From a771dc9b88972940cf21601e350a1fd99b86e1a5 Mon Sep 17 00:00:00 2001
From: pineappleEA <pineaea@gmail.com>
Date: Tue, 22 Mar 2022 23:20:20 +0100
Subject: [PATCH] early-access version 2591

---
 README.md                                     |  2 +-
 .../ir_opt/dead_code_elimination_pass.cpp     | 71 +++----------------
 2 files changed, 11 insertions(+), 62 deletions(-)

diff --git a/README.md b/README.md
index 473979b51..0cd83e751 100755
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 yuzu emulator early access
 =============
 
-This is the source code for early-access 2590.
+This is the source code for early-access 2591.
 
 ## Legal Notice
 
diff --git a/src/shader_recompiler/ir_opt/dead_code_elimination_pass.cpp b/src/shader_recompiler/ir_opt/dead_code_elimination_pass.cpp
index fe03b43ac..400836301 100755
--- a/src/shader_recompiler/ir_opt/dead_code_elimination_pass.cpp
+++ b/src/shader_recompiler/ir_opt/dead_code_elimination_pass.cpp
@@ -7,70 +7,19 @@
 #include "shader_recompiler/ir_opt/passes.h"
 
 namespace Shader::Optimization {
-namespace {
-template <bool TEST_USES>
-void DeadInstElimination(IR::Block* const block) {
-    // We iterate over the instructions in reverse order.
-    // This is because removing an instruction reduces the number of uses for earlier instructions.
-    auto it{block->end()};
-    while (it != block->begin()) {
-        --it;
-        if constexpr (TEST_USES) {
-            if (it->HasUses() || it->MayHaveSideEffects()) {
-                continue;
-            }
-        }
-        it->Invalidate();
-        it = block->Instructions().erase(it);
-    }
-}
-
-void DeadBranchElimination(IR::Program& program) {
-    const auto begin_it{program.syntax_list.begin()};
-    for (auto node_it = begin_it; node_it != program.syntax_list.end(); ++node_it) {
-        if (node_it->type != IR::AbstractSyntaxNode::Type::If) {
-            continue;
-        }
-        IR::Inst* const cond_ref{node_it->data.if_node.cond.Inst()};
-        const IR::U1 cond{cond_ref->Arg(0)};
-        if (!cond.IsImmediate()) {
-            continue;
-        }
-        if (cond.U1()) {
-            continue;
-        }
-        // False immediate condition. Remove condition ref, erase the entire branch.
-        cond_ref->Invalidate();
-        // Account for nested if-statements within the if(false) branch
-        u32 nested_ifs{1u};
-        while (node_it->type != IR::AbstractSyntaxNode::Type::EndIf || nested_ifs > 0) {
-            node_it = program.syntax_list.erase(node_it);
-            switch (node_it->type) {
-            case IR::AbstractSyntaxNode::Type::If:
-                ++nested_ifs;
-                break;
-            case IR::AbstractSyntaxNode::Type::EndIf:
-                --nested_ifs;
-                break;
-            case IR::AbstractSyntaxNode::Type::Block: {
-                IR::Block* const block{node_it->data.block};
-                DeadInstElimination<false>(block);
-                break;
-            }
-            default:
-                break;
-            }
-        }
-        // Erase EndIf node of the if(false) branch
-        node_it = program.syntax_list.erase(node_it);
-    }
-}
-} // namespace
 
 void DeadCodeEliminationPass(IR::Program& program) {
-    DeadBranchElimination(program);
+    // We iterate over the instructions in reverse order.
+    // This is because removing an instruction reduces the number of uses for earlier instructions.
     for (IR::Block* const block : program.post_order_blocks) {
-        DeadInstElimination<true>(block);
+        auto it{block->end()};
+        while (it != block->begin()) {
+            --it;
+            if (!it->HasUses() && !it->MayHaveSideEffects()) {
+                it->Invalidate();
+                it = block->Instructions().erase(it);
+            }
+        }
     }
 }