Scalar: Remove remaining ilist iterator implicit conversions

Remove remaining `ilist_iterator` implicit conversions from
LLVMScalarOpts.

This change exposed some scary behaviour in
lib/Transforms/Scalar/SCCP.cpp around line 1770.  This patch changes a
call from `Function::begin()` to `&Function::front()`, since the return
was immediately being passed into another function that takes a
`Function*`.  `Function::front()` started to assert, since the function
was empty.  Note that `Function::end()` does not point at a legal
`Function*` -- it points at an `ilist_half_node` -- so the other
function was getting garbage before.  (I added the missing check for
`Function::isDeclaration()`.)

Otherwise, no functionality change intended.

llvm-svn: 250211

1 files changed, 5 insertions, 6 deletions

diff --git a/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp b/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
index e4ecf678dff..4161d6f7dd7 100644
--- a/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
+++ b/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
@@ -258,7 +258,7 @@ LoadInst *MergedLoadStoreMotion::canHoistFromBlock(BasicBlock *BB1,
 
   for (BasicBlock::iterator BBI = BB1->begin(), BBE = BB1->end(); BBI != BBE;
        ++BBI) {
-    Instruction *Inst = BBI;
+    Instruction *Inst = &*BBI;
 
     // Only merge and hoist loads when their result in used only in BB
     if (!isa<LoadInst>(Inst) || Inst->isUsedOutsideOfBlock(BB1))
@@ -365,8 +365,7 @@ bool MergedLoadStoreMotion::mergeLoads(BasicBlock *BB) {
   int NLoads = 0;
   for (BasicBlock::iterator BBI = Succ0->begin(), BBE = Succ0->end();
        BBI != BBE;) {
-
-    Instruction *I = BBI;
+    Instruction *I = &*BBI;
     ++BBI;
 
     // Only move non-simple (atomic, volatile) loads.
@@ -444,7 +443,7 @@ PHINode *MergedLoadStoreMotion::getPHIOperand(BasicBlock *BB, StoreInst *S0,
   Value *Opd2 = S1->getValueOperand();
   if (Opd1 != Opd2) {
     NewPN = PHINode::Create(Opd1->getType(), 2, Opd2->getName() + ".sink",
-                            BB->begin());
+                            &BB->front());
     NewPN->addIncoming(Opd1, S0->getParent());
     NewPN->addIncoming(Opd2, S1->getParent());
     if (MD && NewPN->getType()->getScalarType()->isPointerTy())
@@ -478,7 +477,7 @@ bool MergedLoadStoreMotion::sinkStore(BasicBlock *BB, StoreInst *S0,
     // Create the new store to be inserted at the join point.
     StoreInst *SNew = (StoreInst *)(S0->clone());
     Instruction *ANew = A0->clone();
-    SNew->insertBefore(InsertPt);
+    SNew->insertBefore(&*InsertPt);
     ANew->insertBefore(SNew);
 
     assert(S0->getParent() == A0->getParent());
@@ -574,7 +573,7 @@ bool MergedLoadStoreMotion::runOnFunction(Function &F) {
   // Merge unconditional branches, allowing PRE to catch more
   // optimization opportunities.
   for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE;) {
-    BasicBlock *BB = FI++;
+    BasicBlock *BB = &*FI++;
 
     // Hoist equivalent loads and sink stores
     // outside diamonds when possible