From 6b1207267f01877ff9b351786c902cb2ecd354c0 Mon Sep 17 00:00:00 2001 From: Andrew Trick Date: Wed, 8 Dec 2010 20:04:29 +0000 Subject: [PATCH] Generalize PostRAHazardRecognizer so it can be used in any pass for both forward and backward scheduling. Rename it to ScoreboardHazardRecognizer (Scoreboard is one word). Remove integer division from the scoreboard's critical path. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121274 91177308-0d34-0410-b5e6-96231b3b80d8 --- ...ognizer.h => ScoreboardHazardRecognizer.h} | 49 ++++++++++++------- lib/CodeGen/CMakeLists.txt | 2 +- ...zer.cpp => ScoreboardHazardRecognizer.cpp} | 39 +++++++++------ lib/CodeGen/TargetInstrInfoImpl.cpp | 6 +-- lib/Target/ARM/ARMHazardRecognizer.cpp | 12 +++-- lib/Target/ARM/ARMHazardRecognizer.h | 8 +-- 6 files changed, 71 insertions(+), 45 deletions(-) rename include/llvm/CodeGen/{PostRAHazardRecognizer.h => ScoreboardHazardRecognizer.h} (54%) rename lib/CodeGen/{PostRAHazardRecognizer.cpp => ScoreboardHazardRecognizer.cpp} (81%) diff --git a/include/llvm/CodeGen/PostRAHazardRecognizer.h b/include/llvm/CodeGen/ScoreboardHazardRecognizer.h similarity index 54% rename from include/llvm/CodeGen/PostRAHazardRecognizer.h rename to include/llvm/CodeGen/ScoreboardHazardRecognizer.h index ec8d93deb7b..561bf0fecf6 100644 --- a/include/llvm/CodeGen/PostRAHazardRecognizer.h +++ b/include/llvm/CodeGen/ScoreboardHazardRecognizer.h @@ -1,4 +1,4 @@ -//=- llvm/CodeGen/PostRAHazardRecognizer.h - Scheduling Support -*- C++ -*-=// +//=- llvm/CodeGen/ScoreboardHazardRecognizer.h - Schedule Support -*- C++ -*-=// // // The LLVM Compiler Infrastructure // @@ -7,14 +7,14 @@ // //===----------------------------------------------------------------------===// // -// This file implements the PostRAHazardRecognizer class, which -// implements hazard-avoidance heuristics for scheduling, based on the +// This file defines the ScoreboardHazardRecognizer class, which +// encapsulates hazard-avoidance heuristics for scheduling, based on the // scheduling itineraries specified for the target. // //===----------------------------------------------------------------------===// -#ifndef LLVM_CODEGEN_EXACTHAZARDRECOGNIZER_H -#define LLVM_CODEGEN_EXACTHAZARDRECOGNIZER_H +#ifndef LLVM_CODEGEN_SCOREBOARDHAZARDRECOGNIZER_H +#define LLVM_CODEGEN_SCOREBOARDHAZARDRECOGNIZER_H #include "llvm/CodeGen/ScheduleHazardRecognizer.h" #include "llvm/Support/DataTypes.h" @@ -28,13 +28,17 @@ namespace llvm { class InstrItineraryData; class SUnit; -class PostRAHazardRecognizer : public ScheduleHazardRecognizer { - // ScoreBoard to track function unit usage. ScoreBoard[0] is a +class ScoreboardHazardRecognizer : public ScheduleHazardRecognizer { + // Scoreboard to track function unit usage. Scoreboard[0] is a // mask of the FUs in use in the cycle currently being - // schedule. ScoreBoard[1] is a mask for the next cycle. The - // ScoreBoard is used as a circular buffer with the current cycle + // schedule. Scoreboard[1] is a mask for the next cycle. The + // Scoreboard is used as a circular buffer with the current cycle // indicated by Head. - class ScoreBoard { + // + // Scoreboard always counts cycles in forward execution order. If used by a + // bottom-up scheduler, then the scoreboard cycles are the inverse of the + // scheduler's cycles. + class Scoreboard { unsigned *Data; // The maximum number of cycles monitored by the Scoreboard. This @@ -44,16 +48,18 @@ class PostRAHazardRecognizer : public ScheduleHazardRecognizer { // Indices into the Scoreboard that represent the current cycle. size_t Head; public: - ScoreBoard():Data(NULL), Depth(0), Head(0) { } - ~ScoreBoard() { + Scoreboard():Data(NULL), Depth(0), Head(0) { } + ~Scoreboard() { delete[] Data; } size_t getDepth() const { return Depth; } unsigned& operator[](size_t idx) const { - assert(Depth && "ScoreBoard was not initialized properly!"); + // Depth is expected to be a power-of-2. + assert(Depth && !(Depth & (Depth - 1)) && + "Scoreboard was not initialized properly!"); - return Data[(Head + idx) % Depth]; + return Data[(Head + idx) & (Depth-1)]; } void reset(size_t d = 1) { @@ -67,7 +73,11 @@ class PostRAHazardRecognizer : public ScheduleHazardRecognizer { } void advance() { - Head = (Head + 1) % Depth; + Head = (Head + 1) & (Depth-1); + } + + void recede() { + Head = (Head - 1) & (Depth-1); } // Print the scoreboard. @@ -77,18 +87,19 @@ class PostRAHazardRecognizer : public ScheduleHazardRecognizer { // Itinerary data for the target. const InstrItineraryData *ItinData; - ScoreBoard ReservedScoreboard; - ScoreBoard RequiredScoreboard; + Scoreboard ReservedScoreboard; + Scoreboard RequiredScoreboard; public: - PostRAHazardRecognizer(const InstrItineraryData *ItinData); + ScoreboardHazardRecognizer(const InstrItineraryData *ItinData); virtual HazardType getHazardType(SUnit *SU); virtual void Reset(); virtual void EmitInstruction(SUnit *SU); virtual void AdvanceCycle(); + virtual void RecedeCycle(); }; } -#endif +#endif //!LLVM_CODEGEN_SCOREBOARDHAZARDRECOGNIZER_H diff --git a/lib/CodeGen/CMakeLists.txt b/lib/CodeGen/CMakeLists.txt index b5c1ff7f563..70e044d225b 100644 --- a/lib/CodeGen/CMakeLists.txt +++ b/lib/CodeGen/CMakeLists.txt @@ -53,7 +53,7 @@ add_llvm_library(LLVMCodeGen PHIEliminationUtils.cpp Passes.cpp PeepholeOptimizer.cpp - PostRAHazardRecognizer.cpp + ScoreboardHazardRecognizer.cpp PostRASchedulerList.cpp PreAllocSplitting.cpp ProcessImplicitDefs.cpp diff --git a/lib/CodeGen/PostRAHazardRecognizer.cpp b/lib/CodeGen/ScoreboardHazardRecognizer.cpp similarity index 81% rename from lib/CodeGen/PostRAHazardRecognizer.cpp rename to lib/CodeGen/ScoreboardHazardRecognizer.cpp index 2e3919632f8..d78b5d3ecbd 100644 --- a/lib/CodeGen/PostRAHazardRecognizer.cpp +++ b/lib/CodeGen/ScoreboardHazardRecognizer.cpp @@ -1,4 +1,4 @@ -//===----- PostRAHazardRecognizer.cpp - hazard recognizer -------- ---------===// +//===----- ScoreboardHazardRecognizer.cpp - Scheduler Support -------------===// // // The LLVM Compiler Infrastructure // @@ -7,13 +7,14 @@ // //===----------------------------------------------------------------------===// // -// This implements a hazard recognizer using the instructions itineraries -// defined for the current target. +// This file implements the ScoreboardHazardRecognizer class, which +// encapsultes hazard-avoidance heuristics for scheduling, based on the +// scheduling itineraries specified for the target. // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "post-RA-sched" -#include "llvm/CodeGen/PostRAHazardRecognizer.h" +#define DEBUG_TYPE "sched-hazard" +#include "llvm/CodeGen/ScoreboardHazardRecognizer.h" #include "llvm/CodeGen/ScheduleDAG.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" @@ -22,8 +23,8 @@ using namespace llvm; -PostRAHazardRecognizer:: -PostRAHazardRecognizer(const InstrItineraryData *LItinData) : +ScoreboardHazardRecognizer:: +ScoreboardHazardRecognizer(const InstrItineraryData *LItinData) : ScheduleHazardRecognizer(), ItinData(LItinData) { // Determine the maximum depth of any itinerary. This determines the // depth of the scoreboard. We always make the scoreboard at least 1 @@ -40,23 +41,26 @@ PostRAHazardRecognizer(const InstrItineraryData *LItinData) : for (; IS != E; ++IS) ItinDepth += IS->getCycles(); - ScoreboardDepth = std::max(ScoreboardDepth, ItinDepth); + // Find the next power-of-2 >= ItinDepth + while (ItinDepth > ScoreboardDepth) { + ScoreboardDepth *= 2; + } } } ReservedScoreboard.reset(ScoreboardDepth); RequiredScoreboard.reset(ScoreboardDepth); - DEBUG(dbgs() << "Using post-ra hazard recognizer: ScoreboardDepth = " + DEBUG(dbgs() << "Using scoreboard hazard recognizer: Depth = " << ScoreboardDepth << '\n'); } -void PostRAHazardRecognizer::Reset() { +void ScoreboardHazardRecognizer::Reset() { RequiredScoreboard.reset(); ReservedScoreboard.reset(); } -void PostRAHazardRecognizer::ScoreBoard::dump() const { +void ScoreboardHazardRecognizer::Scoreboard::dump() const { dbgs() << "Scoreboard:\n"; unsigned last = Depth - 1; @@ -73,7 +77,7 @@ void PostRAHazardRecognizer::ScoreBoard::dump() const { } ScheduleHazardRecognizer::HazardType -PostRAHazardRecognizer::getHazardType(SUnit *SU) { +ScoreboardHazardRecognizer::getHazardType(SUnit *SU) { if (!ItinData || ItinData->isEmpty()) return NoHazard; @@ -120,7 +124,7 @@ PostRAHazardRecognizer::getHazardType(SUnit *SU) { return NoHazard; } -void PostRAHazardRecognizer::EmitInstruction(SUnit *SU) { +void ScoreboardHazardRecognizer::EmitInstruction(SUnit *SU) { if (!ItinData || ItinData->isEmpty()) return; @@ -174,7 +178,14 @@ void PostRAHazardRecognizer::EmitInstruction(SUnit *SU) { DEBUG(RequiredScoreboard.dump()); } -void PostRAHazardRecognizer::AdvanceCycle() { +void ScoreboardHazardRecognizer::AdvanceCycle() { ReservedScoreboard[0] = 0; ReservedScoreboard.advance(); RequiredScoreboard[0] = 0; RequiredScoreboard.advance(); } + +void ScoreboardHazardRecognizer::RecedeCycle() { + ReservedScoreboard[ReservedScoreboard.getDepth()-1] = 0; + ReservedScoreboard.recede(); + RequiredScoreboard[RequiredScoreboard.getDepth()-1] = 0; + RequiredScoreboard.recede(); +} diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp index cb2292d62be..baad14c5c76 100644 --- a/lib/CodeGen/TargetInstrInfoImpl.cpp +++ b/lib/CodeGen/TargetInstrInfoImpl.cpp @@ -22,7 +22,7 @@ #include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineMemOperand.h" #include "llvm/CodeGen/MachineRegisterInfo.h" -#include "llvm/CodeGen/PostRAHazardRecognizer.h" +#include "llvm/CodeGen/ScoreboardHazardRecognizer.h" #include "llvm/CodeGen/PseudoSourceValue.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" @@ -135,7 +135,7 @@ bool TargetInstrInfoImpl::PredicateInstruction(MachineInstr *MI, const TargetInstrDesc &TID = MI->getDesc(); if (!TID.isPredicable()) return false; - + for (unsigned j = 0, i = 0, e = MI->getNumOperands(); i != e; ++i) { if (TID.OpInfo[i].isPredicate()) { MachineOperand &MO = MI->getOperand(i); @@ -417,5 +417,5 @@ bool TargetInstrInfoImpl::isSchedulingBoundary(const MachineInstr *MI, // Default implementation of CreateTargetPostRAHazardRecognizer. ScheduleHazardRecognizer *TargetInstrInfoImpl:: CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II) const { - return (ScheduleHazardRecognizer *)new PostRAHazardRecognizer(II); + return (ScheduleHazardRecognizer *)new ScoreboardHazardRecognizer(II); } diff --git a/lib/Target/ARM/ARMHazardRecognizer.cpp b/lib/Target/ARM/ARMHazardRecognizer.cpp index 317934faec5..b8d385b6e3d 100644 --- a/lib/Target/ARM/ARMHazardRecognizer.cpp +++ b/lib/Target/ARM/ARMHazardRecognizer.cpp @@ -68,14 +68,14 @@ ARMHazardRecognizer::getHazardType(SUnit *SU) { } } - return PostRAHazardRecognizer::getHazardType(SU); + return ScoreboardHazardRecognizer::getHazardType(SU); } void ARMHazardRecognizer::Reset() { LastMI = 0; Stalls = 0; ITBlockSize = 0; - PostRAHazardRecognizer::Reset(); + ScoreboardHazardRecognizer::Reset(); } void ARMHazardRecognizer::EmitInstruction(SUnit *SU) { @@ -103,12 +103,16 @@ void ARMHazardRecognizer::EmitInstruction(SUnit *SU) { Stalls = 0; } - PostRAHazardRecognizer::EmitInstruction(SU); + ScoreboardHazardRecognizer::EmitInstruction(SU); } void ARMHazardRecognizer::AdvanceCycle() { if (Stalls && --Stalls == 0) // Stalled for 4 cycles but still can't schedule any other instructions. LastMI = 0; - PostRAHazardRecognizer::AdvanceCycle(); + ScoreboardHazardRecognizer::AdvanceCycle(); +} + +void ARMHazardRecognizer::RecedeCycle() { + llvm_unreachable("reverse ARM hazard checking unsupported"); } diff --git a/lib/Target/ARM/ARMHazardRecognizer.h b/lib/Target/ARM/ARMHazardRecognizer.h index d1919d8cf49..9473bc52072 100644 --- a/lib/Target/ARM/ARMHazardRecognizer.h +++ b/lib/Target/ARM/ARMHazardRecognizer.h @@ -14,7 +14,7 @@ #ifndef ARMHAZARDRECOGNIZER_H #define ARMHAZARDRECOGNIZER_H -#include "llvm/CodeGen/PostRAHazardRecognizer.h" +#include "llvm/CodeGen/ScoreboardHazardRecognizer.h" namespace llvm { @@ -23,7 +23,7 @@ class ARMBaseRegisterInfo; class ARMSubtarget; class MachineInstr; -class ARMHazardRecognizer : public PostRAHazardRecognizer { +class ARMHazardRecognizer : public ScoreboardHazardRecognizer { const ARMBaseInstrInfo &TII; const ARMBaseRegisterInfo &TRI; const ARMSubtarget &STI; @@ -38,16 +38,16 @@ public: const ARMBaseInstrInfo &tii, const ARMBaseRegisterInfo &tri, const ARMSubtarget &sti) : - PostRAHazardRecognizer(ItinData), TII(tii), TRI(tri), STI(sti), + ScoreboardHazardRecognizer(ItinData), TII(tii), TRI(tri), STI(sti), LastMI(0), ITBlockSize(0) {} virtual HazardType getHazardType(SUnit *SU); virtual void Reset(); virtual void EmitInstruction(SUnit *SU); virtual void AdvanceCycle(); + virtual void RecedeCycle(); }; - } // end namespace llvm #endif // ARMHAZARDRECOGNIZER_H -- 2.34.1