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

diff --git a/lib/Transforms/Scalar/ObjCARC.cpp b/lib/Transforms/Scalar/ObjCARC.cpp
index 40b0b20616893a81c70dbb283899ab3d3522e862..e64c1866bb5a247e0afd6db55877a27cf953119e 100644 (file)
--- 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<InstructionClass>(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<PointerType>(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<CallInst>(UUser) || isa<InvokeInst>(UUser))
-        continue;
-      // Use by an instruction which copies the value is an escape if the
-      // result is an escape.
-      if (isa<BitCastInst>(UUser) || isa<GetElementPtrInst>(UUser) ||
-          isa<PHINode>(UUser) || isa<SelectInst>(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<BitCastInst>(UUser) || isa<GetElementPtrInst>(UUser) ||
+            isa<PHINode>(UUser) || isa<SelectInst>(UUser)) {
+          Worklist.push_back(UUser);
+          continue;
+        }
+        // Use by a load is not an escape.
+        if (isa<LoadInst>(UUser))
+          continue;
+        // Use by a store is not an escape if the use is the address.
+        if (const StoreInst *SI = dyn_cast<StoreInst>(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<LoadInst>(UUser))
-        continue;
-      // Use by a store is not an escape if the use is the address.
-      if (const StoreInst *SI = dyn_cast<StoreInst>(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 (file)
index 0000000..3f694cf
--- /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 !{}