After much consultation aimed at figuring out what this builtin actually
does, document the results and then implement __builtin_extend_pointer for
platforms where it's a no-op.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97540 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index beaf7b8..1956abf 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -365,6 +365,22 @@
Value *F = CGM.getIntrinsic(Intrinsic::eh_unwind_init, 0, 0);
return RValue::get(Builder.CreateCall(F));
}
+ case Builtin::BI__builtin_extend_pointer: {
+ // Extends a pointer to the size of an _Unwind_Word, which is
+ // generally a uint64_t. Generally this gets poked directly into
+ // a register (or a "register" depending on platform) and then
+ // called, so if the pointer is shorter than a word we need to
+ // zext / sext based on the platform's expectations for pointers
+ // in registers.
+ //
+ // See: http://gcc.gnu.org/ml/gcc-bugs/2002-02/msg00237.html
+ //
+ // FIXME: ptrtoint always zexts; use a target hook if we start
+ // supporting targets where this matters.
+ Value *Ptr = EmitScalarExpr(E->getArg(0));
+ const llvm::Type *Ty = CGM.getTypes().ConvertType(E->getType());
+ return RValue::get(Builder.CreatePtrToInt(Ptr, Ty));
+ }
#if 0
// FIXME: Finish/enable when LLVM backend support stabilizes
case Builtin::BI__builtin_setjmp: {