From 81986781d3f5896c6e38d050dd7bf97b019268eb Mon Sep 17 00:00:00 2001
From: liyufei2025 <yufio@isc.riscas.ac.cn>
Date: Fri, 10 Oct 2025 13:17:36 +0800
Subject: [PATCH 1/2] loopinterchange

---
 .../lib/Transforms/Scalar/LoopInterchange.cpp | 29 +++++++++++++++----
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
index 91286ebcea33..a7f0431233bd 100644
--- a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
@@ -54,7 +54,7 @@ using namespace llvm;
 STATISTIC(LoopsInterchanged, "Number of loops interchanged");
 
 static cl::opt<int> LoopInterchangeCostThreshold(
-    "loop-interchange-threshold", cl::init(0), cl::Hidden,
+    "loop-interchange-threshold", cl::init(1), cl::Hidden,
     cl::desc("Interchange if you gain more than this number"));
 
 namespace {
@@ -114,6 +114,12 @@ static bool populateDependencyMatrix(CharMatrix &DepMatrix, unsigned Level,
 
   for (I = MemInstr.begin(), IE = MemInstr.end(); I != IE; ++I) {
     for (J = I, JE = MemInstr.end(); J != JE; ++J) {
+      
+      if(I==J){
+      	LLVM_DEBUG(dbgs()<<"Skipping self-dependency analysis\n");
+	      continue;
+      }
+
       std::vector<char> Dep;
       Instruction *Src = cast<Instruction>(*I);
       Instruction *Dst = cast<Instruction>(*J);
@@ -540,6 +546,11 @@ struct LoopInterchange {
 
 bool LoopInterchangeLegality::containsUnsafeInstructions(BasicBlock *BB) {
   return any_of(*BB, [](const Instruction &I) {
+    if (auto *St = dyn_cast<StoreInst>(&I))
+      return !St->isSimple();
+    if(auto *Ld = dyn_cast<LoadInst>(&I))
+      return !Ld->isSimple();
+    		  
     return I.mayHaveSideEffects() || I.mayReadFromMemory();
   });
 }
@@ -561,15 +572,19 @@ bool LoopInterchangeLegality::tightlyNested(Loop *OuterLoop, Loop *InnerLoop) {
 
   for (BasicBlock *Succ : successors(OuterLoopHeaderBI))
     if (Succ != InnerLoopPreHeader && Succ != InnerLoop->getHeader() &&
-        Succ != OuterLoopLatch)
-      return false;
+        Succ != OuterLoopLatch){
+       errs() << "first step error" << "\n";
+       return false;
+    }
 
   LLVM_DEBUG(dbgs() << "Checking instructions in Loop header and Loop latch\n");
   // We do not have any basic block in between now make sure the outer header
   // and outer loop latch doesn't contain any unsafe instructions.
   if (containsUnsafeInstructions(OuterLoopHeader) ||
-      containsUnsafeInstructions(OuterLoopLatch))
+      containsUnsafeInstructions(OuterLoopLatch)){
+    errs() << "second step error" << "\n";
     return false;
+  }
 
   // Also make sure the inner loop preheader does not contain any unsafe
   // instructions. Note that all instructions in the preheader will be moved to
@@ -1089,7 +1104,7 @@ int LoopInterchangeProfitability::getInstrOrderCost() {
       }
     }
   }
-  return GoodOrder - BadOrder;
+  return GoodOrder - BadOrder;       
 }
 
 std::optional<bool>
@@ -1123,7 +1138,7 @@ LoopInterchangeProfitability::isProfitablePerInstrOrderCost() {
   // reordering if number of bad orders is more than good.
   int Cost = getInstrOrderCost();
   LLVM_DEBUG(dbgs() << "Cost = " << Cost << "\n");
-  if (Cost < 0 && Cost < LoopInterchangeCostThreshold)
+  if (Cost < 1 && Cost < LoopInterchangeCostThreshold)
     return std::optional<bool>(true);
 
   return std::nullopt;
@@ -1712,6 +1727,8 @@ PreservedAnalyses LoopInterchangePass::run(LoopNest &LN,
                                            LoopAnalysisManager &AM,
                                            LoopStandardAnalysisResults &AR,
                                            LPMUpdater &U) {
+  
+  //errs()<<"the 5th try"<<"\n";
   Function &F = *LN.getParent();
 
   DependenceInfo DI(&F, &AR.AA, &AR.SE, &AR.LI);
-- 
Gitee


From 6138134c3ab94486f7c26d3d1cfe8d3edc50dda1 Mon Sep 17 00:00:00 2001
From: fanxuerun <van202403@163.com>
Date: Fri, 10 Oct 2025 13:25:49 +0800
Subject: [PATCH 2/2] =?UTF-8?q?loopinterchange=E4=BC=98=E5=8C=96?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 llvm/lib/Transforms/Scalar/LoopInterchange.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
index a7f0431233bd..b761e5842f52 100644
--- a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
@@ -49,6 +49,7 @@
 
 using namespace llvm;
 
+
 #define DEBUG_TYPE "loop-interchange"
 
 STATISTIC(LoopsInterchanged, "Number of loops interchanged");
-- 
Gitee