From b4b4fa80bab1387e50c5f1b08e1141f853d35204 Mon Sep 17 00:00:00 2001
From: Akira Hatanaka <ahatanaka@mips.com>
Date: Mon, 11 Feb 2013 22:35:40 +0000
Subject: [PATCH] [mips] Expand pseudo instructions before they are emitted in
 MipsCodeEmitter.cpp.

JALR and NOP are expanded by function emitPseudoExpansionLowering, which is not
called when the old JIT is used.

This fixes the following tests which have been failing on
llvm-mips-linux builder:

LLVM :: ExecutionEngine__2003-01-04-LoopTest.ll
LLVM :: ExecutionEngine__2003-05-06-LivenessClobber.ll
LLVM :: ExecutionEngine__2003-06-04-bzip2-bug.ll
LLVM :: ExecutionEngine__2005-12-02-TailCallBug.ll
LLVM :: ExecutionEngine__2003-10-18-PHINode-ConstantExpr-CondCode-Failure.ll
LLVM :: ExecutionEngine__hello2.ll
LLVM :: ExecutionEngine__stubs.ll
LLVM :: ExecutionEngine__test-branch.ll
LLVM :: ExecutionEngine__test-call.ll
LLVM :: ExecutionEngine__test-common-symbols.ll
LLVM :: ExecutionEngine__test-loadstore.ll
LLVM :: ExecutionEngine__test-loop.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174912 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/Mips/MipsCodeEmitter.cpp | 49 ++++++++++++++++++++++-------
 1 file changed, 38 insertions(+), 11 deletions(-)

diff --git a/lib/Target/Mips/MipsCodeEmitter.cpp b/lib/Target/Mips/MipsCodeEmitter.cpp
index ab3bfd970c6..df877b65484 100644
--- a/lib/Target/Mips/MipsCodeEmitter.cpp
+++ b/lib/Target/Mips/MipsCodeEmitter.cpp
@@ -25,6 +25,7 @@
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/CodeGen/Passes.h"
@@ -80,7 +81,8 @@ public:
   /// machine instructions.
   uint64_t getBinaryCodeForInstr(const MachineInstr &MI) const;
 
-  void emitInstruction(const MachineInstr &MI);
+  void emitInstruction(MachineBasicBlock::instr_iterator MI,
+                       MachineBasicBlock &MBB);
 
 private:
 
@@ -112,6 +114,10 @@ private:
 
   void emitGlobalAddressUnaligned(const GlobalValue *GV, unsigned Reloc,
                                   int Offset) const;
+
+  /// \brief Expand pseudo instruction. Return true if MI was expanded.
+  bool expandPseudos(MachineBasicBlock::instr_iterator &MI,
+                     MachineBasicBlock &MBB) const;
 };
 }
 
@@ -140,8 +146,8 @@ bool MipsCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
         MBB != E; ++MBB){
       MCE.StartMachineBasicBlock(MBB);
       for (MachineBasicBlock::instr_iterator I = MBB->instr_begin(),
-           E = MBB->instr_end(); I != E; ++I)
-        emitInstruction(*I);
+           E = MBB->instr_end(); I != E;)
+        emitInstruction(*I++, *MBB);
     }
   } while (MCE.finishFunction(MF));
 
@@ -266,19 +272,21 @@ void MipsCodeEmitter::emitMachineBasicBlock(MachineBasicBlock *BB,
                                              Reloc, BB));
 }
 
-void MipsCodeEmitter::emitInstruction(const MachineInstr &MI) {
-  DEBUG(errs() << "JIT: " << (void*)MCE.getCurrentPCValue() << ":\t" << MI);
+void MipsCodeEmitter::emitInstruction(MachineBasicBlock::instr_iterator MI,
+                                      MachineBasicBlock &MBB) {
+  DEBUG(errs() << "JIT: " << (void*)MCE.getCurrentPCValue() << ":\t" << *MI);
 
-  MCE.processDebugLoc(MI.getDebugLoc(), true);
-
-  // Skip pseudo instructions.
-  if ((MI.getDesc().TSFlags & MipsII::FormMask) == MipsII::Pseudo)
+  // Expand pseudo instruction. Skip if MI was not expanded.
+  if (((MI->getDesc().TSFlags & MipsII::FormMask) == MipsII::Pseudo) &&
+      !expandPseudos(MI, MBB))
     return;
 
-  emitWord(getBinaryCodeForInstr(MI));
+  MCE.processDebugLoc(MI->getDebugLoc(), true);
+
+  emitWord(getBinaryCodeForInstr(*MI));
   ++NumEmitted;  // Keep track of the # of mi's emitted
 
-  MCE.processDebugLoc(MI.getDebugLoc(), false);
+  MCE.processDebugLoc(MI->getDebugLoc(), false);
 }
 
 void MipsCodeEmitter::emitWord(unsigned Word) {
@@ -290,6 +298,25 @@ void MipsCodeEmitter::emitWord(unsigned Word) {
     MCE.emitWordBE(Word);
 }
 
+bool MipsCodeEmitter::expandPseudos(MachineBasicBlock::instr_iterator &MI,
+                                    MachineBasicBlock &MBB) const {
+  switch (MI->getOpcode()) {
+  case Mips::NOP:
+    BuildMI(MBB, &*MI, MI->getDebugLoc(), II->get(Mips::SLL), Mips::ZERO)
+      .addReg(Mips::ZERO).addImm(0);
+    break;
+  case Mips::JALRPseudo:
+    BuildMI(MBB, &*MI, MI->getDebugLoc(), II->get(Mips::JALR), Mips::RA)
+      .addReg(MI->getOperand(0).getReg());
+    break;
+  default:
+    return false;
+  }
+
+  (MI--)->eraseFromBundle();
+  return true;
+}
+
 /// createMipsJITCodeEmitterPass - Return a pass that emits the collected Mips
 /// code to the specified MCE object.
 FunctionPass *llvm::createMipsJITCodeEmitterPass(MipsTargetMachine &TM,