llvm-6502/lib/Target/X86/X86.h

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//===-- X86.h - Top-level interface for X86 representation ------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the entry points for global functions defined in the x86
// target library, as used by the LLVM JIT.
//
//===----------------------------------------------------------------------===//
#ifndef TARGET_X86_H
#define TARGET_X86_H
#include "MCTargetDesc/X86BaseInfo.h"
#include "MCTargetDesc/X86MCTargetDesc.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Target/TargetMachine.h"
namespace llvm {
class FunctionPass;
class JITCodeEmitter;
class X86TargetMachine;
/// createX86ISelDag - This pass converts a legalized DAG into a
/// X86-specific DAG, ready for instruction scheduling.
///
FunctionPass *createX86ISelDag(X86TargetMachine &TM,
CodeGenOpt::Level OptLevel);
/// createGlobalBaseRegPass - This pass initializes a global base
/// register for PIC on x86-32.
FunctionPass* createGlobalBaseRegPass();
/// createCleanupLocalDynamicTLSPass() - This pass combines multiple accesses
/// to local-dynamic TLS variables so that the TLS base address for the module
/// is only fetched once per execution path through the function.
FunctionPass *createCleanupLocalDynamicTLSPass();
/// createX86FloatingPointStackifierPass - This function returns a pass which
/// converts floating point register references and pseudo instructions into
/// floating point stack references and physical instructions.
///
FunctionPass *createX86FloatingPointStackifierPass();
/// createX86IssueVZeroUpperPass - This pass inserts AVX vzeroupper instructions
/// before each call to avoid transition penalty between functions encoded with
/// AVX and SSE.
FunctionPass *createX86IssueVZeroUpperPass();
/// createX86CodeEmitterPass - Return a pass that emits the collected X86 code
/// to the specified MCE object.
FunctionPass *createX86JITCodeEmitterPass(X86TargetMachine &TM,
JITCodeEmitter &JCE);
/// createX86EmitCodeToMemory - Returns a pass that converts a register
/// allocated function into raw machine code in a dynamically
/// allocated chunk of memory.
///
FunctionPass *createEmitX86CodeToMemory();
Switch TargetTransformInfo from an immutable analysis pass that requires a TargetMachine to construct (and thus isn't always available), to an analysis group that supports layered implementations much like AliasAnalysis does. This is a pretty massive change, with a few parts that I was unable to easily separate (sorry), so I'll walk through it. The first step of this conversion was to make TargetTransformInfo an analysis group, and to sink the nonce implementations in ScalarTargetTransformInfo and VectorTargetTranformInfo into a NoTargetTransformInfo pass. This allows other passes to add a hard requirement on TTI, and assume they will always get at least on implementation. The TargetTransformInfo analysis group leverages the delegation chaining trick that AliasAnalysis uses, where the base class for the analysis group delegates to the previous analysis *pass*, allowing all but tho NoFoo analysis passes to only implement the parts of the interfaces they support. It also introduces a new trick where each pass in the group retains a pointer to the top-most pass that has been initialized. This allows passes to implement one API in terms of another API and benefit when some other pass above them in the stack has more precise results for the second API. The second step of this conversion is to create a pass that implements the TargetTransformInfo analysis using the target-independent abstractions in the code generator. This replaces the ScalarTargetTransformImpl and VectorTargetTransformImpl classes in lib/Target with a single pass in lib/CodeGen called BasicTargetTransformInfo. This class actually provides most of the TTI functionality, basing it upon the TargetLowering abstraction and other information in the target independent code generator. The third step of the conversion adds support to all TargetMachines to register custom analysis passes. This allows building those passes with access to TargetLowering or other target-specific classes, and it also allows each target to customize the set of analysis passes desired in the pass manager. The baseline LLVMTargetMachine implements this interface to add the BasicTTI pass to the pass manager, and all of the tools that want to support target-aware TTI passes call this routine on whatever target machine they end up with to add the appropriate passes. The fourth step of the conversion created target-specific TTI analysis passes for the X86 and ARM backends. These passes contain the custom logic that was previously in their extensions of the ScalarTargetTransformInfo and VectorTargetTransformInfo interfaces. I separated them into their own file, as now all of the interface bits are private and they just expose a function to create the pass itself. Then I extended these target machines to set up a custom set of analysis passes, first adding BasicTTI as a fallback, and then adding their customized TTI implementations. The fourth step required logic that was shared between the target independent layer and the specific targets to move to a different interface, as they no longer derive from each other. As a consequence, a helper functions were added to TargetLowering representing the common logic needed both in the target implementation and the codegen implementation of the TTI pass. While technically this is the only change that could have been committed separately, it would have been a nightmare to extract. The final step of the conversion was just to delete all the old boilerplate. This got rid of the ScalarTargetTransformInfo and VectorTargetTransformInfo classes, all of the support in all of the targets for producing instances of them, and all of the support in the tools for manually constructing a pass based around them. Now that TTI is a relatively normal analysis group, two things become straightforward. First, we can sink it into lib/Analysis which is a more natural layer for it to live. Second, clients of this interface can depend on it *always* being available which will simplify their code and behavior. These (and other) simplifications will follow in subsequent commits, this one is clearly big enough. Finally, I'm very aware that much of the comments and documentation needs to be updated. As soon as I had this working, and plausibly well commented, I wanted to get it committed and in front of the build bots. I'll be doing a few passes over documentation later if it sticks. Commits to update DragonEgg and Clang will be made presently. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171681 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 01:37:14 +00:00
/// \brief Creates an X86-specific Target Transformation Info pass.
ImmutablePass *createX86TargetTransformInfoPass(const X86TargetMachine *TM);
/// createX86PadShortFunctions - Return a pass that pads short functions
/// with NOOPs. This will prevent a stall when returning on the Atom.
FunctionPass *createX86PadShortFunctions();
} // End llvm namespace
#endif