diff options
| -rw-r--r-- | llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp | 13 | ||||
| -rw-r--r-- | llvm/test/Transforms/ObjCARC/rv.ll | 18 |
2 files changed, 30 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp b/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp index 6ffaadc2b5f..9a02174556f 100644 --- a/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp +++ b/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp @@ -600,6 +600,17 @@ ObjCARCOpt::OptimizeRetainRVCall(Function &F, Instruction *RetainRV) { } } + // Track PHIs which are equivalent to our Arg. + SmallDenseSet<const Value*, 2> EquivalentArgs; + EquivalentArgs.insert(Arg); + + // Add PHIs that are equivalent to Arg to ArgUsers. + if (const PHINode *PN = dyn_cast<PHINode>(Arg)) { + SmallVector<const Value *, 2> ArgUsers; + getEquivalentPHIs(*PN, ArgUsers); + EquivalentArgs.insert(ArgUsers.begin(), ArgUsers.end()); + } + // Check for being preceded by an objc_autoreleaseReturnValue on the same // pointer. In this case, we can delete the pair. BasicBlock::iterator I = RetainRV->getIterator(), @@ -609,7 +620,7 @@ ObjCARCOpt::OptimizeRetainRVCall(Function &F, Instruction *RetainRV) { --I; while (I != Begin && IsNoopInstruction(&*I)); if (GetBasicARCInstKind(&*I) == ARCInstKind::AutoreleaseRV && - GetArgRCIdentityRoot(&*I) == Arg) { + EquivalentArgs.count(GetArgRCIdentityRoot(&*I))) { Changed = true; ++NumPeeps; diff --git a/llvm/test/Transforms/ObjCARC/rv.ll b/llvm/test/Transforms/ObjCARC/rv.ll index ca3d7e2f848..3d0d56ca0e5 100644 --- a/llvm/test/Transforms/ObjCARC/rv.ll +++ b/llvm/test/Transforms/ObjCARC/rv.ll @@ -239,6 +239,24 @@ define i8* @test19(i8* %p) { ret i8* %p } +; Delete autoreleaseRV+retainRV pairs when they have equivalent PHIs as inputs + +; CHECK: define i8* @test19phi(i8* %p) { +; CHECK-NEXT: entry: +; CHECK-NEXT: br label %test19bb +; CHECK: test19bb: +; CHECK-NEXT: ret i8* %p +define i8* @test19phi(i8* %p) { +entry: + br label %test19bb +test19bb: + %phi1 = phi i8* [ %p, %entry ] + %phi2 = phi i8* [ %p, %entry ] + call i8* @llvm.objc.autoreleaseReturnValue(i8* %phi1) + call i8* @llvm.objc.retainAutoreleasedReturnValue(i8* %phi2) + ret i8* %p +} + ; Like test19 but with plain autorelease. ; CHECK: define i8* @test20(i8* %p) { |
