From b1e803985d3378538ae9cff7eed4102c002d1e22 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Mon, 25 Jan 2010 23:22:00 +0000
Subject: [PATCH] prep work to support a future where getJumpTableInfo will
 return a null pointer for functions with no jump tables.  No functionality
 change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94469 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/ELFCodeEmitter.cpp           | 7 ++++---
 lib/Target/ARM/ARMBaseInstrInfo.cpp      | 1 +
 lib/Target/ARM/ARMCodeEmitter.cpp        | 3 ++-
 lib/Target/ARM/ARMConstantIslandPass.cpp | 4 ++++
 4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/lib/CodeGen/ELFCodeEmitter.cpp b/lib/CodeGen/ELFCodeEmitter.cpp
index 11a85a0ba79..8416d3bda93 100644
--- a/lib/CodeGen/ELFCodeEmitter.cpp
+++ b/lib/CodeGen/ELFCodeEmitter.cpp
@@ -62,7 +62,8 @@ void ELFCodeEmitter::startFunction(MachineFunction &MF) {
   // They need to be emitted before the function because in some targets
   // the later may reference JT or CP entry address.
   emitConstantPool(MF.getConstantPool());
-  emitJumpTables(MF.getJumpTableInfo());
+  if (MF.getJumpTableInfo())
+    emitJumpTables(MF.getJumpTableInfo());
 }
 
 /// finishFunction - This callback is invoked after the function is completely
@@ -84,7 +85,7 @@ bool ELFCodeEmitter::finishFunction(MachineFunction &MF) {
 
   // Patch up Jump Table Section relocations to use the real MBBs offsets
   // now that the MBB label offsets inside the function are known.
-  if (!MF.getJumpTableInfo()->isEmpty()) {
+  if (MF.getJumpTableInfo()) {
     ELFSection &JTSection = EW.getJumpTableSection();
     for (std::vector<MachineRelocation>::iterator MRI = JTRelocations.begin(),
          MRE = JTRelocations.end(); MRI != MRE; ++MRI) {
@@ -172,7 +173,7 @@ void ELFCodeEmitter::emitJumpTables(MachineJumpTableInfo *MJTI) {
          "PIC codegen not yet handled for elf jump tables!");
 
   const TargetELFWriterInfo *TEW = TM.getELFWriterInfo();
-  unsigned EntrySize = MJTI->getEntrySize();
+  unsigned EntrySize = 4; //MJTI->getEntrySize();
 
   // Get the ELF Section to emit the jump table
   ELFSection &JTSection = EW.getJumpTableSection();
diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
index fd46a4a8c54..1e52211521c 100644
--- a/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -490,6 +490,7 @@ unsigned ARMBaseInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const {
         MI->getOperand(NumOps - (TID.isPredicable() ? 3 : 2));
       unsigned JTI = JTOP.getIndex();
       const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
+      assert(MJTI != 0);
       const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
       assert(JTI < JT.size());
       // Thumb instructions are 2 byte aligned, but JT entries are 4 byte
diff --git a/lib/Target/ARM/ARMCodeEmitter.cpp b/lib/Target/ARM/ARMCodeEmitter.cpp
index 17e7d4479db..81e3db7a7dd 100644
--- a/lib/Target/ARM/ARMCodeEmitter.cpp
+++ b/lib/Target/ARM/ARMCodeEmitter.cpp
@@ -206,7 +206,8 @@ bool Emitter<CodeEmitter>::runOnMachineFunction(MachineFunction &MF) {
   TD = ((ARMTargetMachine&)MF.getTarget()).getTargetData();
   Subtarget = &TM.getSubtarget<ARMSubtarget>();
   MCPEs = &MF.getConstantPool()->getConstants();
-  MJTEs = &MF.getJumpTableInfo()->getJumpTables();
+  MJTEs = 0;
+  if (MF.getJumpTableInfo()) MJTEs = &MF.getJumpTableInfo()->getJumpTables();
   IsPIC = TM.getRelocationModel() == Reloc::PIC_;
   JTI->Initialize(MF, IsPIC);
   MCE.setModuleInfo(&getAnalysis<MachineModuleInfo>());
diff --git a/lib/Target/ARM/ARMConstantIslandPass.cpp b/lib/Target/ARM/ARMConstantIslandPass.cpp
index acd30d2897b..88c268c7ea9 100644
--- a/lib/Target/ARM/ARMConstantIslandPass.cpp
+++ b/lib/Target/ARM/ARMConstantIslandPass.cpp
@@ -1624,6 +1624,8 @@ bool ARMConstantIslands::OptimizeThumb2JumpTables(MachineFunction &MF) {
   // FIXME: After the tables are shrunk, can we get rid some of the
   // constantpool tables?
   MachineJumpTableInfo *MJTI = MF.getJumpTableInfo();
+  if (MJTI == 0) return false;
+  
   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
   for (unsigned i = 0, e = T2JumpTables.size(); i != e; ++i) {
     MachineInstr *MI = T2JumpTables[i];
@@ -1730,6 +1732,8 @@ bool ARMConstantIslands::ReorderThumb2JumpTables(MachineFunction &MF) {
   bool MadeChange = false;
 
   MachineJumpTableInfo *MJTI = MF.getJumpTableInfo();
+  if (MJTI == 0) return false;
+  
   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
   for (unsigned i = 0, e = T2JumpTables.size(); i != e; ++i) {
     MachineInstr *MI = T2JumpTables[i];
-- 
2.34.1