1 //===-- llvm/CallingConv.h - LLVM Calling Conventions -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines LLVM's set of calling conventions.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CALLINGCONV_H
15 #define LLVM_CALLINGCONV_H
19 /// CallingConv Namespace - This namespace contains an enum with a value for
20 /// the well-known calling conventions.
22 namespace CallingConv {
23 /// A set of enums which specify the assigned numeric values for known llvm
24 /// calling conventions.
25 /// @brief LLVM Calling Convention Representation
27 // C - The default llvm calling convention, compatible with C. This
28 // convention is the only calling convention that supports varargs calls.
29 // As with typical C calling conventions, the callee/caller have to tolerate
30 // certain amounts of prototype mismatch.
33 /// CSRet - C Struct Return calling convention. This convention requires
34 /// that the function return void and take a pointer as the first argument
35 /// of the struct. This is used by targets which need to distinguish
36 /// between C functions returning a structure, and C functions taking a
37 /// structure pointer as the first argument to the function.
41 // Generic LLVM calling conventions. None of these calling conventions
42 // support varargs calls, and all assume that the caller and callee
43 // prototype exactly match.
45 // Fast - This calling convention attempts to make calls as fast as possible
46 // (e.g. by passing things in registers).
49 // Cold - This calling convention attempts to make code in the caller as
50 // efficient as possible under the assumption that the call is not commonly
51 // executed. As such, these calls often preserve all registers so that the
52 // call does not break any live ranges in the caller side.
55 // Target - This is the start of the target-specific calling conventions,
56 // e.g. fastcall and thiscall on X86.
59 } // End CallingConv namespace
61 } // End llvm namespace