[llvm] 6734be2 - Revert "[LoopVersioning] Allow versionLoop to create plain branch inst when no runtime check is specified"

[via llvm-commits]

Author: eopXD
Date: 2021-12-16T02:06:11-08:00
New Revision: 6734be290bdd97174b9fccea2be842eb6b085d8b

URL: https://github.com/llvm/llvm-project/commit/6734be290bdd97174b9fccea2be842eb6b085d8b
DIFF: https://github.com/llvm/llvm-project/commit/6734be290bdd97174b9fccea2be842eb6b085d8b.diff

LOG: Revert "[LoopVersioning] Allow versionLoop to create plain branch inst when no runtime check is specified"

This reverts commit fbf6c8ac1589a4be68ee549257f1d528937ac582.

Added: 
    

Modified: 
    llvm/include/llvm/Transforms/Utils/LoopVersioning.h
    llvm/lib/Transforms/Utils/LoopVersioning.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Transforms/Utils/LoopVersioning.h b/llvm/include/llvm/Transforms/Utils/LoopVersioning.h
index abf5acc377e4e..4a8831ed45b25 100644
--- a/llvm/include/llvm/Transforms/Utils/LoopVersioning.h
+++ b/llvm/include/llvm/Transforms/Utils/LoopVersioning.h
@@ -75,12 +75,6 @@ class LoopVersioning {
   /// loop may alias (i.e. one of the memchecks failed).
   Loop *getNonVersionedLoop() { return NonVersionedLoop; }
 
-  /// Returns the basic block that contains the runtime check BranchInst
-  BasicBlock *getRuntimeCheckBB() { return RuntimeCheckBB; }
-
-  /// Returns the runtime check BranchInst
-  BranchInst *getRuntimeCheckBI() { return RuntimeCheckBI; }
-
   /// Annotate memory instructions in the versioned loop with no-alias
   /// metadata based on the memchecks issued.
   ///
@@ -121,12 +115,6 @@ class LoopVersioning {
   /// loop may alias (memchecks failed).
   Loop *NonVersionedLoop;
 
-  /// The basic Block that stores the BranchInst to Versioned / NonVersioned
-  BasicBlock *RuntimeCheckBB;
-
-  /// The branch instruction to Versioned / NonVersioned
-  BranchInst *RuntimeCheckBI;
-
   /// This maps the instructions from VersionedLoop to their counterpart
   /// in NonVersionedLoop.
   ValueToValueMapTy VMap;

diff  --git a/llvm/lib/Transforms/Utils/LoopVersioning.cpp b/llvm/lib/Transforms/Utils/LoopVersioning.cpp
index 15a40cac8c110..771b7d25b0f20 100644
--- a/llvm/lib/Transforms/Utils/LoopVersioning.cpp
+++ b/llvm/lib/Transforms/Utils/LoopVersioning.cpp
@@ -30,9 +30,6 @@
 
 using namespace llvm;
 
-#define LVER_OPTION "loop-versioning"
-#define DEBUG_TYPE LVER_OPTION
-
 static cl::opt<bool>
     AnnotateNoAlias("loop-version-annotate-no-alias", cl::init(true),
                     cl::Hidden,
@@ -87,11 +84,8 @@ void LoopVersioning::versionLoop(
   } else
     RuntimeCheck = MemRuntimeCheck ? MemRuntimeCheck : SCEVRuntimeCheck;
 
-  if (!RuntimeCheck) {
-    LLVM_DEBUG(dbgs() << DEBUG_TYPE " No MemRuntimeCheck or SCEVRuntimeCheck found"
-                      << ", set RuntimeCheck to False\n");
-    RuntimeCheck = ConstantInt::getFalse(RuntimeCheckBB->getContext());
-  }
+  assert(RuntimeCheck && "called even though we don't need "
+                         "any runtime checks");
 
   // Rename the block to make the IR more readable.
   RuntimeCheckBB->setName(VersionedLoop->getHeader()->getName() +
@@ -115,8 +109,8 @@ void LoopVersioning::versionLoop(
 
   // Insert the conditional branch based on the result of the memchecks.
   Instruction *OrigTerm = RuntimeCheckBB->getTerminator();
-  RuntimeCheckBI = BranchInst::Create(NonVersionedLoop->getLoopPreheader(),
-                           VersionedLoop->getLoopPreheader(), RuntimeCheck, OrigTerm);
+  BranchInst::Create(NonVersionedLoop->getLoopPreheader(),
+                     VersionedLoop->getLoopPreheader(), RuntimeCheck, OrigTerm);
   OrigTerm->eraseFromParent();
 
   // The loops merge in the original exit block.  This is now dominated by the
@@ -131,9 +125,6 @@ void LoopVersioning::versionLoop(
   assert(NonVersionedLoop->isLoopSimplifyForm() &&
          VersionedLoop->isLoopSimplifyForm() &&
          "The versioned loops should be in simplify form.");
-
-  // RuntimeCheckBB and RuntimeCheckBI is recorded
-  assert(RuntimeCheckBB && RuntimeCheckBI);
 }
 
 void LoopVersioning::addPHINodes(
@@ -333,6 +324,9 @@ class LoopVersioningLegacyPass : public FunctionPass {
 };
 }
 
+#define LVER_OPTION "loop-versioning"
+#define DEBUG_TYPE LVER_OPTION
+
 char LoopVersioningLegacyPass::ID;
 static const char LVer_name[] = "Loop Versioning";