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Diffstat (limited to 'lib/Target/X86/X86SchedSandyBridge.td')
-rw-r--r-- | lib/Target/X86/X86SchedSandyBridge.td | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/lib/Target/X86/X86SchedSandyBridge.td b/lib/Target/X86/X86SchedSandyBridge.td new file mode 100644 index 0000000000..66d78e4fc4 --- /dev/null +++ b/lib/Target/X86/X86SchedSandyBridge.td @@ -0,0 +1,122 @@ +//=- X86SchedSandyBridge.td - X86 Sandy Bridge Scheduling ----*- tablegen -*-=// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines the machine model for Sandy Bridge to support instruction +// scheduling and other instruction cost heuristics. +// +//===----------------------------------------------------------------------===// + +def SandyBridgeModel : SchedMachineModel { + // All x86 instructions are modeled as a single micro-op, and SB can decode 4 + // instructions per cycle. + // FIXME: Identify instructions that aren't a single fused micro-op. + let IssueWidth = 4; + let MinLatency = 0; // 0 = Out-of-order execution. + let LoadLatency = 4; + let ILPWindow = 30; + let MispredictPenalty = 16; +} + +let SchedModel = SandyBridgeModel in { + +// Sandy Bridge can issue micro-ops to 6 different ports in one cycle. + +// Ports 0, 1, and 5 handle all computation. +def SBPort0 : ProcResource<1>; +def SBPort1 : ProcResource<1>; +def SBPort5 : ProcResource<1>; + +// Ports 2 and 3 are identical. They handle loads and the address half of +// stores. +def SBPort23 : ProcResource<2>; + +// Port 4 gets the data half of stores. Store data can be available later than +// the store address, but since we don't model the latency of stores, we can +// ignore that. +def SBPort4 : ProcResource<1>; + +// Many micro-ops are capable of issuing on multiple ports. +def SBPort05 : ProcResGroup<[SBPort0, SBPort5]>; +def SBPort15 : ProcResGroup<[SBPort1, SBPort5]>; +def SBPort015 : ProcResGroup<[SBPort0, SBPort1, SBPort5]>; + +// Integer division issued on port 0, but uses the non-pipelined divider. +def SBDivider : ProcResource<1> { let Buffered = 0; } + +// Loads are 4 cycles, so ReadAfterLd registers needn't be available until 4 +// cycles after the memory operand. +def : ReadAdvance<ReadAfterLd, 4>; + +// Many SchedWrites are defined in pairs with and without a folded load. +// Instructions with folded loads are usually micro-fused, so they only appear +// as two micro-ops when queued in the reservation station. +// This multiclass defines the resource usage for variants with and without +// folded loads. +multiclass SBWriteResPair<X86FoldableSchedWrite SchedRW, + ProcResourceKind ExePort, + int Lat> { + // Register variant is using a single cycle on ExePort. + def : WriteRes<SchedRW, [ExePort]> { let Latency = Lat; } + + // Memory variant also uses a cycle on port 2/3 and adds 4 cycles to the + // latency. + def : WriteRes<SchedRW.Folded, [SBPort23, ExePort]> { + let Latency = !add(Lat, 4); + } +} + +// A folded store needs a cycle on port 4 for the store data, but it does not +// need an extra port 2/3 cycle to recompute the address. +def : WriteRes<WriteRMW, [SBPort4]>; + +def : WriteRes<WriteStore, [SBPort23, SBPort4]>; +def : WriteRes<WriteLoad, [SBPort23]> { let Latency = 4; } +def : WriteRes<WriteMove, [SBPort015]>; +def : WriteRes<WriteZero, []>; + +defm : SBWriteResPair<WriteALU, SBPort015, 1>; +defm : SBWriteResPair<WriteIMul, SBPort1, 3>; +defm : SBWriteResPair<WriteShift, SBPort05, 1>; +defm : SBWriteResPair<WriteJump, SBPort5, 1>; + +// This is for simple LEAs with one or two input operands. +// The complex ones can only execute on port 1, and they require two cycles on +// the port to read all inputs. We don't model that. +def : WriteRes<WriteLEA, [SBPort15]>; + +// This is quite rough, latency depends on the dividend. +def : WriteRes<WriteIDiv, [SBPort0, SBDivider]> { + let Latency = 25; + let ResourceCycles = [1, 10]; +} +def : WriteRes<WriteIDivLd, [SBPort23, SBPort0, SBDivider]> { + let Latency = 29; + let ResourceCycles = [1, 1, 10]; +} + +// Scalar and vector floating point. +defm : SBWriteResPair<WriteFAdd, SBPort1, 3>; +defm : SBWriteResPair<WriteFMul, SBPort0, 5>; +defm : SBWriteResPair<WriteFDiv, SBPort0, 12>; // 10-14 cycles. +defm : SBWriteResPair<WriteFRcp, SBPort0, 5>; +defm : SBWriteResPair<WriteFSqrt, SBPort0, 15>; +defm : SBWriteResPair<WriteCvtF2I, SBPort1, 3>; +defm : SBWriteResPair<WriteCvtI2F, SBPort1, 4>; +defm : SBWriteResPair<WriteCvtF2F, SBPort1, 3>; + +// Vector integer operations. +defm : SBWriteResPair<WriteVecShift, SBPort05, 1>; +defm : SBWriteResPair<WriteVecLogic, SBPort015, 1>; +defm : SBWriteResPair<WriteVecALU, SBPort15, 1>; +defm : SBWriteResPair<WriteVecIMul, SBPort0, 5>; +defm : SBWriteResPair<WriteShuffle, SBPort15, 1>; + +def : WriteRes<WriteSystem, [SBPort015]> { let Latency = 100; } +def : WriteRes<WriteMicrocoded, [SBPort015]> { let Latency = 100; } +} // SchedModel |