Revert "[CVP] Simplify non-overflowing saturating add/sub"

This reverts commit 1e692d1777ae34dcb93524b5798651a29defae09.

Causes assertion failure in builtins-wasm.c clang test.

llvm-svn: 362254

1 files changed, 1 insertions, 24 deletions

diff --git a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
index 1715838a07e..eab49b5f8b3 100644
--- a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
+++ b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
@@ -63,8 +63,6 @@ STATISTIC(NumUDivs,     "Number of udivs whose width was decreased");
 STATISTIC(NumAShrs,     "Number of ashr converted to lshr");
 STATISTIC(NumSRems,     "Number of srem converted to urem");
 STATISTIC(NumOverflows, "Number of overflow checks removed");
-STATISTIC(NumSaturating,
-    "Number of saturating arithmetics converted to normal arithmetics");
 
 static cl::opt<bool> DontAddNoWrapFlags("cvp-dont-add-nowrap-flags", cl::init(true));
 
@@ -415,7 +413,7 @@ static void processOverflowIntrinsic(WithOverflowInst *WO) {
   IRBuilder<> B(WO);
   Value *NewOp = B.CreateBinOp(
       WO->getBinaryOp(), WO->getLHS(), WO->getRHS(), WO->getName());
-  // Constant-folding could have happened.
+  // Constant-holing could have happened.
   if (auto *Inst = dyn_cast<Instruction>(NewOp)) {
     if (WO->isSigned())
       Inst->setHasNoSignedWrap();
@@ -430,20 +428,6 @@ static void processOverflowIntrinsic(WithOverflowInst *WO) {
   ++NumOverflows;
 }
 
-static void processSaturatingInst(SaturatingInst *SI) {
-  BinaryOperator *BinOp = BinaryOperator::Create(
-      SI->getBinaryOp(), SI->getLHS(), SI->getRHS(), SI->getName(), SI);
-  BinOp->setDebugLoc(SI->getDebugLoc());
-  if (SI->isSigned())
-    BinOp->setHasNoSignedWrap();
-  else
-    BinOp->setHasNoUnsignedWrap();
-
-  SI->replaceAllUsesWith(BinOp);
-  SI->eraseFromParent();
-  ++NumSaturating;
-}
-
 /// Infer nonnull attributes for the arguments at the specified callsite.
 static bool processCallSite(CallSite CS, LazyValueInfo *LVI) {
   SmallVector<unsigned, 4> ArgNos;
@@ -456,13 +440,6 @@ static bool processCallSite(CallSite CS, LazyValueInfo *LVI) {
     }
   }
 
-  if (auto *SI = dyn_cast<SaturatingInst>(CS.getInstruction())) {
-    if (willNotOverflow(SI, LVI)) {
-      processSaturatingInst(SI);
-      return true;
-    }
-  }
-
   // Deopt bundle operands are intended to capture state with minimal
   // perturbance of the code otherwise.  If we can find a constant value for
   // any such operand and remove a use of the original value, that's