R600: Emit CF_ALU and use true kcache register.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178503 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 253 insertions, 0 deletions

diff --git a/lib/Target/R600/R600EmitClauseMarkers.cpp b/lib/Target/R600/R600EmitClauseMarkers.cpp
new file mode 100644
index 0000000000..7c7469a04b
--- /dev/null
+++ b/lib/Target/R600/R600EmitClauseMarkers.cpp
@@ -0,0 +1,253 @@
+//===-- R600EmitClauseMarkers.cpp - Emit CF_ALU ---------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// Add CF_ALU. R600 Alu instructions are grouped in clause which can hold
+/// 128 Alu instructions ; these instructions can access up to 4 prefetched
+/// 4 lines of 16 registers from constant buffers. Such ALU clauses are
+/// initiated by CF_ALU instructions.
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPU.h"
+#include "R600Defines.h"
+#include "R600InstrInfo.h"
+#include "R600MachineFunctionInfo.h"
+#include "R600RegisterInfo.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+
+namespace llvm {
+
+class R600EmitClauseMarkersPass : public MachineFunctionPass {
+
+private:
+  static char ID;
+  const R600InstrInfo *TII;
+
+  unsigned OccupiedDwords(MachineInstr *MI) const {
+    switch (MI->getOpcode()) {
+    case AMDGPU::INTERP_PAIR_XY:
+    case AMDGPU::INTERP_PAIR_ZW:
+    case AMDGPU::INTERP_VEC_LOAD:
+    case AMDGPU::DOT4_eg_pseudo:
+    case AMDGPU::DOT4_r600_pseudo:
+      return 4;
+    case AMDGPU::KILL:
+      return 0;
+    default:
+      break;
+    }
+
+    if(TII->isVector(*MI) ||
+        TII->isCubeOp(MI->getOpcode()) ||
+        TII->isReductionOp(MI->getOpcode()))
+      return 4;
+
+    unsigned NumLiteral = 0;
+    for (MachineInstr::mop_iterator It = MI->operands_begin(),
+        E = MI->operands_end(); It != E; ++It) {
+      MachineOperand &MO = *It;
+      if (MO.isReg() && MO.getReg() == AMDGPU::ALU_LITERAL_X)
+        ++NumLiteral;
+    }
+    return 1 + NumLiteral;
+  }
+
+  bool isALU(const MachineInstr *MI) const {
+    if (MI->getOpcode() == AMDGPU::KILLGT)
+      return false;
+    if (TII->isALUInstr(MI->getOpcode()))
+      return true;
+    if (TII->isVector(*MI) || TII->isCubeOp(MI->getOpcode()))
+      return true;
+    switch (MI->getOpcode()) {
+    case AMDGPU::PRED_X:
+    case AMDGPU::INTERP_PAIR_XY:
+    case AMDGPU::INTERP_PAIR_ZW:
+    case AMDGPU::INTERP_VEC_LOAD:
+    case AMDGPU::COPY:
+    case AMDGPU::DOT4_eg_pseudo:
+    case AMDGPU::DOT4_r600_pseudo:
+      return true;
+    default:
+      return false;
+    }
+  }
+
+  bool IsTrivialInst(MachineInstr *MI) const {
+    switch (MI->getOpcode()) {
+    case AMDGPU::KILL:
+    case AMDGPU::RETURN:
+      return true;
+    default:
+      return false;
+    }
+  }
+
+  // Register Idx, then Const value
+  std::vector<std::pair<unsigned, unsigned> > ExtractConstRead(MachineInstr *MI)
+      const {
+    const R600Operands::Ops OpTable[3][2] = {
+      {R600Operands::SRC0, R600Operands::SRC0_SEL},
+      {R600Operands::SRC1, R600Operands::SRC1_SEL},
+      {R600Operands::SRC2, R600Operands::SRC2_SEL},
+    };
+    std::vector<std::pair<unsigned, unsigned> > Result;
+
+    if (!TII->isALUInstr(MI->getOpcode()))
+      return Result;
+    for (unsigned j = 0; j < 3; j++) {
+      int SrcIdx = TII->getOperandIdx(MI->getOpcode(), OpTable[j][0]);
+      if (SrcIdx < 0)
+        break;
+      if (MI->getOperand(SrcIdx).getReg() == AMDGPU::ALU_CONST) {
+        unsigned Const = MI->getOperand(
+            TII->getOperandIdx(MI->getOpcode(), OpTable[j][1])).getImm();
+        Result.push_back(std::pair<unsigned, unsigned>(SrcIdx, Const));
+      }
+    }
+    return Result;
+  }
+
+  std::pair<unsigned, unsigned> getAccessedBankLine(unsigned Sel) const {
+    // Sel is (512 + (kc_bank << 12) + ConstIndex) << 2
+    // (See also R600ISelLowering.cpp)
+    // ConstIndex value is in [0, 4095];
+    return std::pair<unsigned, unsigned>(
+        ((Sel >> 2) - 512) >> 12, // KC_BANK
+        // Line Number of ConstIndex
+        // A line contains 16 constant registers however KCX bank can lock
+        // two line at the same time ; thus we want to get an even line number.
+        // Line number can be retrieved with (>>4), using (>>5) <<1 generates
+        // an even number.
+        ((((Sel >> 2) - 512) & 4095) >> 5) << 1);
+  }
+
+  bool SubstituteKCacheBank(MachineInstr *MI,
+      std::vector<std::pair<unsigned, unsigned> > &CachedConsts) const {
+    std::vector<std::pair<unsigned, unsigned> > UsedKCache;
+    std::vector<std::pair<unsigned, unsigned> > Consts = ExtractConstRead(MI);
+    assert(TII->isALUInstr(MI->getOpcode()) && "Can't assign Const");
+    for (unsigned i = 0, n = Consts.size(); i < n; ++i) {
+      unsigned Sel = Consts[i].second;
+      unsigned Chan = Sel & 3, Index = ((Sel >> 2) - 512) & 31;
+      unsigned KCacheIndex = Index * 4 + Chan;
+      const std::pair<unsigned, unsigned> &BankLine = getAccessedBankLine(Sel);
+      if (CachedConsts.empty()) {
+        CachedConsts.push_back(BankLine);
+        UsedKCache.push_back(std::pair<unsigned, unsigned>(0, KCacheIndex));
+        continue;
+      }
+      if (CachedConsts[0] == BankLine) {
+        UsedKCache.push_back(std::pair<unsigned, unsigned>(0, KCacheIndex));
+        continue;
+      }
+      if (CachedConsts.size() == 1) {
+        CachedConsts.push_back(BankLine);
+        UsedKCache.push_back(std::pair<unsigned, unsigned>(1, KCacheIndex));
+        continue;
+      }
+      if (CachedConsts[1] == BankLine) {
+        UsedKCache.push_back(std::pair<unsigned, unsigned>(1, KCacheIndex));
+        continue;
+      }
+      return false;
+    }
+
+    for (unsigned i = 0, n = Consts.size(); i < n; ++i) {
+      switch(UsedKCache[i].first) {
+      case 0:
+        MI->getOperand(Consts[i].first).setReg(
+            AMDGPU::R600_KC0RegClass.getRegister(UsedKCache[i].second));
+        break;
+      case 1:
+        MI->getOperand(Consts[i].first).setReg(
+            AMDGPU::R600_KC1RegClass.getRegister(UsedKCache[i].second));
+        break;
+      default:
+        llvm_unreachable("Wrong Cache Line");
+      }
+    }
+    return true;
+  }
+
+  MachineBasicBlock::iterator
+  MakeALUClause(MachineBasicBlock &MBB, MachineBasicBlock::iterator I) const {
+    MachineBasicBlock::iterator ClauseHead = I;
+    std::vector<std::pair<unsigned, unsigned> > KCacheBanks;
+    bool PushBeforeModifier = false;
+    unsigned AluInstCount = 0;
+    for (MachineBasicBlock::iterator E = MBB.end(); I != E; ++I) {
+      if (IsTrivialInst(I))
+        continue;
+      if (!isALU(I))
+        break;
+      if (I->getOpcode() == AMDGPU::PRED_X) {
+        if (TII->getFlagOp(I).getImm() & MO_FLAG_PUSH)
+          PushBeforeModifier = true;
+        AluInstCount ++;
+        continue;
+      }
+      if (TII->isALUInstr(I->getOpcode()) &&
+          !SubstituteKCacheBank(I, KCacheBanks))
+        break;
+      AluInstCount += OccupiedDwords(I);
+      if (AluInstCount > 124)
+        break;
+    }
+    unsigned Opcode = PushBeforeModifier ?
+        AMDGPU::CF_ALU_PUSH_BEFORE : AMDGPU::CF_ALU;
+    BuildMI(MBB, ClauseHead, MBB.findDebugLoc(ClauseHead), TII->get(Opcode))
+        .addImm(0) // ADDR
+        .addImm(KCacheBanks.empty()?0:KCacheBanks[0].first) // KB0
+        .addImm((KCacheBanks.size() < 2)?0:KCacheBanks[1].first) // KB1
+        .addImm(KCacheBanks.empty()?0:2) // KM0
+        .addImm((KCacheBanks.size() < 2)?0:2) // KM1
+        .addImm(KCacheBanks.empty()?0:KCacheBanks[0].second) // KLINE0
+        .addImm((KCacheBanks.size() < 2)?0:KCacheBanks[1].second) // KLINE1
+        .addImm(AluInstCount); // COUNT
+    return I;
+  }
+
+public:
+  R600EmitClauseMarkersPass(TargetMachine &tm) : MachineFunctionPass(ID),
+    TII (static_cast<const R600InstrInfo *>(tm.getInstrInfo())) { }
+
+  virtual bool runOnMachineFunction(MachineFunction &MF) {
+    for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end();
+                                                    BB != BB_E; ++BB) {
+      MachineBasicBlock &MBB = *BB;
+      MachineBasicBlock::iterator I = MBB.begin();
+      if (I->getOpcode() == AMDGPU::CF_ALU)
+        continue; // BB was already parsed
+      for (MachineBasicBlock::iterator E = MBB.end(); I != E;) {
+        if (isALU(I))
+          I = MakeALUClause(MBB, I);
+        else
+          ++I;
+      }
+    }
+    return false;
+  }
+
+  const char *getPassName() const {
+    return "R600 Emit Clause Markers Pass";
+  }
+};
+
+char R600EmitClauseMarkersPass::ID = 0;
+
+}
+
+
+llvm::FunctionPass *llvm::createR600EmitClauseMarkers(TargetMachine &TM) {
+  return new R600EmitClauseMarkersPass(TM);
+}
+