[llvm] InstCombine: Stop handling bitcast in PointerReplacer (PR #92937)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/92937

These should be irrelevant since opaque pointers.

>From 7591bf01c1edfbb8342991a5b9a5b90c5ec7a8d6 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Mon, 13 May 2024 15:14:08 +0200
Subject: [PATCH] InstCombine: Stop handling bitcast in PointerReplacer

These should be irrelevant since opaque pointers.
---
 .../InstCombine/InstCombineLoadStoreAlloca.cpp        | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index 4351a55ea1d30..832f89ed0b642 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -332,7 +332,7 @@ bool PointerReplacer::collectUsersRecursive(Instruction &I) {
       Worklist.insert(SI);
       if (!collectUsersRecursive(*SI))
         return false;
-    } else if (isa<GetElementPtrInst, BitCastInst>(Inst)) {
+    } else if (isa<GetElementPtrInst>(Inst)) {
       Worklist.insert(Inst);
       if (!collectUsersRecursive(*Inst))
         return false;
@@ -393,15 +393,6 @@ void PointerReplacer::replace(Instruction *I) {
     NewI->takeName(GEP);
     NewI->setIsInBounds(GEP->isInBounds());
     WorkMap[GEP] = NewI;
-  } else if (auto *BC = dyn_cast<BitCastInst>(I)) {
-    auto *V = getReplacement(BC->getOperand(0));
-    assert(V && "Operand not replaced");
-    auto *NewT = PointerType::get(BC->getType()->getContext(),
-                                  V->getType()->getPointerAddressSpace());
-    auto *NewI = new BitCastInst(V, NewT);
-    IC.InsertNewInstWith(NewI, BC->getIterator());
-    NewI->takeName(BC);
-    WorkMap[BC] = NewI;
   } else if (auto *SI = dyn_cast<SelectInst>(I)) {
     auto *NewSI = SelectInst::Create(
         SI->getCondition(), getReplacement(SI->getTrueValue()),