From 1428f080a8d2017026648e7e837ea3a829a5763d Mon Sep 17 00:00:00 2001
From: Kevin Qin <Kevin.Qin@arm.com>
Date: Mon, 9 Mar 2015 07:26:37 +0000
Subject: [PATCH] Revert r231630 - Run LICM pass after loop unrolling pass.

As it broke llvm bootstrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231635 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/IPO/PassManagerBuilder.cpp   |  8 +---
 lib/Transforms/Utils/LoopUnrollRuntime.cpp  |  9 +++--
 test/Transforms/LoopUnroll/runtime-loop4.ll | 43 ---------------------
 3 files changed, 7 insertions(+), 53 deletions(-)
 delete mode 100644 test/Transforms/LoopUnroll/runtime-loop4.ll

diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
index 7ff55a7c7e1..21fa34dfbcf 100644
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -364,14 +364,8 @@ void PassManagerBuilder::populateModulePassManager(
   MPM.add(createCFGSimplificationPass());
   MPM.add(createInstructionCombiningPass());
 
-  if (!DisableUnrollLoops) {
+  if (!DisableUnrollLoops)
     MPM.add(createLoopUnrollPass());    // Unroll small loops
-    // Runtime unrollng will introduce runtime check in loop prologue. If the
-    // unrolled loop is a inner loop, then the prologue will be inside the
-    // outer loop. LICM pass can help to promote the runtime check out if the
-    // checked value is loop invariant.
-    MPM.add(createLICMPass());
-  }
 
   // After vectorization and unrolling, assume intrinsics may tell us more
   // about pointer alignments.
diff --git a/lib/Transforms/Utils/LoopUnrollRuntime.cpp b/lib/Transforms/Utils/LoopUnrollRuntime.cpp
index 9e2d8c98b9e..91b688cc8e1 100644
--- a/lib/Transforms/Utils/LoopUnrollRuntime.cpp
+++ b/lib/Transforms/Utils/LoopUnrollRuntime.cpp
@@ -142,7 +142,7 @@ static void CloneLoopBlocks(Loop *L, Value *NewIter, const bool UnrollProlog,
                             BasicBlock *InsertTop, BasicBlock *InsertBot,
                             std::vector<BasicBlock *> &NewBlocks,
                             LoopBlocksDFS &LoopBlocks, ValueToValueMapTy &VMap,
-                            LoopInfo *LI, LPPassManager *LPM) {
+                            LoopInfo *LI) {
   BasicBlock *Preheader = L->getLoopPreheader();
   BasicBlock *Header = L->getHeader();
   BasicBlock *Latch = L->getLoopLatch();
@@ -153,7 +153,10 @@ static void CloneLoopBlocks(Loop *L, Value *NewIter, const bool UnrollProlog,
   Loop *ParentLoop = L->getParentLoop();
   if (!UnrollProlog) {
     NewLoop = new Loop();
-    LPM->insertLoop(NewLoop, ParentLoop);
+    if (ParentLoop)
+      ParentLoop->addChildLoop(NewLoop);
+    else
+      LI->addTopLevelLoop(NewLoop);
   }
 
   // For each block in the original loop, create a new copy,
@@ -387,7 +390,7 @@ bool llvm::UnrollRuntimeLoopProlog(Loop *L, unsigned Count, LoopInfo *LI,
   // the loop, otherwise we create a cloned loop to execute the extra
   // iterations. This function adds the appropriate CFG connections.
   CloneLoopBlocks(L, ModVal, UnrollPrologue, PH, PEnd, NewBlocks, LoopBlocks,
-                  VMap, LI, LPM);
+                  VMap, LI);
 
   // Insert the cloned blocks into function just before the original loop
   F->getBasicBlockList().splice(PEnd, F->getBasicBlockList(), NewBlocks[0],
diff --git a/test/Transforms/LoopUnroll/runtime-loop4.ll b/test/Transforms/LoopUnroll/runtime-loop4.ll
deleted file mode 100644
index 9be0ffd23d3..00000000000
--- a/test/Transforms/LoopUnroll/runtime-loop4.ll
+++ /dev/null
@@ -1,43 +0,0 @@
-; RUN: opt < %s -S -O2 -unroll-runtime=true | FileCheck %s
-
-; Check runtime unrolling prologue can be promoted by LICM pass.
-
-; CHECK: entry:
-; CHECK: %xtraiter
-; CHECK: %lcmp.mod
-; CHECK: loop1:
-; CHECK: br i1 %lcmp.mod
-; CHECK: loop2.prol:
-
-define void @unroll(i32 %iter, i32* %addr1, i32* %addr2) nounwind {
-entry:
-  br label %loop1
-
-loop1:
-  %iv1 = phi i32 [ 0, %entry ], [ %inc1, %loop1.latch ]
-  %offset1 = getelementptr i32, i32* %addr1, i32 %iv1
-  store i32 %iv1, i32* %offset1, align 4
-  br label %loop2.header
-
-loop2.header:
-  br label %loop2
-
-loop2:
-  %iv2 = phi i32 [ 0, %loop2.header ], [ %inc2, %loop2 ]
-  %offset2 = getelementptr i32, i32* %addr2, i32 %iv2
-  store i32 %iv2, i32* %offset2, align 4
-  %inc2 = add i32 %iv2, 1
-  %exitcnd2 = icmp uge i32 %inc2, %iter
-  br i1 %exitcnd2, label %exit2, label %loop2
-
-exit2:
-  br label %loop1.latch
-
-loop1.latch:
-  %inc1 = add i32 %iv1, 1
-  %exitcnd1 = icmp uge i32 %inc1, 1024
-  br i1 %exitcnd1, label %exit, label %loop1
-
-exit:
-  ret void
-}
-- 
2.34.1