R600: Add support for native control flow

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178505 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 264 insertions, 0 deletions

diff --git a/lib/Target/R600/R600ControlFlowFinalizer.cpp b/lib/Target/R600/R600ControlFlowFinalizer.cpp
new file mode 100644
index 0000000000..bd87d741ec
--- /dev/null
+++ b/lib/Target/R600/R600ControlFlowFinalizer.cpp
@@ -0,0 +1,264 @@
+//===-- R600ControlFlowFinalizer.cpp - Finalize Control Flow Inst----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// This pass compute turns all control flow pseudo instructions into native one
+/// computing their address on the fly ; it also sets STACK_SIZE info.
+//===----------------------------------------------------------------------===//
+
+#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 R600ControlFlowFinalizer : public MachineFunctionPass {
+
+private:
+  static char ID;
+  const R600InstrInfo *TII;
+  unsigned MaxFetchInst;
+
+  bool isFetch(const MachineInstr *MI) const {
+    switch (MI->getOpcode()) {
+    case AMDGPU::TEX_VTX_CONSTBUF:
+    case AMDGPU::TEX_VTX_TEXBUF:
+    case AMDGPU::TEX_LD:
+    case AMDGPU::TEX_GET_TEXTURE_RESINFO:
+    case AMDGPU::TEX_GET_GRADIENTS_H:
+    case AMDGPU::TEX_GET_GRADIENTS_V:
+    case AMDGPU::TEX_SET_GRADIENTS_H:
+    case AMDGPU::TEX_SET_GRADIENTS_V:
+    case AMDGPU::TEX_SAMPLE:
+    case AMDGPU::TEX_SAMPLE_C:
+    case AMDGPU::TEX_SAMPLE_L:
+    case AMDGPU::TEX_SAMPLE_C_L:
+    case AMDGPU::TEX_SAMPLE_LB:
+    case AMDGPU::TEX_SAMPLE_C_LB:
+    case AMDGPU::TEX_SAMPLE_G:
+    case AMDGPU::TEX_SAMPLE_C_G:
+    case AMDGPU::TXD:
+    case AMDGPU::TXD_SHADOW:
+     return true;
+    default:
+      return false;
+    }
+  }
+
+  bool IsTrivialInst(MachineInstr *MI) const {
+    switch (MI->getOpcode()) {
+    case AMDGPU::KILL:
+    case AMDGPU::RETURN:
+      return true;
+    default:
+      return false;
+    }
+  }
+
+  MachineBasicBlock::iterator
+  MakeFetchClause(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
+      unsigned CfAddress) const {
+    MachineBasicBlock::iterator ClauseHead = I;
+    unsigned AluInstCount = 0;
+    for (MachineBasicBlock::iterator E = MBB.end(); I != E; ++I) {
+      if (IsTrivialInst(I))
+        continue;
+      if (!isFetch(I))
+        break;
+      AluInstCount ++;
+      if (AluInstCount > MaxFetchInst)
+        break;
+    }
+    BuildMI(MBB, ClauseHead, MBB.findDebugLoc(ClauseHead),
+        TII->get(AMDGPU::CF_TC))
+        .addImm(CfAddress) // ADDR
+        .addImm(AluInstCount); // COUNT
+    return I;
+  }
+  void CounterPropagateAddr(MachineInstr *MI, unsigned Addr) const {
+    switch (MI->getOpcode()) {
+    case AMDGPU::WHILE_LOOP:
+      MI->getOperand(0).setImm(Addr + 1);
+      break;
+    default:
+      MI->getOperand(0).setImm(Addr);
+      break;
+    }
+  }
+  void CounterPropagateAddr(std::set<MachineInstr *> MIs, unsigned Addr)
+      const {
+    for (std::set<MachineInstr *>::iterator It = MIs.begin(), E = MIs.end();
+        It != E; ++It) {
+      MachineInstr *MI = *It;
+      CounterPropagateAddr(MI, Addr);
+    }
+  }
+
+public:
+  R600ControlFlowFinalizer(TargetMachine &tm) : MachineFunctionPass(ID),
+    TII (static_cast<const R600InstrInfo *>(tm.getInstrInfo())) {
+      const AMDGPUSubtarget &ST = tm.getSubtarget<AMDGPUSubtarget>();
+      if (ST.device()->getGeneration() <= AMDGPUDeviceInfo::HD4XXX)
+        MaxFetchInst = 8;
+      else
+        MaxFetchInst = 16;
+  }
+
+  virtual bool runOnMachineFunction(MachineFunction &MF) {
+    unsigned MaxStack = 0;
+    unsigned CurrentStack = 0;
+    for (MachineFunction::iterator MB = MF.begin(), ME = MF.end(); MB != ME;
+        ++MB) {
+      MachineBasicBlock &MBB = *MB;
+      unsigned CfCount = 0;
+      std::vector<std::pair<unsigned, std::set<MachineInstr *> > > LoopStack;
+      std::vector<std::pair<unsigned, MachineInstr *> > IfThenElseStack;
+      R600MachineFunctionInfo *MFI = MF.getInfo<R600MachineFunctionInfo>();
+      if (MFI->ShaderType == 1) {
+        BuildMI(MBB, MBB.begin(), MBB.findDebugLoc(MBB.begin()),
+            TII->get(AMDGPU::CF_CALL_FS));
+        CfCount++;
+      }
+      for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end();
+          I != E;) {
+        if (isFetch(I)) {
+          I = MakeFetchClause(MBB, I, 0);
+          CfCount++;
+          continue;
+        }
+
+        MachineBasicBlock::iterator MI = I;
+        I++;
+        switch (MI->getOpcode()) {
+        case AMDGPU::CF_ALU_PUSH_BEFORE:
+          CurrentStack++;
+          MaxStack = std::max(MaxStack, CurrentStack);
+        case AMDGPU::KILLGT:
+        case AMDGPU::CF_ALU:
+          CfCount++;
+          break;
+        case AMDGPU::WHILELOOP: {
+          CurrentStack++;
+          MaxStack = std::max(MaxStack, CurrentStack);
+          MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
+              TII->get(AMDGPU::WHILE_LOOP))
+              .addImm(0);
+          std::pair<unsigned, std::set<MachineInstr *> > Pair(CfCount,
+              std::set<MachineInstr *>());
+          Pair.second.insert(MIb);
+          LoopStack.push_back(Pair);
+          MI->eraseFromParent();
+          CfCount++;
+          break;
+        }
+        case AMDGPU::ENDLOOP: {
+          CurrentStack--;
+          std::pair<unsigned, std::set<MachineInstr *> > Pair =
+              LoopStack.back();
+          LoopStack.pop_back();
+          CounterPropagateAddr(Pair.second, CfCount);
+          BuildMI(MBB, MI, MBB.findDebugLoc(MI), TII->get(AMDGPU::END_LOOP))
+              .addImm(Pair.first + 1);
+          MI->eraseFromParent();
+          CfCount++;
+          break;
+        }
+        case AMDGPU::IF_PREDICATE_SET: {
+          MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
+              TII->get(AMDGPU::CF_JUMP))
+              .addImm(0)
+              .addImm(0);
+          std::pair<unsigned, MachineInstr *> Pair(CfCount, MIb);
+          IfThenElseStack.push_back(Pair);
+          MI->eraseFromParent();
+          CfCount++;
+          break;
+        }
+        case AMDGPU::ELSE: {
+          std::pair<unsigned, MachineInstr *> Pair = IfThenElseStack.back();
+          IfThenElseStack.pop_back();
+          CounterPropagateAddr(Pair.second, CfCount);
+          MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
+              TII->get(AMDGPU::CF_ELSE))
+              .addImm(0)
+              .addImm(1);
+          std::pair<unsigned, MachineInstr *> NewPair(CfCount, MIb);
+          IfThenElseStack.push_back(NewPair);
+          MI->eraseFromParent();
+          CfCount++;
+          break;
+        }
+        case AMDGPU::ENDIF: {
+          CurrentStack--;
+          std::pair<unsigned, MachineInstr *> Pair = IfThenElseStack.back();
+          IfThenElseStack.pop_back();
+          CounterPropagateAddr(Pair.second, CfCount + 1);
+          BuildMI(MBB, MI, MBB.findDebugLoc(MI), TII->get(AMDGPU::POP))
+              .addImm(CfCount + 1)
+              .addImm(1);
+          MI->eraseFromParent();
+          CfCount++;
+          break;
+        }
+        case AMDGPU::PREDICATED_BREAK: {
+          CurrentStack--;
+          CfCount += 3;
+          BuildMI(MBB, MI, MBB.findDebugLoc(MI), TII->get(AMDGPU::CF_JUMP))
+              .addImm(CfCount)
+              .addImm(1);
+          MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
+              TII->get(AMDGPU::LOOP_BREAK))
+              .addImm(0);
+          BuildMI(MBB, MI, MBB.findDebugLoc(MI), TII->get(AMDGPU::POP))
+              .addImm(CfCount)
+              .addImm(1);
+          LoopStack.back().second.insert(MIb);
+          MI->eraseFromParent();
+          break;
+        }
+        case AMDGPU::CONTINUE: {
+          MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
+              TII->get(AMDGPU::CF_CONTINUE))
+              .addImm(CfCount);
+          LoopStack.back().second.insert(MIb);
+          MI->eraseFromParent();
+          CfCount++;
+          break;
+        }
+        default:
+          break;
+        }
+      }
+      BuildMI(MBB, MBB.begin(), MBB.findDebugLoc(MBB.begin()),
+          TII->get(AMDGPU::STACK_SIZE))
+          .addImm(MaxStack);
+    }
+
+    return false;
+  }
+
+  const char *getPassName() const {
+    return "R600 Control Flow Finalizer Pass";
+  }
+};
+
+char R600ControlFlowFinalizer::ID = 0;
+
+}
+
+
+llvm::FunctionPass *llvm::createR600ControlFlowFinalizer(TargetMachine &TM) {
+  return new R600ControlFlowFinalizer(TM);
+}
+