From 24bf921ff9cc0376ebd3bb1bd7158191dad6320a Mon Sep 17 00:00:00 2001
From: Merry <git@mary.rs>
Date: Tue, 30 Jan 2024 23:10:23 +0000
Subject: [PATCH] constant_propagation_pass: x + 0 == x

---
 src/dynarmic/ir/opt/constant_propagation_pass.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/dynarmic/ir/opt/constant_propagation_pass.cpp b/src/dynarmic/ir/opt/constant_propagation_pass.cpp
index f63f6464..83ed8499 100644
--- a/src/dynarmic/ir/opt/constant_propagation_pass.cpp
+++ b/src/dynarmic/ir/opt/constant_propagation_pass.cpp
@@ -96,10 +96,18 @@ void FoldAdd(IR::Inst& inst, bool is_32_bit) {
         const IR::Inst* lhs_inst = lhs.GetInstRecursive();
         if (lhs_inst->GetOpcode() == inst.GetOpcode() && lhs_inst->GetArg(1).IsImmediate() && lhs_inst->GetArg(2).IsImmediate()) {
             const u64 combined = rhs.GetImmediateAsU64() + lhs_inst->GetArg(1).GetImmediateAsU64() + lhs_inst->GetArg(2).GetU1();
+            if (combined == 0) {
+                inst.ReplaceUsesWith(lhs_inst->GetArg(0));
+                return;
+            }
             inst.SetArg(0, lhs_inst->GetArg(0));
             inst.SetArg(1, Value(is_32_bit, combined));
             return;
         }
+        if (rhs.IsZero() && carry.IsZero()) {
+            inst.ReplaceUsesWith(lhs);
+            return;
+        }
     }
 
     if (inst.AreAllArgsImmediates()) {