enhance vmcore to know that udiv's can be exact, and add a trivial

instcombine xform to exercise this.

Nothing forms exact udivs yet though.  This is progress on PR8862



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124992 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 10 insertions, 4 deletions

diff --git a/lib/VMCore/AsmWriter.cpp b/lib/VMCore/AsmWriter.cpp
index 1a11d9c..5b56cb5 100644
--- a/lib/VMCore/AsmWriter.cpp
+++ b/lib/VMCore/AsmWriter.cpp
@@ -831,7 +831,8 @@ static void WriteOptimizationInfo(raw_ostream &Out, const User *U) {
       Out << " nuw";
     if (OBO->hasNoSignedWrap())
       Out << " nsw";
-  } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(U)) {
+  } else if (const PossiblyExactOperator *Div =
+               dyn_cast<PossiblyExactOperator>(U)) {
     if (Div->isExact())
       Out << " exact";
   } else if (const GEPOperator *GEP = dyn_cast<GEPOperator>(U)) {
diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index 62117b2..d2359e5 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -683,7 +683,12 @@ Constant* ConstantExpr::getNUWMul(Constant* C1, Constant* C2) {
 
 Constant* ConstantExpr::getExactSDiv(Constant* C1, Constant* C2) {
   return getTy(C1->getType(), Instruction::SDiv, C1, C2,
-               SDivOperator::IsExact);
+               PossiblyExactOperator::IsExact);
+}
+
+Constant* ConstantExpr::getExactUDiv(Constant* C1, Constant* C2) {
+  return getTy(C1->getType(), Instruction::UDiv, C1, C2,
+               PossiblyExactOperator::IsExact);
 }
 
 // Utility function for determining if a ConstantExpr is a CastOp or not. This
diff --git a/lib/VMCore/Instructions.cpp b/lib/VMCore/Instructions.cpp
index 6b561f3..d129028 100644
--- a/lib/VMCore/Instructions.cpp
+++ b/lib/VMCore/Instructions.cpp
@@ -1822,7 +1822,7 @@ void BinaryOperator::setHasNoSignedWrap(bool b) {
 }
 
 void BinaryOperator::setIsExact(bool b) {
-  cast<SDivOperator>(this)->setIsExact(b);
+  cast<PossiblyExactOperator>(this)->setIsExact(b);
 }
 
 bool BinaryOperator::hasNoUnsignedWrap() const {
@@ -1834,7 +1834,7 @@ bool BinaryOperator::hasNoSignedWrap() const {
 }
 
 bool BinaryOperator::isExact() const {
-  return cast<SDivOperator>(this)->isExact();
+  return cast<PossiblyExactOperator>(this)->isExact();
 }
 
 //===----------------------------------------------------------------------===//