From 784e8d9177a692bf627695476e32c000fdb6eb73 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sun, 30 Aug 2009 20:06:40 +0000
Subject: [PATCH] add getPointerAddressSpace() to GEP instruction, use the
 method in a few scalar xforms to simplify things.

llvm-svn: 80506
---
 include/llvm/Instructions.h                    |  4 ++++
 lib/Transforms/Scalar/InstructionCombining.cpp | 10 ++++------
 lib/Transforms/Scalar/SCCP.cpp                 |  3 +--
 lib/Transforms/Scalar/SimplifyCFGPass.cpp      |  2 +-
 4 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/include/llvm/Instructions.h b/include/llvm/Instructions.h
index ee9657dbba9..4460f8890a5 100644
--- a/include/llvm/Instructions.h
+++ b/include/llvm/Instructions.h
@@ -570,6 +570,10 @@ public:
   static unsigned getPointerOperandIndex() {
     return 0U;                      // get index for modifying correct operand
   }
+  
+  unsigned getPointerAddressSpace() const {
+    return cast<PointerType>(getType())->getAddressSpace();
+  }
 
   /// getPointerOperandType - Method to return the pointer operand as a
   /// PointerType.
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 47e6f4d5582..478068c95b5 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -11289,8 +11289,7 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
   if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(Op)) {
     const Value *GEPI0 = GEPI->getOperand(0);
     // TODO: Consider a target hook for valid address spaces for this xform.
-    if (isa<ConstantPointerNull>(GEPI0) &&
-        cast<PointerType>(GEPI0->getType())->getAddressSpace() == 0) {
+    if (isa<ConstantPointerNull>(GEPI0) && GEPI->getPointerAddressSpace() == 0){
       // Insert a new store to null instruction before the load to indicate
       // that this code is not reachable.  We do this instead of inserting
       // an unreachable instruction directly because we cannot modify the
@@ -11304,8 +11303,8 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
   if (Constant *C = dyn_cast<Constant>(Op)) {
     // load null/undef -> undef
     // TODO: Consider a target hook for valid address spaces for this xform.
-    if (isa<UndefValue>(C) || (C->isNullValue() && 
-        cast<PointerType>(Op->getType())->getAddressSpace() == 0)) {
+    if (isa<UndefValue>(C) ||
+        (C->isNullValue() && LI.getPointerAddressSpace() == 0)) {
       // Insert a new store to null instruction before the load to indicate that
       // this code is not reachable.  We do this instead of inserting an
       // unreachable instruction directly because we cannot modify the CFG.
@@ -11640,8 +11639,7 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) {
   if (SI.isVolatile()) return 0;  // Don't hack volatile stores.
 
   // store X, null    -> turns into 'unreachable' in SimplifyCFG
-  if (isa<ConstantPointerNull>(Ptr) &&
-      cast<PointerType>(Ptr->getType())->getAddressSpace() == 0) {
+  if (isa<ConstantPointerNull>(Ptr) && SI.getPointerAddressSpace() == 0) {
     if (!isa<UndefValue>(Val)) {
       SI.setOperand(0, UndefValue::get(Val->getType()));
       if (Instruction *U = dyn_cast<Instruction>(Val))
diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp
index 3c6dcadaa76..155e91ec7b4 100644
--- a/lib/Transforms/Scalar/SCCP.cpp
+++ b/lib/Transforms/Scalar/SCCP.cpp
@@ -1131,8 +1131,7 @@ void SCCPSolver::visitLoadInst(LoadInst &I) {
   if (PtrVal.isConstant() && !I.isVolatile()) {
     Value *Ptr = PtrVal.getConstant();
     // TODO: Consider a target hook for valid address spaces for this xform.
-    if (isa<ConstantPointerNull>(Ptr) && 
-        cast<PointerType>(Ptr->getType())->getAddressSpace() == 0) {
+    if (isa<ConstantPointerNull>(Ptr) && I.getPointerAddressSpace() == 0) {
       // load null -> null
       markConstant(IV, &I, Constant::getNullValue(I.getType()));
       return;
diff --git a/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/lib/Transforms/Scalar/SimplifyCFGPass.cpp
index 5de79c49cfb..ca4292bcaa1 100644
--- a/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ b/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -132,7 +132,7 @@ static bool MarkAliveBlocks(BasicBlock *BB,
         
         if (isa<UndefValue>(Ptr) ||
             (isa<ConstantPointerNull>(Ptr) &&
-             cast<PointerType>(Ptr->getType())->getAddressSpace() == 0)) {
+             SI->getPointerAddressSpace() == 0)) {
           ChangeToUnreachable(SI, Context);
           Changed = true;
           break;