src/cpu/StaticInstFlags.py

   1 # Copyright (c) 2003-2005 The Regents of The University of Michigan
   2 # Copyright (c) 2013 Advanced Micro Devices, Inc.
   3 # All rights reserved.
   4 #
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  14 # this software without specific prior written permission.
  15 #
  16 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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  27 #
  28 # Authors: Steve Reinhardt
  29
  30 from m5.params import *
  31
  32 # Set of boolean static instruction properties.
  33 #
  34 # Notes:
  35 # - The IsInteger and IsFloating flags are based on the class of registers
  36 # accessed by the instruction.  Although most instructions will have exactly
  37 # one of these two flags set, it is possible for an instruction to have
  38 # neither (e.g., direct unconditional branches, memory barriers) or both
  39 # (e.g., an FP/int conversion).
  40 # - If IsMemRef is set, then exactly one of IsLoad or IsStore will be set.
  41 # - If IsControl is set, then exactly one of IsDirectControl or IsIndirect
  42 # Control will be set, and exactly one of IsCondControl or IsUncondControl
  43 # will be set.
  44 # - IsSerializing, IsMemBarrier, and IsWriteBarrier are implemented as flags
  45 # since in the current model there's no other way for instructions to inject
  46 # behavior into the pipeline outside of fetch.  Once we go to an exec-in-exec
  47 # CPU model we should be able to get rid of these flags and implement this
  48 # behavior via the execute() methods.
  49
  50 class StaticInstFlags(Enum):
  51     wrapper_name = 'StaticInstFlags'
  52     wrapper_is_struct = True
  53     enum_name = 'Flags'
  54
  55     vals = [
  56         'IsNop',            # Is a no-op (no effect at all).
  57
  58         'IsInteger',        # References integer regs.
  59         'IsFloating',       # References FP regs.
  60         'IsCC',             # References CC regs.
  61
  62         'IsMemRef',         # References memory (load, store, or prefetch)
  63         'IsLoad',           # Reads from memory (load or prefetch).
  64         'IsStore',          # Writes to memory.
  65         'IsStoreConditional',   # Store conditional instruction.
  66         'IsIndexed',        # Accesses memory with an indexed address
  67                             # computation
  68         'IsInstPrefetch',   # Instruction-cache prefetch.
  69         'IsDataPrefetch',   # Data-cache prefetch.
  70
  71         'IsControl',        # Control transfer instruction.
  72         'IsDirectControl',  # PC relative control transfer.
  73         'IsIndirectControl',# Register indirect control transfer.
  74         'IsCondControl',    # Conditional control transfer.
  75         'IsUncondControl',  # Unconditional control transfer.
  76         'IsCall',           # Subroutine call.
  77         'IsReturn',         # Subroutine return.
  78
  79         'IsCondDelaySlot',  # Conditional Delay-Slot Instruction
  80
  81         'IsThreadSync',     # Thread synchronization operation.
  82
  83         'IsSerializing',    # Serializes pipeline: won't execute until all
  84                             # older instructions have committed.
  85         'IsSerializeBefore',
  86         'IsSerializeAfter',
  87         'IsMemBarrier',     # Is a memory barrier
  88         'IsWriteBarrier',   # Is a write barrier
  89         'IsReadBarrier',    # Is a read barrier
  90         'IsERET',           # <- Causes the IFU to stall (MIPS ISA)
  91
  92         'IsNonSpeculative', # Should not be executed speculatively
  93         'IsQuiesce',        # Is a quiesce instruction
  94
  95         'IsIprAccess',      # Accesses IPRs
  96         'IsUnverifiable',   # Can't be verified by a checker
  97
  98         'IsSyscall',        # Causes a system call to be emulated in syscall
  99                             # emulation mode.
 100
 101         # Flags for microcode
 102         'IsMacroop',        # Is a macroop containing microops
 103         'IsMicroop',        # Is a microop
 104         'IsDelayedCommit',  # This microop doesn't commit right away
 105         'IsLastMicroop',    # This microop ends a microop sequence
 106         'IsFirstMicroop',   # This microop begins a microop sequence
 107         # This flag doesn't do anything yet
 108         'IsMicroBranch',    # This microop branches within the microcode for
 109                             # a macroop
 110         'IsDspOp',
 111         'IsSquashAfter'     # Squash all uncommitted state after executed
 112         ]