[llvm] r347486 - Disable LoopSimplifyCFG terminator folding by default

[Max Kazantsev via llvm-commits]

Author: mkazantsev
Date: Fri Nov 23 01:14:53 2018
New Revision: 347486

URL: http://llvm.org/viewvc/llvm-project?rev=347486&view=rev
Log:
Disable LoopSimplifyCFG terminator folding by default

Modified:
    llvm/trunk/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
    llvm/trunk/test/Transforms/LoopSimplifyCFG/constant-fold-branch.ll
    llvm/trunk/test/Transforms/LoopSimplifyCFG/lcssa.ll

Modified: llvm/trunk/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopSimplifyCFG.cpp?rev=347486&r1=347485&r2=347486&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopSimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopSimplifyCFG.cpp Fri Nov 23 01:14:53 2018
@@ -41,6 +41,9 @@ using namespace llvm;
 
 #define DEBUG_TYPE "loop-simplifycfg"
 
+static cl::opt<bool> EnableTermFolding("enable-loop-simplifycfg-term-folding",
+                                       cl::init(false));
+
 STATISTIC(NumTerminatorsFolded,
           "Number of terminators folded to unconditional branches");
 
@@ -352,6 +355,9 @@ public:
 /// Turn branches and switches with known constant conditions into unconditional
 /// branches.
 static bool constantFoldTerminators(Loop &L, DominatorTree &DT, LoopInfo &LI) {
+  if (!EnableTermFolding)
+    return false;
+
   // To keep things simple, only process loops with single latch. We
   // canonicalize most loops to this form. We can support multi-latch if needed.
   if (!L.getLoopLatch())

Modified: llvm/trunk/test/Transforms/LoopSimplifyCFG/constant-fold-branch.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopSimplifyCFG/constant-fold-branch.ll?rev=347486&r1=347485&r2=347486&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopSimplifyCFG/constant-fold-branch.ll (original)
+++ llvm/trunk/test/Transforms/LoopSimplifyCFG/constant-fold-branch.ll Fri Nov 23 01:14:53 2018
@@ -1,8 +1,8 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; REQUIRES: asserts
-; RUN: opt -S -loop-simplifycfg -debug-only=loop-simplifycfg -verify-loop-info -verify-dom-info -verify-loop-lcssa 2>&1 < %s | FileCheck %s
-; RUN: opt -S -passes='require<domtree>,loop(simplify-cfg)' -debug-only=loop-simplifycfg -verify-loop-info -verify-dom-info -verify-loop-lcssa 2>&1 < %s | FileCheck %s
-; RUN: opt -S -loop-simplifycfg -enable-mssa-loop-dependency=true -verify-memoryssa -debug-only=loop-simplifycfg -verify-loop-info -verify-dom-info -verify-loop-lcssa 2>&1 < %s | FileCheck %s
+; RUN: opt -S -enable-loop-simplifycfg-term-folding=true -loop-simplifycfg -debug-only=loop-simplifycfg -verify-loop-info -verify-dom-info -verify-loop-lcssa 2>&1 < %s | FileCheck %s
+; RUN: opt -S -enable-loop-simplifycfg-term-folding=true -passes='require<domtree>,loop(simplify-cfg)' -debug-only=loop-simplifycfg -verify-loop-info -verify-dom-info -verify-loop-lcssa 2>&1 < %s | FileCheck %s
+; RUN: opt -S -enable-loop-simplifycfg-term-folding=true -loop-simplifycfg -enable-mssa-loop-dependency=true -verify-memoryssa -debug-only=loop-simplifycfg -verify-loop-info -verify-dom-info -verify-loop-lcssa 2>&1 < %s | FileCheck %s
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128-ni:1"
 

Modified: llvm/trunk/test/Transforms/LoopSimplifyCFG/lcssa.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopSimplifyCFG/lcssa.ll?rev=347486&r1=347485&r2=347486&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopSimplifyCFG/lcssa.ll (original)
+++ llvm/trunk/test/Transforms/LoopSimplifyCFG/lcssa.ll Fri Nov 23 01:14:53 2018
@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -S -loop-simplifycfg -verify-loop-info -verify-dom-info -verify-loop-lcssa < %s | FileCheck %s
-; RUN: opt -S -passes='require<domtree>,loop(simplify-cfg)' -verify-loop-info -verify-dom-info -verify-loop-lcssa < %s | FileCheck %s
-; RUN: opt -S -loop-simplifycfg -enable-mssa-loop-dependency=true -verify-memoryssa -verify-loop-info -verify-dom-info -verify-loop-lcssa < %s | FileCheck %s
+; RUN: opt -S -enable-loop-simplifycfg-term-folding=true -loop-simplifycfg -verify-loop-info -verify-dom-info -verify-loop-lcssa < %s | FileCheck %s
+; RUN: opt -S -enable-loop-simplifycfg-term-folding=true -passes='require<domtree>,loop(simplify-cfg)' -verify-loop-info -verify-dom-info -verify-loop-lcssa < %s | FileCheck %s
+; RUN: opt -S -enable-loop-simplifycfg-term-folding=true -loop-simplifycfg -enable-mssa-loop-dependency=true -verify-memoryssa -verify-loop-info -verify-dom-info -verify-loop-lcssa < %s | FileCheck %s
 
 target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"