Fixup codegen for volatile structs in the trivial cases (a a=a and a=a=a).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@72439 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index c558d13..2a3e21f 100644
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -34,10 +34,13 @@
CGBuilderTy &Builder;
llvm::Value *DestPtr;
bool VolatileDest;
+ bool IgnoreResult;
+
public:
- AggExprEmitter(CodeGenFunction &cgf, llvm::Value *destPtr, bool volatileDest)
+ AggExprEmitter(CodeGenFunction &cgf, llvm::Value *destPtr, bool volatileDest,
+ bool IgnoreResult)
: CGF(cgf), Builder(CGF.Builder),
- DestPtr(destPtr), VolatileDest(volatileDest) {
+ DestPtr(destPtr), VolatileDest(volatileDest), IgnoreResult(IgnoreResult) {
}
//===--------------------------------------------------------------------===//
@@ -50,8 +53,8 @@
void EmitAggLoadOfLValue(const Expr *E);
/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
- void EmitFinalDestCopy(const Expr *E, LValue Src);
- void EmitFinalDestCopy(const Expr *E, RValue Src);
+ void EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore = false);
+ void EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore = false);
//===--------------------------------------------------------------------===//
// Visitor Methods
@@ -127,17 +130,16 @@
}
/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
-void AggExprEmitter::EmitFinalDestCopy(const Expr *E, RValue Src) {
+void AggExprEmitter::EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore) {
assert(Src.isAggregate() && "value must be aggregate value!");
// If the result is ignored, don't copy from the value.
if (DestPtr == 0) {
- if (Src.isVolatileQualified())
- // If the source is volatile, we must read from it; to do that, we need
- // some place to put it.
- DestPtr = CGF.CreateTempAlloca(CGF.ConvertType(E->getType()), "agg.tmp");
- else
+ if (!Src.isVolatileQualified() || (IgnoreResult && Ignore))
return;
+ // If the source is volatile, we must read from it; to do that, we need
+ // some place to put it.
+ DestPtr = CGF.CreateTempAlloca(CGF.ConvertType(E->getType()), "agg.tmp");
}
// If the result of the assignment is used, copy the LHS there also.
@@ -149,11 +151,12 @@
}
/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
-void AggExprEmitter::EmitFinalDestCopy(const Expr *E, LValue Src) {
+void AggExprEmitter::EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore) {
assert(Src.isSimple() && "Can't have aggregate bitfield, vector, etc");
EmitFinalDestCopy(E, RValue::getAggregate(Src.getAddress(),
- Src.isVolatileQualified()));
+ Src.isVolatileQualified()),
+ Ignore);
}
//===----------------------------------------------------------------------===//
@@ -244,7 +247,7 @@
} else {
// Codegen the RHS so that it stores directly into the LHS.
CGF.EmitAggExpr(E->getRHS(), LHS.getAddress(), LHS.isVolatileQualified());
- EmitFinalDestCopy(E, LHS);
+ EmitFinalDestCopy(E, LHS, true);
}
}
@@ -470,13 +473,14 @@
/// the value of the aggregate expression is not needed. If VolatileDest is
/// true, DestPtr cannot be 0.
void CodeGenFunction::EmitAggExpr(const Expr *E, llvm::Value *DestPtr,
- bool VolatileDest) {
+ bool VolatileDest, bool IgnoreResult) {
assert(E && hasAggregateLLVMType(E->getType()) &&
"Invalid aggregate expression to emit");
assert ((DestPtr != 0 || VolatileDest == false)
&& "volatile aggregate can't be 0");
- AggExprEmitter(*this, DestPtr, VolatileDest).Visit(const_cast<Expr*>(E));
+ AggExprEmitter(*this, DestPtr, VolatileDest, IgnoreResult)
+ .Visit(const_cast<Expr*>(E));
}
void CodeGenFunction::EmitAggregateClear(llvm::Value *DestPtr, QualType Ty) {
@@ -522,9 +526,8 @@
// a = b;
// }
//
- // either, we need to use a differnt call here, or the backend needs to be
- // taught to not do this. We use isVolatile to indicate when either the
- // source or the destination is volatile.
+ // we need to use a differnt call here. We use isVolatile to indicate when
+ // either the source or the destination is volatile.
Builder.CreateCall4(CGM.getMemCpyFn(),
DestPtr, SrcPtr,
// TypeInfo.first describes size in bits.