From ce4d4b5f5b9035639bb75442864be858cbde6233 Mon Sep 17 00:00:00 2001
From: rain2133 <1370973498@qq.com>
Date: Tue, 19 Aug 2025 01:08:05 +0800
Subject: [PATCH] =?UTF-8?q?[midend-phielimination]=E5=A2=9E=E5=8A=A0phi?=
 =?UTF-8?q?=E6=8C=87=E4=BB=A4=E6=B6=88=E9=99=A4=E6=A3=80=E6=9F=A5?=
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---
 .../midend/Pass/Optimize/SysYIROptUtils.h     | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/include/midend/Pass/Optimize/SysYIROptUtils.h b/src/include/midend/Pass/Optimize/SysYIROptUtils.h
index 48d2f26..71c0532 100644
--- a/src/include/midend/Pass/Optimize/SysYIROptUtils.h
+++ b/src/include/midend/Pass/Optimize/SysYIROptUtils.h
@@ -109,6 +109,28 @@ public:
   }
 
   
+  // PHI指令消除相关方法
+  static void eliminateRedundantPhisInFunction(Function* func){
+    std::vector<Instruction *> toDelete;
+    for (auto &bb : func->getBasicBlocks()) {
+      for (auto &inst : bb->getInstructions()) {
+        if (auto phi = dynamic_cast<PhiInst *>(inst.get())) {
+          auto incoming = phi->getIncomingValues();
+          if (incoming.size() == 1) {
+            Value *singleVal = incoming[0].first;
+            inst->replaceAllUsesWith(singleVal);
+            toDelete.push_back(inst.get());
+          }
+        }
+        else
+          break; // 只处理Phi指令
+      }
+    }
+    for (auto *phi : toDelete) {
+      usedelete(phi);
+    }
+  }
+
   //该实现参考了libdivide的算法
   static std::pair<int, int> computeMulhMagicNumbers(int divisor) {