[Intrinsic] Signed Fixed Point Saturation Multiplication Intrinsic

Add an intrinsic that takes 2 signed integers with the scale of them provided
as the third argument and performs fixed point multiplication on them. The
result is saturated and clamped between the largest and smallest representable
values of the first 2 operands.

This is a part of implementing fixed point arithmetic in clang where some of
the more complex operations will be implemented as intrinsics.

Differential Revision: https://reviews.llvm.org/D55720

llvm-svn: 361289

1 files changed, 7 insertions, 6 deletions

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 67d43ce7740..fc8d210e67a 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -4595,27 +4595,28 @@ void Verifier::visitIntrinsicCall(Intrinsic::ID ID, CallBase &Call) {
     break;
   }
   case Intrinsic::smul_fix:
+  case Intrinsic::smul_fix_sat:
   case Intrinsic::umul_fix: {
     Value *Op1 = Call.getArgOperand(0);
     Value *Op2 = Call.getArgOperand(1);
     Assert(Op1->getType()->isIntOrIntVectorTy(),
-           "first operand of [us]mul_fix must be an int type or vector "
+           "first operand of [us]mul_fix[_sat] must be an int type or vector "
            "of ints");
     Assert(Op2->getType()->isIntOrIntVectorTy(),
-           "second operand of [us]mul_fix must be an int type or vector "
+           "second operand of [us]mul_fix_[sat] must be an int type or vector "
            "of ints");
 
     auto *Op3 = cast<ConstantInt>(Call.getArgOperand(2));
     Assert(Op3->getType()->getBitWidth() <= 32,
-           "third argument of [us]mul_fix must fit within 32 bits");
+           "third argument of [us]mul_fix[_sat] must fit within 32 bits");
 
-    if (ID == Intrinsic::smul_fix) {
+    if (ID == Intrinsic::smul_fix || ID == Intrinsic::smul_fix_sat) {
       Assert(
           Op3->getZExtValue() < Op1->getType()->getScalarSizeInBits(),
-          "the scale of smul_fix must be less than the width of the operands");
+          "the scale of smul_fix[_sat] must be less than the width of the operands");
     } else {
       Assert(Op3->getZExtValue() <= Op1->getType()->getScalarSizeInBits(),
-             "the scale of umul_fix must be less than or equal to the width of "
+             "the scale of umul_fix[_sat] must be less than or equal to the width of "
              "the operands");
     }
     break;