From 0860d0ba2f14e62572434cd159a086f91b20895d Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Thu, 16 Jun 2011 20:57:14 +0000
Subject: [PATCH] Fix ARCOpt to insert releases on both successors of an invoke
 rather than trying to insert them immediately after the invoke.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133188 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/ObjCARC.cpp | 37 ++++++++++++-----
 test/Transforms/ObjCARC/invoke.ll | 67 +++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+), 10 deletions(-)
 create mode 100644 test/Transforms/ObjCARC/invoke.ll

diff --git a/lib/Transforms/Scalar/ObjCARC.cpp b/lib/Transforms/Scalar/ObjCARC.cpp
index e65e2853c2a..6cd35e5c9e7 100644
--- a/lib/Transforms/Scalar/ObjCARC.cpp
+++ b/lib/Transforms/Scalar/ObjCARC.cpp
@@ -2550,16 +2550,33 @@ void ObjCARCOpt::MoveCalls(Value *Arg,
   for (SmallPtrSet<Instruction *, 2>::const_iterator
        PI = RetainsToMove.ReverseInsertPts.begin(),
        PE = RetainsToMove.ReverseInsertPts.end(); PI != PE; ++PI) {
-    Instruction *InsertPt = llvm::next(BasicBlock::iterator(*PI));
-    Value *MyArg = ArgTy == ParamTy ? Arg :
-                   new BitCastInst(Arg, ParamTy, "", InsertPt);
-    CallInst *Call = CallInst::Create(ReleaseFunc, MyArg, "", InsertPt);
-    // Attach a clang.imprecise_release metadata tag, if appropriate.
-    if (MDNode *M = ReleasesToMove.ReleaseMetadata)
-      Call->setMetadata(ImpreciseReleaseMDKind, M);
-    Call->setDoesNotThrow();
-    if (ReleasesToMove.IsTailCallRelease)
-      Call->setTailCall();
+    Instruction *LastUse = *PI;
+    Instruction *InsertPts[] = { 0, 0, 0 };
+    if (InvokeInst *II = dyn_cast<InvokeInst>(LastUse)) {
+      // We can't insert code immediately after an invoke instruction, so
+      // insert code at the beginning of both successor blocks instead.
+      // The invoke's return value isn't available in the unwind block,
+      // but our releases will never depend on it, because they must be
+      // paired with retains from before the invoke.
+      InsertPts[0] = II->getNormalDest()->getFirstNonPHI();
+      InsertPts[1] = II->getUnwindDest()->getFirstNonPHI();
+    } else {
+      // Insert code immediately after the last use.
+      InsertPts[0] = llvm::next(BasicBlock::iterator(LastUse));
+    }
+
+    for (Instruction **I = InsertPts; *I; ++I) {
+      Instruction *InsertPt = *I;
+      Value *MyArg = ArgTy == ParamTy ? Arg :
+                     new BitCastInst(Arg, ParamTy, "", InsertPt);
+      CallInst *Call = CallInst::Create(ReleaseFunc, MyArg, "", InsertPt);
+      // Attach a clang.imprecise_release metadata tag, if appropriate.
+      if (MDNode *M = ReleasesToMove.ReleaseMetadata)
+        Call->setMetadata(ImpreciseReleaseMDKind, M);
+      Call->setDoesNotThrow();
+      if (ReleasesToMove.IsTailCallRelease)
+        Call->setTailCall();
+    }
   }
 
   // Delete the original retain and release calls.
diff --git a/test/Transforms/ObjCARC/invoke.ll b/test/Transforms/ObjCARC/invoke.ll
new file mode 100644
index 00000000000..a1b87d230bd
--- /dev/null
+++ b/test/Transforms/ObjCARC/invoke.ll
@@ -0,0 +1,67 @@
+; RUN: opt -S -objc-arc < %s | FileCheck %s
+
+declare i8* @objc_retain(i8*)
+declare void @objc_release(i8*)
+declare i8* @objc_msgSend(i8*, i8*, ...)
+declare void @use_pointer(i8*)
+declare void @callee()
+
+; ARCOpt shouldn't try to move the releases to the block containing the invoke.
+
+; CHECK: define void @test0(
+; CHECK: invoke.cont:
+; CHECK:   call void @objc_release(i8* %zipFile) nounwind, !clang.imprecise_release !0
+; CHECK:   ret void
+; CHECK: lpad:
+; CHECK:   call void @objc_release(i8* %zipFile) nounwind, !clang.imprecise_release !0
+; CHECK:   ret void
+define void @test0(i8* %zipFile) {
+entry:
+  call i8* @objc_retain(i8* %zipFile) nounwind
+  call void @use_pointer(i8* %zipFile)
+  invoke void bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to void (i8*)*)(i8* %zipFile) 
+          to label %invoke.cont unwind label %lpad
+
+invoke.cont:                                      ; preds = %entry
+  call void @objc_release(i8* %zipFile) nounwind, !clang.imprecise_release !0
+  ret void
+
+lpad:                                             ; preds = %entry
+  call void @objc_release(i8* %zipFile) nounwind, !clang.imprecise_release !0
+  ret void
+}
+
+; ARCOpt should move the release before the callee calls.
+
+; CHECK: define void @test1(
+; CHECK: invoke.cont:
+; CHECK:   call void @objc_release(i8* %zipFile) nounwind, !clang.imprecise_release !0
+; CHECK:   call void @callee()
+; CHECK:   br label %done
+; CHECK: lpad:
+; CHECK:   call void @objc_release(i8* %zipFile) nounwind, !clang.imprecise_release !0
+; CHECK:   call void @callee()
+; CHECK:   br label %done
+; CHECK: done:
+; CHECK-NEXT: ret void
+define void @test1(i8* %zipFile) {
+entry:
+  call i8* @objc_retain(i8* %zipFile) nounwind
+  call void @use_pointer(i8* %zipFile)
+  invoke void bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to void (i8*)*)(i8* %zipFile)
+          to label %invoke.cont unwind label %lpad
+
+invoke.cont:                                      ; preds = %entry
+  call void @callee()
+  br label %done
+
+lpad:                                             ; preds = %entry
+  call void @callee()
+  br label %done
+
+done:
+  call void @objc_release(i8* %zipFile) nounwind, !clang.imprecise_release !0
+  ret void
+}
+
+!0 = metadata !{}
-- 
2.34.1