src/llvm/lib/Target/PowerPC/PPCScheduleP7.td

   1 //===-- PPCScheduleP7.td - PPC P7 Scheduling Definitions ---*- tablegen -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file defines the itinerary class data for the POWER7 processor.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 // Primary reference:
  15 // IBM POWER7 multicore server processor
  16 // B. Sinharoy, et al.
  17 // IBM J. Res. & Dev. (55) 3. May/June 2011.
  18
  19 // Scheduling for the P7 involves tracking two types of resources:
  20 //  1. The dispatch bundle slots
  21 //  2. The functional unit resources
  22
  23 // Dispatch units:
  24 def P7_DU1    : FuncUnit;
  25 def P7_DU2    : FuncUnit;
  26 def P7_DU3    : FuncUnit;
  27 def P7_DU4    : FuncUnit;
  28 def P7_DU5    : FuncUnit;
  29 def P7_DU6    : FuncUnit;
  30
  31 def P7_LS1    : FuncUnit; // Load/Store pipeline 1
  32 def P7_LS2    : FuncUnit; // Load/Store pipeline 2
  33
  34 def P7_FX1    : FuncUnit; // FX pipeline 1
  35 def P7_FX2    : FuncUnit; // FX pipeline 2
  36
  37 // VS pipeline 1 (vector integer ops. always here)
  38 def P7_VS1    : FuncUnit; // VS pipeline 1
  39 // VS pipeline 2 (128-bit stores and perms. here)
  40 def P7_VS2    : FuncUnit; // VS pipeline 2
  41
  42 def P7_CRU    : FuncUnit; // CR unit (CR logicals and move-from-SPRs)
  43 def P7_BRU    : FuncUnit; // BR unit
  44
  45 // Notes:
  46 // Each LSU pipeline can also execute FX add and logical instructions.
  47 // Each LSU pipeline can complete a load or store in one cycle.
  48 //
  49 // Each store is broken into two parts, AGEN goes to the LSU while a
  50 // "data steering" op. goes to the FXU or VSU.
  51 //
  52 // FX loads have a two cycle load-to-use latency (so one "bubble" cycle).
  53 // VSU loads have a three cycle load-to-use latency (so two "bubble" cycle).
  54 //
  55 // Frequent FX ops. take only one cycle and results can be used again in the
  56 // next cycle (there is a self-bypass). Getting results from the other FX
  57 // pipeline takes an additional cycle.
  58 //
  59 // The VSU XS is similar to the POWER6, but with a pipeline length of 2 cycles
  60 // (instead of 3 cycles on the POWER6). VSU XS handles vector FX-style ops.
  61 // Dispatch of an instruction to VS1 that uses four single prec. inputs
  62 // (either to a float or XC op). prevents dispatch in that cycle to VS2 of any
  63 // floating point instruction.
  64 //
  65 // The VSU PM is similar to the POWER6, but with a pipeline length of 3 cycles
  66 // (instead of 4 cycles on the POWER6). vsel is handled by the PM pipeline
  67 // (unlike on the POWER6).
  68 //
  69 // FMA from the VSUs can forward results in 6 cycles. VS1 XS and vector FP
  70 // share the same write-back, and have a 5-cycle latency difference, so the
  71 // IFU/IDU will not dispatch an XS instructon 5 cycles after a vector FP
  72 // op. has been dispatched to VS1.
  73 //
  74 // Three cycles after an L1 cache hit, a dependent VSU instruction can issue.
  75 //
  76 // Instruction dispatch groups have (at most) four non-branch instructions, and
  77 // two branches. Unlike on the POWER4/5, a branch does not automatically
  78 // end the dispatch group, but a second branch must be the last in the group.
  79
  80 def P7Itineraries : ProcessorItineraries<
  81   [P7_DU1, P7_DU2, P7_DU3, P7_DU4, P7_DU5, P7_DU6,
  82    P7_LS1, P7_LS2, P7_FX1, P7_FX2, P7_VS1, P7_VS2, P7_CRU, P7_BRU], [], [
  83   InstrItinData<IIC_IntSimple   , [InstrStage<1, [P7_DU1, P7_DU2,
  84                                                   P7_DU3, P7_DU4], 0>,
  85                                    InstrStage<1, [P7_FX1, P7_FX2,
  86                                                   P7_LS1, P7_LS2]>],
  87                                   [1, 1, 1]>,
  88   InstrItinData<IIC_IntGeneral  , [InstrStage<1, [P7_DU1, P7_DU2,
  89                                                   P7_DU3, P7_DU4], 0>,
  90                                    InstrStage<1, [P7_FX1, P7_FX2]>],
  91                                   [1, 1, 1]>,
  92   InstrItinData<IIC_IntCompare  , [InstrStage<1, [P7_DU1, P7_DU2,
  93                                                   P7_DU3, P7_DU4], 0>,
  94                                    InstrStage<1, [P7_FX1, P7_FX2]>],
  95                                   [1, 1, 1]>,
  96   // FIXME: Add record-form itinerary data.
  97   InstrItinData<IIC_IntDivW     , [InstrStage<1, [P7_DU1], 0>,
  98                                    InstrStage<1, [P7_DU2], 0>,
  99                                    InstrStage<36, [P7_FX1, P7_FX2]>],
 100                                   [36, 1, 1]>,
 101   InstrItinData<IIC_IntDivD     , [InstrStage<1, [P7_DU1], 0>,
 102                                    InstrStage<1, [P7_DU2], 0>,
 103                                    InstrStage<68, [P7_FX1, P7_FX2]>],
 104                                   [68, 1, 1]>,
 105   InstrItinData<IIC_IntMulHW    , [InstrStage<1, [P7_DU1, P7_DU2,
 106                                                   P7_DU3, P7_DU4], 0>,
 107                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 108                                   [4, 1, 1]>,
 109   InstrItinData<IIC_IntMulHWU   , [InstrStage<1, [P7_DU1, P7_DU2,
 110                                                   P7_DU3, P7_DU4], 0>,
 111                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 112                                   [4, 1, 1]>,
 113   InstrItinData<IIC_IntMulLI    , [InstrStage<1, [P7_DU1, P7_DU2,
 114                                                   P7_DU3, P7_DU4], 0>,
 115                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 116                                   [4, 1, 1]>,
 117   InstrItinData<IIC_IntRotate   , [InstrStage<1, [P7_DU1, P7_DU2,
 118                                                   P7_DU3, P7_DU4], 0>,
 119                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 120                                    [1, 1, 1]>,
 121   InstrItinData<IIC_IntRotateD  , [InstrStage<1, [P7_DU1, P7_DU2,
 122                                                   P7_DU3, P7_DU4], 0>,
 123                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 124                                    [1, 1, 1]>,
 125   InstrItinData<IIC_IntShift    , [InstrStage<1, [P7_DU1, P7_DU2,
 126                                                   P7_DU3, P7_DU4], 0>,
 127                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 128                                   [1, 1, 1]>,
 129   InstrItinData<IIC_IntTrapW    , [InstrStage<1, [P7_DU1, P7_DU2,
 130                                                   P7_DU3, P7_DU4], 0>,
 131                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 132                                   [1, 1]>,
 133   InstrItinData<IIC_IntTrapD    , [InstrStage<1, [P7_DU1, P7_DU2,
 134                                                   P7_DU3, P7_DU4], 0>,
 135                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 136                                   [1, 1]>,
 137   InstrItinData<IIC_BrB         , [InstrStage<1, [P7_DU5, P7_DU6], 0>,
 138                                    InstrStage<1, [P7_BRU]>],
 139                                   [3, 1, 1]>,
 140   InstrItinData<IIC_BrCR        , [InstrStage<1, [P7_DU1], 0>,
 141                                    InstrStage<1, [P7_CRU]>],
 142                                   [3, 1, 1]>,
 143   InstrItinData<IIC_BrMCR       , [InstrStage<1, [P7_DU5, P7_DU6], 0>,
 144                                    InstrStage<1, [P7_BRU]>],
 145                                   [3, 1, 1]>,
 146   InstrItinData<IIC_BrMCRX      , [InstrStage<1, [P7_DU5, P7_DU6], 0>,
 147                                    InstrStage<1, [P7_BRU]>],
 148                                   [3, 1, 1]>,
 149   InstrItinData<IIC_LdStLoad    , [InstrStage<1, [P7_DU1, P7_DU2,
 150                                                   P7_DU3, P7_DU4], 0>,
 151                                    InstrStage<1, [P7_LS1, P7_LS2]>],
 152                                   [2, 1, 1]>,
 153   InstrItinData<IIC_LdStLoadUpd , [InstrStage<1, [P7_DU1], 0>,
 154                                    InstrStage<1, [P7_DU2], 0>,
 155                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 156                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 157                                   [2, 2, 1, 1]>,
 158   InstrItinData<IIC_LdStLoadUpdX, [InstrStage<1, [P7_DU1], 0>,
 159                                    InstrStage<1, [P7_DU2], 0>,
 160                                    InstrStage<1, [P7_DU3], 0>,
 161                                    InstrStage<1, [P7_DU4], 0>,
 162                                    InstrStage<1, [P7_FX1, P7_FX2]>,
 163                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 164                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 165                                   [3, 3, 1, 1]>,
 166   InstrItinData<IIC_LdStLD      , [InstrStage<1, [P7_DU1, P7_DU2,
 167                                                   P7_DU3, P7_DU4], 0>,
 168                                    InstrStage<1, [P7_LS1, P7_LS2]>],
 169                                   [2, 1, 1]>,
 170   InstrItinData<IIC_LdStLDU     , [InstrStage<1, [P7_DU1], 0>,
 171                                    InstrStage<1, [P7_DU2], 0>,
 172                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 173                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 174                                   [2, 2, 1, 1]>,
 175   InstrItinData<IIC_LdStLDUX    , [InstrStage<1, [P7_DU1], 0>,
 176                                    InstrStage<1, [P7_DU2], 0>,
 177                                    InstrStage<1, [P7_DU3], 0>,
 178                                    InstrStage<1, [P7_DU4], 0>,
 179                                    InstrStage<1, [P7_FX1, P7_FX2]>,
 180                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 181                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 182                                   [3, 3, 1, 1]>,
 183   InstrItinData<IIC_LdStLFD     , [InstrStage<1, [P7_DU1, P7_DU2,
 184                                                   P7_DU3, P7_DU4], 0>,
 185                                    InstrStage<1, [P7_LS1, P7_LS2]>],
 186                                   [3, 1, 1]>,
 187   InstrItinData<IIC_LdStLVecX   , [InstrStage<1, [P7_DU1, P7_DU2,
 188                                                   P7_DU3, P7_DU4], 0>,
 189                                    InstrStage<1, [P7_LS1, P7_LS2]>],
 190                                   [3, 1, 1]>,
 191   InstrItinData<IIC_LdStLFDU    , [InstrStage<1, [P7_DU1], 0>,
 192                                    InstrStage<1, [P7_DU2], 0>,
 193                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 194                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 195                                   [3, 3, 1, 1]>,
 196   InstrItinData<IIC_LdStLFDUX   , [InstrStage<1, [P7_DU1], 0>,
 197                                    InstrStage<1, [P7_DU2], 0>,
 198                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 199                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 200                                   [3, 3, 1, 1]>,
 201   InstrItinData<IIC_LdStLHA     , [InstrStage<1, [P7_DU1], 0>,
 202                                    InstrStage<1, [P7_DU2], 0>,
 203                                    InstrStage<1, [P7_LS1, P7_LS2]>,
 204                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 205                                   [3, 1, 1]>,
 206   InstrItinData<IIC_LdStLHAU    , [InstrStage<1, [P7_DU1], 0>,
 207                                    InstrStage<1, [P7_DU2], 0>,
 208                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 209                                    InstrStage<1, [P7_FX1, P7_FX2]>,
 210                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 211                                   [4, 4, 1, 1]>,
 212   InstrItinData<IIC_LdStLHAUX   , [InstrStage<1, [P7_DU1], 0>,
 213                                    InstrStage<1, [P7_DU2], 0>,
 214                                    InstrStage<1, [P7_DU3], 0>,
 215                                    InstrStage<1, [P7_DU4], 0>,
 216                                    InstrStage<1, [P7_FX1, P7_FX2]>,
 217                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 218                                    InstrStage<1, [P7_FX1, P7_FX2]>,
 219                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 220                                   [4, 4, 1, 1]>,
 221   InstrItinData<IIC_LdStLWA     , [InstrStage<1, [P7_DU1], 0>,
 222                                    InstrStage<1, [P7_DU2], 0>,
 223                                    InstrStage<1, [P7_LS1, P7_LS2]>,
 224                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 225                                   [3, 1, 1]>,
 226   InstrItinData<IIC_LdStLWARX,    [InstrStage<1, [P7_DU1], 0>,
 227                                    InstrStage<1, [P7_DU2], 0>,
 228                                    InstrStage<1, [P7_DU3], 0>,
 229                                    InstrStage<1, [P7_DU4], 0>,
 230                                    InstrStage<1, [P7_LS1, P7_LS2]>],
 231                                   [3, 1, 1]>,
 232   InstrItinData<IIC_LdStLDARX,    [InstrStage<1, [P7_DU1], 0>,
 233                                    InstrStage<1, [P7_DU2], 0>,
 234                                    InstrStage<1, [P7_DU3], 0>,
 235                                    InstrStage<1, [P7_DU4], 0>,
 236                                    InstrStage<1, [P7_LS1, P7_LS2]>],
 237                                   [3, 1, 1]>,
 238   InstrItinData<IIC_LdStLMW     , [InstrStage<1, [P7_DU1, P7_DU2,
 239                                                   P7_DU3, P7_DU4], 0>,
 240                                    InstrStage<1, [P7_LS1, P7_LS2]>],
 241                                   [2, 1, 1]>,
 242   InstrItinData<IIC_LdStStore   , [InstrStage<1, [P7_DU1, P7_DU2,
 243                                                   P7_DU3, P7_DU4], 0>,
 244                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 245                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 246                                   [1, 1, 1]>,
 247   InstrItinData<IIC_LdStSTD     , [InstrStage<1, [P7_DU1, P7_DU2,
 248                                                   P7_DU3, P7_DU4], 0>,
 249                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 250                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 251                                   [1, 1, 1]>,
 252   InstrItinData<IIC_LdStSTDU    , [InstrStage<1, [P7_DU1], 0>,
 253                                    InstrStage<1, [P7_DU2], 0>,
 254                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 255                                    InstrStage<1, [P7_FX1, P7_FX2]>,
 256                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 257                                   [2, 1, 1, 1]>,
 258   InstrItinData<IIC_LdStSTDUX   , [InstrStage<1, [P7_DU1], 0>,
 259                                    InstrStage<1, [P7_DU2], 0>,
 260                                    InstrStage<1, [P7_DU3], 0>,
 261                                    InstrStage<1, [P7_DU4], 0>,
 262                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 263                                    InstrStage<1, [P7_FX1, P7_FX2]>,
 264                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 265                                   [2, 1, 1, 1]>,
 266   InstrItinData<IIC_LdStSTFD    , [InstrStage<1, [P7_DU1, P7_DU2,
 267                                                   P7_DU3, P7_DU4], 0>,
 268                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 269                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 270                                   [1, 1, 1]>,
 271   InstrItinData<IIC_LdStSTFDU   , [InstrStage<1, [P7_DU1], 0>,
 272                                    InstrStage<1, [P7_DU2], 0>,
 273                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 274                                    InstrStage<1, [P7_FX1, P7_FX2], 0>,
 275                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 276                                   [2, 1, 1, 1]>,
 277   InstrItinData<IIC_LdStSTVEBX  , [InstrStage<1, [P7_DU1, P7_DU2,
 278                                                   P7_DU3, P7_DU4], 0>,
 279                                    InstrStage<1, [P7_LS1, P7_LS2], 0>,
 280                                    InstrStage<1, [P7_VS2]>],
 281                                   [1, 1, 1]>,
 282   InstrItinData<IIC_LdStSTDCX   , [InstrStage<1, [P7_DU1], 0>,
 283                                    InstrStage<1, [P7_DU2], 0>,
 284                                    InstrStage<1, [P7_DU3], 0>,
 285                                    InstrStage<1, [P7_DU4], 0>,
 286                                    InstrStage<1, [P7_LS1, P7_LS2]>],
 287                                   [1, 1, 1]>,
 288   InstrItinData<IIC_LdStSTWCX   , [InstrStage<1, [P7_DU1], 0>,
 289                                    InstrStage<1, [P7_DU2], 0>,
 290                                    InstrStage<1, [P7_DU3], 0>,
 291                                    InstrStage<1, [P7_DU4], 0>,
 292                                    InstrStage<1, [P7_LS1, P7_LS2]>],
 293                                   [1, 1, 1]>,
 294   InstrItinData<IIC_BrMCRX      , [InstrStage<1, [P7_DU1], 0>,
 295                                    InstrStage<1, [P7_DU2], 0>,
 296                                    InstrStage<1, [P7_DU3], 0>,
 297                                    InstrStage<1, [P7_DU4], 0>,
 298                                    InstrStage<1, [P7_CRU]>,
 299                                    InstrStage<1, [P7_FX1, P7_FX2]>],
 300                                   [3, 1]>, // mtcr
 301   InstrItinData<IIC_SprMFCR     , [InstrStage<1, [P7_DU1], 0>,
 302                                    InstrStage<1, [P7_CRU]>],
 303                                   [6, 1]>,
 304   InstrItinData<IIC_SprMFCRF    , [InstrStage<1, [P7_DU1], 0>,
 305                                    InstrStage<1, [P7_CRU]>],
 306                                   [3, 1]>,
 307   InstrItinData<IIC_SprMTSPR    , [InstrStage<1, [P7_DU1], 0>,
 308                                    InstrStage<1, [P7_FX1]>],
 309                                   [4, 1]>, // mtctr
 310   InstrItinData<IIC_FPGeneral   , [InstrStage<1, [P7_DU1, P7_DU2,
 311                                                   P7_DU3, P7_DU4], 0>,
 312                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 313                                   [5, 1, 1]>,
 314   InstrItinData<IIC_FPCompare   , [InstrStage<1, [P7_DU1, P7_DU2,
 315                                                   P7_DU3, P7_DU4], 0>,
 316                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 317                                   [8, 1, 1]>,
 318   InstrItinData<IIC_FPDivD      , [InstrStage<1, [P7_DU1, P7_DU2,
 319                                                   P7_DU3, P7_DU4], 0>,
 320                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 321                                   [33, 1, 1]>,
 322   InstrItinData<IIC_FPDivS      , [InstrStage<1, [P7_DU1, P7_DU2,
 323                                                   P7_DU3, P7_DU4], 0>,
 324                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 325                                   [27, 1, 1]>,
 326   InstrItinData<IIC_FPSqrtD     , [InstrStage<1, [P7_DU1, P7_DU2,
 327                                                   P7_DU3, P7_DU4], 0>,
 328                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 329                                   [44, 1, 1]>,
 330   InstrItinData<IIC_FPSqrtS     , [InstrStage<1, [P7_DU1, P7_DU2,
 331                                                   P7_DU3, P7_DU4], 0>,
 332                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 333                                   [32, 1, 1]>,
 334   InstrItinData<IIC_FPFused     , [InstrStage<1, [P7_DU1, P7_DU2,
 335                                                   P7_DU3, P7_DU4], 0>,
 336                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 337                                   [5, 1, 1, 1]>,
 338   InstrItinData<IIC_FPRes       , [InstrStage<1, [P7_DU1, P7_DU2,
 339                                                   P7_DU3, P7_DU4], 0>,
 340                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 341                                   [5, 1, 1]>,
 342   InstrItinData<IIC_VecGeneral  , [InstrStage<1, [P7_DU1], 0>,
 343                                    InstrStage<1, [P7_VS1]>],
 344                                   [2, 1, 1]>,
 345   InstrItinData<IIC_VecVSL      , [InstrStage<1, [P7_DU1], 0>,
 346                                    InstrStage<1, [P7_VS1]>],
 347                                   [2, 1, 1]>,
 348   InstrItinData<IIC_VecVSR      , [InstrStage<1, [P7_DU1], 0>,
 349                                    InstrStage<1, [P7_VS1]>],
 350                                   [2, 1, 1]>,
 351   InstrItinData<IIC_VecFP       , [InstrStage<1, [P7_DU1], 0>,
 352                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 353                                   [6, 1, 1]>,
 354   InstrItinData<IIC_VecFPCompare, [InstrStage<1, [P7_DU1], 0>,
 355                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 356                                   [6, 1, 1]>,
 357   InstrItinData<IIC_VecFPRound  , [InstrStage<1, [P7_DU1], 0>,
 358                                    InstrStage<1, [P7_VS1, P7_VS2]>],
 359                                   [6, 1, 1]>,
 360   InstrItinData<IIC_VecComplex  , [InstrStage<1, [P7_DU1], 0>,
 361                                    InstrStage<1, [P7_VS1]>],
 362                                   [7, 1, 1]>,
 363   InstrItinData<IIC_VecPerm     , [InstrStage<1, [P7_DU1, P7_DU2], 0>,
 364                                    InstrStage<1, [P7_VS2]>],
 365                                   [3, 1, 1]>
 366 ]>;
 367
 368 // ===---------------------------------------------------------------------===//
 369 // P7 machine model for scheduling and other instruction cost heuristics.
 370
 371 def P7Model : SchedMachineModel {
 372   let IssueWidth = 6;  // 4 (non-branch) instructions are dispatched per cycle.
 373                        // Note that the dispatch bundle size is 6 (including
 374                        // branches), but the total internal issue bandwidth per
 375                        // cycle (from all queues) is 8.
 376
 377   let MinLatency = 0;  // Out-of-order dispatch.
 378   let LoadLatency = 3; // Optimistic load latency assuming bypass.
 379                        // This is overriden by OperandCycles if the
 380                        // Itineraries are queried instead.
 381   let MispredictPenalty = 16;
 382
 383   // Try to make sure we have at least 10 dispatch groups in a loop.
 384   let LoopMicroOpBufferSize = 40;
 385
 386   let Itineraries = P7Itineraries;
 387 }
 388