Revert 260705, it appears to be causing pr26628

The root issue appears to be a confusion around what makeNoWrapRegion actually does.   It seems likely we need two versions of this function with slightly different semantics.

llvm-svn: 260981

1 files changed, 0 insertions, 21 deletions

diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
index d21b1bd8937..8f121110051 100644
--- a/llvm/lib/Analysis/LazyValueInfo.cpp
+++ b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -961,27 +961,6 @@ bool LazyValueInfoCache::solveBlockValueConstantRange(LVILatticeVal &BBLV,
   if (isa<BinaryOperator>(BBI)) {
     if (ConstantInt *RHS = dyn_cast<ConstantInt>(BBI->getOperand(1))) {
       RHSRange = ConstantRange(RHS->getValue());
-
-      // Try to use information about wrap flags to refine the range LHS can
-      // legally have.  This is a slightly weird way to implement forward
-      // propagation over overflowing instructions, but it seems to be the only
-      // clean one we have.  NOTE: Because we may have speculated the
-      // instruction, we can't constrain other uses of LHS even if they would
-      // seem to be equivelent control dependent with this op.
-      if (auto *OBO = dyn_cast<OverflowingBinaryOperator>(BBI)) {
-        unsigned WrapKind = 0;
-        if (OBO->hasNoSignedWrap())
-          WrapKind |= OverflowingBinaryOperator::NoSignedWrap;
-        if (OBO->hasNoUnsignedWrap())
-          WrapKind |= OverflowingBinaryOperator::NoUnsignedWrap;
-
-        if (WrapKind) {
-          auto OpCode = static_cast<Instruction::BinaryOps>(BBI->getOpcode());
-          auto NoWrapCR =
-            ConstantRange::makeNoWrapRegion(OpCode, RHS->getValue(), WrapKind);
-          LHSRange = LHSRange.intersectWith(NoWrapCR);
-        }
-      }
     } else {
       BBLV.markOverdefined();
       return true;