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5ee67e8e76
PowerPC has a conditional branch to the link register (return) instruction: BCLR. This should be used any time when we'd otherwise have a conditional branch to a return. This adds a small pass, PPCEarlyReturn, which runs just prior to the branch selection pass (and, importantly, after block placement) to generate these conditional returns when possible. It will also eliminate unconditional branches to returns (these happen rarely; most of the time these have already been tail duplicated by the time PPCEarlyReturn is invoked). This is a nice optimization for small functions that do not maintain a stack frame. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179026 91177308-0d34-0410-b5e6-96231b3b80d8
92 lines
3.0 KiB
C++
92 lines
3.0 KiB
C++
//===-- PPC.h - Top-level interface for PowerPC Target ----------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file contains the entry points for global functions defined in the LLVM
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// PowerPC back-end.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_TARGET_POWERPC_H
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#define LLVM_TARGET_POWERPC_H
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#include "MCTargetDesc/PPCMCTargetDesc.h"
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#include <string>
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// GCC #defines PPC on Linux but we use it as our namespace name
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#undef PPC
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namespace llvm {
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class PPCTargetMachine;
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class FunctionPass;
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class ImmutablePass;
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class JITCodeEmitter;
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class MachineInstr;
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class AsmPrinter;
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class MCInst;
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FunctionPass *createPPCCTRLoops();
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FunctionPass *createPPCEarlyReturnPass();
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FunctionPass *createPPCBranchSelectionPass();
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FunctionPass *createPPCISelDag(PPCTargetMachine &TM);
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FunctionPass *createPPCJITCodeEmitterPass(PPCTargetMachine &TM,
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JITCodeEmitter &MCE);
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void LowerPPCMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
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AsmPrinter &AP, bool isDarwin);
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/// \brief Creates an PPC-specific Target Transformation Info pass.
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ImmutablePass *createPPCTargetTransformInfoPass(const PPCTargetMachine *TM);
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namespace PPCII {
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/// Target Operand Flag enum.
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enum TOF {
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//===------------------------------------------------------------------===//
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// PPC Specific MachineOperand flags.
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MO_NO_FLAG,
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/// MO_DARWIN_STUB - On a symbol operand "FOO", this indicates that the
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/// reference is actually to the "FOO$stub" symbol. This is used for calls
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/// and jumps to external functions on Tiger and earlier.
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MO_DARWIN_STUB = 1,
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/// MO_PIC_FLAG - If this bit is set, the symbol reference is relative to
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/// the function's picbase, e.g. lo16(symbol-picbase).
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MO_PIC_FLAG = 2,
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/// MO_NLP_FLAG - If this bit is set, the symbol reference is actually to
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/// the non_lazy_ptr for the global, e.g. lo16(symbol$non_lazy_ptr-picbase).
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MO_NLP_FLAG = 4,
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/// MO_NLP_HIDDEN_FLAG - If this bit is set, the symbol reference is to a
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/// symbol with hidden visibility. This causes a different kind of
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/// non-lazy-pointer to be generated.
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MO_NLP_HIDDEN_FLAG = 8,
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/// The next are not flags but distinct values.
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MO_ACCESS_MASK = 0xf0,
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/// MO_LO16, MO_HA16 - lo16(symbol) and ha16(symbol)
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MO_LO16 = 1 << 4,
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MO_HA16 = 2 << 4,
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MO_TPREL16_HA = 3 << 4,
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MO_TPREL16_LO = 4 << 4,
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/// These values identify relocations on immediates folded
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/// into memory operations.
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MO_DTPREL16_LO = 5 << 4,
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MO_TLSLD16_LO = 6 << 4,
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MO_TOC16_LO = 7 << 4
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};
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} // end namespace PPCII
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} // end namespace llvm;
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#endif
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