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Don't emit read barriers for reading __weak __block variables 

in non-GC mode.

llvm-svn: 127725
This commit is contained in:
John McCall 2011-03-16 02:53:38 +00:00
parent a3d4749e24
commit e99e5dcbd3
2 changed files with 15 additions and 4 deletions
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6
clang/lib/CodeGen/CGExprScalar.cpp
View File

@ -1221,10 +1221,8 @@ Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) {
}
Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) {
llvm::Value *V = CGF.GetAddrOfBlockDecl(E);
if (E->getType().isObjCGCWeak())
return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V);
return CGF.EmitLoadOfScalar(V, false, 0, E->getType());
LValue LV = CGF.EmitBlockDeclRefLValue(E);
return CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal();
}
//===----------------------------------------------------------------------===//

13
clang/test/CodeGenObjC/blocks.m
View File

@ -87,3 +87,16 @@ void test2(Test2 *x) {
__weak __block Test2 *weakX = x;
test2_helper(^{ [weakX destroy]; });
}
// rdar://problem/9124263
// In the test above, check that the use in the invocation function
// doesn't require a read barrier.
// CHECK: define internal void @__test2_block_invoke_
// CHECK: [[BLOCK:%.*]] = bitcast i8* {{%.*}} to [[BLOCK_T]]*
// CHECK-NEXT: [[T0:%.*]] = getelementptr inbounds [[BLOCK_T]]* [[BLOCK]], i32 0, i32 5
// CHECK-NEXT: [[T1:%.*]] = load i8** [[T0]]
// CHECK-NEXT: [[T2:%.*]] = bitcast i8* [[T1]] to [[WEAK_T]]*
// CHECK-NEXT: [[T3:%.*]] = getelementptr inbounds [[WEAK_T]]* [[T2]], i32 0, i32 1
// CHECK-NEXT: [[T4:%.*]] = load [[WEAK_T]]** [[T3]]
// CHECK-NEXT: [[WEAKX:%.*]] = getelementptr inbounds [[WEAK_T]]* [[T4]], i32 0, i32 6
// CHECK-NEXT: [[T0:%.*]] = load [[TEST2]]** [[WEAKX]], align 4