From 6d9eae69a07d6ea55bad53eff217ea2f0737e5a0 Mon Sep 17 00:00:00 2001
From: Fariborz Jahanian <fjahanian@apple.com>
Date: Mon, 24 Aug 2009 21:55:06 +0000
Subject: [PATCH] Remove ivarlayout bitmap optimization, instead if all zeros,
 put out the bitmap when all objects are scanned.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@79947 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGObjCMac.cpp                  |  4 +++-
 test/CodeGenObjC/ivar-layout-no-optimize.m | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)
 create mode 100644 test/CodeGenObjC/ivar-layout-no-optimize.m

diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index f97b80aa40..ab53ddea55 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -3354,11 +3354,13 @@ llvm::Constant *CGObjCCommonMac::BuildIvarLayout(
         printf("0x%x%s",  s[i], s[i] != 0 ? ", " : "");
     printf("\n");
   }
-
+// Turn off this optimization.
+#if 0
   // if ivar_layout bitmap is all 1 bits (nothing skipped) then use NULL as
   // final layout.
   if (ForStrongLayout && !BytesSkipped)
     return llvm::Constant::getNullValue(PtrTy);
+#endif
   llvm::GlobalVariable * Entry =
     CreateMetadataVar("\01L_OBJC_CLASS_NAME_",
                       llvm::ConstantArray::get(VMContext, BitMap.c_str()),
diff --git a/test/CodeGenObjC/ivar-layout-no-optimize.m b/test/CodeGenObjC/ivar-layout-no-optimize.m
new file mode 100644
index 0000000000..d7796bc279
--- /dev/null
+++ b/test/CodeGenObjC/ivar-layout-no-optimize.m
@@ -0,0 +1,18 @@
+// RUN: clang-cc -fobjc-gc -triple x86_64-apple-darwin -O0 -S %s -o %t-64.s &&
+// RUN: FileCheck -check-prefix LP64 --input-file=%t-64.s %s &&
+// RUN: true
+
+@interface NSObject {
+  id isa;
+}
+@end
+
+@interface AllPointers : NSObject {
+    id foo;
+    void *__strong bar;    NSObject *bletch;}
+@end
+@implementation AllPointers
+@end
+
+// CHECK-LP64: L_OBJC_CLASS_NAME_6:
+// CHECK-LP64-NEXT: .asciz	"\004"
-- 
2.40.0