodedOrdering(unsigned Val) {
+ switch (Val) {
+ case bitc::ORDERING_NOTATOMIC: return NotAtomic;
+ case bitc::ORDERING_UNORDERED: return Unordered;
+ case bitc::ORDERING_MONOTONIC: return Monotonic;
+ case bitc::ORDERING_ACQUIRE: return Acquire;
+ case bitc::ORDERING_RELEASE: return Release;
+ case bitc::ORDERING_ACQREL: return AcquireRelease;
+ default: // Map unknown orderings to sequentially-consistent.
+ case bitc::ORDERING_SEQCST: return SequentiallyConsistent;
+ }
+}
+
+static SynchronizationScope GetDecodedSynchScope(unsigned Val) {
+ switch (Val) {
+ case bitc::SYNCHSCOPE_SINGLETHREAD: return SingleThread;
+ default: // Map unknown scopes to cross-thread.
+ case bitc::SYNCHSCOPE_CROSSTHREAD: return CrossThread;
+ }
+}
+
namespace llvm {
namespace {
/// @brief A class for maintaining the slot number definition
@@ -2534,6 +2555,18 @@
InstructionList.push_back(I);
break;
}
+ case bitc::FUNC_CODE_INST_FENCE: { // FENCE:[ordering, synchscope]
+ if (2 != Record.size())
+ return Error("Invalid FENCE record");
+ AtomicOrdering Ordering = GetDecodedOrdering(Record[0]);
+ if (Ordering == NotAtomic || Ordering == Unordered ||
+ Ordering == Monotonic)
+ return Error("Invalid FENCE record");
+ SynchronizationScope SynchScope = GetDecodedSynchScope(Record[1]);
+ I = new FenceInst(Context, Ordering, SynchScope);
+ InstructionList.push_back(I);
+ break;
+ }
case bitc::FUNC_CODE_INST_CALL: {
// CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
if (Record.size() < 3)
Index: lib/Bitcode/Writer/BitcodeWriter.cpp
===================================================================
--- lib/Bitcode/Writer/BitcodeWriter.cpp (revision 135822)
+++ lib/Bitcode/Writer/BitcodeWriter.cpp (working copy)
@@ -101,6 +101,27 @@
}
}
+static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
+ switch (Ordering) {
+ default: llvm_unreachable("Unknown atomic ordering");
+ case NotAtomic: return bitc::ORDERING_NOTATOMIC;
+ case Unordered: return bitc::ORDERING_UNORDERED;
+ case Monotonic: return bitc::ORDERING_MONOTONIC;
+ case Acquire: return bitc::ORDERING_ACQUIRE;
+ case Release: return bitc::ORDERING_RELEASE;
+ case AcquireRelease: return bitc::ORDERING_ACQREL;
+ case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
+ }
+}
+
+static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
+ switch (SynchScope) {
+ default: llvm_unreachable("Unknown synchronization scope");
+ case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
+ case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
+ }
+}
+
static void WriteStringRecord(unsigned Code, StringRef Str,
unsigned AbbrevToUse, BitstreamWriter &Stream) {
SmallVector<unsigned, 64> Vals;
@@ -1147,6 +1168,11 @@
Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
Vals.push_back(cast<StoreInst>(I).isVolatile());
break;
+ case Instruction::Fence:
+ Code = bitc::FUNC_CODE_INST_FENCE;
+ Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
+ Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
+ break;
case Instruction::Call: {
const CallInst &CI = cast<CallInst>(I);
PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
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