From 4179f4026410314bee17461bc33de47943494d48 Mon Sep 17 00:00:00 2001
From: lzkk <956449176@qq.com>
Date: Thu, 28 May 2026 13:16:24 +0800
Subject: [PATCH] =?UTF-8?q?perf(mir):=20leaf=20=E5=87=BD=E6=95=B0=E7=9C=81?=
 =?UTF-8?q?=E7=95=A5=E5=B8=A7=E6=8C=87=E9=92=88=E2=80=94=E2=80=94=E6=97=A0?=
 =?UTF-8?q?=E8=B0=83=E7=94=A8+=E6=97=A0=E6=A0=88=E5=B8=A7=E6=97=B6?=
 =?UTF-8?q?=E8=B7=B3=E8=BF=87=20stp/ldp=20x29,x30?=
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crypto 1482→1458（-24 指令），crc 306→303。
---
 src/mir/AsmPrinter.cpp | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/mir/AsmPrinter.cpp b/src/mir/AsmPrinter.cpp
index ab451cd0..a29d65d1 100644
--- a/src/mir/AsmPrinter.cpp
+++ b/src/mir/AsmPrinter.cpp
@@ -422,6 +422,18 @@ namespace mir
             case Opcode::Prologue:
             {
                 const auto &cs_regs = function.GetCalleeSavedRegs();
+                // 若函数无需帧（leaf + 无栈槽 + 无被调用者保存寄存器），跳过帧设置
+                bool has_frame = function.GetFrameSize() > 0 || !cs_regs.empty();
+                if (!has_frame) {
+                    // 检查是否有 Call 指令，若有则需要保存 LR
+                    for (const auto &blk : function.GetBlocks()) {
+                        for (const auto &i : blk->GetInstructions()) {
+                            if (i.GetOpcode() == Opcode::Call) { has_frame = true; break; }
+                        }
+                        if (has_frame) break;
+                    }
+                }
+                if (!has_frame) return;  // leaf 函数，无需帧
                 os << "    stp x29, x30, [sp, #-16]!\n";
                 os << "    mov x29, sp\n";
                 if (function.GetFrameSize() > 0)
@@ -448,6 +460,16 @@ namespace mir
             case Opcode::Epilogue:
             {
                 const auto &cs_regs = function.GetCalleeSavedRegs();
+                bool has_frame = function.GetFrameSize() > 0 || !cs_regs.empty();
+                if (!has_frame) {
+                    for (const auto &blk : function.GetBlocks()) {
+                        for (const auto &i : blk->GetInstructions()) {
+                            if (i.GetOpcode() == Opcode::Call) { has_frame = true; break; }
+                        }
+                        if (has_frame) break;
+                    }
+                }
+                if (!has_frame) { os << "    ret\n"; return; }
                 int cs_offset = 0;
                 for (auto r : cs_regs)
                 {