[LLVMdev] Creation of Intrinsics with Pointer Return Types

[aditya vishnubhotla]

Hi, I tried creating intrinsics which are to be placeholders for a  set of instructions (actually a section of a basic block) to be executed elsewhere(for e.g. in HW). These intrinsics are to take care of the data dependencies of the set of instructions being replaced by them. In the process I created a "migrate_begin" variable argument intrinsic which handles the incoming data dependenices to these set of instructions. Entry  in the  Intrinsics.td file: def int_migrate_begin : Intrinsic<[llvm_i32_ty,llvm_vararg_ty],[IntrWriteMem],"llvm.migrate_begin">;     I want to replace the instructions from this set , having outgoing data dependencies, with " migrate_end " intrinsic instructions. I created two migrate_end intrinsics with return types anyint(iAny Value Type) and any float(fAny Value Type). Entries  in the Intrinsics.td file: def int_migrate_end_int : Intrinsic<[llvm_anyint_ty,llvm_i32_ty,llvm_i32_ty],[IntrWriteMem],"llvm.migrate_end_int">; def int_migrate_end_float : Intrinsic<[llvm_anyfloat_ty,llvm_i32_ty,llvm_i32_ty],[IntrWriteMem],"llvm.migrate_end_float">; I am not able to handle all of the pointer return type instructions. I tried using the types such as: def llvm_vararg_ty     : LLVMType<isVoid>;   // this means vararg here def llvm_iPTR_ty       : LLVMType<iPTR> def llvm_descriptor_ty : LLVMPointerType<llvm_empty_ty>;    and adding  types def llvm_ptriAny_ty    : LLVMPointerType<llvm_anyint_ty>;             def llvm_ptrfAny_ty    : LLVMPointerType<llvm_anyfloat_ty>; but in vain.   I would be happy to know the type or types required for handling a pointer return type for an LLVM instruction, to create the "migrate_end" intrinsic. Thank You, Aditya

---

Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.

[Dan Gohman]

Hello,

LLVM's intrinsic overloading mechanism does not currently support
overloading on pointer types. Patches to implement this would be
welcome.

Dan

> Be a better friend, newshound, and know-it-all with Yahoo! Mobile.

> Try it now. _______________________________________________
> LLVM Developers mailing list
> LLV...@cs.uiuc.edu http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

_______________________________________________
LLVM Developers mailing list
LLV...@cs.uiuc.edu http://llvm.cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

[Gordon Henriksen]

I'm not sure how you'd encode the pointer type name in the type.

Another option is bitcast pointers to some fixed type. i8* is a good
choice. The GC intrinsics do this.

— Gordon