It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCCodeEmitter.cpp b/lib/Target/PowerPC/PPCCodeEmitter.cpp
new file mode 100644
index 0000000..5dceffd
--- /dev/null
+++ b/lib/Target/PowerPC/PPCCodeEmitter.cpp
@@ -0,0 +1,237 @@
+//===-- PPCCodeEmitter.cpp - JIT Code Emitter for PowerPC32 -------*- C++ -*-=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the PowerPC 32-bit CodeEmitter and associated machinery to
+// JIT-compile bitcode to native PowerPC.
+//
+//===----------------------------------------------------------------------===//
+
+#include "PPCTargetMachine.h"
+#include "PPCRelocations.h"
+#include "PPC.h"
+#include "llvm/Module.h"
+#include "llvm/PassManager.h"
+#include "llvm/CodeGen/MachineCodeEmitter.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/Support/Debug.h"                   
+#include "llvm/Support/Compiler.h"
+#include "llvm/Target/TargetOptions.h"
+using namespace llvm;
+
+namespace {
+  class VISIBILITY_HIDDEN PPCCodeEmitter : public MachineFunctionPass {
+    TargetMachine &TM;
+    MachineCodeEmitter &MCE;
+
+    /// MovePCtoLROffset - When/if we see a MovePCtoLR instruction, we record
+    /// its address in the function into this pointer.
+    void *MovePCtoLROffset;
+    
+    /// getMachineOpValue - evaluates the MachineOperand of a given MachineInstr
+    ///
+    int getMachineOpValue(MachineInstr &MI, MachineOperand &MO);
+
+  public:
+    static char ID;
+    PPCCodeEmitter(TargetMachine &T, MachineCodeEmitter &M)
+      : MachineFunctionPass((intptr_t)&ID), TM(T), MCE(M) {}
+
+    const char *getPassName() const { return "PowerPC Machine Code Emitter"; }
+
+    /// runOnMachineFunction - emits the given MachineFunction to memory
+    ///
+    bool runOnMachineFunction(MachineFunction &MF);
+
+    /// emitBasicBlock - emits the given MachineBasicBlock to memory
+    ///
+    void emitBasicBlock(MachineBasicBlock &MBB);
+
+    /// getValueBit - return the particular bit of Val
+    ///
+    unsigned getValueBit(int64_t Val, unsigned bit) { return (Val >> bit) & 1; }
+
+    /// getBinaryCodeForInstr - This function, generated by the
+    /// CodeEmitterGenerator using TableGen, produces the binary encoding for
+    /// machine instructions.
+    ///
+    unsigned getBinaryCodeForInstr(MachineInstr &MI);
+  };
+  char PPCCodeEmitter::ID = 0;
+}
+
+/// createPPCCodeEmitterPass - Return a pass that emits the collected PPC code
+/// to the specified MCE object.
+FunctionPass *llvm::createPPCCodeEmitterPass(PPCTargetMachine &TM,
+                                             MachineCodeEmitter &MCE) {
+  return new PPCCodeEmitter(TM, MCE);
+}
+
+#ifdef __APPLE__ 
+extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
+#endif
+
+bool PPCCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
+  assert((MF.getTarget().getRelocationModel() != Reloc::Default ||
+          MF.getTarget().getRelocationModel() != Reloc::Static) &&
+         "JIT relocation model must be set to static or default!");
+  do {
+    MovePCtoLROffset = 0;
+    MCE.startFunction(MF);
+    for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB)
+      emitBasicBlock(*BB);
+  } while (MCE.finishFunction(MF));
+
+  return false;
+}
+
+void PPCCodeEmitter::emitBasicBlock(MachineBasicBlock &MBB) {
+  MCE.StartMachineBasicBlock(&MBB);
+  
+  for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ++I){
+    MachineInstr &MI = *I;
+    switch (MI.getOpcode()) {
+    default:
+      MCE.emitWordBE(getBinaryCodeForInstr(*I));
+      break;
+    case PPC::IMPLICIT_DEF_GPRC:
+    case PPC::IMPLICIT_DEF_G8RC:
+    case PPC::IMPLICIT_DEF_F8:
+    case PPC::IMPLICIT_DEF_F4:
+    case PPC::IMPLICIT_DEF_VRRC:
+      break; // pseudo opcode, no side effects
+    case PPC::MovePCtoLR:
+    case PPC::MovePCtoLR8:
+      assert(TM.getRelocationModel() == Reloc::PIC_);
+      MovePCtoLROffset = (void*)MCE.getCurrentPCValue();
+      MCE.emitWordBE(0x48000005);   // bl 1
+      break;
+    }
+  }
+}
+
+int PPCCodeEmitter::getMachineOpValue(MachineInstr &MI, MachineOperand &MO) {
+
+  intptr_t rv = 0; // Return value; defaults to 0 for unhandled cases
+                   // or things that get fixed up later by the JIT.
+  if (MO.isRegister()) {
+    rv = PPCRegisterInfo::getRegisterNumbering(MO.getReg());
+
+    // Special encoding for MTCRF and MFOCRF, which uses a bit mask for the
+    // register, not the register number directly.
+    if ((MI.getOpcode() == PPC::MTCRF || MI.getOpcode() == PPC::MFOCRF) &&
+        (MO.getReg() >= PPC::CR0 && MO.getReg() <= PPC::CR7)) {
+      rv = 0x80 >> rv;
+    }
+  } else if (MO.isImmediate()) {
+    rv = MO.getImmedValue();
+  } else if (MO.isGlobalAddress() || MO.isExternalSymbol() ||
+             MO.isConstantPoolIndex() || MO.isJumpTableIndex()) {
+    unsigned Reloc = 0;
+    if (MI.getOpcode() == PPC::BL_Macho || MI.getOpcode() == PPC::BL8_Macho ||
+        MI.getOpcode() == PPC::BL_ELF || MI.getOpcode() == PPC::BL8_ELF)
+      Reloc = PPC::reloc_pcrel_bx;
+    else {
+      if (TM.getRelocationModel() == Reloc::PIC_) {
+        assert(MovePCtoLROffset && "MovePCtoLR not seen yet?");
+      }
+      switch (MI.getOpcode()) {
+      default: MI.dump(); assert(0 && "Unknown instruction for relocation!");
+      case PPC::LIS:
+      case PPC::LIS8:
+      case PPC::ADDIS:
+      case PPC::ADDIS8:
+        Reloc = PPC::reloc_absolute_high;       // Pointer to symbol
+        break;
+      case PPC::LI:
+      case PPC::LI8:
+      case PPC::LA:
+      // Loads.
+      case PPC::LBZ:
+      case PPC::LBZ8:
+      case PPC::LHA:
+      case PPC::LHA8:
+      case PPC::LHZ:
+      case PPC::LHZ8:
+      case PPC::LWZ:
+      case PPC::LWZ8:
+      case PPC::LFS:
+      case PPC::LFD:
+      
+      // Stores.
+      case PPC::STB:
+      case PPC::STB8:
+      case PPC::STH:
+      case PPC::STH8:
+      case PPC::STW:
+      case PPC::STW8:
+      case PPC::STFS:
+      case PPC::STFD:
+        Reloc = PPC::reloc_absolute_low;
+        break;
+
+      case PPC::LWA:
+      case PPC::LD:
+      case PPC::STD:
+      case PPC::STD_32:
+        Reloc = PPC::reloc_absolute_low_ix;
+        break;
+      }
+    }
+    
+    MachineRelocation R;
+    if (MO.isGlobalAddress()) {
+      R = MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc,
+                                   MO.getGlobal(), 0);
+    } else if (MO.isExternalSymbol()) {
+      R = MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
+                                       Reloc, MO.getSymbolName(), 0);
+    } else if (MO.isConstantPoolIndex()) {
+      R = MachineRelocation::getConstPool(MCE.getCurrentPCOffset(),
+                                          Reloc, MO.getConstantPoolIndex(), 0);
+    } else {
+      assert(MO.isJumpTableIndex());
+      R = MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(),
+                                          Reloc, MO.getJumpTableIndex(), 0);
+    }
+    
+    // If in PIC mode, we need to encode the negated address of the
+    // 'movepctolr' into the unrelocated field.  After relocation, we'll have
+    // &gv-&movepctolr-4 in the imm field.  Once &movepctolr is added to the imm
+    // field, we get &gv.  This doesn't happen for branch relocations, which are
+    // always implicitly pc relative.
+    if (TM.getRelocationModel() == Reloc::PIC_ && Reloc != PPC::reloc_pcrel_bx){
+      assert(MovePCtoLROffset && "MovePCtoLR not seen yet?");
+      R.setConstantVal(-(intptr_t)MovePCtoLROffset - 4);
+    }
+    MCE.addRelocation(R);
+    
+  } else if (MO.isMachineBasicBlock()) {
+    unsigned Reloc = 0;
+    unsigned Opcode = MI.getOpcode();
+    if (Opcode == PPC::B || Opcode == PPC::BL_Macho ||
+        Opcode == PPC::BLA_Macho || Opcode == PPC::BL_ELF || 
+        Opcode == PPC::BLA_ELF)
+      Reloc = PPC::reloc_pcrel_bx;
+    else // BCC instruction
+      Reloc = PPC::reloc_pcrel_bcx;
+    MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
+                                               Reloc,
+                                               MO.getMachineBasicBlock()));
+  } else {
+    cerr << "ERROR: Unknown type of MachineOperand: " << MO << "\n";
+    abort();
+  }
+
+  return rv;
+}
+
+#include "PPCGenCodeEmitter.inc"
+