From ed4964e8924abfec65d429edcdbb89eb83a17016 Mon Sep 17 00:00:00 2001
From: yesfish <huwpascoe@users.noreply.github.com>
Date: Thu, 19 Oct 2017 02:41:49 +0100
Subject: [PATCH] reg_alloc: Improve performance of HostLocInfo (#112)

This commit changes the type of HostLocInfo::values from std::vector<Inst*> to std::forward_list<Inst*>.
---
 src/backend_x64/reg_alloc.cpp | 6 +++---
 src/backend_x64/reg_alloc.h   | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/backend_x64/reg_alloc.cpp b/src/backend_x64/reg_alloc.cpp
index 20eb147d..c5720790 100644
--- a/src/backend_x64/reg_alloc.cpp
+++ b/src/backend_x64/reg_alloc.cpp
@@ -5,6 +5,7 @@
  */
 
 #include <algorithm>
+#include <vector>
 
 #include <xbyak.h>
 
@@ -99,12 +100,11 @@ void HostLocInfo::WriteLock() {
 }
 
 void HostLocInfo::AddValue(IR::Inst* inst) {
-    values.push_back(inst);
+    values.push_front(inst);
 }
 
 void HostLocInfo::EndOfAllocScope() {
-    const auto to_erase = std::remove_if(values.begin(), values.end(), [](const auto& inst) { return !inst->HasUses(); });
-    values.erase(to_erase, values.end());
+    values.remove_if([](const auto& inst) { return !inst->HasUses(); });
 
     is_being_used = false;
     is_scratch = false;
diff --git a/src/backend_x64/reg_alloc.h b/src/backend_x64/reg_alloc.h
index 6a54819f..bf0a37f1 100644
--- a/src/backend_x64/reg_alloc.h
+++ b/src/backend_x64/reg_alloc.h
@@ -7,7 +7,7 @@
 #pragma once
 
 #include <array>
-#include <vector>
+#include <forward_list>
 
 #include <boost/optional.hpp>
 #include <xbyak.h>
@@ -40,7 +40,7 @@ public:
     void EndOfAllocScope();
 
 private:
-    std::vector<IR::Inst*> values;
+    std::forward_list<IR::Inst*> values;
     bool is_being_used = false;
     bool is_scratch = false;
 };