Combine MovePCtoStack + POP32r into one instruction MOVPC32r so it can be moved if needed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45605 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86ATTAsmPrinter.cpp

@@ -32,14 +32,14 @@ using namespace llvm;
 
 STATISTIC(EmittedInsts, "Number of machine instrs printed");
 
-static std::string computePICLabel(unsigned FnNum,
+static std::string getPICLabelString(unsigned FnNum,
-                                   const TargetAsmInfo *TAI,
+                                     const TargetAsmInfo *TAI,
-                                   const X86Subtarget* Subtarget)  {
+                                     const X86Subtarget* Subtarget) {
   std::string label;
   if (Subtarget->isTargetDarwin())
     label =  "\"L" + utostr_32(FnNum) + "$pb\"";
   else if (Subtarget->isTargetELF())
-    label = ".Lllvm$" + utostr_32(FnNum) + "$piclabel";
+    label = ".Lllvm$" + utostr_32(FnNum) + "." + "$piclabel";
   else
     assert(0 && "Don't know how to print PIC label!\n");
 
@@ -318,8 +318,7 @@ void X86ATTAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
       }
       
       if (!isCallOp && TM.getRelocationModel() == Reloc::PIC_)
-        O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
+        O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget);
-          << "$pb\"";
     } else {
       if (GV->hasDLLImportLinkage()) {
         O << "__imp_";          
@@ -420,7 +419,7 @@ void X86ATTAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
         //   popl %some_register
         //   addl $_GLOBAL_ADDRESS_TABLE_ + [.-piclabel], %some_register
         O << " + [.-"
-          << computePICLabel(getFunctionNumber(), TAI, Subtarget) << "]";
+          << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << "]";
 
       if (isCallOp)
         O << "@PLT";
@@ -515,11 +514,11 @@ void X86ATTAsmPrinter::printPICJumpTableSetLabel(unsigned uid,
     O << '-' << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber() 
       << '_' << uid << '\n';
   else
-    O << '-' << computePICLabel(getFunctionNumber(), TAI, Subtarget) << '\n';
+    O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << '\n';
 }
 
 void X86ATTAsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op) {
-  std::string label = computePICLabel(getFunctionNumber(), TAI, Subtarget);
+  std::string label = getPICLabelString(getFunctionNumber(), TAI, Subtarget);
   O << label << "\n" << label << ":";
 }
 

lib/Target/X86/X86CodeEmitter.cpp

@@ -58,7 +58,8 @@ namespace {
       return "X86 Machine Code Emitter";
     }
 
-    void emitInstruction(const MachineInstr &MI);
+    void emitInstruction(const MachineInstr &MI,
+                         const TargetInstrDescriptor *Desc);
 
   private:
     void emitPCRelativeBlockAddress(MachineBasicBlock *MBB);
@@ -112,8 +113,14 @@ bool Emitter::runOnMachineFunction(MachineFunction &MF) {
          MBB != E; ++MBB) {
       MCE.StartMachineBasicBlock(MBB);
       for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
-           I != E; ++I)
+           I != E; ++I) {
-        emitInstruction(*I);
+        const TargetInstrDescriptor *Desc = I->getInstrDescriptor();
+        emitInstruction(*I, Desc);
+        // MOVPC32r is basically a call plus a pop instruction.
+        if (Desc->Opcode == X86::MOVPC32r)
+          emitInstruction(*I, &II->get(X86::POP32r));
+        NumEmitted++;  // Keep track of the # of mi's emitted
+      }
     }
   } while (MCE.finishFunction(MF));
 
@@ -519,10 +526,8 @@ unsigned Emitter::determineREX(const MachineInstr &MI) {
   return REX;
 }
 
-void Emitter::emitInstruction(const MachineInstr &MI) {
+void Emitter::emitInstruction(const MachineInstr &MI,
-  NumEmitted++;  // Keep track of the # of mi's emitted
+                              const TargetInstrDescriptor *Desc) {
-
-  const TargetInstrDescriptor *Desc = MI.getInstrDescriptor();
   unsigned Opcode = Desc->Opcode;
 
   // Emit the repeat opcode prefix as needed.
@@ -587,8 +592,10 @@ void Emitter::emitInstruction(const MachineInstr &MI) {
   switch (Desc->TSFlags & X86II::FormMask) {
   default: assert(0 && "Unknown FormMask value in X86 MachineCodeEmitter!");
   case X86II::Pseudo:
-#ifndef NDEBUG
+    // Remember the current PC offset, this is the PIC relocation
+    // base address.
     switch (Opcode) {
+#ifndef NDEBUG
     default: 
       assert(0 && "psuedo instructions should be removed before code emission");
     case TargetInstrInfo::INLINEASM:
@@ -607,13 +614,20 @@ void Emitter::emitInstruction(const MachineInstr &MI) {
     case X86::IMPLICIT_DEF_VR128:
     case X86::FP_REG_KILL:
       break;
-    }
 #endif
+    case X86::MOVPC32r:
+      // This emits the "call" portion of this pseudo instruction.
+      MCE.emitByte(BaseOpcode);
+      emitConstant(0, sizeOfImm(Desc));
+      PICBase = MCE.getCurrentPCOffset();
+      break;
+    }
     CurOp = NumOps;
     break;
 
   case X86II::RawFrm:
     MCE.emitByte(BaseOpcode);
+
     if (CurOp != NumOps) {
       const MachineOperand &MO = MI.getOperand(CurOp++);
       if (MO.isMachineBasicBlock()) {
@@ -631,11 +645,6 @@ void Emitter::emitInstruction(const MachineInstr &MI) {
         assert(0 && "Unknown RawFrm operand!");
       }
     }
-
-    // Remember the current PC offset, this is the PIC relocation
-    // base address.
-    if (Opcode == X86::MovePCtoStack)
-      PICBase = MCE.getCurrentPCOffset();
     break;
 
   case X86II::AddRegFrm:

lib/Target/X86/X86ISelDAGToDAG.cpp

@@ -16,6 +16,7 @@
 #include "X86.h"
 #include "X86InstrBuilder.h"
 #include "X86ISelLowering.h"
+#include "X86MachineFunctionInfo.h"
 #include "X86RegisterInfo.h"
 #include "X86Subtarget.h"
 #include "X86TargetMachine.h"
@@ -988,25 +989,24 @@ SDNode *X86DAGToDAGISel::getGlobalBaseReg() {
   assert(!Subtarget->is64Bit() && "X86-64 PIC uses RIP relative addressing");
   if (!GlobalBaseReg) {
     // Insert the set of GlobalBaseReg into the first MBB of the function
-    MachineBasicBlock &FirstMBB = BB->getParent()->front();
+    MachineFunction *MF = BB->getParent();
+    MachineBasicBlock &FirstMBB = MF->front();
     MachineBasicBlock::iterator MBBI = FirstMBB.begin();
-    MachineRegisterInfo &RegInfo = BB->getParent()->getRegInfo();
+    MachineRegisterInfo &RegInfo = MF->getRegInfo();
     unsigned PC = RegInfo.createVirtualRegister(X86::GR32RegisterClass);
     
     const TargetInstrInfo *TII = TM.getInstrInfo();
     // Operand of MovePCtoStack is completely ignored by asm printer. It's
     // only used in JIT code emission as displacement to pc.
-    BuildMI(FirstMBB, MBBI, TII->get(X86::MovePCtoStack)).addImm(0);
+    BuildMI(FirstMBB, MBBI, TII->get(X86::MOVPC32r), PC).addImm(0);
-    BuildMI(FirstMBB, MBBI, TII->get(X86::POP32r), PC);
     
     // If we're using vanilla 'GOT' PIC style, we should use relative addressing
     // not to pc, but to _GLOBAL_ADDRESS_TABLE_ external
     if (TM.getRelocationModel() == Reloc::PIC_ &&
         Subtarget->isPICStyleGOT()) {
       GlobalBaseReg = RegInfo.createVirtualRegister(X86::GR32RegisterClass);
-      BuildMI(FirstMBB, MBBI, TII->get(X86::ADD32ri), GlobalBaseReg).
+      BuildMI(FirstMBB, MBBI, TII->get(X86::ADD32ri), GlobalBaseReg)
-        addReg(PC).
+        .addReg(PC).addExternalSymbol("_GLOBAL_OFFSET_TABLE_");
-        addExternalSymbol("_GLOBAL_OFFSET_TABLE_");
     } else {
       GlobalBaseReg = PC;
     }

lib/Target/X86/X86InstrInfo.td

@@ -281,6 +281,9 @@ def IMPLICIT_DEF_GR32  : I<0, Pseudo, (outs GR32:$dst), (ins),
 // Nop
 def NOOP : I<0x90, RawFrm, (outs), (ins), "nop", []>;
 
+// PIC base
+def MOVPC32r : Ii32<0xE8, Pseudo, (outs GR32:$reg), (ins piclabel:$label),
+                    "call\t$label\n\tpop{l}\t$reg", []>;
 
 //===----------------------------------------------------------------------===//
 //  Control Flow Instructions...
@@ -408,9 +411,6 @@ def POPFD    : I<0x9D, RawFrm, (outs), (ins), "popf", []>;
 let Defs = [ESP], Uses = [ESP, EFLAGS] in
 def PUSHFD   : I<0x9C, RawFrm, (outs), (ins), "pushf", []>;
 
-def MovePCtoStack : Ii32<0xE8, RawFrm, (outs), (ins piclabel:$label),
-                         "call\t$label", []>;
-
 let isTwoAddress = 1 in                               // GR32 = bswap GR32
   def BSWAP32r : I<0xC8, AddRegFrm,
                    (outs GR32:$dst), (ins GR32:$src),

lib/Target/X86/X86MachineFunctionInfo.h

@@ -37,20 +37,20 @@ class X86MachineFunctionInfo : public MachineFunctionInfo {
   /// stack frame in bytes.
   unsigned CalleeSavedFrameSize;
 
-  /// BytesToPopOnReturn - amount of bytes function pops on return.
+  /// BytesToPopOnReturn - Number of bytes function pops on return.
   /// Used on windows platform for stdcall & fastcall name decoration
   unsigned BytesToPopOnReturn;
 
-  /// If the function requires additional name decoration, DecorationStyle holds
+  /// DecorationStyle - If the function requires additional name decoration,
-  /// the right way to do so.
+  /// DecorationStyle holds the right way to do so.
   NameDecorationStyle DecorationStyle;
 
-  // FrameIndex for return slot.
+  /// ReturnAddrIndex - FrameIndex for return slot.
   int ReturnAddrIndex;
 
-  // Delta the ReturnAddr stack slot is moved
+  /// TailCallReturnAddrDelta - Delta the ReturnAddr stack slot is moved
-  // Used for creating an area before the register spill area on the stack
+  /// Used for creating an area before the register spill area on the stack
-  // the returnaddr can be savely move to this area
+  /// the returnaddr can be savely move to this area
   int TailCallReturnAddrDelta;
 
 public:
@@ -59,7 +59,7 @@ public:
                              BytesToPopOnReturn(0),
                              DecorationStyle(None),
                              ReturnAddrIndex(0),
-                             TailCallReturnAddrDelta(0){}
+                             TailCallReturnAddrDelta(0) {}
   
   X86MachineFunctionInfo(MachineFunction &MF) : ForceFramePointer(false),
                                                 CalleeSavedFrameSize(0),