| //===-- IntrinsicLowering.h - Intrinsic Function Lowering -------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and is distributed under |
| // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines the IntrinsicLowering interface. This interface allows |
| // addition of domain-specific or front-end specific intrinsics to LLVM without |
| // having to modify all of the code generators to support the new intrinsic. |
| // Later, as desired, targets can incrementally add support for particular |
| // intrinsic functions, as desired, to generate better code. |
| // |
| // If a code generator cannot handle or does not know about an intrinsic |
| // function, it will use the intrinsic lowering interface to change an intrinsic |
| // function name into a concrete function name which can be used to implement |
| // the functionality of the intrinsic. For example, llvm.memcpy can be |
| // implemented as a call to the math library 'memcpy' function if the target |
| // doesn't have hardware support for the intrinsic, or if it has not yet been |
| // implemented yet. |
| // |
| // Another use for this interface is the addition of domain-specific intrinsics. |
| // The default implementation of this interface would then lower the intrinsics |
| // to noop calls, allowing the direct execution of programs with instrumentation |
| // or other hooks placed in them. When a specific tool or flag is used, a |
| // different implementation of these interfaces may be used, which activates the |
| // intrinsics in some way. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CODEGEN_INTRINSICLOWERING_H |
| #define LLVM_CODEGEN_INTRINSICLOWERING_H |
| |
| #include "llvm/Intrinsics.h" |
| |
| namespace llvm { |
| class CallInst; |
| class Module; |
| |
| class IntrinsicLowering { |
| public: |
| virtual ~IntrinsicLowering() {} |
| |
| /// AddPrototypes - This method, if called, causes all of the prototypes |
| /// that might be needed by an intrinsic lowering implementation to be |
| /// inserted into the module specified. |
| virtual void AddPrototypes(Module &M) = 0; |
| |
| /// LowerIntrinsicCall - This method returns the LLVM function which should |
| /// be used to implement the specified intrinsic function call. If an |
| /// intrinsic function must be implemented by the code generator (such as |
| /// va_start), this function should print a message and abort. |
| /// |
| /// Otherwise, if an intrinsic function call can be lowered, the code to |
| /// implement it (often a call to a non-intrinsic function) is inserted |
| /// _after_ the call instruction and the call is deleted. The caller must |
| /// be capable of handling this kind of change. |
| /// |
| virtual void LowerIntrinsicCall(CallInst *CI) = 0; |
| }; |
| |
| /// DefaultIntrinsicLower - This is the default intrinsic lowering pass which |
| /// is used if no other one is specified. Custom intrinsic lowering |
| /// implementations should pass any unhandled intrinsics to this |
| /// implementation to allow for future extensibility. |
| struct DefaultIntrinsicLowering : public IntrinsicLowering { |
| virtual void AddPrototypes(Module &M); |
| virtual void LowerIntrinsicCall(CallInst *CI); |
| }; |
| } |
| |
| #endif |