[llvm] r240599 - Add simplify_type<const WeakVH>; simplify IndVarSimplify

[Duncan P. N. Exon Smith]

Author: dexonsmith
Date: Wed Jun 24 17:23:21 2015
New Revision: 240599

URL: http://llvm.org/viewvc/llvm-project?rev=240599&view=rev
Log:
Add simplify_type<const WeakVH>; simplify IndVarSimplify

r240214 fixed some UB in IndVarSimplify, and it needed a temporary
`WeakVH` to do it.  Add `simplify_type<const WeakVH>` so that this
temporary isn't necessary.

Modified:
    llvm/trunk/include/llvm/IR/ValueHandle.h
    llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp

Modified: llvm/trunk/include/llvm/IR/ValueHandle.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/ValueHandle.h?rev=240599&r1=240598&r2=240599&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/ValueHandle.h (original)
+++ llvm/trunk/include/llvm/IR/ValueHandle.h Wed Jun 24 17:23:21 2015
@@ -159,11 +159,13 @@ public:
 
 // Specialize simplify_type to allow WeakVH to participate in
 // dyn_cast, isa, etc.
-template<> struct simplify_type<WeakVH> {
-  typedef Value* SimpleType;
-  static SimpleType getSimplifiedValue(WeakVH &WVH) {
-    return WVH;
-  }
+template <> struct simplify_type<WeakVH> {
+  typedef Value *SimpleType;
+  static SimpleType getSimplifiedValue(WeakVH &WVH) { return WVH; }
+};
+template <> struct simplify_type<const WeakVH> {
+  typedef Value *SimpleType;
+  static SimpleType getSimplifiedValue(const WeakVH &WVH) { return WVH; }
 };
 
 /// \brief Value handle that asserts if the Value is deleted.

Modified: llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp?rev=240599&r1=240598&r2=240599&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp Wed Jun 24 17:23:21 2015
@@ -2013,11 +2013,10 @@ bool IndVarSimplify::runOnLoop(Loop *L,
 
   // Now that we're done iterating through lists, clean up any instructions
   // which are now dead.
-  while (!DeadInsts.empty()) {
-    Value *V = static_cast<Value *>(DeadInsts.pop_back_val());
-    if (Instruction *Inst = dyn_cast_or_null<Instruction>(V))
+  while (!DeadInsts.empty())
+    if (Instruction *Inst =
+            dyn_cast_or_null<Instruction>(DeadInsts.pop_back_val()))
       RecursivelyDeleteTriviallyDeadInstructions(Inst, TLI);
-  }
 
   // The Rewriter may not be used from this point on.