Add comdat key field to llvm.global_ctors and llvm.global_dtors
This allows us to put dynamic initializers for weak data into the same
comdat group as the data being initialized. This is necessary for MSVC
ABI compatibility. Once we have comdats for guard variables, we can use
the combination to help GlobalOpt fire more often for weak data with
guarded initialization on other platforms.
Reviewers: nlewycky
Differential Revision: http://reviews.llvm.org/D3499
llvm-svn: 209015
diff --git a/llvm/lib/Transforms/ObjCARC/ObjCARCAPElim.cpp b/llvm/lib/Transforms/ObjCARC/ObjCARCAPElim.cpp
index 9d36b72..1a25391 100644
--- a/llvm/lib/Transforms/ObjCARC/ObjCARCAPElim.cpp
+++ b/llvm/lib/Transforms/ObjCARC/ObjCARCAPElim.cpp
@@ -155,8 +155,8 @@
for (User::op_iterator OI = Init->op_begin(), OE = Init->op_end();
OI != OE; ++OI) {
Value *Op = *OI;
- // llvm.global_ctors is an array of pairs where the second members
- // are constructor functions.
+ // llvm.global_ctors is an array of three-field structs where the second
+ // members are constructor functions.
Function *F = dyn_cast<Function>(cast<ConstantStruct>(Op)->getOperand(1));
// If the user used a constructor function with the wrong signature and
// it got bitcasted or whatever, look the other way.