[IR] Add SaturatingInst and BinaryOpIntrinsic classes

Based on the suggestion in D62447, this adds a SaturatingInst class
that represents the saturating add/sub family of intrinsics. It
exposes the same interface as WithOverflowInst, for this reason I
have also added a common base class BinaryOpIntrinsic that holds the
actual implementation code and will be useful in some places handling
both overflowing and saturating math.

Differential Revision: https://reviews.llvm.org/D62466

llvm-svn: 361857

1 files changed, 9 insertions, 3 deletions

diff --git a/llvm/lib/IR/IntrinsicInst.cpp b/llvm/lib/IR/IntrinsicInst.cpp
index 7ff8631c76f..793e2895dce 100644
--- a/llvm/lib/IR/IntrinsicInst.cpp
+++ b/llvm/lib/IR/IntrinsicInst.cpp
@@ -171,13 +171,17 @@ bool ConstrainedFPIntrinsic::isTernaryOp() const {
   }
 }
 
-Instruction::BinaryOps WithOverflowInst::getBinaryOp() const {
+Instruction::BinaryOps BinaryOpIntrinsic::getBinaryOp() const {
   switch (getIntrinsicID()) {
     case Intrinsic::uadd_with_overflow:
     case Intrinsic::sadd_with_overflow:
+    case Intrinsic::uadd_sat:
+    case Intrinsic::sadd_sat:
       return Instruction::Add;
     case Intrinsic::usub_with_overflow:
     case Intrinsic::ssub_with_overflow:
+    case Intrinsic::usub_sat:
+    case Intrinsic::ssub_sat:
       return Instruction::Sub;
     case Intrinsic::umul_with_overflow:
     case Intrinsic::smul_with_overflow:
@@ -187,18 +191,20 @@ Instruction::BinaryOps WithOverflowInst::getBinaryOp() const {
   }
 }
 
-bool WithOverflowInst::isSigned() const {
+bool BinaryOpIntrinsic::isSigned() const {
   switch (getIntrinsicID()) {
     case Intrinsic::sadd_with_overflow:
     case Intrinsic::ssub_with_overflow:
     case Intrinsic::smul_with_overflow:
+    case Intrinsic::sadd_sat:
+    case Intrinsic::ssub_sat:
       return true;
     default:
       return false;
   }
 }
 
-unsigned WithOverflowInst::getNoWrapKind() const {
+unsigned BinaryOpIntrinsic::getNoWrapKind() const {
   if (isSigned())
     return OverflowingBinaryOperator::NoSignedWrap;
   else