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| author | Dan Gohman <gohman@apple.com> | 2011-09-29 22:27:34 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2011-09-29 22:27:34 +0000 |
| commit | 27e0666725c6558574cb7a55f8c91e7532e09548 (patch) | |
| tree | edade80c839f45c971878899d08c9710caab95f1 | |
| parent | 597fece886fb4551d1f26ec7749d86e89970d8c2 (diff) | |
| download | external_llvm-27e0666725c6558574cb7a55f8c91e7532e09548.tar.gz external_llvm-27e0666725c6558574cb7a55f8c91e7532e09548.tar.bz2 external_llvm-27e0666725c6558574cb7a55f8c91e7532e09548.zip | |
When eliminating unnecessary retain+autorelease on return values,
handle the case where the retain is in a different basic block.
rdar://10210274.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140815 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Scalar/ObjCARC.cpp | 3 | ||||
| -rw-r--r-- | test/Transforms/ObjCARC/empty-block.ll | 59 |
2 files changed, 61 insertions, 1 deletions
diff --git a/lib/Transforms/Scalar/ObjCARC.cpp b/lib/Transforms/Scalar/ObjCARC.cpp index 29d0fe6a2e..da74e9c3ec 100644 --- a/lib/Transforms/Scalar/ObjCARC.cpp +++ b/lib/Transforms/Scalar/ObjCARC.cpp @@ -3198,7 +3198,8 @@ void ObjCARCOpt::OptimizeReturns(Function &F) { // Check that there is nothing that can affect the reference // count between the retain and the call. - FindDependencies(CanChangeRetainCount, Arg, BB, Retain, + // Note that Retain need not be in BB. + FindDependencies(CanChangeRetainCount, Arg, Retain->getParent(), Retain, DependingInstructions, Visited, PA); if (DependingInstructions.size() != 1) goto next_block; diff --git a/test/Transforms/ObjCARC/empty-block.ll b/test/Transforms/ObjCARC/empty-block.ll new file mode 100644 index 0000000000..ca5541365a --- /dev/null +++ b/test/Transforms/ObjCARC/empty-block.ll @@ -0,0 +1,59 @@ +; RUN: opt -S -objc-arc < %s | FileCheck %s +; rdar://10210274 + +%0 = type opaque + +declare i8* @objc_retain(i8*) + +declare void @objc_release(i8*) + +declare i8* @objc_autoreleaseReturnValue(i8*) + +; Don't delete the autorelease. + +; CHECK: define %0* @test0( +; CHECK: @objc_retain +; CHECK: .lr.ph: +; CHECK-NOT: @objc_r +; CHECK: @objc_autoreleaseReturnValue +; CHECK-NOT: @objc_ +; CHECK: } +define %0* @test0(%0* %buffer) nounwind { + %1 = bitcast %0* %buffer to i8* + %2 = tail call i8* @objc_retain(i8* %1) nounwind + br i1 undef, label %.lr.ph, label %._crit_edge + +.lr.ph: ; preds = %.lr.ph, %0 + br i1 false, label %.lr.ph, label %._crit_edge + +._crit_edge: ; preds = %.lr.ph, %0 + %3 = tail call i8* @objc_retain(i8* %1) nounwind + tail call void @objc_release(i8* %1) nounwind, !clang.imprecise_release !0 + %4 = tail call i8* @objc_autoreleaseReturnValue(i8* %1) nounwind + ret %0* %buffer +} + +; Do delete the autorelease, even with the retain in a different block. + +; CHECK: define %0* @test1( +; CHECK-NOT: @objc +; CHECK: } +define %0* @test1() nounwind { + %buffer = call %0* @foo() + %1 = bitcast %0* %buffer to i8* + %2 = tail call i8* @objc_retain(i8* %1) nounwind + br i1 undef, label %.lr.ph, label %._crit_edge + +.lr.ph: ; preds = %.lr.ph, %0 + br i1 false, label %.lr.ph, label %._crit_edge + +._crit_edge: ; preds = %.lr.ph, %0 + %3 = tail call i8* @objc_retain(i8* %1) nounwind + tail call void @objc_release(i8* %1) nounwind, !clang.imprecise_release !0 + %4 = tail call i8* @objc_autoreleaseReturnValue(i8* %1) nounwind + ret %0* %buffer +} + +declare %0* @foo() + +!0 = metadata !{} |