From 83228a81235a2286129074b4378edfed0533e446 Mon Sep 17 00:00:00 2001
From: lzkk <956449176@qq.com>
Date: Wed, 27 May 2026 16:24:57 +0800
Subject: [PATCH] =?UTF-8?q?fix(mir):=20GPR32/GPR64=E5=88=AB=E5=90=8D?=
 =?UTF-8?q?=E6=A3=80=E6=9F=A5=E7=A7=BB=E9=99=A4segments.empty()=E6=9D=A1?=
 =?UTF-8?q?=E4=BB=B6?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Wn和Xn是同一硬件寄存器（如W12和X12），GPR32和GPR64 vreg
在同一phys_reg上总是冲突，无论segments是否为空。
原代码要求!segments.empty()，导致某些情况下别名冲突被漏检。

参考: AArch64寄存器别名机制，Wn为Xn的低32位
---
 src/mir/GreedyAlloc.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/mir/GreedyAlloc.cpp b/src/mir/GreedyAlloc.cpp
index 491d5c7e..803c9e38 100644
--- a/src/mir/GreedyAlloc.cpp
+++ b/src/mir/GreedyAlloc.cpp
@@ -482,7 +482,7 @@ bool LiveRegMatrix::CheckInterference(const LiveInterval &li, int phys_reg) cons
         bool gpr32_64_alias =
             (li.reg_class == RegClass::GPR32 && other->reg_class == RegClass::GPR64) ||
             (li.reg_class == RegClass::GPR64 && other->reg_class == RegClass::GPR32);
-        if (gpr32_64_alias && !li.segments.empty() && !other->segments.empty())
+        if (gpr32_64_alias)
             return true;
         for (auto &sa : li.segments)
             for (auto &sb : other->segments)
@@ -501,7 +501,7 @@ LiveInterval *LiveRegMatrix::GetConflict(const LiveInterval &li,
         bool gpr32_64_alias =
             (li.reg_class == RegClass::GPR32 && other->reg_class == RegClass::GPR64) ||
             (li.reg_class == RegClass::GPR64 && other->reg_class == RegClass::GPR32);
-        if (gpr32_64_alias && !li.segments.empty() && !other->segments.empty())
+        if (gpr32_64_alias)
             return other;
         for (auto &sa : li.segments)
             for (auto &sb : other->segments)