[llvm] 2f29341 - Revert "Revert "SimplifyCFG: Clean up optforfuzzing implementation""

[Zequan Wu via llvm-commits]

Author: Zequan Wu
Date: 2020-10-21T17:08:56-07:00
New Revision: 2f29341114ed2e32af9c68506fe9a7f6868675e2

URL: https://github.com/llvm/llvm-project/commit/2f29341114ed2e32af9c68506fe9a7f6868675e2
DIFF: https://github.com/llvm/llvm-project/commit/2f29341114ed2e32af9c68506fe9a7f6868675e2.diff

LOG: Revert "Revert "SimplifyCFG: Clean up optforfuzzing implementation""

This reverts commit 716f7636e1ec7880a6d2f2205f54f65191cf8f9a.

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
    llvm/lib/Transforms/Utils/SimplifyCFG.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
index 7b7231fd094e..1798e017bfad 100644
--- a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -273,6 +273,14 @@ struct CFGSimplifyPass : public FunctionPass {
       return false;
 
     Options.AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
+    if (F.hasFnAttribute(Attribute::OptForFuzzing)) {
+      Options.setSimplifyCondBranch(false)
+             .setFoldTwoEntryPHINode(false);
+    } else {
+      Options.setSimplifyCondBranch(true)
+             .setFoldTwoEntryPHINode(true);
+    }
+
     auto &TTI = getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
     return simplifyFunctionCFG(F, TTI, Options);
   }

diff  --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 197f2baaa523..124a7c423e72 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -2415,9 +2415,6 @@ static bool FoldTwoEntryPHINode(PHINode *PN, const TargetTransformInfo &TTI,
   // dependence information for this check, but simplifycfg can't keep it up
   // to date, and this catches most of the cases we care about anyway.
   BasicBlock *BB = PN->getParent();
-  const Function *Fn = BB->getParent();
-  if (Fn && Fn->hasFnAttribute(Attribute::OptForFuzzing))
-    return false;
 
   BasicBlock *IfTrue, *IfFalse;
   Value *IfCond = GetIfCondition(BB, IfTrue, IfFalse);
@@ -6058,8 +6055,7 @@ static BasicBlock *allPredecessorsComeFromSameSource(BasicBlock *BB) {
 
 bool SimplifyCFGOpt::simplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) {
   BasicBlock *BB = BI->getParent();
-  const Function *Fn = BB->getParent();
-  if (Fn && Fn->hasFnAttribute(Attribute::OptForFuzzing))
+  if (!Options.SimplifyCondBranch)
     return false;
 
   // Conditional branch
@@ -6274,11 +6270,13 @@ bool SimplifyCFGOpt::simplifyOnce(BasicBlock *BB) {
 
   IRBuilder<> Builder(BB);
 
-  // If there is a trivial two-entry PHI node in this basic block, and we can
-  // eliminate it, do so now.
-  if (auto *PN = dyn_cast<PHINode>(BB->begin()))
-    if (PN->getNumIncomingValues() == 2)
-      Changed |= FoldTwoEntryPHINode(PN, TTI, DL);
+  if (Options.FoldTwoEntryPHINode) {
+    // If there is a trivial two-entry PHI node in this basic block, and we can
+    // eliminate it, do so now.
+    if (auto *PN = dyn_cast<PHINode>(BB->begin()))
+      if (PN->getNumIncomingValues() == 2)
+        Changed |= FoldTwoEntryPHINode(PN, TTI, DL);
+  }
 
   Instruction *Terminator = BB->getTerminator();
   Builder.SetInsertPoint(Terminator);