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1//=- ARMScheduleM7.td - ARM Cortex-M7 Scheduling Definitions -*- tablegen -*-=//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file defines the SchedRead/Write data for the ARM Cortex-M7 processor.10//11//===----------------------------------------------------------------------===//12 13def CortexM7Model : SchedMachineModel {14  let IssueWidth = 2;        // Dual issue for most instructions.15  let MicroOpBufferSize = 0; // The Cortex-M7 is in-order.16  let LoadLatency = 2;       // Best case for load-use case.17  let MispredictPenalty = 4; // Mispredict cost for forward branches is 6,18                             // but 4 works better19  let CompleteModel = 0;20}21 22let SchedModel = CortexM7Model in {23 24//===--------------------------------------------------------------------===//25// The Cortex-M7 has two ALU, two LOAD, a STORE, a MAC, a BRANCH and a VFP26// pipe. The stages relevant to scheduling are as follows:27//28//   EX1: address generation  shifts29//   EX2: fast load data      ALUs                  FP operation30//   EX3: slow load data      integer writeback     FP operation31//   EX4: store data                                FP writeback32//33// There are shifters in both EX1 and EX2, and some instructions can be34// flexibly allocated between them.  EX2 is used as the "zero" point35// for scheduling, so simple ALU operations executing in EX2 will have36// ReadAdvance<0> (the default) for their source operands and Latency = 1.37 38def M7UnitLoadL  : ProcResource<1> { let BufferSize = 0; }39def M7UnitLoadH  : ProcResource<1> { let BufferSize = 0; }40def M7UnitLoad   : ProcResGroup<[M7UnitLoadL,M7UnitLoadH]> { let BufferSize = 0; }41def M7UnitStore  : ProcResource<1> { let BufferSize = 0; }42def M7UnitALU    : ProcResource<2>;43def M7UnitShift1 : ProcResource<1> { let BufferSize = 0; }44def M7UnitShift2 : ProcResource<1> { let BufferSize = 0; }45def M7UnitMAC    : ProcResource<1> { let BufferSize = 0; }46def M7UnitBranch : ProcResource<1> { let BufferSize = 0; }47def M7UnitVFP    : ProcResource<1> { let BufferSize = 0; }48def M7UnitVPortL : ProcResource<1> { let BufferSize = 0; }49def M7UnitVPortH : ProcResource<1> { let BufferSize = 0; }50def M7UnitVPort  : ProcResGroup<[M7UnitVPortL,M7UnitVPortH]> { let BufferSize = 0; }51def M7UnitSIMD   : ProcResource<1> { let BufferSize = 0; }52 53//===---------------------------------------------------------------------===//54// Subtarget-specific SchedWrite types with map ProcResources and set latency.55 56def : WriteRes<WriteALU, [M7UnitALU]> { let Latency = 1; }57 58// Basic ALU with shifts.59let Latency = 1 in {60  def : WriteRes<WriteALUsi,  [M7UnitALU, M7UnitShift1]>;61  def : WriteRes<WriteALUsr,  [M7UnitALU, M7UnitShift1]>;62  def : WriteRes<WriteALUSsr, [M7UnitALU, M7UnitShift1]>;63}64 65// Compares.66def : WriteRes<WriteCMP,   [M7UnitALU]> { let Latency = 1; }67def : WriteRes<WriteCMPsi, [M7UnitALU, M7UnitShift1]> { let Latency = 2; }68def : WriteRes<WriteCMPsr, [M7UnitALU, M7UnitShift1]> { let Latency = 2; }69 70// Multiplies.71let Latency = 2 in {72  def : WriteRes<WriteMUL16,   [M7UnitMAC]>;73  def : WriteRes<WriteMUL32,   [M7UnitMAC]>;74  def : WriteRes<WriteMUL64Lo, [M7UnitMAC]>;75  def : WriteRes<WriteMUL64Hi, []> { let NumMicroOps = 0; }76}77 78// Multiply-accumulates.79let Latency = 2 in {80  def : WriteRes<WriteMAC16,   [M7UnitMAC]>;81  def : WriteRes<WriteMAC32,   [M7UnitMAC]>;82  def : WriteRes<WriteMAC64Lo, [M7UnitMAC]> { let Latency = 2; }83  def : WriteRes<WriteMAC64Hi, []> { let NumMicroOps = 0; }84}85 86// Divisions.87// These cannot be dual-issued with any instructions.88def : WriteRes<WriteDIV, [M7UnitALU]> {89  let Latency = 7;90  let SingleIssue = 1;91}92 93// Loads/Stores.94def : WriteRes<WriteLd,    [M7UnitLoad]> { let Latency = 1; }95def : WriteRes<WritePreLd, [M7UnitLoad]> { let Latency = 2; }96def : WriteRes<WriteST,    [M7UnitStore]> { let Latency = 2; }97 98// Branches.99def : WriteRes<WriteBr,    [M7UnitBranch]> { let Latency = 2; }100def : WriteRes<WriteBrL,   [M7UnitBranch]> { let Latency = 2; }101def : WriteRes<WriteBrTbl, [M7UnitBranch]> { let Latency = 2; }102 103// Noop.104def : WriteRes<WriteNoop, []> { let Latency = 0; }105 106//===---------------------------------------------------------------------===//107// Sched definitions for floating-point instructions108//109// Floating point conversions.110def : WriteRes<WriteFPCVT, [M7UnitVFP, M7UnitVPort]> { let Latency = 3; }111def : WriteRes<WriteFPMOV, [M7UnitVPort]>            { let Latency = 3; }112def M7WriteFPMOV64 : SchedWriteRes<[M7UnitVPortL, M7UnitVPortH]> {113  let Latency = 3;114}115 116// The FP pipeline has a latency of 3 cycles.117// ALU operations (32/64-bit).  These go down the FP pipeline.118def : WriteRes<WriteFPALU32, [M7UnitVFP, M7UnitVPort]>  { let Latency = 3; }119def : WriteRes<WriteFPALU64, [M7UnitVFP, M7UnitVPortL, M7UnitVPortH]> {120  let Latency = 4;121  let BeginGroup = 1;122}123 124// Multiplication125def : WriteRes<WriteFPMUL32, [M7UnitVFP, M7UnitVPort]> { let Latency = 3; }126def : WriteRes<WriteFPMUL64, [M7UnitVFP, M7UnitVPortL, M7UnitVPortH]> {127  let Latency = 7;128  let BeginGroup = 1;129}130 131// Multiply-accumulate.  FPMAC goes down the FP Pipeline.132def : WriteRes<WriteFPMAC32, [M7UnitVFP, M7UnitVPort]> { let Latency = 6; }133def : WriteRes<WriteFPMAC64, [M7UnitVFP, M7UnitVPortL, M7UnitVPortH]> {134  let Latency = 11;135  let BeginGroup = 1;136}137 138// Division.   Effective scheduling latency is 3, though real latency is larger139def : WriteRes<WriteFPDIV32, [M7UnitVFP, M7UnitVPort]>  { let Latency = 16; }140def : WriteRes<WriteFPDIV64, [M7UnitVFP, M7UnitVPortL, M7UnitVPortH]> {141  let Latency = 30;142  let BeginGroup = 1;143}144 145// Square-root.  Effective scheduling latency is 3; real latency is larger146def : WriteRes<WriteFPSQRT32, [M7UnitVFP, M7UnitVPort]> { let Latency = 16; }147def : WriteRes<WriteFPSQRT64, [M7UnitVFP, M7UnitVPortL, M7UnitVPortH]> {148  let Latency = 30;149  let BeginGroup = 1;150}151 152def M7WriteShift2   : SchedWriteRes<[M7UnitALU, M7UnitShift2]> {}153 154// Not used for M7, but needing definitions anyway155def : WriteRes<WriteVLD1, []>;156def : WriteRes<WriteVLD2, []>;157def : WriteRes<WriteVLD3, []>;158def : WriteRes<WriteVLD4, []>;159def : WriteRes<WriteVST1, []>;160def : WriteRes<WriteVST2, []>;161def : WriteRes<WriteVST3, []>;162def : WriteRes<WriteVST4, []>;163 164def M7SingleIssue : SchedWriteRes<[]> {165  let SingleIssue = 1;166  let NumMicroOps = 0;167}168def M7Slot0Only   : SchedWriteRes<[]> {169  let BeginGroup = 1;170  let NumMicroOps = 0;171}172 173// What pipeline stage operands need to be ready for depending on174// where they come from.175def : ReadAdvance<ReadALUsr, 0>;176def : ReadAdvance<ReadMUL, 0>;177def : ReadAdvance<ReadMAC, 1>;178def : ReadAdvance<ReadALU, 0>;179def : ReadAdvance<ReadFPMUL, 0>;180def : ReadAdvance<ReadFPMAC, 3>;181def M7Read_ISS : SchedReadAdvance<-1>;     // operands needed at EX1182def M7Read_EX2   : SchedReadAdvance<1>;    // operands needed at EX3183def M7Read_EX3   : SchedReadAdvance<2>;    // operands needed at EX4184 185// Non general purpose instructions may not be dual issued. These186// use both issue units.187def M7NonGeneralPurpose : SchedWriteRes<[]> {188  // Assume that these will go down the main ALU pipeline.189  // In reality, many look likely to stall the whole pipeline.190  let Latency = 3;191  let SingleIssue = 1;192}193 194// List the non general purpose instructions.195def : InstRW<[M7NonGeneralPurpose], (instregex "t2MRS", "tSVC", "tBKPT",196                                     "t2MSR", "t2DMB", "t2DSB", "t2ISB",197                                     "t2HVC", "t2SMC", "t2UDF", "ERET",198                                     "tHINT", "t2HINT", "t2CLREX", "BUNDLE")>;199 200//===---------------------------------------------------------------------===//201// Sched definitions for load/store202//203// Mark whether the loads/stores must be single-issue204// Address operands are needed earlier205// Data operands are needed later206 207def M7BaseUpdate : SchedWriteRes<[]> {208    let Latency = 0; // Update is bypassable out of EX1209    let NumMicroOps = 0;210}211def M7LoadLatency1 : SchedWriteRes<[]> {212    let Latency = 1;213    let NumMicroOps = 0;214}215def M7SlowLoad : SchedWriteRes<[M7UnitLoad]>            { let Latency = 2; }216 217// Byte and half-word loads should have greater latency than other loads.218// So should load exclusive.219 220def : InstRW<[M7SlowLoad],221      (instregex "t2LDR(B|H|SB|SH)pc")>;222def : InstRW<[M7SlowLoad, M7Read_ISS],223      (instregex "t2LDR(B|H|SB|SH)T", "t2LDR(B|H|SB|SH)i",224                 "tLDR(B|H)i")>;225def : InstRW<[M7SlowLoad, M7Read_ISS, M7Read_ISS],226      (instregex "t2LDR(B|H|SB|SH)s", "tLDR(B|H)r", "tLDR(SB|SH)")>;227def : InstRW<[M7SlowLoad, M7BaseUpdate, M7Read_ISS],228      (instregex "t2LDR(B|H|SB|SH)_(POST|PRE)")>;229 230// Exclusive loads/stores cannot be dual-issued231def : InstRW<[WriteLd, M7Slot0Only, M7Read_ISS],232      (instregex "t2LDREX$")>;233def : InstRW<[M7SlowLoad, M7Slot0Only, M7Read_ISS],234      (instregex "t2LDREX(B|H)")>;235def : InstRW<[WriteST, M7SingleIssue, M7Read_EX2, M7Read_ISS],236      (instregex "t2STREX(B|H)?$")>;237 238// Load/store multiples cannot be dual-issued.  Note that default scheduling239// occurs around read/write times of individual registers in the list; read240// time for STM cannot be overridden because it is a variadic source operand.241 242def : InstRW<[WriteLd, M7SingleIssue, M7Read_ISS],243      (instregex "(t|t2)LDM(DB|IA)$")>;244def : InstRW<[WriteST, M7SingleIssue, M7Read_ISS],245      (instregex "(t|t2)STM(DB|IA)$")>;246def : InstRW<[M7BaseUpdate, WriteLd, M7SingleIssue, M7Read_ISS],247      (instregex "(t|t2)LDM(DB|IA)_UPD$", "tPOP")>;248def : InstRW<[M7BaseUpdate, WriteST, M7SingleIssue, M7Read_ISS],249      (instregex "(t|t2)STM(DB|IA)_UPD$", "tPUSH")>;250 251// Load/store doubles cannot be dual-issued.252 253def : InstRW<[M7BaseUpdate, WriteST, M7SingleIssue,254              M7Read_EX2, M7Read_EX2, M7Read_ISS],255      (instregex "t2STRD_(PRE|POST)")>;256def : InstRW<[WriteST, M7SingleIssue, M7Read_EX2, M7Read_EX2, M7Read_ISS],257      (instregex "t2STRDi")>;258def : InstRW<[WriteLd, M7LoadLatency1, M7SingleIssue, M7BaseUpdate, M7Read_ISS],259      (instregex "t2LDRD_(PRE|POST)")>;260def : InstRW<[WriteLd, M7LoadLatency1, M7SingleIssue, M7Read_ISS],261      (instregex "t2LDRDi")>;262 263// Word load / preload264def : InstRW<[WriteLd],265      (instregex "t2LDRpc", "t2PL[DI]pci", "tLDRpci")>;266def : InstRW<[WriteLd, M7Read_ISS],267      (instregex "t2LDR(i|T)", "t2PL[DI](W)?i", "tLDRi", "tLDRspi")>;268def : InstRW<[WriteLd, M7Read_ISS, M7Read_ISS],269      (instregex "t2LDRs", "t2PL[DI](w)?s", "tLDRr")>;270def : InstRW<[WriteLd, M7BaseUpdate, M7Read_ISS],271      (instregex "t2LDR_(POST|PRE)")>;272 273// Stores274def : InstRW<[M7BaseUpdate, WriteST, M7Read_EX2, M7Read_ISS],275      (instregex "t2STR(B|H)?_(POST|PRE)")>;276def : InstRW<[WriteST, M7Read_EX2, M7Read_ISS, M7Read_ISS],277      (instregex "t2STR(B|H)?s$", "tSTR(B|H)?r$")>;278def : InstRW<[WriteST, M7Read_EX2, M7Read_ISS],279      (instregex "t2STR(B|H)?(i|T)", "tSTR(B|H)?i$", "tSTRspi")>;280 281// TBB/TBH - single-issue only; takes two cycles to issue282 283def M7TableLoad : SchedWriteRes<[M7UnitLoad]> {284  let NumMicroOps = 2;285  let SingleIssue = 1;286}287 288def : InstRW<[M7TableLoad, M7Read_ISS, M7Read_ISS], (instregex "t2TB")>;289 290// VFP loads and stores291 292def M7LoadSP  : SchedWriteRes<[M7UnitLoad, M7UnitVPort]> { let Latency = 1; }293def M7LoadDP  : SchedWriteRes<[M7UnitLoadL, M7UnitLoadH, M7UnitVPortL, M7UnitVPortH]> {294  let Latency = 2;295  let SingleIssue = 1;296}297def M7StoreSP : SchedWriteRes<[M7UnitStore, M7UnitVPort]>;298def M7StoreDP : SchedWriteRes<[M7UnitStore, M7UnitVPortL, M7UnitVPortH]> {299  let SingleIssue = 1;300}301 302def : InstRW<[M7LoadSP, M7Read_ISS],                 (instregex "VLDR(S|H)$")>;303def : InstRW<[M7LoadDP, M7Read_ISS],                 (instregex "VLDRD$")>;304def : InstRW<[M7StoreSP, M7Read_EX3, M7Read_ISS],    (instregex "VSTR(S|H)$")>;305def : InstRW<[M7StoreDP, M7Read_EX3, M7Read_ISS],    (instregex "VSTRD$")>;306 307// Load/store multiples cannot be dual-issued.308 309def : InstRW<[WriteLd, M7SingleIssue, M7Read_ISS],310      (instregex "VLDM(S|D|Q)(DB|IA)$")>;311def : InstRW<[WriteST, M7SingleIssue, M7Read_ISS],312      (instregex "VSTM(S|D|Q)(DB|IA)$")>;313def : InstRW<[M7BaseUpdate, WriteLd, M7SingleIssue, M7Read_ISS],314      (instregex "VLDM(S|D|Q)(DB|IA)_UPD$")>;315def : InstRW<[M7BaseUpdate, WriteST, M7SingleIssue, M7Read_ISS],316      (instregex "VSTM(S|D|Q)(DB|IA)_UPD$")>;317 318//===---------------------------------------------------------------------===//319// Sched definitions for ALU320//321 322// Shifted ALU operands are read a cycle early.323def M7Ex1ReadNoFastBypass : SchedReadAdvance<-1, [WriteLd, M7LoadLatency1]>;324 325def : InstRW<[WriteALUsi, M7Ex1ReadNoFastBypass, M7Read_ISS],326             (instregex "t2(ADC|ADDS|ADD|BIC|EOR|ORN|ORR|RSBS|RSB|SBC|SUBS)rs$",327                        "t2(SUB|CMP|CMNz|TEQ|TST)rs$",328                        "t2(A|L)SRs1$")>;329def : InstRW<[WriteALUsi, M7Read_ISS],330             (instregex "t2MVNs")>;331 332// Treat pure shift operations (except for RRX) as if they used the EX1333// shifter but have timing as if they used the EX2 shifter as they usually334// can choose the EX2 shifter when needed.  Will miss a few dual-issue cases,335// but the results prove to be better than trying to get them exact.336 337def : InstRW<[M7WriteShift2, M7Read_ISS], (instregex "t2RRX$")>;338def : InstRW<[WriteALUsi], (instregex "(t|t2)(LSL|LSR|ASR|ROR)r", "tROR")>;339 340// Instructions that use the shifter, but have normal timing.341 342def : InstRW<[WriteALUsi,M7Slot0Only], (instregex "t2(BFC|BFI)$")>;343 344// Instructions which are slot zero only but otherwise normal.345 346def : InstRW<[WriteALU, M7Slot0Only], (instregex "t2CLZ")>;347 348// MAC operations that don't have SchedRW set.349 350def : InstRW<[WriteMAC32, ReadMUL, ReadMUL, ReadMAC], (instregex "t2SML[AS]D")>;351 352// Divides are special because they stall for their latency, and so look like a353// single-cycle as far as scheduling opportunities go.  By putting WriteALU354// first, we make the operand latency 1, but keep the instruction latency 7.355 356def : InstRW<[WriteALU, WriteDIV], (instregex "t2(S|U)DIV")>;357 358// DSP extension operations359 360def M7WriteSIMD1   : SchedWriteRes<[M7UnitSIMD, M7UnitALU]> {361  let Latency = 1;362  let BeginGroup = 1;363}364def M7WriteSIMD2   : SchedWriteRes<[M7UnitSIMD, M7UnitALU]> {365  let Latency = 2;366  let BeginGroup = 1;367}368def M7WriteShSIMD1 : SchedWriteRes<[M7UnitSIMD, M7UnitALU, M7UnitShift1]> {369  let Latency = 1;370  let BeginGroup = 1;371}372def M7WriteShSIMD0 : SchedWriteRes<[M7UnitSIMD, M7UnitALU, M7UnitShift1]> {373  let Latency = 0;      // Bypassable out of EX1374  let BeginGroup = 1;375}376def M7WriteShSIMD2 : SchedWriteRes<[M7UnitSIMD, M7UnitALU, M7UnitShift1]> {377  let Latency = 2;378  let BeginGroup = 1;379}380 381def : InstRW<[M7WriteShSIMD2, M7Read_ISS],382             (instregex "t2(S|U)SAT")>;383def : InstRW<[M7WriteSIMD1, ReadALU],384             (instregex "(t|t2)(S|U)XT(B|H)")>;385def : InstRW<[M7WriteSIMD1, ReadALU, ReadALU],386             (instregex "t2(S|SH|U|UH)(ADD16|ADD8|ASX|SAX|SUB16|SUB8)",387                        "t2SEL")>;388def : InstRW<[M7WriteSIMD2, ReadALU, ReadALU],389             (instregex "t2(Q|UQ)(ADD|ASX|SAX|SUB)", "t2USAD8")>;390def : InstRW<[M7WriteShSIMD2, M7Read_ISS, M7Read_ISS],391             (instregex "t2QD(ADD|SUB)")>;392def : InstRW<[M7WriteShSIMD0, M7Read_ISS],393             (instregex "t2(RBIT|REV)", "tREV")>;394def : InstRW<[M7WriteShSIMD1, M7Read_ISS],395             (instregex "t2(SBFX|UBFX)")>;396def : InstRW<[M7WriteShSIMD1, ReadALU, M7Read_ISS],397             (instregex "t2PKH(BT|TB)", "t2(S|U)XTA")>;398def : InstRW<[M7WriteSIMD2, ReadALU, ReadALU, M7Read_EX2],399             (instregex "t2USADA8")>;400 401// MSR/MRS402def : InstRW<[M7NonGeneralPurpose], (instregex "MSR", "MRS")>;403 404//===---------------------------------------------------------------------===//405// Sched definitions for FP operations406//407 408// Effective scheduling latency is really 3 for nearly all FP operations,409// even if their true latency is higher.410def M7WriteVFPLatOverride : SchedWriteRes<[]> {411  let Latency = 3;412  let NumMicroOps = 0;413}414def M7WriteVFPExtraVPort  : SchedWriteRes<[M7UnitVPort]> {415  let Latency = 3;416  let NumMicroOps = 0;417}418 419// Instructions which are missing default schedules.420def : InstRW<[WriteFPALU32],421             (instregex "V(ABS|CVT.*|NEG|FP_VMAX.*|FP_VMIN.*|RINT.*)S$")>;422def : InstRW<[M7WriteVFPLatOverride, WriteFPALU64],423             (instregex "V(ABS|CVT.*|NEG|FP_VMAX.*|FP_VMIN.*|RINT.*)D$")>;424 425// VCMP426def M7WriteVCMPS : SchedWriteRes<[M7UnitVFP, M7UnitVPort]> { let Latency = 0; }427def M7WriteVCMPD : SchedWriteRes<[M7UnitVFP, M7UnitVPort, M7UnitVPort]> {428  let Latency = 0;429  let BeginGroup = 1;430}431def : InstRW<[M7WriteVCMPS], (instregex "VCMPS$")>;432def : InstRW<[M7WriteVCMPD], (instregex "VCMPD$")>;433 434    // VMRS/VMSR435def M7VMRS : SchedWriteRes<[M7UnitVFP, M7UnitVPort]> { let SingleIssue = 1; }436def M7VMSR : SchedWriteRes<[M7UnitVFP, M7UnitVPort]> { let SingleIssue = 1; }437def : InstRW<[M7VMRS], (instregex "FMSTAT")>;438def : InstRW<[M7VMSR], (instregex "VMSR")>;439 440// VSEL cannot bypass in its implied $cpsr operand; model as earlier read441def : InstRW<[WriteFPALU32, M7Slot0Only, ReadALU, ReadALU, M7Read_ISS],442             (instregex "VSEL.*S$")>;443def : InstRW<[M7WriteVFPLatOverride, WriteFPALU64, M7Slot0Only,444              ReadALU, ReadALU, M7Read_ISS],445             (instregex "VSEL.*D$")>;446 447// VMOV448def : InstRW<[WriteFPMOV],449             (instregex "VMOV(H|S)$", "FCONST(H|S)")>;450def : InstRW<[WriteFPMOV, M7WriteVFPExtraVPort, M7Slot0Only],451             (instregex "VMOVD$")>;452def : InstRW<[WriteFPMOV, M7WriteVFPExtraVPort, M7Slot0Only],453             (instregex "FCONSTD")>;454def : InstRW<[WriteFPMOV, M7WriteVFPExtraVPort, M7SingleIssue],455             (instregex "VMOV(DRR|RRD|RRS|SRR)")>;456 457// Larger-latency overrides.458 459def : InstRW<[M7WriteVFPLatOverride, WriteFPDIV32],  (instregex "VDIVS")>;460def : InstRW<[M7WriteVFPLatOverride, WriteFPDIV64],  (instregex "VDIVD")>;461def : InstRW<[M7WriteVFPLatOverride, WriteFPSQRT32], (instregex "VSQRTS")>;462def : InstRW<[M7WriteVFPLatOverride, WriteFPSQRT64], (instregex "VSQRTD")>;463def : InstRW<[M7WriteVFPLatOverride, WriteFPMUL64],464             (instregex "V(MUL|NMUL)D")>;465def : InstRW<[M7WriteVFPLatOverride, WriteFPALU64],466             (instregex "V(ADD|SUB)D")>;467 468// Multiply-accumulate.  Chained SP timing is correct; rest need overrides469// Double-precision chained MAC stalls the pipeline behind it for 3 cycles,470// making it appear to have 3 cycle latency for scheduling.471 472def : InstRW<[M7WriteVFPLatOverride, WriteFPMAC64,473              ReadFPMAC, ReadFPMUL, ReadFPMUL],474             (instregex "V(N)?ML(A|S)D$")>;475 476// Single-precision fused MACs look like latency 5 with advance of 2.477 478def M7WriteVFPLatOverride5 : SchedWriteRes<[]> {479  let Latency = 5;480  let NumMicroOps = 0;481}482def M7ReadFPMAC2   : SchedReadAdvance<2>;483 484def : InstRW<[M7WriteVFPLatOverride5, WriteFPMAC32,485              M7ReadFPMAC2, ReadFPMUL, ReadFPMUL],486             (instregex "VF(N)?M(A|S)S$")>;487 488// Double-precision fused MAC stalls the pipeline behind it for 2 cycles, making489// it appear to have 3 cycle latency for scheduling.490 491def : InstRW<[M7WriteVFPLatOverride, WriteFPMAC64,492              ReadFPMAC, ReadFPMUL, ReadFPMUL],493             (instregex "VF(N)?M(A|S)D$")>;494 495}  // SchedModel = CortexM7Model496