commit 7a7ee3033e44b45630981355460ef89efa0bdcc4
author David Chisnall <csdavec@swan.ac.uk> Mon Jan 16 17:27:18 2012 +0000
committer David Chisnall <csdavec@swan.ac.uk> Mon Jan 16 17:27:18 2012 +0000
tree 2d566bcdd0dc4e2f73b95747eac6a198b1dfc619
parent 52e4c60e31fee851e2988f7909aebf488e57fc12

Some improvements to the handling of C11 atomic types:

- Add atomic-to/from-nonatomic cast types
- Emit atomic operations for arithmetic on atomic types
- Emit non-atomic stores for initialisation of atomic types, but atomic stores and loads for every other store / load
- Add a __atomic_init() intrinsic which does a non-atomic store to an _Atomic() type.  This is needed for the corresponding C11 stdatomic.h function.
- Enables the relevant __has_feature() checks.  The feature isn't 100% complete yet, but it's done enough that we want people testing it.

Still to do:

- Make the arithmetic operations on atomic types (e.g. Atomic(int) foo = 1; foo++;) use the correct LLVM intrinsic if one exists, not a loop with a cmpxchg.
- Add a signal fence builtin
- Properly set the fenv state in atomic operations on floating point values
- Correctly handle things like _Atomic(_Complex double) which are too large for an atomic cmpxchg on some platforms (this requires working out what 'correctly' means in this context)
- Fix the many remaining corner cases



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148242 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/ExprConstant.cpp

diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index ae68e19..89e8ab7 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -2277,6 +2277,8 @@
     default:
       break;
 
+    case CK_AtomicToNonAtomic:
+    case CK_NonAtomicToAtomic:
     case CK_NoOp:
       return StmtVisitorTy::Visit(E->getSubExpr());
 
@@ -4531,6 +4533,8 @@
     return Error(E);
 
   case CK_LValueToRValue:
+  case CK_AtomicToNonAtomic:
+  case CK_NonAtomicToAtomic:
   case CK_NoOp:
     return ExprEvaluatorBaseTy::VisitCastExpr(E);
 
@@ -4997,6 +5001,8 @@
     llvm_unreachable("invalid cast kind for complex value");
 
   case CK_LValueToRValue:
+  case CK_AtomicToNonAtomic:
+  case CK_NonAtomicToAtomic:
   case CK_NoOp:
     return ExprEvaluatorBaseTy::VisitCastExpr(E);
 
@@ -5855,6 +5861,8 @@
     }
     switch (cast<CastExpr>(E)->getCastKind()) {
     case CK_LValueToRValue:
+    case CK_AtomicToNonAtomic:
+    case CK_NonAtomicToAtomic:
     case CK_NoOp:
     case CK_IntegralToBoolean:
     case CK_IntegralCast: