Simplify atomic load/store IRGen.
Also fixes a couple minor bugs along the way; see testcases.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186049 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index 8efe018..a67f659 100644
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -29,14 +29,6 @@
// Aggregate Expression Emitter
//===----------------------------------------------------------------------===//
-llvm::Value *AggValueSlot::getPaddedAtomicAddr() const {
- assert(isValueOfAtomic());
- llvm::GEPOperator *op = cast<llvm::GEPOperator>(getAddr());
- assert(op->getNumIndices() == 2);
- assert(op->hasAllZeroIndices());
- return op->getPointerOperand();
-}
-
namespace {
class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
CodeGenFunction &CGF;
@@ -202,38 +194,6 @@
CGF.EmitAtomicExpr(E, EnsureSlot(E->getType()).getAddr());
}
};
-
-/// A helper class for emitting expressions into the value sub-object
-/// of a padded atomic type.
-class ValueDestForAtomic {
- AggValueSlot Dest;
-public:
- ValueDestForAtomic(CodeGenFunction &CGF, AggValueSlot dest, QualType type)
- : Dest(dest) {
- assert(!Dest.isValueOfAtomic());
- if (!Dest.isIgnored() && CGF.CGM.isPaddedAtomicType(type)) {
- llvm::Value *valueAddr = CGF.Builder.CreateStructGEP(Dest.getAddr(), 0);
- Dest = AggValueSlot::forAddr(valueAddr,
- Dest.getAlignment(),
- Dest.getQualifiers(),
- Dest.isExternallyDestructed(),
- Dest.requiresGCollection(),
- Dest.isPotentiallyAliased(),
- Dest.isZeroed(),
- AggValueSlot::IsValueOfAtomic);
- }
- }
-
- const AggValueSlot &getDest() const { return Dest; }
-
- ~ValueDestForAtomic() {
- // Kill the GEP if we made one and it didn't end up used.
- if (Dest.isValueOfAtomic()) {
- llvm::Instruction *addr = cast<llvm::GetElementPtrInst>(Dest.getAddr());
- if (addr->use_empty()) addr->eraseFromParent();
- }
- }
-};
} // end anonymous namespace.
//===----------------------------------------------------------------------===//
@@ -248,8 +208,7 @@
// If the type of the l-value is atomic, then do an atomic load.
if (LV.getType()->isAtomicType()) {
- ValueDestForAtomic valueDest(CGF, Dest, LV.getType());
- CGF.EmitAtomicLoad(LV, valueDest.getDest());
+ CGF.EmitAtomicLoad(LV, Dest);
return;
}
@@ -653,34 +612,33 @@
}
// If we're converting an r-value of non-atomic type to an r-value
- // of atomic type, just make an atomic temporary, emit into that,
- // and then copy the value out. (FIXME: do we need to
- // zero-initialize it first?)
+ // of atomic type, just emit directly into the relevant sub-object.
if (isToAtomic) {
- ValueDestForAtomic valueDest(CGF, Dest, atomicType);
+ AggValueSlot valueDest = Dest;
+ if (!valueDest.isIgnored() && CGF.CGM.isPaddedAtomicType(atomicType)) {
+ // Zero-initialize. (Strictly speaking, we only need to intialize
+ // the padding at the end, but this is simpler.)
+ if (!Dest.isZeroed())
+ CGF.EmitNullInitialization(Dest.getAddr(), type);
+
+ // Build a GEP to refer to the subobject.
+ llvm::Value *valueAddr =
+ CGF.Builder.CreateStructGEP(valueDest.getAddr(), 0);
+ valueDest = AggValueSlot::forAddr(valueAddr,
+ valueDest.getAlignment(),
+ valueDest.getQualifiers(),
+ valueDest.isExternallyDestructed(),
+ valueDest.requiresGCollection(),
+ valueDest.isPotentiallyAliased(),
+ AggValueSlot::IsZeroed);
+ }
+
CGF.EmitAggExpr(E->getSubExpr(), valueDest.getDest());
return;
}
// Otherwise, we're converting an atomic type to a non-atomic type.
-
- // If the dest is a value-of-atomic subobject, drill back out.
- if (Dest.isValueOfAtomic()) {
- AggValueSlot atomicSlot =
- AggValueSlot::forAddr(Dest.getPaddedAtomicAddr(),
- Dest.getAlignment(),
- Dest.getQualifiers(),
- Dest.isExternallyDestructed(),
- Dest.requiresGCollection(),
- Dest.isPotentiallyAliased(),
- Dest.isZeroed(),
- AggValueSlot::IsNotValueOfAtomic);
- CGF.EmitAggExpr(E->getSubExpr(), atomicSlot);
- return;
- }
-
- // Otherwise, make an atomic temporary, emit into that, and then
- // copy the value out.
+ // Make an atomic temporary, emit into that, and then copy the value out.
AggValueSlot atomicSlot =
CGF.CreateAggTemp(atomicType, "atomic-to-nonatomic.temp");
CGF.EmitAggExpr(E->getSubExpr(), atomicSlot);