Revert "Recommit "[LoopFlatten] Enable it by default""

This reverts commit 5b9597f59a445523bd59b5251ab1c2865e74919f.

A miscompilation was reported:
https://github.com/llvm/llvm-project/issues/58441

Reverting this while I look at that.

diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index 95ccc06..292efe0 100644 (file)
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -12,7 +12,6 @@ LLVM |release| Release Notes
      Release notes for previous releases can be found on
      `the Download Page <https://releases.llvm.org/download.html>`_.
 
-* The LoopFlatten pass is now enabled by default.
 
 Introduction
 ============

diff --git a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
index 0c41db1..52e4fa4 100644 (file)
--- a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -83,7 +83,7 @@ cl::opt<bool> EnableUnrollAndJam("enable-unroll-and-jam", cl::init(false),
                                  cl::Hidden,
                                  cl::desc("Enable Unroll And Jam Pass"));
 
-cl::opt<bool> EnableLoopFlatten("enable-loop-flatten", cl::init(true),
+cl::opt<bool> EnableLoopFlatten("enable-loop-flatten", cl::init(false),
                                 cl::Hidden,
                                 cl::desc("Enable the LoopFlatten Pass"));
 

diff --git a/llvm/lib/Transforms/Scalar/LoopFlatten.cpp b/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
index 944b449..c530e77 100644 (file)
--- a/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
@@ -762,7 +762,6 @@ static bool DoFlattenLoopPair(FlattenInfo &FI, DominatorTree *DT, LoopInfo *LI,
   // deleted, and any information that have about the outer loop invalidated.
   SE->forgetLoop(FI.OuterLoop);
   SE->forgetLoop(FI.InnerLoop);
-  SE->forgetLoopDispositions();
   if (U)
     U->markLoopAsDeleted(*FI.InnerLoop, FI.InnerLoop->getName());
   LI->erase(FI.InnerLoop);

diff --git a/llvm/test/Other/new-pm-defaults.ll b/llvm/test/Other/new-pm-defaults.ll
index 2b57c04..162663a 100644 (file)
--- a/llvm/test/Other/new-pm-defaults.ll
+++ b/llvm/test/Other/new-pm-defaults.ll
@@ -174,7 +174,6 @@
 ; CHECK-O-NEXT: Running pass: LICM
 ; CHECK-O-NEXT: Running pass: SimpleLoopUnswitchPass
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
-; CHECK-O-NEXT: Running pass: LoopFlattenPass
 ; CHECK-O-NEXT: Running pass: SimplifyCFGPass
 ; CHECK-O-NEXT: Running pass: InstCombinePass
 ; CHECK-O-NEXT: Running pass: LoopSimplifyPass

diff --git a/llvm/test/Other/new-pm-lto-defaults.ll b/llvm/test/Other/new-pm-lto-defaults.ll
index aa772c1..6432d80 100644 (file)
--- a/llvm/test/Other/new-pm-lto-defaults.ll
+++ b/llvm/test/Other/new-pm-lto-defaults.ll
@@ -116,7 +116,6 @@
 ; CHECK-O23SZ-NEXT: Running pass: MergedLoadStoreMotionPass on foo
 ; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass on foo
 ; CHECK-O23SZ-NEXT: Running pass: LCSSAPass on foo
-; CHECK-O23SZ-NEXT: Running pass: LoopFlattenPass on loop
 ; CHECK-O23SZ-NEXT: Running pass: IndVarSimplifyPass on loop
 ; CHECK-O23SZ-NEXT: Running pass: LoopDeletionPass on loop
 ; CHECK-O23SZ-NEXT: Running pass: LoopFullUnrollPass on loop

diff --git a/llvm/test/Other/new-pm-thinlto-defaults.ll b/llvm/test/Other/new-pm-thinlto-defaults.ll
index 811047b..7ef6ac1 100644 (file)
--- a/llvm/test/Other/new-pm-thinlto-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-defaults.ll
@@ -149,7 +149,6 @@
 ; CHECK-O-NEXT: Running pass: LICM
 ; CHECK-O-NEXT: Running pass: SimpleLoopUnswitchPass
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
-; CHECK-O-NEXT: Running pass: LoopFlattenPass
 ; CHECK-O-NEXT: Running pass: SimplifyCFGPass
 ; CHECK-O-NEXT: Running pass: InstCombinePass
 ; CHECK-O-NEXT: Running pass: LoopSimplifyPass

diff --git a/llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll b/llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll
index b9933d5..524e671 100644 (file)
--- a/llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll
@@ -110,7 +110,6 @@
 ; CHECK-O-NEXT: Running pass: LICM
 ; CHECK-O-NEXT: Running pass: SimpleLoopUnswitchPass
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
-; CHECK-O-NEXT: Running pass: LoopFlattenPass
 ; CHECK-O-NEXT: Running pass: SimplifyCFGPass
 ; CHECK-O-NEXT: Running pass: InstCombinePass
 ; CHECK-O-NEXT: Running pass: LoopSimplifyPass

diff --git a/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll b/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll
index 687011e..64344aa 100644 (file)
--- a/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll
@@ -119,7 +119,6 @@
 ; CHECK-O-NEXT: Running pass: LICM
 ; CHECK-O-NEXT: Running pass: SimpleLoopUnswitchPass
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
-; CHECK-O-NEXT: Running pass: LoopFlattenPass
 ; CHECK-O-NEXT: Running pass: SimplifyCFGPass
 ; CHECK-O-NEXT: Running pass: InstCombinePass
 ; CHECK-O-NEXT: Running pass: LoopSimplifyPass

diff --git a/llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll b/llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll
index bc3f523..812212d 100644 (file)
--- a/llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll
@@ -148,7 +148,6 @@
 ; CHECK-O-NEXT: Running pass: LICM
 ; CHECK-O-NEXT: Running pass: SimpleLoopUnswitchPass
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
-; CHECK-O-NEXT: Running pass: LoopFlattenPass
 ; CHECK-O-NEXT: Running pass: SimplifyCFGPass
 ; CHECK-O-NEXT: Running pass: InstCombinePass
 ; CHECK-O-NEXT: Running pass: LoopSimplifyPass

diff --git a/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll b/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll
index 1275d2d..0d51942 100644 (file)
--- a/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll
@@ -114,7 +114,6 @@
 ; CHECK-O-NEXT: Running pass: LICM
 ; CHECK-O-NEXT: Running pass: SimpleLoopUnswitchPass
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
-; CHECK-O-NEXT: Running pass: LoopFlattenPass
 ; CHECK-O-NEXT: Running pass: SimplifyCFGPass
 ; CHECK-O-NEXT: Running pass: InstCombinePass
 ; CHECK-O-NEXT: Running pass: LoopSimplifyPass