Convert some ObjC msgSends to runtime calls.

It is faster to directly call the ObjC runtime for methods such as alloc/allocWithZone instead of sending a message to those functions.

This patch adds support for converting messages to alloc/allocWithZone to their equivalent runtime calls.

Tests included for the positive case of applying this transformation, negative tests that we ensure we only convert "alloc" to objc_alloc, not "alloc2", and also a driver test to ensure we enable this only for supported runtime versions.

Reviewed By: rjmccall

https://reviews.llvm.org/D55349

llvm-svn: 348687

1 files changed, 7 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index fe42b8beb9c..a97cce3a552 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -119,7 +119,13 @@ struct OrderGlobalInits {
 struct ObjCEntrypoints {
   ObjCEntrypoints() { memset(this, 0, sizeof(*this)); }
 
-    /// void objc_autoreleasePoolPop(void*);
+  /// void objc_alloc(id);
+  llvm::Constant *objc_alloc;
+
+  /// void objc_allocWithZone(id);
+  llvm::Constant *objc_allocWithZone;
+
+  /// void objc_autoreleasePoolPop(void*);
   llvm::Constant *objc_autoreleasePoolPop;
 
   /// void *objc_autoreleasePoolPush(void);