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, 4 insertions, 5 deletions

diff --git a/llvm/lib/Transforms/Scalar/Reg2Mem.cpp b/llvm/lib/Transforms/Scalar/Reg2Mem.cpp
index 1b46727c17b..915f89780c0 100644
--- a/llvm/lib/Transforms/Scalar/Reg2Mem.cpp
+++ b/llvm/lib/Transforms/Scalar/Reg2Mem.cpp
@@ -82,10 +82,9 @@ bool RegToMem::runOnFunction(Function &F) {
   BasicBlock::iterator I = BBEntry->begin();
   while (isa<AllocaInst>(I)) ++I;
 
-  CastInst *AllocaInsertionPoint =
-    new BitCastInst(Constant::getNullValue(Type::getInt32Ty(F.getContext())),
-                    Type::getInt32Ty(F.getContext()),
-                    "reg2mem alloca point", I);
+  CastInst *AllocaInsertionPoint = new BitCastInst(
+      Constant::getNullValue(Type::getInt32Ty(F.getContext())),
+      Type::getInt32Ty(F.getContext()), "reg2mem alloca point", &*I);
 
   // Find the escaped instructions. But don't create stack slots for
   // allocas in entry block.
@@ -95,7 +94,7 @@ bool RegToMem::runOnFunction(Function &F) {
     for (BasicBlock::iterator iib = ibb->begin(), iie = ibb->end();
          iib != iie; ++iib) {
       if (!(isa<AllocaInst>(iib) && iib->getParent() == BBEntry) &&
-          valueEscapes(iib)) {
+          valueEscapes(&*iib)) {
         WorkList.push_front(&*iib);
       }
     }