From 44234775486a0bd8fb6dae4048666ea5567caa11 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Fri, 13 Apr 2012 18:28:58 +0000 Subject: [PATCH] Consider ObjC runtime calls objc_storeWeak and others which make a copy of their argument as "escape" points for objc_retainBlock optimization. This fixes rdar://11229925. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154682 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/ObjCARC.cpp | 43 ++++++---- test/Transforms/ObjCARC/escape.ll | 131 ++++++++++++++++++++++++++++++ 2 files changed, 160 insertions(+), 14 deletions(-) create mode 100644 test/Transforms/ObjCARC/escape.ll diff --git a/lib/Transforms/Scalar/ObjCARC.cpp b/lib/Transforms/Scalar/ObjCARC.cpp index 40b0b206168..e64c1866bb5 100644 --- a/lib/Transforms/Scalar/ObjCARC.cpp +++ b/lib/Transforms/Scalar/ObjCARC.cpp @@ -162,6 +162,7 @@ namespace { IC_MoveWeak, ///< objc_moveWeak (derived) IC_CopyWeak, ///< objc_copyWeak (derived) IC_DestroyWeak, ///< objc_destroyWeak (derived) + IC_StoreStrong, ///< objc_storeStrong (derived) IC_CallOrUser, ///< could call objc_release and/or "use" pointers IC_Call, ///< could call objc_release IC_User, ///< could "use" a pointer @@ -262,6 +263,7 @@ static InstructionClass GetFunctionClass(const Function *F) { return StringSwitch(F->getName()) .Case("objc_storeWeak", IC_StoreWeak) .Case("objc_initWeak", IC_InitWeak) + .Case("objc_storeStrong", IC_StoreStrong) .Default(IC_CallOrUser); // Second argument is i8**. if (PointerType *Pte1 = dyn_cast(ETy1)) @@ -618,22 +620,35 @@ static bool DoesObjCBlockEscape(const Value *BlockPtr) { const User *UUser = *UI; // Special - Use by a call (callee or argument) is not considered // to be an escape. - if (isa(UUser) || isa(UUser)) - continue; - // Use by an instruction which copies the value is an escape if the - // result is an escape. - if (isa(UUser) || isa(UUser) || - isa(UUser) || isa(UUser)) { - Worklist.push_back(UUser); + switch (GetBasicInstructionClass(UUser)) { + case IC_StoreWeak: + case IC_InitWeak: + case IC_StoreStrong: + case IC_Autorelease: + case IC_AutoreleaseRV: + // These special functions make copies of their pointer arguments. + return true; + case IC_User: + case IC_None: + // Use by an instruction which copies the value is an escape if the + // result is an escape. + if (isa(UUser) || isa(UUser) || + isa(UUser) || isa(UUser)) { + Worklist.push_back(UUser); + continue; + } + // Use by a load is not an escape. + if (isa(UUser)) + continue; + // Use by a store is not an escape if the use is the address. + if (const StoreInst *SI = dyn_cast(UUser)) + if (V != SI->getValueOperand()) + continue; + break; + default: + // Regular calls and other stuff are not considered escapes. continue; } - // Use by a load is not an escape. - if (isa(UUser)) - continue; - // Use by a store is not an escape if the use is the address. - if (const StoreInst *SI = dyn_cast(UUser)) - if (V != SI->getValueOperand()) - continue; // Otherwise, conservatively assume an escape. return true; } diff --git a/test/Transforms/ObjCARC/escape.ll b/test/Transforms/ObjCARC/escape.ll new file mode 100644 index 00000000000..3f694cf1d5a --- /dev/null +++ b/test/Transforms/ObjCARC/escape.ll @@ -0,0 +1,131 @@ +; RUN: opt -objc-arc -S < %s | FileCheck %s +; rdar://11229925 + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" + +%struct.__block_byref_weakLogNTimes = type { i8*, %struct.__block_byref_weakLogNTimes*, i32, i32, i8*, i8*, void (...)* } +%struct.__block_descriptor = type { i64, i64 } + +; Don't optimize away the retainBlock, because the object's address "escapes" +; with the objc_storeWeak call. + +; CHECK: define void @test0( +; CHECK: %tmp7 = call i8* @objc_retainBlock(i8* %tmp6) nounwind, !clang.arc.copy_on_escape !0 +; CHECK: call void @objc_release(i8* %tmp7) nounwind, !clang.imprecise_release !0 +; CHECK: } +define void @test0() nounwind { +entry: + %weakLogNTimes = alloca %struct.__block_byref_weakLogNTimes, align 8 + %block = alloca <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>, align 8 + %byref.isa = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 0 + store i8* null, i8** %byref.isa, align 8 + %byref.forwarding = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 1 + store %struct.__block_byref_weakLogNTimes* %weakLogNTimes, %struct.__block_byref_weakLogNTimes** %byref.forwarding, align 8 + %byref.flags = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 2 + store i32 33554432, i32* %byref.flags, align 8 + %byref.size = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 3 + store i32 48, i32* %byref.size, align 4 + %tmp1 = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 4 + store i8* bitcast (void (i8*, i8*)* @__Block_byref_object_copy_ to i8*), i8** %tmp1, align 8 + %tmp2 = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 5 + store i8* bitcast (void (i8*)* @__Block_byref_object_dispose_ to i8*), i8** %tmp2, align 8 + %weakLogNTimes1 = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 6 + %tmp3 = bitcast void (...)** %weakLogNTimes1 to i8** + %tmp4 = call i8* @objc_initWeak(i8** %tmp3, i8* null) nounwind + %block.isa = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 0 + store i8* null, i8** %block.isa, align 8 + %block.flags = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 1 + store i32 1107296256, i32* %block.flags, align 8 + %block.reserved = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 2 + store i32 0, i32* %block.reserved, align 4 + %block.invoke = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 3 + store i8* bitcast (void (i8*, i32)* @__main_block_invoke_0 to i8*), i8** %block.invoke, align 8 + %block.descriptor = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 4 + store %struct.__block_descriptor* null, %struct.__block_descriptor** %block.descriptor, align 8 + %block.captured = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 5 + %tmp5 = bitcast %struct.__block_byref_weakLogNTimes* %weakLogNTimes to i8* + store i8* %tmp5, i8** %block.captured, align 8 + %tmp6 = bitcast <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block to i8* + %tmp7 = call i8* @objc_retainBlock(i8* %tmp6) nounwind, !clang.arc.copy_on_escape !0 + %tmp8 = load %struct.__block_byref_weakLogNTimes** %byref.forwarding, align 8 + %weakLogNTimes3 = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %tmp8, i64 0, i32 6 + %tmp9 = bitcast void (...)** %weakLogNTimes3 to i8** + %tmp10 = call i8* @objc_storeWeak(i8** %tmp9, i8* %tmp7) nounwind + %tmp11 = getelementptr inbounds i8* %tmp7, i64 16 + %tmp12 = bitcast i8* %tmp11 to i8** + %tmp13 = load i8** %tmp12, align 8 + %tmp14 = bitcast i8* %tmp13 to void (i8*, i32)* + call void %tmp14(i8* %tmp7, i32 10) nounwind, !clang.arc.no_objc_arc_exceptions !0 + call void @objc_release(i8* %tmp7) nounwind, !clang.imprecise_release !0 + call void @_Block_object_dispose(i8* %tmp5, i32 8) nounwind + call void @objc_destroyWeak(i8** %tmp3) nounwind + ret void +} + +; Like test0, but it makes a regular call instead of a storeWeak call, +; so the optimization is valid. + +; CHECK: define void @test1( +; CHECK-NOT: @objc_retainBlock +; CHECK: } +define void @test1() nounwind { +entry: + %weakLogNTimes = alloca %struct.__block_byref_weakLogNTimes, align 8 + %block = alloca <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>, align 8 + %byref.isa = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 0 + store i8* null, i8** %byref.isa, align 8 + %byref.forwarding = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 1 + store %struct.__block_byref_weakLogNTimes* %weakLogNTimes, %struct.__block_byref_weakLogNTimes** %byref.forwarding, align 8 + %byref.flags = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 2 + store i32 33554432, i32* %byref.flags, align 8 + %byref.size = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 3 + store i32 48, i32* %byref.size, align 4 + %tmp1 = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 4 + store i8* bitcast (void (i8*, i8*)* @__Block_byref_object_copy_ to i8*), i8** %tmp1, align 8 + %tmp2 = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 5 + store i8* bitcast (void (i8*)* @__Block_byref_object_dispose_ to i8*), i8** %tmp2, align 8 + %weakLogNTimes1 = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %weakLogNTimes, i64 0, i32 6 + %tmp3 = bitcast void (...)** %weakLogNTimes1 to i8** + %tmp4 = call i8* @objc_initWeak(i8** %tmp3, i8* null) nounwind + %block.isa = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 0 + store i8* null, i8** %block.isa, align 8 + %block.flags = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 1 + store i32 1107296256, i32* %block.flags, align 8 + %block.reserved = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 2 + store i32 0, i32* %block.reserved, align 4 + %block.invoke = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 3 + store i8* bitcast (void (i8*, i32)* @__main_block_invoke_0 to i8*), i8** %block.invoke, align 8 + %block.descriptor = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 4 + store %struct.__block_descriptor* null, %struct.__block_descriptor** %block.descriptor, align 8 + %block.captured = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 5 + %tmp5 = bitcast %struct.__block_byref_weakLogNTimes* %weakLogNTimes to i8* + store i8* %tmp5, i8** %block.captured, align 8 + %tmp6 = bitcast <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block to i8* + %tmp7 = call i8* @objc_retainBlock(i8* %tmp6) nounwind, !clang.arc.copy_on_escape !0 + %tmp8 = load %struct.__block_byref_weakLogNTimes** %byref.forwarding, align 8 + %weakLogNTimes3 = getelementptr inbounds %struct.__block_byref_weakLogNTimes* %tmp8, i64 0, i32 6 + %tmp9 = bitcast void (...)** %weakLogNTimes3 to i8** + %tmp10 = call i8* @not_really_objc_storeWeak(i8** %tmp9, i8* %tmp7) nounwind + %tmp11 = getelementptr inbounds i8* %tmp7, i64 16 + %tmp12 = bitcast i8* %tmp11 to i8** + %tmp13 = load i8** %tmp12, align 8 + %tmp14 = bitcast i8* %tmp13 to void (i8*, i32)* + call void %tmp14(i8* %tmp7, i32 10) nounwind, !clang.arc.no_objc_arc_exceptions !0 + call void @objc_release(i8* %tmp7) nounwind, !clang.imprecise_release !0 + call void @_Block_object_dispose(i8* %tmp5, i32 8) nounwind + call void @objc_destroyWeak(i8** %tmp3) nounwind + ret void +} + +declare void @__Block_byref_object_copy_(i8*, i8*) nounwind +declare void @__Block_byref_object_dispose_(i8*) nounwind +declare void @objc_destroyWeak(i8**) +declare i8* @objc_initWeak(i8**, i8*) +declare void @__main_block_invoke_0(i8* nocapture, i32) nounwind ssp +declare void @_Block_object_dispose(i8*, i32) +declare i8* @objc_retainBlock(i8*) +declare i8* @objc_storeWeak(i8**, i8*) +declare i8* @not_really_objc_storeWeak(i8**, i8*) +declare void @objc_release(i8*) + +!0 = metadata !{}