Hexagon: Fix Small Data support to handle -G 0 correctly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181331 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 176 insertions, 0 deletions

diff --git a/lib/Target/Hexagon/HexagonSplitConst32AndConst64.cpp b/lib/Target/Hexagon/HexagonSplitConst32AndConst64.cpp
new file mode 100644
index 00000000000..3bf2f20457e
--- /dev/null
+++ b/lib/Target/Hexagon/HexagonSplitConst32AndConst64.cpp
@@ -0,0 +1,176 @@
+//=== HexagonSplitConst32AndConst64.cpp - split CONST32/Const64 into HI/LO ===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// When the compiler is invoked with no small data, for instance, with the -G0
+// command line option, then all CONST32_* opcodes should be broken down into
+// appropriate LO and HI instructions. This splitting is done by this pass.
+// The only reason this is not done in the DAG lowering itself is that there
+// is no simple way of getting the register allocator to allot the same hard
+// register to the result of LO and HI instructions. This pass is always
+// scheduled after register allocation.
+//
+//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "xfer"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/ScheduleDAGInstrs.h"
+#include "llvm/CodeGen/LatencyPriorityQueue.h"
+#include "llvm/CodeGen/SchedulerRegistry.h"
+#include "llvm/CodeGen/MachineDominators.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "HexagonTargetMachine.h"
+#include "HexagonSubtarget.h"
+#include "HexagonMachineFunctionInfo.h"
+#include <map>
+#include <iostream>
+
+#include "llvm/Support/CommandLine.h"
+#define DEBUG_TYPE "xfer"
+
+
+using namespace llvm;
+
+namespace {
+
+class HexagonSplitConst32AndConst64 : public MachineFunctionPass {
+    const HexagonTargetMachine& QTM;
+    const HexagonSubtarget &QST;
+
+ public:
+    static char ID;
+    HexagonSplitConst32AndConst64(const HexagonTargetMachine& TM)
+      : MachineFunctionPass(ID), QTM(TM), QST(*TM.getSubtargetImpl()) {}
+
+    const char *getPassName() const {
+      return "Hexagon Split Const32s and Const64s";
+    }
+    bool runOnMachineFunction(MachineFunction &Fn);
+};
+
+
+char HexagonSplitConst32AndConst64::ID = 0;
+
+
+bool HexagonSplitConst32AndConst64::runOnMachineFunction(MachineFunction &Fn) {
+
+  const TargetInstrInfo *TII = QTM.getInstrInfo();
+
+  // Loop over all of the basic blocks
+  for (MachineFunction::iterator MBBb = Fn.begin(), MBBe = Fn.end();
+       MBBb != MBBe; ++MBBb) {
+    MachineBasicBlock* MBB = MBBb;
+    // Traverse the basic block
+    MachineBasicBlock::iterator MII = MBB->begin();
+    MachineBasicBlock::iterator MIE = MBB->end ();
+    while (MII != MIE) {
+      MachineInstr *MI = MII;
+      int Opc = MI->getOpcode();
+      if (Opc == Hexagon::CONST32_set) {
+        int DestReg = MI->getOperand(0).getReg();
+        MachineOperand &Symbol = MI->getOperand (1);
+
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::LO), DestReg).addOperand(Symbol);
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::HI), DestReg).addOperand(Symbol);
+        // MBB->erase returns the iterator to the next instruction, which is the
+        // one we want to process next
+        MII = MBB->erase (MI);
+        continue;
+      }
+      else if (Opc == Hexagon::CONST32_set_jt) {
+        int DestReg = MI->getOperand(0).getReg();
+        MachineOperand &Symbol = MI->getOperand (1);
+
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::LO_jt), DestReg).addOperand(Symbol);
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::HI_jt), DestReg).addOperand(Symbol);
+        // MBB->erase returns the iterator to the next instruction, which is the
+        // one we want to process next
+        MII = MBB->erase (MI);
+        continue;
+      }
+      else if (Opc == Hexagon::CONST32_Label) {
+        int DestReg = MI->getOperand(0).getReg();
+        MachineOperand &Symbol = MI->getOperand (1);
+
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::LO_label), DestReg).addOperand(Symbol);
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::HI_label), DestReg).addOperand(Symbol);
+        // MBB->erase returns the iterator to the next instruction, which is the
+        // one we want to process next
+        MII = MBB->erase (MI);
+        continue;
+      }
+      else if (Opc == Hexagon::CONST32_Int_Real) {
+        int DestReg = MI->getOperand(0).getReg();
+        int64_t ImmValue = MI->getOperand(1).getImm ();
+
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::LOi), DestReg).addImm(ImmValue);
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::HIi), DestReg).addImm(ImmValue);
+        MII = MBB->erase (MI);
+        continue;
+      }
+      else if (Opc == Hexagon::CONST64_Int_Real) {
+        int DestReg = MI->getOperand(0).getReg();
+        int64_t ImmValue = MI->getOperand(1).getImm ();
+        unsigned DestLo =
+          QTM.getRegisterInfo()->getSubReg (DestReg, Hexagon::subreg_loreg);
+        unsigned DestHi =
+          QTM.getRegisterInfo()->getSubReg (DestReg, Hexagon::subreg_hireg);
+
+        int32_t LowWord = (ImmValue & 0xFFFFFFFF);
+        int32_t HighWord = (ImmValue >> 32) & 0xFFFFFFFF;
+
+        // Lower Registers Lower Half
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::LOi), DestLo).addImm(LowWord);
+        // Lower Registers Higher Half
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::HIi), DestLo).addImm(LowWord);
+        // Higher Registers Lower Half
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::LOi), DestHi).addImm(HighWord);
+        // Higher Registers Higher Half.
+        BuildMI (*MBB, MII, MI->getDebugLoc(),
+                 TII->get(Hexagon::HIi), DestHi).addImm(HighWord);
+        MII = MBB->erase (MI);
+        continue;
+       }
+      ++MII;
+    }
+  }
+
+  return true;
+}
+
+}
+
+//===----------------------------------------------------------------------===//
+//                         Public Constructor Functions
+//===----------------------------------------------------------------------===//
+
+FunctionPass *
+llvm::createHexagonSplitConst32AndConst64(const HexagonTargetMachine &TM) {
+  return new HexagonSplitConst32AndConst64(TM);
+}