Revert r277556. Add -lowertypetests-bitsets-level to control bitsets generation

Summary:
We don't currently need this facility for CFI. Disabling individual hot methods proved
to be a better strategy in Chrome.

Also, the design of the feature is suboptimal, as pointed out by Peter Collingbourne.

Reviewers: pcc

Subscribers: kcc

Differential Revision: https://reviews.llvm.org/D24948

llvm-svn: 282461

1 files changed, 2 insertions, 9 deletions

diff --git a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
index 374333d33fc..8f9d665ef05 100644
--- a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
+++ b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -48,11 +48,6 @@ static cl::opt<bool> AvoidReuse(
     cl::desc("Try to avoid reuse of byte array addresses using aliases"),
     cl::Hidden, cl::init(true));
 
-static cl::opt<unsigned> BitsetsLevel(
-    "lowertypetests-bitsets-level",
-    cl::desc("Whether to generate bitsets: 0 - never, 1 - only if no loads, 2 - always."),
-    cl::Hidden, cl::init(2));
-
 bool BitSetInfo::containsGlobalOffset(uint64_t Offset) const {
   if (Offset < ByteOffset)
     return false;
@@ -490,10 +485,8 @@ Value *LowerTypeTestsModule::lowerBitSetCall(
   Constant *BitSizeConst = ConstantInt::get(IntPtrTy, BSI.BitSize);
   Value *OffsetInRange = B.CreateICmpULT(BitOffset, BitSizeConst);
 
-  // If the bit set is all ones (or we treat it as such), testing against it
-  // is unnecessary.
-  if (BSI.isAllOnes() || BitsetsLevel == 0 ||
-      (BitsetsLevel == 1 && BSI.BitSize > 64))
+  // If the bit set is all ones, testing against it is unnecessary.
+  if (BSI.isAllOnes())
     return OffsetInRange;
 
   TerminatorInst *Term = SplitBlockAndInsertIfThen(OffsetInRange, CI, false);